Cardiac Catheterization in Congenital Heart Disease: Pediatric and Adult - Part 10 doc

The laser or RF techniques for valveperforation also are used in patients with pulmonary atre-sia and a ventricular septal defect, but only when there is a well-developed main pulmonary

C H A P T E R 3 1 Purposeful vascular perforations

and to the valve Valve perforations with each of these

“instruments”, and from both approaches, occasionally

were successful Unfortunately, the force and “push” that

were necessary to penetrate the valve, often pushed the

supporting catheter, which contained the stiff needle

and/or the retrograde wire, backwards and away from

the plate-like valve rather than causing the perforating

instrument to puncture the valve When the guide or

sup-port catheter was pushed away, it prevented the

perfora-tion, or even worse, displaced the sharp instrument away

from the center of the “plate-like” valve and into the

perivalvular area A puncture into the adjacent areas

resulted in perforation into the pericardium and/or an

adjacent chamber/vessel, often with catastrophic results

Experimental, and recently, clinical experience

demon-strated the feasibility of “drilling” through tissue, and

more specifically pulmonary valve tissue, with laser or

radio-frequency (RF) energy Both energy sources have

demonstrated considerable success in penetrating the

valve When this is followed by a balloon dilation of

the valve, very adequate pulmonary valve openings

are achieved allowing unobstructed prograde blood flow

into the pulmonary artery The amount of this prograde

flow then is dependent on the size of the tricuspid

valve, the potential volume and the compliance of the

right ventricle

Laser energy was the first energy source to be used in

clinical trials in Europe5–7 The laser energy is delivered

through a fine fiberoptic strand or “wire” to a very specific

area, and proved very successful at perforating the atretic

pulmonary valve in patients with pulmonary valve

atre-sia by essentially vaporizing the tissue in front of the

beam The laser beam, unfortunately, also easily continues

to perforate any tissues in its path beyond and/or

adja-cent to the valve The laser energy was successful at

perforating an opening in the atretic pulmonary valve

in approximately 80% of the small number of patients in

whom it was tried initially The opening allowed the

pas-sage of a guide wire through the valve and subsequent

dilation of the valve

Although successful in perforating the valve, the laser

system has several disadvantages in addition to the poor

controllability of the depth of penetration The Excimer

Laser™ generator is large and very expensive Unless

the particular pediatric cardiac catheterization laboratory

works in conjunction with an adult catheterization

labor-atory and/or performs many laser-assisted pacemaker

lead extractions, the capital expense of the laser generator

“just” for the very few pulmonary atresia patients who

present to even large pediatric cardiac centers, cannot be

justified easily In addition to the ease of perforating

unwanted structures within the heart with the laser, the

intense laser energy also carries a risk of “stray” laser

beams in the area of the patient, which can create retinal

damage to the operators and other employees in thecatheterization laboratory As a consequence, all person-nel in the laboratory are required to wear special, some-what cumbersome, protective eye wear The fiberopticlaser “wires” are expensive and finally, and absolutely thegreatest deterrent to operators in the US until very

recently: there was no laser “wire” that was approved for

use outside of specific protocols in the United States

As an excellent alternative to laser energy, frequency energy delivered through a very fine insulatedwire can also be used to perforate atretic tissues, and theatretic pulmonary valve in particular The RF energy isless powerful for perforating structures, but it is consider-ably more controllable than the laser energy A radio-frequency generator for perforation is considerably lessexpensive and less complex than any laser generator Inaddition, radio-frequency generators are commonly avail-able in pediatric and congenital catheterization labor-atories, where they are used for the ablation of abnormalintracardiac “electrical” conduction tracts However, thecurrent, and now standard RF “ablation” generator, which

radio-is low impedance and uses low-voltage (30–50 volts), power (30–50 watts) sustained (60–90 second) energy

high-for the “ablation” of tissues without perhigh-foration, requires

significant electrical modifications to convert the ator into a high-impedance, high-voltage (150–180 volts),low-power (3–5 watts) and short-duration (1–2 second)energy generator, which is necessary for “perforation”.The special BMC Radio Frequency PerforationSystem™ (Baylis Medical Co Inc., Montreal, Canada) is agenerator that is designed and dedicated specially for

gener-“perforation” The generator now is available cially (even in the US) and is reasonably priced This generator has built into it the necessary high-voltage, low-power and short-duration pulses of energy that arenecessary to generate the high impedance necessary forperforation A single use RF perforating “catheter”matched to the RF generator along with an “injection”coaxial catheter and a connecting cable are available as

commer-“perforating kits” to be used with the specific RF ator The total RF generator and the “catheter kit” areapproved for “intravascular perforation”, even in theUnited States

gener-The disposable “kit” consists of the Nykanen RadioFrequency Perforation Catheter™ and a special CoaxialInjectable Catheter™ (Baylis Medical Co Inc., Montreal,Canada) The “perforation catheter” is a 0.024″, 265 cmlong, teflon “catheter” tightly bound over a 0.016″ conduct-

ance wire Only the distal 1.5 mm and several mm of

the proximal bare wire are exposed The teflon over thewire provides an insulated coating to the wire and pro-duces a relatively stiff, “pushable” shaft for the combina-tion The distal region of the “catheter” is flexible and can

be bent or pre-formed into a specific curve for easier

C H A P T E R 3 1 Purposeful vascular perforations

maneuverability This allows the perforating “catheter”

to be maneuvered similarly to a fine torque-controlled

guide wire The proximal end of the teflon “catheter” has

no “hub” but attaches to a removable connecting cable,

which, in turn connects it to the generator The “coaxial

injectable catheters” are thin walled 0.035″ or 0.038″

dia-meter, 145 cm long catheters with a distal radio-opaque

marker and a floppy, distal 10 cm tip The inner diameters

of the two catheters are 0.024″ and 0.027″, respectively

These catheters also have removable hubs so that the

coaxial catheter and the contained perforation catheter

together can act as a “thick guide wire” over which other

catheters (balloon catheters) can be introduced

Technique for perforation of the pulmonary

valve in patients with pulmonary atresia and

intact ventricular septum

The diagnosis of pulmonary atresia with or without a

ventricular septal defect usually is made clinically in the

newborn period with confirmation by echocardiographic

evaluation By the time these infants are seen by a

cardi-ologist, they usually already are receiving prostaglandin

to keep the ductus arteriosus open, and this provide the

infants with some pulmonary flow Rarely infants with

pulmonary atresia and intact ventricular septum arrive

in the catheterization laboratory at several months of age,

having had a naturally persistent ductus arteriosus and/

or a previously created systemic to pulmonary artery

surgical shunt as palliation As opposed to patients with

pulmonary atresia and an intact ventricular septum,

patients with pulmonary valve atresia and a ventricular

septal defect often have extensive systemic to pulmonary

collateral flow to the lungs and/or, occasionally, a large

persistent patent ductus arteriosus and, as a consequence,

these patients can survive to an older age with no prior

intervention

A cardiac catheterization laboratory that has very

high-quality, biplane X-ray imaging and angulation

capabilit-ies for the X-ray tubes, is necessary for these perforation

procedures Because of the precarious nature of these

infants, the extensive catheter manipulation required and

the potential for inadvertent occlusion of the ductus

arter-iosus during the procedure, these infants are intubated

and ventilated before starting the catheterization Any

patient in whom a purposeful perforation is considered, is

type and cross-matched for one or two units of fresh

whole blood If the replacement of blood becomes

neces-sary, the clotting factors as well as the oxygen carrying

capacity of whole blood are desirable When an RF

perfora-tion is anticipated, a large “grounding plate” is placed

under the back of the patient at the very beginning of

the procedure The grounding plate is attached to the RF

generator via the conductive cable as the patient is being

positioned on the catheterization table Percutaneousaccess to at least one femoral vein and a femoral artery isestablished

In the catheterization laboratory, the diagnosis is firmed and the details of the right ventricular and pul-monary artery anatomy are defined with selective biplaneright ventricular (outflow tract!) and aortic angiography.The angiograms not only define the anatomy of the valve,but demonstrate any right ventricular to coronary arteryfistulae in patients with pulmonary atresia with an intactventricular septum In these patients, who usually dohave a good pulmonary artery in the presence of coronaryartery to RV fistulae, a right ventricular (RV) dependent

con-coronary circulation must be excluded before valve

perfora-tion is considered The laser or RF techniques for valveperforation also are used in patients with pulmonary atre-sia and a ventricular septal defect, but only when there

is a well-developed main pulmonary artery and the RFcatheter/wire or laser wire, which is advanced from the

ventricle, can be advanced into the right ventricular

infundibulum and supported exactly at and against the

“valve” area Whether using laser (which has onlyrecently become available in the US) or RF energy, thetechniques for pulmonary valve perforation are similar

Radio-frequency perforation of the pulmonary valve from the right ventricular approach in patients with pulmonary atresia and intact ventricular septum

The technique for pulmonary valve perforation using theradio-frequency perforating system, which is designedspecifically for RF tissue perforation and is availablearound the world (even in the United States), is described

in detail in this chapter In addition to quality, biplaneangiograms in the right ventricular outflow tract, abiplane angiogram of the main pulmonary artery is neces-sary to visualize the valve annulus from the pulmonaryside It is desirable to position a catheter in the main pul-monary artery against the pulmonary side of the atreticpulmonary valve The catheter in the pulmonary artery isintroduced retrograde and passed into the pulmonaryartery through either the patent ductus arteriosus or a pre-viously placed shunt The ductus in the newborn, and par-ticularly when the infant is on prostaglandins, is very

“mushy”, friable and often tortuous Force never should

be used in crossing the ductus If the ductus cannot becrossed readily and almost inadvertently, a biplane aorto-gram is performed in the descending aorta with the injection of contrast immediately adjacent and/or slightlydistal to the aortic end of the ductus This aortogram willdetermine the exact course of the ductus and will definethe pulmonary artery/pulmonary valve more precisely.Occasionally, even with the course of the ductus clearly

C H A P T E R 3 1 Purposeful vascular perforations

defined, it is necessary first to cross the ductus with a

small, soft tipped, torque-controlled wire and then to

advance a multipurpose angiographic catheter over this

wire into the pulmonary artery The catheter itself in the

pulmonary artery serves as a constant “target” during the

perforation from the right ventricle, and is used for

repeated angiography in the pulmonary artery during

the perforation

If a catheter cannot be placed in the pulmonary artery,

at the very least there must be some capability of

obtain-ing repeated, good quality, biplane angiographic imagobtain-ing of

the main pulmonary artery/pulmonary valve When the

pulmonary artery cannot be entered reasonably, the

pul-monary artery imaging is obtained from the contrast

injected in the aorta and the flow through the ductus,

through a previous shunt or through collaterals The tip of

the angiographic catheter for these injections in the aorta

is maintained immediately adjacent to or actually in the

origin of the vessel(s) providing the pulmonary flow in

order that the maximum contrast reaches the pulmonary

artery with each injection

In the very rare instance where there is no demonstrable

systemic to pulmonary artery flow, the biplane imaging of

the pulmonary artery is obtained from a biplane

pul-monary vein wedge angiocardiogram This technique is

satisfactory only if the main pulmonary artery can be

visu-alized adequately and repeatedly by this technique The

use of repeated pulmonary vein wedge angiograms to

visualize the pulmonary arteries requires the presence of

an additional venous catheter situated in the vein wedge

position throughout the entire perforation procedure

Biplane “freeze frame” images from the right

ventricu-lar angiogram, which demonstrate the right ventricuventricu-lar

outflow and the atretic pulmonary valve areas most

satis-factorily, are displayed as “road maps” for the subsequent

catheter positioning After the pulmonary artery is

visual-ized angiographically and/or the retrograde catheter is

placed in the pulmonary artery adjacent to the pulmonary

valve, a 4- or 5-French, pre-shaped “right coronary” or

“cobra” guiding catheter is advanced into the right

vent-ricle and manipulated very carefully and precisely into the

right ventricular outflow tract (RVOT) This “guiding”

catheter is maneuvered until it is against the center of

the atretic valve in the right ventricular outflow tract The

specific guiding catheter that is used depends upon the

size and, particularly, the right ventricular anatomy of

each individual patient The angle at the tip of the

parti-cular guiding catheter, which is positioned in the RVOT,

should point the tip of the catheter directly at the other

catheter in the pulmonary artery and/or at the center of

the atretic valve in both the PA and lateral views as seen on

previous angiograms Several different shaped guiding

catheters often must be tried in order to position the tip

of the guiding catheter pointing precisely in the exact

direction in both X-ray planes As much time and effort is

taken as is necessary to achieve this precise positioningbefore proceeding with the perforation Any misalign-ment in either plane very likely will result in perforationout of the vascular channels and into the pericardium.When the right ventricular catheter tip appears to be in theideal, proper position, a repeat, small, not too forceful,hand injected, biplane angiocardiogram is performedthrough this catheter This angiogram demonstrates theoutflow tract and valve even better and illustrates clearlyany distortion to the area created by the catheter itself.When the tip of the catheter is aligned precisely, theseimages are displayed as the new “road map”

If none of the available pre-shaped guiding catheterscan be positioned precisely in a direct line to, and against,the valve, the guiding catheter is withdrawn The tip ofthe catheter is softened by immersing it in sterile, boilingwater Once softened, a different, more appropriate curve

is formed at the tip After reshaping the guiding catheter,

it is reintroduced and positioned properly against the valve.Alternatively or in addition, a Mullins™ deflector wire

outside of the body is pre-shaped with very smooth curves

to correspond to the desired course from the right atrium,

to the right ventricle, to the right ventricular lum and finally against the atretic valve All of the bends

infundibu-on the wire are formed “tighter” than the existing curvesthrough the right heart to allow for some straightening ofthe wire as it passes within the guiding catheter When aMullins™ wire is used to hold the guiding catheter tip inplace, the guiding catheter must be at least one French sizelarger in order to accommodate both the Mullins™ wireand the perforating catheter side by side within the lumen

of the guiding catheter

The Mullins™ wire is introduced into the pre-shapedand previously positioned catheter through a Tuohy™/side port back-bleed valve The wire is advanced within

the catheter to a position just within the distal tip of the

catheter The purpose of the Mullins™ wire is to redirectand maintain the guiding catheter in its position against,

and pointing directly at, the center of the atretic valve

while the perforating wire/catheter is introduced Again,

it is even more important that once this considerablystiffer combination is positioned against the valve a re-peat small biplane angiogram is performed through theguiding catheter to demonstrate any further distortion

of the area

Once the catheters are in place, preferably on both sides

of the valve, the RF perforation catheter, which has beenadvanced through the BMC coaxial catheter while theystill are outside of the body, is introduced into the guidingcatheter that is pre-positioned in the right ventricularoutflow tract against the atretic valve The perforating/coaxial catheter is introduced through a wire back-bleedflush valve or a Tuohy™ side port adaptor attached to the

C H A P T E R 3 1 Purposeful vascular perforations

hub of the guiding catheter Otherwise, with the

sig-nificantly larger lumen of the guiding catheter than the

diameter of the perforating/coaxial catheter and with

the high pressure in the right ventricle, there will be

significant bleeding into and externally out of the catheter

around the perforating catheter through the hub of the

guiding catheter The guiding catheter is cleared of blood

by allowing it to bleed back passively through the

Tuohy™ valve and then placed on a continuous flush

Any blood that remains in the catheter can clot, and

potenti-ally represents an embolus The Tuohy™ type side port

adaptor also allows contrast injections through the side

port into the guiding catheter and around the

perforat-ing/coaxial catheters If a Mullins™ wire is used to

sup-port the guiding catheter, a second Tuohy™ side sup-port

valve is “piggy-backed” onto the angled side port of the

first Tuohy™ The R-F wire is passed through the first

Tuohy™ adaptor, which is attached directly to the guide

catheter The Mullins™ wire is introduced through the

second Tuohy™ valve, which is attached to the angled

port of the first Tuohy™

The perforating catheter, which is within the coaxial

catheter, is advanced to the tip of the guiding catheter An

alternative technique in a small, very tight RVOT is to

introduce only the “perforation catheter” into the guiding

catheter without the covering coaxial catheter The

“perfor-ating catheter” alone is more flexible and causes less

dis-placement of the precisely positioned guiding catheter In

this circumstance, the coaxial catheter can be introduced

and advanced over the perforating catheter after the valve

has been perforated Once the perforation catheter is in

the RVOT at the tip of the pre-positioned guiding catheter,

a repeat biplane angiogram of the RVOT/pulmonary

valve is performed to verify that the catheter in the RVOT

is still pointing exactly at the center of the pulmonary

valve If the tip of the guiding catheter is displaced at all

away from the center of the atretic valve, the guiding

catheter with the contained perforating catheter is

read-justed by very slight torque and/or to-and-fro motion

The biplane angiogram is repeated to verify the exact

rela-tionships after any readjustment

When the tip of the guiding catheter is in position and

pointing in the precise direction, the proximal end of the

wire of the perforation catheter is attached to the

genera-tor with the BMC™ connecting cable The tip of the RF

perforation catheter is advanced just barely out of the tip

of the guiding catheter and into the tissue of the atretic

valve The flush on the side port of the catheter is stopped

The generator is set for a one second duration and 5 watts

power While continuously observing the tip of the

per-forating catheter on biplane stored fluoroscopy or slow

frame rate biplane cine angiography, a single burst of RF

energy is delivered while simultaneously holding, but not

advancing, the tip of the perforating catheter against the

valve Usually this is sufficient for the perforating catheter

to pass through the valve into the pulmonary artery Ifnot, the positioning of the guide and perforating cathetertips is rechecked on biplane fluoroscopy If the positionsare still not ideal, the perforating catheter is withdrawnwithin the tip of the guiding catheter while the guidingcatheter repositioned When the guiding catheter is in theexact position, the perforating catheter tip is re-advancedinto the valve tissues When both catheters are in the pre-cise position, the RF energy is reapplied to the perforatingcatheter while again holding the tip of the perforating

catheter against the valve without pushing forcefully This

process is repeated until the perforating catheter advancesthrough the valve “plate” and into a “free” positionwithin the pulmonary artery just beyond the valve while

no energy is being applied Any advancing of the tip of theperforating catheter within the pulmonary artery must bewith no energy applied, as any RF energy applied to thetip will allow the tip to perforate any structure (wall!) in itsvicinity! The exact position of the tip of the perforatingcatheter in the pulmonary artery is verified with a biplanepulmonary artery angiogram before proceeding further.Once the tip of the perforating catheter has entered the pulmonary artery freely, the perforating catheter is

advanced with no energy applied as far as possible distally

into the branch pulmonary artery or through the patentductus into the descending aorta When the perforating

catheter is well into the pulmonary artery or the

descend-ing aorta, the coaxial catheter is advanced over the forating catheter to the tip of the perforating catheter The subsequent maneuvers depend upon the associatedanatomy and the position of the perforating/coaxial cath-eters after they are advanced following the perforation

per-If the perforating/coaxial catheters pass into thedescending aorta, together they are snared there with asnare catheter, which is introduced retrograde from thefemoral artery With traction held on the perforating/coaxial catheter with the snare catheter, the guide catheter

is removed from the femoral vein over the combined forating/coaxial catheter and replaced with a 2–4 mmdiameter low-profile dilation balloon When passed overthe combined perforating/coaxial catheter, this requires aballoon catheter with a catheter lumen that will accommo-date a 0.035″ guide wire An alternative technique, whenthe perforating/coaxial catheters pass into the descendingaorta, is to withdraw the perforating catheter from thecoaxial catheter and exchange it for a stiff 0.014″ or 0.016″exchange length “coronary” guide wire This exchange ofthe perforating catheter for wire is performed while theguiding catheter still is in position in the RVOT and the

per-snare is around and gripping the coaxial catheter loosely.

If the coaxial catheter begins to withdraw or buckle whilethe new, stiffer wire is introduced into it, the distal end ofthe coaxial catheter is grasped firmly with the snare in the

C H A P T E R 3 1 Purposeful vascular perforations

descending aorta This supports the passage of the stiffer

exchange guide wire through the relatively flimsy coaxial

catheter as it passes through the tortuous course from the

inferior vena cava through the right heart, pulmonary

artery and ductus to the descending aorta

Once the stiffer, smaller exchange wire emerges from

the tip of the coaxial catheter in the descending aorta, this

wire alone is grasped securely with the retrograde snare.

The snared distal end is withdrawn into the femoral area

or even out through the femoral artery sheath Either way,

a very secure “through-and-through” or “rail” wire

sys-tem is created The coaxial and the guiding catheters are

removed over the fixed wire The through-and-through

wire allows simultaneous strong traction from the two

ends of the wire which, in turn, allows a very forceful

for-ward push on the balloon dilation catheter without the

catheter and/or the wire buckling in the right ventricle as

the balloon passes through the tight valve With the

trac-tion applied at both ends of the exchange wire, the very

low profile 2–4 mm diameter coronary balloon is passed

over the wire and advanced through the “plate” of the

pul-monary valve to initiate a sequential dilation of the valve

After the dilation with the initial, small coronary

bal-loon, the balloon is exchanged over the same “rail” wire

for a larger dilating balloon Dilation balloons of

progres-sively increasing size are used until a balloon that is

appropriate in diameter for a single balloon pulmonary

valve dilation of the particular valve annulus can be

introduced

An alternative technique, which can be used when there

is a patent ductus that can be traversed easily, is to

posi-tion a retrograde snare catheter instead of an angiographic

catheter in the pulmonary artery before and during the

actual perforation of the valve Instead of maneuvering

the original retrograde angiographic catheter into the

pul-monary artery, a 4-French Microvena™ snare catheter is

passed retrograde through the patent ductus into the

pul-monary artery The standard snare catheter often is easier

and safer to position in the pulmonary artery than an

angiographic catheter A floppy, soft tipped,

torque-controlled wire is advanced totally atraumatically from

the aorta through the ductus and against the atretic

pul-monary valve The end-hole snare catheter then advances

easily over this previously positioned wire A small 5 or

10 mm diameter snare (depending upon the diameter of the

pulmonary annulus) is opened in the annulus of the

pul-monary valve on the main pulpul-monary artery side of the

valve The properly sized snare aligns perpendicular to

the long axis of the pulmonary artery, around and

outlin-ing the circumference of the valve annulus The “circle” of

the snare serves as a very clear “target” for the perforation

with the RF catheter As soon as the RF catheter with the

coaxial catheter has advanced through the valve tissue,

the perforating catheter also will be through the loop of

the snare in the pulmonary artery! If there is any difficultypassing the coaxial catheter along with the RF perforatingcatheter through the new “puncture”, the RF perforatingcatheter alone can be advanced through the valve andgrasped with the snare Once the RF catheter is snaredsecurely, traction is placed on the RF catheter and thecoaxial catheter is drawn into the descending aorta withthe snare Either the coaxial catheter or a balloon dilationcatheter is advanced over this fixed RF catheter andthrough the valve as described previously

If a retrograde angiographic catheter is positioned fromthe aorta, through the ductus and into the pulmonary

artery, and the perforating catheter is not manipulated on

its own from the pulmonary artery through the ductusinto the descending aorta after the perforation of thevalve, the retrograde angiographic catheter in the pul-monary artery is replaced with a snare catheter Again,because of the frequent tortuosity and “mushy” nature ofthe ductus in these patients, the ductus is crossed with avery soft tipped torque wire and the snare catheter isadvanced through the ductus over this wire Once thesnare is open in the main pulmonary artery, the perforat-

ing wire/catheter almost automatically will be through the

loop of the snare! The perforating catheter is grasped withthe snare in the pulmonary artery and withdrawn into thedescending aorta through the ductus, as described above.The worst-case scenario is when there is no patent duc-tus, or when present, the ductus cannot be crossed fromeither direction In that case, the perforating catheter,immediately after perforating the valve, is manipulated as

far as possible into a distal right or left branch pulmonary

artery With the guiding catheter still positioned in theRVOT and forced against the pulmonary valve over theperforating catheter, the coaxial catheter is advanced overthe perforating catheter, through the valve and to the tip

of the perforating catheter/wire With the guiding and

coaxial catheters both fixed in these positions, the

perforat-ing catheter/wire is withdrawn carefully and replacedwith a 0.014–0.018″ (depending upon which coronarydilation balloons are available) stiff, exchange length,

“coronary” guide wire The guide wire is advanced out ofthe tip of the coaxial catheter until the long floppy tip of

the guide wire is “balled up” completely in a distal

pul-monary artery branch This “wadding up” of the floppy

tip is essential in order to ensure that the stiff portion of the guide wire will be across the valve and well out into the

branch pulmonary artery.

Once the stiffer exchange guide wire is in this secureposition in the distal pulmonary artery, the guide catheterand then the coaxial catheter are removed over the guide

wire and replaced with a very low-profile, 2–3 mm

dia-meter, “coronary” dilation balloon Occasionally, even thevery low-profile balloon will not follow over the wirethrough the thick valve tissue In that circumstance, the

C H A P T E R 3 1 Purposeful vascular perforations

balloon is withdrawn over the wire and replaced with a

larger guiding catheter that can accommodate the

low-profile balloon The guiding catheter is manipulated very

gingerly over the wire through the right ventricle and up

against the pulmonary valve With the guiding catheter as

an additional support, the low-profile balloon is passed

over the wire, through the guiding catheter and through

the valve

The sequential dilation of the valve is started over this

wire Once the “waist” in the initial balloon has been

elim-inated, the balloon is removed over the wire and replaced

with a slightly larger, 3–5 mm balloon The balloons are

replaced sequentially until a balloon is introduced that is

appropriate in size for a single-balloon valve dilation,

according to the annulus diameter of the pulmonary

valve Occasionally, the initial smaller wire must be

ex-changed for a larger and stiffer wire to support the larger

balloons, which will not pass through the guiding catheter.

Laser technique for perforation of the

pulmonary valve in pulmonary atresia with

intact ventricular septumCfrom the right

ventricular approach

Excimer Laser™ energy has been used for the perforation

of the atretic pulmonary valve outside of the United States

for over a decade, but the lack of a small laser catheter

approved by the US FDA precluded its use in the US until

recently6,7 The Excimer Laser uses ultraviolet light with a

wavelength of 308 nm to ablate tissues in the path of the

laser light The laser energy is generated with a VCX-300

Excimer Laser System (Spectranetics, Colorado Springs,

CO), which often is available in an interventional

catheter-ization laboratory for laser lead extractions The recent

approval by the US FDA of the Point 9™ Extreme Excimer

Laser catheter (Spectranetics, Colorado Springs, CO) for

the treatment of total occlusions of peripheral and

coron-ary arteries in humans has made this very small laser

catheter available for use for selected congenital lesions in

the US The Point 9™ Laser catheter is a 0.9 mm diameter,

fairly flexible catheter, consisting of multiple layers of

optical fiber strands, which run the length of the catheter

and through which the laser energy is delivered The

bun-dled fibers surround an open lumen, which accepts a

0.014″ wire

The Point 9™ Laser catheter is advanced to the atretic

pulmonary valve through a pre-positioned guiding

catheter that has a lumen of at least 1 mm (3-French)

dia-meter The specific guide catheter that is optimal for the

particular patient varies with the size and anatomy of each

individual patient The guide catheter should have

pre-formed curves at the distal end that correspond to the

course from the inflow to the outflow of the particular

right ventricle The guide catheter is maneuvered into the

narrow outflow tract of the right ventricle to a position asclose to the center of the “plate” of the atretic valve as pos-sible The Point 9™ Laser catheter is delivered over a stiff0.014″ guide wire with a fine floppy tip as well as throughthe guiding catheter The floppy tip of the guide wireextends beyond the tip of the laser catheter and oftenloops back on itself in the right ventricular outflow tract asthe Point 9™ catheter is maneuvered to the atretic valve

As the tip of the Point 9™ catheter approaches the valve,the wire is withdrawn into the laser catheter

Once positioned against the “plate” of the valve, 45microJoules, at 15 kV and 25 Hz, of laser energy are deliv-ered through the catheter in one second bursts The tip ofthe catheter usually passes through the atretic tissue with

1 or 2 bursts of energy with each burst penetrating

approximately 100 microns If there is any forward push

applied to the catheter during the delivery of the energy,the laser catheter will continue through any tissue in front

of it including out of the vascular space! Once the tip of thelaser catheter has advanced through the atretic tissue intothe main pulmonary artery, the guide wire is advancedout of the catheter and preferably into the descendingaorta through the ductus Once the wire is successfullythrough the “valve” the remainder of the procedure isidentical to the procedure using RF energy

Laser energy has the disadvantages of requiring a largeand expensive generator, which may not be available inall congenital heart catheterization laboratories, and thepotential of retinal injury to surrounding personnel fromthe “scatter” of the high-intensity ultraviolet light Untilmore experience shows a distinct advantage of laser over

RF energy, the RF systems now appear preferable for monary valve perforation in congenital heart lesions

pul-Technique for perforation of the pulmonary valve in pulmonary atresia with intact ventricular septum retrograde through the patent ductus from the pulmonary arterial approach

When there is significant difficulty or even the absoluteimpossibility of positioning the guiding catheter properly

in the right ventricular outflow tract (RVOT) and/or therealso is an easily crossed patent ductus, the perforation ofthe pulmonary valve in patients with pulmonary atresiawith intact ventricular septum can be performed from thepulmonary artery side of the valve using a retrogradeapproach through the ductus9 Before the availability ofthe current and safer “burning” techniques to perform theperforation, stiff wires in association with the use of

“brute force” had been used to push through the atreticpulmonary valves into the right ventricular outflow tractfrom the pulmonary artery approach Because the “tar-get” area of the right ventricular outflow tract is small and

C H A P T E R 3 1 Purposeful vascular perforations

very narrow, the strong force (push), which necessarily

had to be applied to the retrograde catheter, could easily

displace the direction of the catheter tip with the result

that this technique had a very high likelihood of

perfora-tion into the pericardium instead of into the right

vent-ricle The retrograde perforation of the pulmonary valve is

far more reasonable with the availability of RF wires and

RF energy for the perforation

When the guiding catheter cannot be positioned in the

RVOT with the tip of the catheter directed precisely at the

valve in both X-ray planes, the retrograde approach for

perforating the valve should be considered The

retro-grade perforation still requires that a catheter is

posi-tioned in the RVOT for the purpose of performing

selective biplane angiography even if the catheter cannot

be directed precisely at the valve The RVOT must be

visu-alized very clearly, precisely and repeatedly with biplane

imaging during a retrograde perforation The right

ven-tricular outflow tract usually tapers to a very fine tip or

point just below the atretic valve As a consequence, the

RVOT presents a much smaller “target” when perforating

from the pulmonary artery toward the RVOT

With a prograde venous catheter positioned in the

RVOT, a Swan™ floating balloon catheter (Arrow

International Inc., Reading, PA) is introduced retrograde

into the femoral artery and advanced retrograde through

the patent ductus and into the pulmonary artery with or

without a pre-positioned floppy tipped wire through the

ductus With some retrograde “push” applied to the

Swan™ catheter, the balloon is inflated in the main

pul-monary artery directly in the pulpul-monary valve annulus

and against the atretic valve The inflated balloon in

con-junction with the usual course through the ductus usually

orients the lumen of the Swan™ catheter parallel to the

long axis of the pulmonary artery and also often points the

end hole of the Swan™ catheter directly toward the blind

RVOT The precise direction of the tip of the catheter that

is seated in the atretic pulmonary valve is changed in

order to point the lumen exactly toward the RVOT by

varying the amount of “push” and/or torque on the

Swan™ catheter When the tip of the Swan™ catheter

is pointing in the exact direction, the RF perforating

wire/catheter is advanced through the Swan™ catheter to

its tip, until the RF perforating wire is positioned against

the atretic pulmonary valve The relative relationships of

the tip of the Swan™ and the RF catheter to the RVOT are

verified with a small selective biplane angiocardiogram in

the RVOT The angle of the Swan™ catheter/perforating

catheter together also can be adjusted slightly by minimal

to-and-fro motion on the shaft of the Swan™ catheter

while the perforating catheter is passing through it When

the tip of the Swan™ catheter/perforating wire/catheter

is “aimed” exactly at the small, blind RVOT, the RF

perfo-rating wire/catheter is advanced until the tip of the wire

is embedded in the “valve” tissue The position isrechecked with a repeat small selective biplane angio-cardiogram in the RVOT, and adjustments to align theSwan™ catheter again are made as necessary Since theRVOT “target” is so small, perforation from the retro-grade approach is not attempted unless the perforatingwire/catheter tip and the narrow RVOT are aligned

exactly When the RF perforating wire/catheter is

point-ing precisely at the RVOT, and only then, is the RF energy

applied while the perforating wire/catheter is held in thevalve adjacent to the small RVOT

Instead of the retrograde Swan™ catheter, a formed, end-hole only catheter can be used for the retro-grade perforation The tip of a non-Swan™ type catheter

pre-is harder to keep exactly aligned in the center of the

pul-monary valve on the pulpul-monary side of the atretic valve.This can be accomplished eventually with patience andoften multiple exchanges of catheters with different curves

RF perforating wire alone is advanced through the valveafter the perforation and grasped with the snare in theRVOT If possible, the snared wire and/or catheter iswithdrawn through the ventricle and tricuspid valve andexteriorized through the femoral vein but, once the per-forating wire/catheter is held securely, the Swan™ bal-loon catheter is withdrawn from the femoral artery overthe proximal end of the perforating wire/catheter and isreplaced over the perforating wire/catheter with eitherthe coaxial catheter or a 4-French, multipurpose, end-holecatheter with a tapered tip This step is unnecessary if theoriginal retrograde catheter for the perforation was a non-Swan™ end-hole catheter With traction held on the tip ofthe perforating wire/catheter in the right ventricle withthe snare catheter, the coaxial or tapered end-hole catheter

is advanced over the perforating wire/catheter, grade through the ductus and then push–pulled acrossthe pulmonary valve using traction at both ends of theperforating wire/catheter Once the end-hole, retrogradecatheter is in the RV, the snare around the wire is loosened

retro-enough to allow the catheter to pass over the perforating

wire/catheter and through the snare The perforatingwire/catheter is withdrawn out of the femoral arterycatheter and replaced with a floppy tipped, exchangelength wire If necessary during this exchange, the snare istightened over the end-hole catheter that is passingthrough the pulmonary valve to hold the catheter in place

C H A P T E R 3 1 Purposeful vascular perforations

Snaring the distal end of the catheter in the RVOT

sup-ports the retrograde passage of the stiffer exchange wire

through the ductus, the pulmonary artery, the perforated

pulmonary valve and into the right ventricle

Once the tip of the exchange wire is through the valve

and in the right ventricle, the floppy tip of the wire is

grasped in the right ventricle with the snare and the

com-bination wire and catheter is pulled back, and very

care-fully through the tricuspid valve Extra care is taken not to

catch on the tricuspid valve structures and/or to pull too

vigorously through the tricuspid valve If the combination

cannot be pulled easily through the valve, the snare is

opened, releasing the grip on the wire The retrograde

catheter is withdrawn partially off the tip of the wire and

back toward the pulmonary valve The floppy tip of the

wire alone is re-grasped with the snare, which is still

within the right ventricle, and a repeat attempt is made

to withdraw the snare catheter with the grasped

retro-grade wire back through the tricuspid valve and into the

right atrium

If the snare/wire still catches on the tricuspid valve, the

wire is released from the snare and the snare loop

with-drawn completely into the snare catheter The snare

catheter is withdrawn into the right atrium A very careful

attempt then is made at manipulating the retrograde

catheter/wire, which is passing through the pulmonary

valve, through the tricuspid valve and back into the right

atrium The catheter may “bind” in the thick, tight

pul-monary valve structure and care must be taken to prevent

it from buckling and pulling out of the recently perforated

valve! If the wire is maneuvered to the right atrium, the tip

of the wire is re-snared in the right atrium

If the wire/catheter cannot be maneuvered back to the

right atrium, the snare catheter is manipulated through a

different area of the tricuspid valve and back into the right

ventricle, and/or an end-hole Swan™ balloon catheter is

introduced from the femoral vein and used to cross the

tri-cuspid valve into the right ventricle from the right atrium

and then the Swan™ catheter is used as the snare delivery

catheter When an inflated Swan™ balloon advances

across the small tricuspid valve, there is a better chance

that the balloon will pass through the largest orifice of the

tricuspid valve, and the snare wire can be used through

the Swan™ catheter The small size of the hypoplastic

tri-cuspid valve and/or the tritri-cuspid valve regurgitation,

however, may prevent a Swan™ balloon catheter from

“floating” into the right ventricle

Once the floppy tip of the wire is grasped with the snare

in the right ventricle with either catheter that has passed

through a different area of the tricuspid valve, the

retro-grade exchange wire is pulled carefully into the right

atrium From the right atrium, the exchange wire is

exteriorized through the femoral vein sheath, creating a

through-and-through femoral vein to femoral artery wire

The remainder of the procedure is the same as when theperforation of the atretic pulmonary valve was from the prograde approach Sequential dilations of the pul-monary valve are accomplished introducing the dilation

balloons from the femoral vein over the

through-and-through wire, as described previously

Once the pulmonary valve is open and there is grade access to the pulmonary artery, the necessity forfurther palliation of the patient in the catheterization lab-oratory during the same procedure is determined in thelaboratory at that time Following a perforation and dila-tion of the pulmonary valve in patients with pulmonaryatresia and intact ventricular septum, there almost always

pro-is a question about the adequacy of the right ventricularvolume and the need for a systemic to pulmonary shuntand/or an atrial septostomy These patients usually weredependent upon the patent ductus for most of the pul-monary flow and all have an existing patent foramenovale/atrial septal defect; however, usually one or both ofthese sources of blood flow is/are inadequate

Once the infant stabilizes after the valve perforation/

dilation and there is adequate pulmonary flow, then

fur-ther clinical assessment determines the need for an atrialseptostomy In the presence of a very small right ventricu-lar cavity and/or persistent very high right ventricularend diastolic and/or systolic pressures, the right ventricleoften is not capable of accommodating an adequate dias-tolic volume from the systemic venous blood return Theresultant small right ventricular systolic volume then will

be inadequate to provide enough forward blood flowthrough the lungs to the left heart to sustain an adequatesystemic output In the absence of an adequate opening or

“vent” at the atrial level, the systemic venous blood pools

in the systemic venous vascular bed and right atrium, theright atrium becomes massively dilated with the systemicvenous return, and the cardiac output remains low Whenthis occurs acutely in the catheterization laboratory, a bal-loon or blade and balloon atrial septostomy is performedduring the same catheterization

At the same time, when the patient does have even amarginal systemic cardiac output without significantright atrial/hepatic congestion after the pulmonary valveperforation, atrial septostomy is not performed during the initial catheterization Some elevation of the rightatrial pressure may augment the right ventricular filling

of these small ventricles When an atrial septostomy isperformed, it lowers the right atrial pressure, and in turn,may compromise right ventricular filling! By eliminatingthis extra filling pressure and volume, the potentialgrowth of the right ventricle also may be compromised.The balloon or a blade/balloon atrial septostomy alwayscan be performed hours, days or weeks later if the sys-temic output decreases and/or the right atrium and liverbecome distended

C H A P T E R 3 1 Purposeful vascular perforations

In addition to the question of adequate return of the

sys-temic venous blood to the syssys-temic output, the adequacy

of the net pulmonary flow is assessed before the infant

leaves the catheterization laboratory After the valve has

been opened successfully, the adequacy of the forward

flow through the opened valve, the effect of the

pul-monary regurgitation on the net forward flow and how

much of the pulmonary flow still is from the ductus are

determined from the angiograms If a catheter

interven-tion to increase the pulmonary flow is even considered, a

catheter is advanced either prograde or retrograde across

the ductus, prostaglandin is stopped and the infant

observed in the laboratory for 30 minutes or longer

When the ductus remains patent after the prostaglandin

has been stopped, no further intervention is considered

at that time When the ductus patency and flow are

prostaglandin dependent, the 30 minutes usually are

sufficient time for the prostaglandin effect to wear off and

for the ductus to close functionally When the net

pro-grade pulmonary flow is insufficient after the ductus

closes, the infant will become significantly desaturated

and/or hypoxic The choices at that time are to restart

prostaglandin and terminate the case with plans for a

sub-sequent surgical shunt or to consider the implant of a stent

in the patent ductus arteriosus as a means of establishing a

more permanent systemic to pulmonary artery “shunt”

With the newer, pre-mounted, flexible, small stents this is

a much more viable option

The technical details of the atrial septostomy

proced-ures are discussed in Chapters 13 and 14 and the

tech-nique for stenting the patent ductus are discussed in

Chapter 25 Until far more definitive data are available

about which ventricles grow after the pulmonary valve is

open and which patients have adequate pulmonary flow

with the ductus closed, the decisions for further catheter

intervention are “on-the-spot”, somewhat arbitrary

judg-ment decisions in the catheterization laboratory during

each individual case, but usually some type of an

aug-mented systemic to pulmonary shunt, if not an atrial

septostomy, is required

Perforation of the pulmonary valve in patients

with pulmonary atresia and an associated

ventricular septal defect

Hausdorf and associates extended the use of

radio-frequency perforation of the plate-like pulmonary valve to

perforation of the “muscular tract” between the right

vent-ricular outflow tract (RVOT) and the main pulmonary

artery for the attempted palliation of ten patients with

pulmonary atresia and a ventricular septal defect10 The

distance between the RVOT and the main pulmonary

artery varied between 1.2 and 12 mm Except for two

new-borns, their ten patients were much larger and older

patients, some even years past the newborn period All

of the patients except the two newborns had eithersignificant systemic to pulmonary collaterals or a surg-ically placed systemic to pulmonary artery shunt as theirsource of pulmonary artery blood flow

Because patients with pulmonary atresia and a ricular septal defect have either a very tortuous patent duc-tus arteriosus and/or present at a later age with no ductusarteriosus, perforation of the atretic pulmonary valvewithout the use of a through-and-through wire usually isnecessary in these patients Before being considered forvalve perforation, patients with pulmonary atresia and aventricular septal defect should have an adequate dia-meter, main pulmonary artery documented angiographi-cally This angiographic anatomy is obtained from biplaneangiograms in the aorta adjacent to the “source” vesselsfor the pulmonary flow, from selective biplane injectionsinto aortopulmonary collaterals, or even from biplanepulmonary vein wedge angiograms The “indirect” angio-graphic pictures of the main pulmonary artery are stored

vent-as “road maps”

After the anatomy of the main pulmonary artery and itsprecise location are identified, an end-hole “guiding”catheter is pre-shaped to conform to the course from theright atrium to the right ventricular outflow tract (RVOT).This guiding catheter must be manipulated into the rightventricular infundibulum with the tip directed exactly inthe direction of the pulmonary artery as visualized on thebiplane “road maps” It may be possible to advance the tip

of the guiding catheter only to the proximal, or inflow end,

of the infundibulum The RF perforating catheter isadvanced through and out of the tip of the guidingcatheter With occasional good fortune or even luck, thevery thin perforating catheter passes through the in-fundibulum until it is close to, or against, the area of a tinyatretic valve structure When this occurs, the coursethrough the traversed infundibulum tends to align the tip

of the perforating catheter more directly at the center ofthe stump of the atretic main pulmonary artery segment.The position is verified with biplane angiography, inject-ing through the guiding or a separate venous catheter.With the tip of the RF wire pushed against the atretic tis-sues and in the precise direction of the pulmonary artery

as visualized in both PA and LAT X-ray planes, RF energy

is applied for several seconds The perforating wire isadvanced in short steps toward the pulmonary artery

between bursts of RF energy, and the RF energy re-applied.

Very rarely, the RF perforating catheter is advanced in

very short distances during the application of the energy while observing the course through the tissue very care-

fully Once through the atretic tissues and into the

pul-monary artery, the perforating catheter is advancedwithout energy applied to it into a distal pulmonaryartery branch and distally as far as is possible The tract

C H A P T E R 3 1 Purposeful vascular perforations

of the RF wire from the RVOT to the pulmonary artery is

examined carefully to verify that the wire is in the center

of the muscular tract in both planes The procedure then

is similar to a pulmonary atresia with intact ventricular

septum where the ductus arteriosus was not traversed,

although maneuvering through the tract of RVOT tissue

usually is even more difficult

More often, in patients with pulmonary atresia and a

ventricular septal defect, the perforating catheter/wire

cannot be advanced beyond the tip of the guiding catheter

positioned at the proximal end of the infundibulum If, on

biplane imaging, the guiding catheter is pointing directly

toward, although still some distance away from, a

pul-monary artery of an adequate diameter, the RF energy is

utilized to perforate through the infundibulum, to the

area of the “valve”, and then through the remaining

tis-sues into the pulmonary artery This is performed with

very short bursts of RF energy and small advances of the

perforating catheter/wire between the applications of

energy Between each advance, the position of the

perfo-rating catheter/wire and its orientation toward the valve

is rechecked with small, selective, hand injected, biplane

angiograms in both planes of imaging and injecting

through the guiding catheter or an adjacent venous

catheter in the outflow tract The attempted perforation is

continued only as long as the perforating catheter/wire

stays on a direct course to the valve and the patient

exhibits no hemodynamic deterioration during the

proced-ure Once the valve is crossed, the wire positioning and

dilation procedure are the same as previously described

for pulmonary atresia with intact ventricular septum

with-out a patent ductus After the communication has been

established and the tract partially dilated, usually the tract

is maintained open with an intravascular stent

Purposeful perforation of other vascular

structures or total vessel obstructions

Pediatric and congenital catheterization laboratory

inter-ventionalists who are very comfortable with transseptal

atrial puncture have extended the needle puncture

tech-nique of the transseptal procedure to the perforation of

multiple other structures, some for diagnostic purposes

and others in order to create permanent openings

Puncture of surgically created interatrial baffles and/or

patches were the logical extension of the standard atrial

transseptal procedure The venous approach usually is

used, however, for baffles and some patches, the needle

tip is positioned and directed very differently according to

the orientation of the patch or baffle11 Usually, more force

must be applied to the needle/transseptal set to penetrate

the thicker structures of a baffle/patch The extra force

required increases the risk of the perforating needle

continuing forward beyond or on the “other side” of the

desired perforation into unwanted structures The use of

an RF perforating catheter through a special transseptalsheath/dilator set (Baylis Medical Co Inc., Montreal,Canada) eliminates the extra force (and in turn, extra risk) necessary for these “transseptal” perforations Un-fortunately, RF perforation is not applicable throughpatches and/or baffles that are made of synthetic (non-tissue) materials

In addition to the native atrial septum, patches in the interatrial septum and baffles within the atria, thetransseptal needle and set are used to perforate and, inturn, re-cannulate totally occluded vascular channels Thetransseptal needle requires a relatively straight line ofaccess or “straight shot” from the site of catheter introduc-tion to the site being “re-cannulated” in order to transmitthe forward force from outside of the body, along the needle and to the needle tip at the puncture site When forward force is applied within any significant, “non-contained” curve in the course of the needle, the forceapplied to the proximal needle causes the needle to “bow”proximally and, in turn, the forward force is dissipatedinto the curve rather than being delivered to the tip, andthe direction of the tip is changed significantly

Even with this limitation, the transseptal needle hasbeen used successfully to puncture and rebuild long (5–

6 cm!) total obstructions in multiple different vascular

chan-nels (see Chapter 24, “Venous Stents”) These include total

obstructions in the native superior vena cava, the superiorlimbs of intracardiac venous baffles, totally disconnectedright pulmonary arteries in postoperative “hemi-Fontan”patients12, aortic coarctations with a discrete membranousinterruption, and all varieties of ilio-femoral/IVC totalvenous obstruction13 The access for these punctures isfrom the femoral, jugular or hepatic vein approachdepending upon the vessel, the location and orientation of

the obstruction and which approach provides the

straight-est route to and through the obstruction.

The availability of the radio-frequency perforating tems has extended the possible sites of vascular obstruc-tion that might be perforated and reconstituted With theflexibility of the RF perforating catheter (wire), and sincelittle or no forward “force” is required for the perforation,

sys-RF perforating catheters can traverse a very tortuousroute to the site to be perforated Perforating RF catheters(wires) readily pass around relatively acute curves and, inturn, can approach the area to be punctured from sharp oracute angles The use of the RF wire allows the perforation

of the atrial septum14, atrial baffles and other vascularstructures from a variety of venous access sites As long as

contact is maintained against the surface to be punctured

by the RF perforating catheter, the RF energy will trate native tissues

pene-The usual interatrial septum is aligned parallel to, andeven away from, a catheter that is introduced from the

C H A P T E R 3 1 Purposeful vascular perforations

superior vena cava (SVC) The curved tip of a transseptal

needle, even with an added curve formed on the shaft of

the needle, often cannot engage the interatrial septum

from a superior vena cava approach Even when a very

curved needle does “catch” on the septum from the SVC

approach, the straight direction necessary to apply

for-ward force to the tip of the needle for perforation is not

possible Using the RF perforation system, a pre-formed

guiding catheter or special RF transseptal set with nearly a

right angle curve at the tip can be introduced from the

jugular vein/superior vena cava approach and then the

catheter/set is rotated until the pre-formed curve at

the tip of the catheter positions the tip against, and nearly

perpendicular to, the interatrial septum The RF

perfora-tion wire and coaxial catheter are advanced through the

guiding catheter and just against the septum The RF

energy is applied as the RF perforation wire and coaxial

catheter are advanced through the septum with virtually

no force Once the RF perforation wire and catheter are in

the left atrium, they are exchanged through the coaxial

catheter for a stiffer exchange length wire, and then

what-ever sheath/catheter system is desired

Excimer Laser™ energy also has been used to perforate

other totally occluded structures in addition to atretic

pul-monary valves In our institution, a very scarred-in

dis-tance of 5–6 mm between the side of the main/right

pulmonary artery and the totally disconnected stump of

the proximal left pulmonary artery was perforated

suc-cessfully with a laser catheter on a compassionate use

basis The left pulmonary artery had been totally

discon-nected as a consequence of multiple prior surgeries Both

of the vessels were encased in dense scar tissue The

con-vex, cephalad and left side of the main/right pulmonary

artery just at the origin of the right pulmonary artery was

parallel to the side of the disconnected proximal LPA The

perforation was performed through the convex, left side

of the main/right pulmonary artery, through scar tissue

surrounding the walls of the two adjacent vessels and

through the side and into the discontinuous LPA After

perforation, the tract between the two vessels could be

dilated and an intravascular stent implanted in the

chan-nel to maintain the patency

Laser energy has the advantage of greater perforating

capability The RF energy for perforation is more

control-lable and is readily avaicontrol-lable in more catheterization

laboratories The RF techniques now are used for almost

all of the applications for which laser perforations

previ-ously were utilized in previous studies even outside of the

United States

The dedicated RF perforating system with the RF

perforating catheter has extended the type and number

of obstructed structures that can be opened or

recom-municated in the catheterization laboratory RF

perfora-tion already has been used to reconnect a chronic total

left pulmonary artery obstruction15 In that patient, thedistal left pulmonary artery became totally isolated fouryears earlier following an even earlier surgical patchrepair of the artery The intravascular course to theobstruction was the usual intracardiac tortuous course to

a left pulmonary artery The distal pulmonary arterybeyond the obstruction was identified by pulmonary veinwedge angiography The obstruction could not be crossedwith any type of mechanical wire probing but was crossedwith a 2-French RF catheter using 11 watts of power deliv-ered for 11 seconds

When a totally obstructed vascular structure is tered, maximum information should be obtained aboutthe length and course of the obstruction as well as the sta-tus and size of the chamber or vessel lumen that is open atboth ends or on both sides of the obstruction This infor-

encoun-mation is acquired from magnetic resonance imaging and

with biplane angiography before a perforation throughthe obstruction is considered In branch pulmonary arteryocclusions, information about the distal vessel is obtainedangiographically from the flow into the obstructed vesselthrough shunts, systemic to pulmonary collaterals and/orfrom pulmonary vein wedge angiograms The length andthe course of the obstruction are “road mapped” andplaced in the longest axis of the biplane review screens

A guiding catheter is chosen which, when placed in theproximal end of the obstruction, aligns the tip of thecatheter parallel to the long axis of the two discontinuoussegments of the obstructed vessel Changing the guidingcatheter, changing the curve of the guiding catheterand/or the use of a Mullins™ wire within the guidingcatheter adjacent to the RF perforating catheter are used to

accomplish the precise direction of the guiding catheter.

The RF perforating catheter is passed through the tip ofthe pre-positioned guiding catheter and engaged in theproximal end of the obstruction The guiding catheter, thetip of the RF perforating catheter and the entire length ofthe obstruction are visualized in both X-ray planes withbiplane fluoroscopy or biplane cine imaging while the RFenergy is delivered to the RF catheter The tip of the RFperforating catheter is advanced only between the appli-cations of RF energy, and must follow a precise “roadmapped” course through the obstructed area and towardthe area of the previously visualized “lumen” at the otherend of the obstruction

If the RF perforating catheter begins to detour awayfrom this precise course at all, the RF energy is not appliedand the RF catheter is withdrawn The “tract” created isvisualized with a biplane angiogram performed with a

very small contrast injection through the guiding catheter.

This angiogram demonstrates any new and/or erroneous

“tract” that has been created with the RF catheter If thetract is precisely in line between the two portions of thevessel, the RF catheter is advanced back into the tract and

C H A P T E R 3 1 Purposeful vascular perforations

the energy delivery repeated If the newly created tract is

angling away from the distal vessel but is not outside of

the vessel, the guiding catheter is repositioned into the

proper direction and the process restarted If the new tract

extended out of the vessel, extravasation of contrast will

be seen With a small amount of contained extravasation,

the patient remains stable, particularly the post-operative

patient, who usually will have extensive scarring around

the vessel In the presence of significant extravasation, the

perforation attempt is abandoned at least temporarily

The area is observed intermittently on fluoroscopy for at

least 30 minutes as long as the patient remains stable

If the extravasation continues to increase, occlusion of

the newly created tract with a micro coil is carried out The

fine delivery catheter for the micro coil is delivered

directly into the tract through the already positioned

guiding catheter A small, “straight” micro occluding coil

is used for the occlusion, as described in Chapter 26

If there is no extension of the extravasation and/or once

the extravasation is stable, the guiding catheter is

reposi-tioned to redirect the RF catheter in the more appropriate

direction and the RF perforation restarted As long as the

patient remains clinically stable and there still is a desire

to open the obstruction, the process is continued until the

distal segment of the vessel is entered Once the distal

ves-sel is entered, the coaxial catheter is advanced over the RF

perforating catheter and the RF perforating catheter is

withdrawn The position in the distal vessel is confirmed

angiographically through the coaxial catheter Once the

position in the distal segment is verified, a stiff exchange

guide wire is advanced through the coaxial catheter and

positioned as far distally in the vessel as possible The

exchange guide wire must be small enough in diameter

to accommodate a small “coronary” balloon dilation

catheter The newly created communicating tract is

dilated sequentially as described previously Once the

perforated tract is enlarged to the diameter of the adjacent

vessel, intravascular stents are implanted to maintain the

new communication

Recannulation of total venous occlusions

Acute total venous occlusion usually is a result of an acute

thrombus formation in a vein that has sluggish flow

and/or has been damaged by surgical or catheter

inter-vention, including chronic indwelling intravenous

catheters and infusions Occlusions of small veins usually

go unrecognized until access to the specific vein is desired

at a later time Acute occlusions of large, central veins

present with the acute onset of venous congestion

“upstream” from the obstruction The most notable

exam-ples are the appearance of the “superior vena cava

syn-drome” with distention of the head, neck and arm veins

and swelling of the head and face when the superior vena

cava becomes obstructed, or lower extremity venous gestion and edema when the iliofemoral and/or inferiorvena cava become(s) obstructed

con-Venous occlusions usually involve very large thrombiand should be addressed when they occur (or are recog-nized) and very aggressively The goal is to remove thethrombus along with the cause of thrombus if possible.The fresh venous thrombus is crossed with a standardguide and/or Terumo™ wire If an indwelling venousline is in place, the line is removed Once the thrombus iscrossed, it is macerated and the debris from the macera-tion withdrawn with a mechanical thrombectomy device/catheter, as described in Chapter 12 Once the debris hasbeen removed, any remaining clot is compressed againstthe vessel wall with an angioplasty balloon and/orintravascular stent The balloon used should be the size ofthe unobstructed vein or the diameter of adjacent non-involved veins If there is a discrete narrowing and/ornarrowing of a surgical anastomosis in the vein as thesource of the thrombus, the stenotic lesion is treated withdilation and the implant of an intravascular stent

When not recognized and/or not treated acutely,venous thrombi result in permanent chronic venousocclusions Even long, chronic, total occlusions of periph-eral as well as central veins frequently can be traversedand recanalized using long needles and/or stiff wires inconjunction with finely tapered dilators, as described inChapter 21 This is accomplished relatively blindly using

“brute force” to penetrate through the obstructions Theperforation of the obstruction usually is directed by aim-ing for a catheter or wire that is positioned in the vessel atthe opposite end of the obstruction

It appears that the directional control of the Safe SteerWire™ (Intraluminal Therapeutics Inc., Carlsbad, CA)combined with a radio frequency source of energy in theSafe Cross System™ (Intraluminal Therapeutics Inc.,Carlsbad, CA) adds purposeful directional control to re-cannulations, while the RF energy produces a more con-trolled perforation and, as a unit, it reduces the “force”necessary to recanalize totally occluded vascular tracts16.The Safe Steer Wire™ uses optical coherence reflectome-try to distinguish between thrombus and the viable tis-sues of the vascular wall in order to navigate the wire onlywithin the limits of the vascular walls The addition ofradio-frequency energy delivered through the same

“wire” provides the penetrating ability of the Safe CrossSystem™ The Safe Cross System™ has been used suc-cessfully for recanalization of totally occluded coronaryarteries, totally occluded intravascular stents and totallyoccluded peripheral vessels17

Recently intravascular ultra sound (IVUS) has beenadded to the armamentarium to help identify the truelumen during the recanalization of totally occluded cor-onary arteries18 Both the Safe Cross System™ and the use

C H A P T E R 3 1 Purposeful vascular perforations

of IVUS potentially could be used in the treatment of the

vascular obstructions (both arterial and venous) that are

en-countered in pediatric and congenital heart patients and

present exciting challenges for new developments in the

pediatric/congenital cardiac catheterization laboratory

Recannulation of total acute arterial occlusions

Acute occlusion of a femoral artery during, and/or

imme-diately following, a retrograde arterial catheterization is

not an uncommon complication of cardiac catheterization

in pediatric and congenital heart patients Arterial

occlu-sions, like most other complications, are best treated by

prevention The meticulous handling of the arterial access

sites to prevent complications is discussed in Chapter 4

However, particularly during interventional procedures

that require the introduction of large sheaths and/or

catheters into sometimes relatively small arteries,

com-promise of the artery may be inevitable Occlusion of an

artery may be manifest with any of a very wide spectrum

of signs and symptoms A totally obstructed artery can

manifest as only a decreased pulse in the involved

extrem-ity, as decreased (or absent) capillary perfusion in the

extremity, as an absent pulse with a cool and pale

extrem-ity or, in the worst case, as a cold, very pale and painful

extremity The latter, more extreme signs of obstruction

obviously need immediate attention, while various

degrees of urgency are applied to the treatment of the

“lesser” signs of obstruction When any degree of arterial

compromise is recognized, it should be treated at that time.

Usually, even decreased peripheral pulses in the involved

extremity indicate an artery that is totally occluded by

thrombus although, because of collateral flow around the

obstruction, the totally occluded artery may not cause

acute symptoms Any arterial occlusion eventually may

result in claudication, growth retardation of the extremity

and/or loss of a potential access site for a future and

essential intervention

The initial management of an acute arterial occlusion is

to continue or initiate treatment with intravenous heparin

in therapeutic doses for one to two hours while observing

the extremity closely With return of the pulse/perfusion,

the heparin is discontinued If the pulse/perfusion does

not return to normal and/or if there is any deterioration in

the pulse/perfusion of the extremity, further more

vigor-ous intervention is recommended One alternative, more

aggressive courses of management is to begin intravenous

thrombolytic therapy with streptokinase, urokinase or

rtPA, which is covered in Chapters 2 and 4 When the

pulse and perfusion return with thrombolytic therapy, the

thrombolytic infusion is stopped while continuing

intra-venous heparin for at least another 24 hours The situation

becomes more complicated when thrombolytic therapy is

initiated but is not effective and/or there is progression of

the signs of obstruction in spite of the thrombolytic In thatsituation, surgical or catheter intervention is required.However, following the use of a thrombolytic, mechanicalintervention can be very hazardous This has led somecenters to proceed with catheter recannulation of theartery immediately when the initial heparin therapy wasnot effective

When mechanical intervention in the catheterizationlaboratory is instituted, heparin therapy is continued Inthe infant and small child, the involved femoral artery can

be approached with a catheter/wire introduced from the

venous system, advanced prograde through the left heart,

into the aorta, manipulated to the descending aorta andeventually, the involved artery The entry into the leftheart is through a pre-existing PFO/ASD or through atransseptal atrial puncture The prograde approachallows the introduction of multiple and larger cathetersand their use for longer periods of time without compro-mise of an additional artery The prograde approach does hinder the precise control over the tip of thecatheter/wire somewhat and requires the availability ofvery long exchange wires, and long diagnostic and bal-loon dilation catheters

In larger adolescent and adult patients, the approach

to the involved femoral artery is usually from the tralateral femoral artery or even from a brachial artery.The catheters and/or balloon dilation catheters used aremuch smaller relative to the vessel in the larger patient,and the turn into the contralateral femoral artery is lessacute, making the manipulations from another introduct-

con-ory artery less traumatic in the larger patient Also the

available catheters and/or balloon dilation catheters oftenare not long enough to allow a prograde approach in thelarger patient, where the catheter would have to extendfrom a femoral vein to the heart, loop through the leftheart and then back to a femoral artery

Whichever route is used, first an angiogram is obtainedwith an injection in the descending aorta proximal to theobstruction in order to identify the area of obstruction and to provide a “mirror image” view of the uninvolved,opposite iliofemoral arterial system as a representation ofthe normal vessel anatomy With the lesion localized, anend-hole catheter is manipulated selectively into theinvolved vessel and a floppy tipped guide wire and/or astraight Terumo™ wire is used to probe through the freshobstruction (clot ± spasm) as the catheter is advancedalong with the wire Once successfully probed, thecatheter is replaced over the wire with an appropriatelysized, low-profile, balloon angioplasty catheter In theinfant and small child coronary artery balloons are ideal insize and have very long catheter shafts In smaller patientsthe initial catheter is replaced over the wire with the ap-propriate coronary balloon and/or the wire and catheterare replaced with a fixed wire, coronary angioplasty

C H A P T E R 3 1 Purposeful vascular perforations

balloon catheter The obstructed area is dilated to a

dia-meter equal to the normal, comparative, ipsilateral vessel

A repeat small angiogram is performed to visualize the

degree of opening and whether further repeat dilations

are necessary Once the lumen is open and flow

estab-lished, the balloon and wires are removed The patients

are maintained on intravenous heparin for at least an

additional 24 hours

Complications of “purposeful

perforations”

The purposeful perforation techniques are designed to

do just thataperforate! The only, very slight, differences

between the desired, purposeful perforation and an

in-advertent, catastrophic, erroneous perforation are the

meticulous attention to the details of the planned

per-foration, total awareness of the anatomy adjacent to the

structure being perforated and the very early recognition

of the beginning of an abnormal course of the perforating

device A purposeful perforation that goes astray

com-pletely usually results in a perforation of the external

wall of a vascular structure into the pericardium, pleura

and/or peritoneum and, as a consequence, results in a

major adverse event

Awareness, and, in turn, prevention are the best

treat-ments of inadvertent perforations Repeated biplane

angio-graphic visualization of the anatomy, before and during the

purposeful perforation, continually verifies the direction

and location of the perforating device Any deviation in

the desired direction of the perforating device necessitates

a redirection of the device or termination of the procedure

When either the fine tip of a transseptal needle or the tip

of a 2-French RF wire alone perforates through the wall of

a vascular structure, an extremely small opening is

cre-ated These small perforations, if recognized and if

noth-ing larger is pushed through the opennoth-ing, often seal on

their own When an erroneous perforation occurs in a

patient who has had previous surgery, the area almost

always is encased in dense scar with no “space” for

“extravasation” and, in turn, is “self sealing” In “native”

(not previously operated) areas and/or when the pressure

in the vascular structure that is perforated is very high

(e.g the right ventricle in pulmonary atresia with intact

ventricular septum or the left atrium with severe mitral

stenosis), sealing of the perforation usually does not

occur, and certainly the perforation cannot be relied upon

to seal on its own The abnormal perforations also cannot

seal if the abnormal course is not recognized and a larger

catheter/dilator is advanced through the initial tiny

erron-eous opening

When an abnormal perforation occurs, the surgical and

anesthesia services are notified immediately of a pending

emergency case When extravasation continues through

an erroneous perforation, the opening occasionally can be

“tamponaded” by the inflation of a Swan™ or angioplastytype balloon within the vessel or chamber adjacentand/or proximal to the site of perforation This can beaccomplished only in vascular channels that are not thesole vascular supply to a vital structure If available, a

“covered stent” can be used to “cover the area” in the wall

of a perforated vessel When a small perforation is nized while the perforating wire/needle is still in theopening, occasionally a micro coil can be used through acoaxial catheter over the wire/needle to occlude the per-foration Rarely one of the vascular occlusion devices (acoil, umbrella or an Amplatzer™ device) can be placed inthe abnormal opening to seal a larger opening Each unex-pected perforation creates its own separate circumstancesand should be anticipated before attempting a desiredperforation

recog-Even as attempts are made to “tamponade” or occludethe leaking perforation, a blood infusion with the previ-ously “typed and crossed” whole blood is started The areainto which the blood is draining (pericardium, pleura) istapped and an adequate sized drain secured in the space.When significant blood loss continues, the withdrawnblood is returned to the patient by autotransfusionthrough a filtered blood administration set The patient

is prepared for surgical intervention as expediently aspossible

Another, somewhat rare complication during monary valve perforations in newborn patients is the pre-mature and unexpected closure of the ductus arteriosusdue to the manipulations through the ductus during theprocedure When the ductus is the sole source of pul-monary blood flow, the closure of the ductus results inprogressive hypoxemia and acidosis and can lead todeath The likelihood of spontaneous occlusion of the duc-tus occurring is reduced by minimizing the manipulationsthrough the ductus, accurately maintaining and/orincreasing the prostaglandin infusion to the patient, andmaintaining the infant’s fluid volume In the event of aspontaneous closure of the ductus, the rate of theprostaglandin infusion is increased and an attempt ismade to cross the ductus gently with a fine, floppy tippedguide wire If the ductus can be crossed expediently withthe wire, the implant of a stent in the ductus to maintain itspatency should be considered The definitive treatmentonce intractable ductus occlusion occurs, however, usu-ally is an emergency surgical shunt

pul-Conclusion

As with all interventional therapeutic catheter ures, the definite risks of each procedure must be weighed

proced-C H A P T E R 3 1 Purposeful vascular perforations

against the potential benefits of the procedure

Considera-tion of the alternative procedure should include the risks

of the alternative procedure Cardiac lesions undergoing

purposeful catheter perforations are all very complex, and

the alternative surgical procedures for these lesions all

carry significant risks The purposeful transcatheter

per-foration of most lesions in an experienced catheterization

laboratory are more than justified and are considered as

the first-line of therapy

References

1 Ross J Jr, Braunwald E, and Morrow AG Transseptal left

atrial puncture; new technique for the measurement of left

atrial pressure in man Am J Cardiol 1959; 3(5): 653–655.

2 Park SC et al A new atrial septostomy technique Cathet

Cardiovasc Diagn 1975; 1(2): 195–201.

3 Kan JS et al Percutaneous transluminal balloon

valvulo-plasty for pulmonary valve stenosis Circulation 1984; 69: 554.

4 Latson LA Nonsurgical treatment of a neonate with

pulmon-ary atresia and intact ventricular septum by transcatheter

puncture and balloon dilation of the atretic valve membrane.

Am J Cardiol 1991; 68(2): 277–279.

5 Parsons JM, Rees MR, and Gibbs JL Percutaneous laser

valvotomy with balloon dilatation of the pulmonary valve as

primary treatment for pulmonary atresia Br Heart J 1991;

66(1): 36–38.

6 Qureshi SA et al Transcatheter laser-assisted balloon

pul-monary valve dilation in pulmonic valve atresia Am J Cardiol

1991; 67(5): 428–431.

7 Redington AN, Cullen S, and Rigby ML Laser or

radiofre-quency pulmonary valvotomy in neonates with pulmonary

atresia and intact ventricular septumadescription of a new

method avoiding arterial catheterization Cardiol Young 1992;

2: 387–390.

8 Rosenthal E et al Radiofrequency-assisted balloon dilatation

in patients with pulmonary valve atresia and an intact

ven-tricular septum Br Heart J 1993; 69(4): 347–351.

9 Coe JY et al Transaortic balloon valvoplasty of the

pul-monary valve Am J Cardiol 1996; 78(1): 124–126.

10 Hausdorf G, Schneider M, and Lange P Catheter creation of

an open outflow tract in previously atretic right ventricular

outflow tract associated with ventricular septal defect Am J

Cardiol 1993; 72(3): 354–356.

11 El-Said HG et al 18-year experience with transseptal

proced-ures through baffles, conduits, and other intra-atrial patches.

Catheter Cardiovasc Interv 2000; 50(4): 434–439; discussion

13 Ing FF et al Reconstruction of stenotic or occluded

iliofemoral veins and inferior vena cava using intravascular stents: re-establishing access for future cardiac catheteriza-

tion and cardiac surgery J Am Coll Cardiol 2001; 37(1):

251–257.

14 Justino H, Benson LN, and Nykanen DG Transcatheter ation of an atrial septal defect using radiofrequency perfora-

cre-tion Catheter Cardiovasc Interv 2001; 54(1): 83–87.

15 Fink C et al Transcatheter recanalization of the left main

pulmonary artery after four years of complete occlusion.

Catheter Cardiovasc Interv 2001; 53(1): 81–84.

16 Cordero H et al Initial experience and safety in the treatment

of chronic total occlusions with fiberoptic guidance

technol-ogy: optical coherent reflectometry Catheter Cardiovasc Interv

2001; 54(2): 180–187.

17 Lee PY et al Percutaneous recanalization of chronic

subcla-vian artery occlusion using optical coherence

reflectometry-guided radiofrequency ablation guidewire Catheter Cardiovasc

Interv 2003; 60(4): 558–561.

18 Matsubara T et al IVUS-guided wiring technique: promising approach for the chronic total occlusion Catheter Cardiovasc

Interv 2004; 61(3): 381–386.

Percutaneous pulmonary valve implant

A transcatheter-delivered valve mounted within a stent

and a technique for its delivery were devised and

devel-oped by Dr Philip Bonhoeffer in conjunction with Alan

Tower of the NuMED™ Corporation1 The Bonhoeffer™

valve and technique introduce an exciting new era to the

catheter treatment of congenital heart patients Although

not yet a “routine” procedure, this unique device and

technique for the implant of a prosthetic valve into the

right ventricular outflow tract/pulmonary artery have

been demonstrated to be, not only doable, but an effective

and safe procedure2 This technique should become an

integral part of the armamentarium of the interventional

cardiologist for use in congenital heart lesions

There are a large number of patients with congenital

heart disease who have very significant pulmonary valve

regurgitation as a result of prior surgical and/or

interven-tional procedures on the pulmonary valve and/or right

ventricular outflow tract (RVOT) These prior procedures

include all surgical patches/reconstructions of the RVOT,

surgical ventricular to pulmonary artery conduits

(includ-ing the RVOT in the Ross™ procedure), most, if not

all, surgical pulmonary valvotomies and possibly even

balloon dilation of the pulmonary valveaall regardless

of the original underlying lesion There is an increasing

number of these patients who, over time, have developed

severe right ventricular dilation and significant right

ventricular failure as a consequence of the pulmonary

valve regurgitation (with or without residual stenosis)

The current standard therapy for these patients who have

pulmonary valve regurgitation and significant right

ven-tricular failure is the surgical implant and/or replacement

of a valved conduit Most of these patients already have

had at least several prior major surgical procedures, and

all of the valved conduits that are implanted have their

own relatively short (relative to the life span of the

patient) duration of functional competence These factors

make the prospect of repeat surgery even less palatableand the idea of replacing the valve at least once percutan-eously during a cardiac catheterization, a very desirablealternative

The Bonhoeffer™ valve is a glutaraldehyde-preservedvalve, which is harvested from a bovine jugular vein and mounted within a Cheatham-Platinum™ (C-P™)stent (NuMED Inc., Hopkinton, NY) The stent/valve ismounted on a specially designed balloon dilation/deliv-ery catheter (NuMED Inc., Hopkinton, NY) and is deliv-ered percutaneously from a femoral vein puncture Theballoon delivery catheter is specially manufactured with

a 16-French shaft and a 20 mm (or desired diameter less than 20 mm) BIB™ delivery balloon (NuMED Inc.,Hopkinton, NY), a transparent, thin-walled, plastic “cov-ering” sheath which extends from the shaft of the catheterover the entire catheter/balloon/stent/valve, and a spe-cial 18-French “carrot” dilator tip which is incorporatedonto the tip of the delivery catheter just distal to the balloon

The candidates for percutaneous valve replacement arelarge adolescent and adult patients with predominantlypulmonary valve regurgitation and a fixed diameter pul-monary valve annulus and/or RVOT At the present timethese valves are suitable only when the valve annulus/

RVOT is no larger than 22 mm in diameter The stent/

valves are best suited for implant in previous RVOT

conduits, which provide some length as well as the fixed

diameter of the outflow tract The valves can be implanted

in smaller outflow tracts, however an attempt is made todilate the stent/valve up to 18–20 mm in diameter in

order to create the optimal diameter for the function of the

valve within the stent and to accommodate the total cardiac output of most full grown adult patients The presence of associated stenosis and/or calcification in theoriginal valve/valve annulus do/does not, necessarily,represent a contraindication to the implant of a percutan-eous pulmonary valve implant; however, any stenoticarea where the valve is to be implanted always should be

32 Special innovative or new, therapeutic

catheterization procedures and devices

C H A P T E R 3 2 Innovative, new therapeutic procedures

pre-dilated to within 2 mm of the proposed implant

dia-meter of the valve in order to ensure that the percutaneous

stent/valve can be expanded to its functional diameter

Before the patient is even considered for a stent/valve

implant, the area of the pulmonary annulus and the RVOT

where the valve is to be implanted are imaged and

measured very accurately using biplane angiography The

measurements for the seating of the stent/valve are very

critical and are made using a very accurate and reliable

calibration system for the measurements, as described in

Chapter 11 Often, the angles of one or both of the X-ray

tubes must be changed in order to orient the area of

implant precisely on edge and to obtain the most accurate

measurements of this area At the same time, it usually is

more “comfortable” and convenient to perform the valve

implant in the straight PA and lateral views If necessary,

“road map” images are obtained in these views to be

used for the implant in addition to the views used for the

measurements

Once the angiograms have been obtained, the

measure-ments are verified and even before the stent/valve is

opened from its sterile packaging, a 0.035″ Super Stiff ™

delivery wire with a short floppy tip (Medi-Tech, Boston

Scientific, Natick, MA) is positioned as far distally as

possible into a branch pulmonary artery The wire must

be positioned so that only the stiff portion of the wire

remains positioned across the RVOT and that the wire is

in a very secure and stable position This Super Stiff™

wire must be able to support the passage of the large,

stiff, delivery balloon/catheter on which the stent/valve

is mounted through the often curved and/or circuitous

course to the RVOT Since these patients almost always

have very large dilated right ventricles, marked

pul-monary valve regurgitation and often tricuspid valve

regurgitation, the manipulation of any catheter into a

sat-isfactory distal pulmonary artery location for this

posi-tioning of the wire represents a significant challenge in

each of these procedures Any extra time spent in

achiev-ing a very secure position of the wire in a very distal branch

pulmonary artery, is time well spent during the

catheter-ization procedure Once the wire is in place the catheter

that was used for the delivery of the wire is left in place

over the wire and kept on a slow continuous flush through

a wire back-bleed valve to protect the ventricle and valve

structures from the rough surface of the wire, to keep clots

from forming on the wire, and to allow repositioning of

the wire should it work its way backward while the

stent/valve is being prepared Although not essential, it

simplifies the procedure to introduce a separate

angio-graphic catheter from a separate vein and position it in the

area of the proposed stent/valve implant Although

angiograms can be performed with injection through the

protective sheath over the balloon/stent once it has been

withdrawn off the balloon/stent/valve, these angiograms

cannot be performed before the sheath is withdrawn, andthe limited angiograms through the sheath and aroundthe catheter never are as satisfactory as an angiogramobtained with a power injection through a separatecatheter in the area

Once the wire is in place, the packaged valve is opened,inspected and the valve is checked for its competency Thetissue valve comes mounted within a 40 mm long C-P™

stent The stent/valve is packaged in the dilated

configura-tion with the stent/valve opened to a 20 mm diameter.Before the stent/valve is used, it is washed sequentiallyfour, or more, times, each time in a separate, fresh solution

of normal saline or Ringer’s lactate During the wash, thevalve function is tested The stent is pulled longitudinallythrough the flush solution so that the solution enters one

of the open ends of the stent When the fluid enters fromthe distal (pulmonary artery) end of the stent, the flow ofthe fluid entering the stent closes the valve and should notallow the fluid to pass through it When the stent/valve

is filled with fluid and is held upright (vertically) with

the distal end up, the fluid within the stent/valve is held

within the stent/valve like a cup When the stent is pulledthrough the fluid in the opposite direction (from proximal

to distal), the fluid passing into the stent opens the valvecompletely and allows the fluid to flow freely through it.Once the Super Stiff ™ delivery wire is in place and thevalve has been tested, the valve/stent is mounted on thedelivery balloon/catheter First, a separate, deflated, 8 or

10 mm diameter, 4 cm long, but very smooth, standardangioplasty balloon is passed gently through the fullyexpanded valve/stent from the proximal to the distal endand the balloon is inflated carefully, but to its designateddiameter and pressure The stent/valve then is com-pressed (crimped) circumferentially over the inflated bal-loon very carefully, in slow, sequential steps movingcircumferentially around the stent until the stent with thecontained valve is compressed fairly tightly over the 8 or

10 mm balloon This balloon is deflated and very carefully

withdrawn from the valve/stent The withdrawal must bevery meticulous in order not to catch the valve nor put anytension on the valve leaflets within the stent since the surface of the deflated balloon, which was previouslyinflated, will be rough and the balloon is being withdrawn

against the opening direction of the valve mechanism The

large special balloon delivery catheter for the stent/valvethen is introduced into the partially compressed stent/valve, paying very careful attention to inserting the tip of

the balloon delivery catheter into the proximal (right

vent-ricular) end of the stent/valve As a “reminder”, the stent

valve has blue sutures around its distal (pulmonary artery)

end to correspond to the “blue carrot” dilator tip of theintroducer balloon/catheter

The stent/valve is centered exactly over the BIB™delivery balloon and again circumferentially and firmly

C H A P T E R 3 2 Innovative, new therapeutic procedures

but carefully, slowly and sequentially compressed and

crimped over the deflated balloon Once the stent/valve is

compressed tightly on the balloon, the clear protective

sheath is advanced off the more proximal shaft of the

delivery catheter to cover the balloon/stent/valve The

initial introduction of the protective sheath over the

prox-imal end of the stent is performed very meticulously with

manual compression of the tip of each of the struts of the

stent in order to be sure that each separate tip passes

inside of the protective sheath as it is advanced onto the

stent The protective sheath is advanced until it abuts the

proximal end of the “carrot” dilator tip The valve/stent

then is ready for introduction and delivery There are two

separate marks on the shaft of the catheter, which

corre-spond to the two separate positions of the proximal end of

the protective sheath when the tip of the sheath is entirely

over, or withdrawn completely off the stent/valve These

marks are embedded in the walls at the proximal end of

the shaft of the delivery catheter The protective sheath

is not radio-opaque, so these marks represent the only

way of verifying the position of the protective sheath in

relation to the stent/valve

The catheter that was utilized for positioning the wire

and the short introductory sheath are removed over the

wire, being very careful to maintain the wire in its secure

distal position in the pulmonary artery Once the short

sheath and catheter are removed, the skin incision and

subcutaneous tissues over the wire are enlarged enough

to accommodate the circumference of a 22-French system

over the wire The skin/subcutaneous tract/vein are

pre-dilated with a separate 22-French short dilator A dilator

that is larger than the delivery catheter is used to ensure

the easy passage of the mounted stent/valve/balloon

through the skin/subcutaneous tissues and the wall of the

vein at the introductory site The dilator is removed over

the wire and the stent/valve on the special balloon

deliv-ery catheter is introduced over the wire and through the

dilated tract With careful observation of the tip and the

course of the wire on fluoroscopy, the mounted stent/

valve is advanced over the wire to the area of implant

This part of the procedure can be very difficult, as even

the 0.035″ Super Stiff™ wire may not support the stent/

valve/balloon delivery catheter adequately Advancing

the catheter/stent/valve usually pushes the combination

to the “outer circumference” of the curved path to the

position in the outflow tract Pushing the catheter/stent/

valve a short distance over the wire and then alternately

withdrawing the shaft of the wire an equally short

dis-tance (without allowing the tip of the wire to withdraw!)

usually allows the catheter/stent/valve to be “inched”

forward over the wire and into position

Once the balloon/valve/stent has reached the area of

implant, a biplane angiogram is performed and compared

with the baseline, “road map” angiogram in the same

views Often the large and stiff catheter/stent/valve overthe wire will change the relative position of structures

in the area Any necessary adjustments of the balloon/valve/stent position compared to the exact location forimplant are made and then the protective sheath is with-drawn off the valve The protective sheath is not visible

on fluoroscopy, however its position is checked by the calibrated marks at the proximal end of the deliverycatheter After the protective sheath is withdrawn, arepeat angiogram is performed to ensure that the with-drawal of the sheath did not change the relative position

of the balloon and stent in relation to the desired positionfor implant When the stent appears to be in the precise,desired position and the measurements appear satisfac-tory, the inner balloon of the BIB™ dilation balloon isinflated Once the inner balloon is inflated completely, theposition in the annulus area is rechecked with a repeatangiogram, the position of the stent/valve adjusted, andthe outer balloon inflated to fix the stent/valve in position.The BIB™ balloon is inflated at least one more time toensure full dilation and fixation of the stent in the annulus.Subsequent maneuvers depend upon the degree of

“fixation” of the stent/valve in the annulus A repeat gram is performed through the second catheter (or theprotective sheath) to verify the location and fixation of the stent/valve When the stent is fixed in a satisfactoryposition, the balloon/delivery catheter is withdrawn verycarefully over the wire and out of the stent/valve This is avery critical part of the procedure as the deflated BIB™

angio-delivery balloon has a very rough and irregular surface

and easily catches on the valve and/or the supportingstent It frequently must be “teased” out of the stent/valve It may be possible to re-advance the protectivesheath at least partially over the balloon as the balloon isdeflating within the stent/valve Once over the balloon,the smooth surface of the sheath provides a separationbetween the rough balloon and the valve When the original pulmonary/RVOT annulus was only a few mmsmaller than the expanded diameter of the stent/valve,the withdrawal is even more precarious and must be performed very cautiously

Once the delivery balloon/catheter has been drawn from the stent, the second angiographic catheter

with-is manipulated gently through the stent/valve and arepeat pulmonary artery angiogram is recorded If a sec-ond catheter is not utilized, the balloon/delivery catheter

is withdrawn over the wire and replaced with an hole, multipurpose catheter or a Multi-track™ catheter (B Braun Medical Inc., Bethlehem, PA), which then is re-advanced carefully through the valve to the pulmonaryartery distal to the valve Repeat hemodynamics are meas-ured and a repeat pulmonary artery angiogram recordedwith the injection of the contrast performed distal to thevalve If the stent/valve appears at all precarious in its

end-C H A P T E R 3 2 Innovative, new therapeutic procedures

freshly implanted position, the hemodynamic/anatomic

assessment of the valve postimplant is performed by

echo/Doppler interrogation only, without any attempt to

cross the freshly implanted stent/valve with a catheter

Annulus/outflow tract “reduction” with a

“banded” self-expanding covered stent

In its present configuration, the Bonhoeffer™ stent/valve

is suitable only for patients with a rigid, fixed diameter,

outflow tract of 20 mm or less To overcome this problem,

a unique catheter-delivered self-expanding covered

stent/internal band has been developed and tested in

animals to percutaneously reduce the diameter of the

widely dilated pulmonary artery/RVOT3,4 It has been

tested with a self-contained bovine jugular vein valve and

as an internal stent/band only device The basis of this

device is a self-expanding, covered, Nitinol™ stent, which

has a central, open tubular portion of a fixed diameter and

with both ends of the tubular device widely flared (AMF,

Groupe Lepine, Lyon, France) The entire stent is covered

with a 0.3 mm polytetrafluoroethylene (PTFE) membrane

(Zeus Inc., Orangeburg, SC) to make the walls

impervi-ous The central tubular portion creates a lumen with a

fixed diameter of 18 mm while both of the distal ends

“flare” away from the central portion and are capable of

expanding up to 30 mm in diameter The very wide

dia-meter of the ends allows fixation of the stent/band into

much larger diameter areas in an aneurysmal vessel/

outflow tract The expanded device has the appearance

of a large “dumbbell” with a large lumen extending

from end to end through its center This configuration

allows the creation of a circumferential band with a

fixed lumen, which is the diameter of the central portion,

while the expanded ends fix the stent/band into very

large, aneurysmally dilated right ventricular outflow

tracts/pulmonary arteries (RVOT/PA) and occlude flow

from around the central lumen by the PTFE covering This

covered stent/band can be implanted either as only

the tubular covered stent/band or can have a bovine

jugular vein valve incorporated into the tubular portion

of the central lumen for a “one-stage” outflow tract

reduction–valve implant procedure

Most patients with significant pulmonary regurgitation

do have some remnant of the original and/or a tissue

pul-monary valve, which may or may not be stenotic Even in

a markedly aneurysmal pulmonary artery/right

ventricu-lar outflow tract, when there is any residual stenosis of the

outflow tract, the stenosis is pre-dilated before the implant

of the stent/band with or without the incorporated bovine

valve The minimal diameter of the outflow tract must

allow the full expansion of the valve segment of the stent/

band device and the eventual valve

When the stent/band is implanted with no ated valve, it creates a fixed, rigid diameter of the RVOTwith a maximum diameter of 18 mm This tubular “band”

incorpor-is ideal for the subsequent percutaneous implant of

a Bonhoeffer™ stent/valve in its present configuration.The compressed stent/band is delivered percutaneously from the femoral vein, over a pre-positioned Super Stiff™wire The band portion of the self-expanding stent is cen-tered in the area where the valve is to be implanted andthe entire stent/band is extruded from the deliverysheath As the stent/band is extruded, the ends flare totheir predetermined wide diameters with the central areafixed at the diameter of the band The wide diameters ofthe ends of the self-expanding stent fix the stent/band inplace, while the central tubular area serves as an eventualsite to fix a stent/valve The covering of the flared ends

of the stent funnel the entire flow through the lumen of the central, “banded” area When the valve is implantedseparately, the valved stent is delivered with the enclosedbovine valve and is implanted in this tubular portion

of the stent/band approximately two months after the

“stent/band” was placed

Percutaneous valve implant in the aortic position

The bovine jugular vein valve mounted within a stent alsoprovides the possibility for a “percutaneous” aortic valvereplacement This concept has been tried in animals andperformed at least once in a human5 –7 The percutaneousaortic valves are mounted in much shorter and strongerstents There still are problems in placing such a stent/valve in the aortic position, which are significantly greater than in the pulmonary position The stent/valveimplanted in the aortic root must not occlude the orifices

of the coronary arteries In most cases, particularly in theolder adult patient, dilation of the aortic sinuses displacesthe orifices of the coronary arteries far laterally and awayfrom a stent placed in the aortic annulus In addition to theproblem of the coronary ostia, the very large stent/valvedelivery system is introduced into an artery, which at thepresent size and configuration of the stent/valve requires

a surgical cut-down on the femoral or even iliac artery Analternative is the delivery of the stent-mounted valve pro-grade through a transseptal puncture, the mitral valveand the left ventricle Although the larger delivery systemcan be introduced percutaneously into a vein, it thenrequires the extensive manipulation of the large and stiffdelivery system/stent/valve through a circuitous coursethrough the left heart The aortic roots of patients withaortic regurgitation usually are markedly dilated and farlarger in diameter than the currently available bovine

or other tissue valves At the same time the percutaneous

C H A P T E R 3 2 Innovative, new therapeutic procedures

aortic valve is placed within the thickened (calcified)

ori-ginal valve, which reduces the diameter significantly and

allows a very secure implant

In spite of the present obstacles, this concept for a

trans-catheter replacement of the aortic valve appears very

promising for future developments

Prospective catheterization laboratory

completion of lateral tunnel/Fontan

circuits

In spite of the lack of prospective and/or planned

com-mercial development in this area, the most innovative

uses of covered stents in humans to date have been in

pediatric/congenital heart lesions Covered stents were

used to “rebuild” disrupted intra-atrial, venous

chan-nels/baffles in several complex patients with single

ventricles who had undergone “Fontan” cavopulmonary

type single ventricle repairs, and where the baffles and/or

venous channels were disrupted and leaking

significant-ly Two very different types of covered stent were used

initially for this purpose in two similar, very sick patients,

and both under very extenuating circumstances The

cov-ered stents were placed in disrupted lateral tunnel

chan-nels to percutaneously repair the “tunchan-nels” The covered

stents extended from the inferior vena cava, at the caudal

end of the right atrium, through the area of the “true”

right atrium and superiorly into the base of the caval–

pulmonary anastomosis with the right pulmonary artery

In doing so the channels that were created with the

cov-ered stents directed all of the systemic venous flow from

the inferior cava to the pulmonary arteries and eliminated

all of the intra-atrial leaking8

With some collaborative cardiology–surgery

“pre-planning” in prospective studies and with very little

change in either the surgical or the catheterization

pro-cedure, the use of covered stents in “Fontan” patients is

being extended to provide an elective final phase of the

“Fontan completion” in the catheterization laboratory9,10

The “catheter completion” still requires further

improve-ments in the design of the covered stents and a specifically

“pre-planned” second stage, “bi-directional Glenn”, using

one of two different proposed methods

When performing the bi-directional Glenn, the surgeon

creates a contiguous “floor” or, at the most, a very small

restrictive opening, between the caudal surface of the

right pulmonary artery and the most cephalic “roof” of

the right atrium Ideally, the circumference of this “roof ”

and the orifice of the inferior vena cava into the right

atrium both are outlined with opaque sutures to assist the

later catheter steps in the procedure A wide open interatrial

communication (common atrium!) also must be ensured

at the time of the bi-directional Glenn anastomosis For the

“completion” of the Fontan in the catheterization atory, the “roof/floor” of the right atrium/right pul-monary artery is punctured with a “transseptal” typepuncture from either the right atrium into the pulmonaryartery or from the superior vena cava/pulmonary arteryinto the right atrium, and the opening is dilated to a dia-meter 2–3 mm smaller than the diameter of the stent/graftwhich will be implanted A channel is created from theinferior vena cava to the opening in the right pulmonaryartery with a large, long, specifically manufactured, covered stent, which is implanted extending from thecephalic, newly created opening in the floor of the rightpulmonary artery, through the cavity of the right atriumand caudally, well into the inferior vena cava This creates

labor-a seplabor-arlabor-ate, confined inferior clabor-avlabor-al to pulmonlabor-ary labor-arterychannel This technique requires relatively little change inthe “second-stage” surgical procedure, but is very chal-lenging for the interventionist in the catheterization labor-atory The interposed covered stent must create a channellarge enough in diameter to carry two thirds of the sys-temic venous blood flow and, after the “stent” shrinks inlength during the implant, still be long enough to extend

exactly from the IVC through the right atrium and into the

pulmonary artery An even greater challenge for this

pro-cedure is generated by the subsequent eventual growth of

the patients The new “tube graft” must be large enough in

diameter to accommodate the increasing volume in bloodflow and the growth of the patient and the patient’s heart,

in particular the length of the right atrium! The diameter

of some stent grafts may be adjustable with subsequent balloon dilation, but the implant length is fixedaor pos- sibly it could shrinkawith further dilation of the stent that

creates the channel!

An alternative technique requires an open-heart, ical procedure on bypass by the surgeon with opening ofthe right atrium at the earlier “Glenn” stage, but currentlymakes the procedure more suitable for patients of all sizesand makes the final stage, which is performed in thecatheterization laboratory by the interventionist, muchmore straightforward During the surgical “bidirectionalGlenn” stage of the procedure, the surgeon ensures thatthere is an adequate intra-atrial communication and then

surg-establishes the complete lateral tunnel, caval–pulmonary baffle within the right atrium, however, with two very

significant variations from the standard lateral tunnel First,

a large (15–20 mm) window or “fenestration” Which municates with the right atrium, is created in the medialwall of the baffle of the lateral tunnel Secondly, the ceph-

com-alad end of the newly created lateral tunnel is attached

to the caudal surface of the intact right pulmonary artery, but no opening or communication is made between the right

atrium/lateral tunnel and the pulmonary artery at the

time of the bidirectional “Glenn” surgical procedurea i.e the inferior vena cava/right atrial blood flow is not

C H A P T E R 3 2 Innovative, new therapeutic procedures

opened into the pulmonary artery and, as a consequence,

the patients function as though they only have had the

bidirectional Glenn anastomosis!

For the “completion” of the “Fontan” the interventional

cardiologist in the catheterization laboratory punctures

through the intact roof/floor between the right atrium

and the right pulmonary artery, into the right pulmonary

artery at the cephalad end of the lateral tunnel, dilates the

tunnel to right pulmonary artery communication and

implants a large diameter, but short stent (covered?) to

widen the opening and to keep this newly created channel

open This stage of the procedure is performed from a

per-cutaneous femoral venous approach The large

“fenestra-tion” that the surgeon has created in the medial wall of the

lateral tunnel is closed with a percutaneous atrial septal

occlusion device! The advantage of this version of the

“Fontan completion” would be that the native tissue of the

“lateral tunnel” will grow in “diameter” to accommodate

the patient’s growth and increased blood flow with the

growth The partial native tissue lateral tunnel also has a

better chance of accommodating the growth of the patient

in “length” as occurs with the current lateral tunnel,

cavopulmonary anastomoses

The capability of having custom-designed, large,

cov-ered stents, which are made to fit specific lesions/patients,

would make it conceivable to perform a conversion of a

failed, classic, right atrial to pulmonary artery “Fontan” to

a lateral tunnel cavopulmonary “Fontan” in the

catheter-ization laboratory These special covered stents could

be modifications of the aortic “stent grafts”, which already

are used for the catheter treatment of aortic aneurysms11

The stent graft would have to be built to the specific

dimensions of each individual patient (e.g length of RA,

diameter of IVC–RA junction and proposed SVC–PA

diameters)

In the catheterization laboratory, first the original atrial

septum/septal patch would require reopening widely in

order to allow the coronary sinus blood to return back into

the circulation once the “lateral tunnel” is completed The

cephalic end of the catheter-implanted, stent graft “lateral

tunnel” could be implanted in the original direct right

atrial to pulmonary artery connection or a puncture could

be performed from the most cephalic portion of the stump

of the right atrium through the bottom (caudal surface) of

the adjacent right pulmonary artery and then the cephalic

end of the custom “lateral tunnel” stent graft implanted

directly into the pulmonary artery The stent graft would

form a tunnel through the right atrium between the

inferior vena cava and the right pulmonary artery

sim-ilar to the catheterization “completion” of the “Fontan”

described above If the cephalad end of the

catheter-implanted “lateral tunnel” was not catheter-implanted through the

original connection between the right atrium and

pul-monary artery connection, then this original right atrial to

pulmonary artery connection would be occluded ately with a catheter-delivered device The superior venacava still would need connecting to the pulmonary artery.Once the cephalic end of the stent graft, which passesthrough the right atrium to the right pulmonary artery,was anchored into the right pulmonary artery, the super-ior vena cava still would have its native connection to theright atrium and be draining past the pulmonary artery,around and outside of the stent graft, with the result thatthe superior vena cava blood still would pass through theatrial septal defect into the systemic output An additionalpuncture would be necessary from the superior vena cavainto the top (cephalad surface) of the right pulmonary

separ-artery A second, short, 18–20 mm diameter covered stent

would be implanted in this communication, which woulddivert all of the superior vena caval blood into the pul-monary artery Since the surrounding area would be

so densely scarred from two previous cardiac surgeries (at least one systemic to pulmonary shunt and/or a

“Glenn” plus the original “Fontan”), this extra vascularvessel-to-vessel puncture would not result in a significantextravasation of blood into the surrounding thorax.Although “catheterization revision” would represent avery extensive procedure in the catheterization labor-atory, with the proper equipment, it should be very doableand still would be less of a procedure than the current surgical revision of a classic “Fontan”

Perforation of vessel walls with creation

of a vessel-to-vessel communication and/or shunt

Dr Kurt Amplatz reported the possibility of neously creating communications between native, vascu-lar structures using a modification of the Nitinol™ mesh,Amplatzer™ occluders from a preliminary study in ani-mals Dr Chigogidze from the Bakuolev Scientific Center

percuta-of Cardio-Vascular Surgery in Russia also has performedsome animal work on the successful percutaneous cre-ation in the cardiac catheterization laboratory of vascularshunts between adjacent major vascular structures Com-munications were created between adjacent venous struc-tures, the aorta and vena cava, the pulmonary artery andthe superior vena cava and even between the aorta and apulmonary artery The minute details of the procedure arenot available to this author, however, the general conceptwas presented and represents a very exciting develop-ment in the area of transcatheter therapy12

Tiny intravascular magneto-mechanical devices areplaced in the adjacent vessels ostensibly to pull the vesselstogether and to direct a flexible “kinetic” needle as it punc-tures from one vessel to the other Once the magnets are inplace in the adjacent vessels, a puncture from one vessel

C H A P T E R 3 2 Innovative, new therapeutic procedures

into the adjacent vessel is performed with the special

“kinetic” needle attached to a flexible wire The exact

mechanism of the needle puncture is unclear Once the

needle has entered the adjacent vessel, it is captured

with a snare catheter and the needle with the attached

wire is withdrawn through the peripheral entry site of

this vessel The exteriorization of this wire creates a

through-and-through “rail” wire A large sheath/dilator

set is advanced over the wire and pulled through the new

communication between the vessels Presumably, the

presence of the large sheath/dilator within the newly

created openings in the walls of both of the vessels

pre-vents exsanguination from the now large puncture sites in

the walls of these vessels

Once the sheath has passed through the puncture site

into the adjacent vessel, the dilator is removed over the

wire A specially prepared, Nitinol™ self-expanding,

cov-ered, stent graft, which is flared widely at both ends, is

implanted in the area between the two vessels by

with-drawing the sheath off the stent graft The Nitinol™ stent

graft is covered with polyurethane and has a central

dia-meter of the desired opening between the two vessels Once

implanted, the covered stent creates a channel between

the two vessels while at the same time sealing the

open-ings in the walls of the vessel

Reportedly, vena cava to portal vein, superior vena

cava to pulmonary artery and aorta to pulmonary artery

communications all have been created successfully in

ani-mals! In addition, with an extension of this technique, a

normal heart in an animal was converted to a completed

“Fontan” circuit by the creation of: (1) a superior vena

cava to right pulmonary artery communication with one

stent graft (i.e a “Glenn” shunt); (2) exclusion of the main

pulmonary artery trunk and the pulmonary valve from

the circulation by a covered stent which bridged across

the main pulmonary artery from the right to the left

pul-monary artery; and (3) the completion of the “Fontan

atrial lateral tunnel” with a covered stent, which extended

from the inferior vena cava and through the right atrium,

connecting into the right pulmonary artery/superior vena

caval channel To date, these procedures have been

per-formed only in animals, but the concept certainly is an

exciting evolution into the immediate future of

interven-tional cardiology

Completion of the first stage “Norwood”

procedure for hypoplastic left heart

syndome in the catheterization laboratory

By the combination of implanting a stent in the ductus

arteriosus to maintain its patency and the implant of “flow

restrictors” in the proximal branch pulmonary arteries to

reduce pulmonary artery flow and pressure, Drs Boucek

and Chan in conjunction with AGA Medical Corporation(AGA Medical Corp., Golden Valley, MN) have devel-oped a procedure for the initial palliation of patients withhypoplastic left heart syndrome entirely in the cardiaccatheterization laboratory13

The special flow restricting devices (AGA MedicalCorp., Golden Valley, MN) are very similar to theAmplatzer™ Intravascular Plugs (AGA Medical Corp.,Golden Valley, MN), however the flow restrictors haveholes of a specific diameter passing through the devices.After very accurate sizing of both the proximal right andleft pulmonary arteries, flow restrictors that are severalmillimeters larger in diameter than each pulmonaryartery are placed precisely in each proximal branch pul-monary artery If the flow restrictor devices are under-sized, they can migrate distally and/or change theirorientation in the vessel and totally obstruct flow to theentire lung and/or a major branch If the flow restrictor

is too large for the particular vessel, the openings in thecentral portion of the device may not open entirely orsufficiently to allow any flow through the device

Once the flow restrictors are placed in the separate rightand left pulmonary arteries, the ductus arteriosus isstented with a self-expanding stent, which again, is sev-eral millimeters larger in diameter than the existing duc-tus The stent also must be long enough to cover all of theductal tissue, but at the same time not so long as to inter-fere with the pulmonary valve and/or compromise theentrance of the transverse aortic arch into the descendingaorta at the area of the ductus Presently, the Precise™

or Smart™ stents (Cordis Corp., Miami Lakes, FL) or theProtégé™ stents (ev3, Plymouth, MN) appear to be themost suitable for this use The Protégé™ stents have the advantage of having a separate attach–release mechan-ism, which allows withdrawal or repositioning of thestent up until the moment of final deployment Because ofthe limited lengths of these stents that are available, occa-sionally several stents must be overlapped in the ductus tocover all of the ductal tissue adequately

At present, the flow restrictor devices are custom factured for the specific investigational study and are notavailable commercially The procedure is technically verychallenging in small sick hypoplastic left heart syndromepatients, however, certainly it is less traumatic than thecomparable “standard” surgical “first stage Norwood”procedure As the equipment is developed and improves,this innovative approach should replace the initial sur-gery for many (most) of these patients

manu-Radio-frequency tissue desiccation

Sigwart introduced the concept of “ablation” of an mal portion of the ventricular septum for the treatment of

abnor-C H A P T E R 3 2 Innovative, new therapeutic procedures

obstructive hypertrophic cardiomyopathy by the

sub-selective infusion of alcohol into a septal perforating

coron-ary artery14 The relief of the obstruction is accomplished

by the purposeful creation of a localized myocardial

in-farction in the abnormal septal tissues The procedure is

very effective for the relief of left ventricular outflow tract

obstruction, however the procedure seldom is used in

pediatric patients and, as a consequence, is technically

very challenging for the majority of physicians who

perform therapeutic interventions primarily on pediatric

and/or congenital heart patients The alcohol septal ablation

procedure definitely is not without some significant

complications

More recently the ablation of left ventricular septal

tis-sue has been performed using radio-frequency (RF)

energy “Excavation” of the left ventricular outflow tract

with reduction of the gradient across the outflow tract

has been accomplished using an RF catheter with an 8 or

10 mm electrode tip, a high output 100-w RF generator

(Boston Scientific, Natick, MA), which is set at 60 watts for

1 minute with the tip cooled with a continuous saline flush

of 300 to 600 ml/hour while the RF is active The catheter

tip, which is deflected against the tissue while the energy

is applied, is drawn along the area of abnormal muscle in

the outflow tract in order to create a channel or groove

in the tissues The RF energy apparently “excavates” the

area of the septum by desiccation of the tissues without

any resultant adverse effects from the disseminated

(embolized) materials (gases?) This particular use of

radio-frequency energy is very new and the long-term

effects/consequences certainly are not known

Hypertrophic cardiomyopathy with left ventricular

obstruction is a relatively rare lesion in the pediatric

popu-lation, however, if RF energy is effective in relieving and

sustaining the relief of the left sided muscular obstruction,

then this procedure should have extensive application for

the innumerable congenital heart patients who have

mus-cular right ventrimus-cular outflow tract obstruction with or

with-out other lesions

Sideris “frameless” transcatheter patch

occlusion devices

The latest, and completely different entry into the

pro-cedures and devices for the occlusion of intracardiac

de-fects are the Sideris™ “frameless” Transcatheter Patches

(Pediatric Cardiology Custom Medical Devices, Athens,

Greece), which were developed to eliminate the perceived

problems of the metal frames that are present in all of

the current intracardiac occlusion devices15 The Sideris

“Patches” and techniques are based on experimental

information that the porous material of polyurethane

foam, when firmly fixed in place against a surface within

the circulation for the relatively short time of 23–48 hours, stimulates adhesions, which adhere to tissues securely

enough to hold the patch in place permanently in thatlength of time The fixation is secure enough to withstanddisplacement from the pressures/flow within or through

an intracardiac defect16,17 This has been demonstrated inanimal models and is reported to be successful in atrialseptal defects, ventricular septal defects and very largepatent ductus in humans

ASD frameless patch device

The occlusion of atrial septal defects with a “frameless”patch was performed in animals and, on a compassionateuse basis, in humans outside of the United States18 Thedelivery system consists of two relatively large, inflatablespherical latex balloons attached in series, immediatelyadjacent to each other, at the distal end of a triple lumen,end-hole catheter (Pediatric Cardiology Custom MedicalDevices, Athens, Greece) The most distal balloon, whichcommunicates with one lumen of the catheter, is covered

completely with a “sleeve patch” or “sack”, which is

com-posed of a thin layer of polyurethane foam The sheet offoam is wrapped over the distal balloon so that the “openend” of the folded patch extends proximally against thesecond, more proximal balloon The second balloon ismounted on the triple lumen catheter immediately prox-imal to the first balloon and communicates with the secondlumen The central (third) lumen of the catheter extendsthrough the distal end of the catheter and, in turn, throughthe center of the patch and allows the balloons/patch to bedelivered over a wire

The polyurethane patch has a radio-opaque suture ning through the proximal margins of the patch for radio-graphic visualization of the general area of the patch.During implant and while the patch is “fixing” on the sep-tum, there also is a very long loop of “retrieval” nylonsuture passing through an edge of the “patch” material.Both ends of this suture extend from the patch, which ispositioned in the atrial septum, and exit out of the body inthe inguinal area adjacent to the catheter This sutureserves as a retrieval mechanism should the patch notadhere to the particular area after the balloon is deflated.The atrial defect is measured very accurately with astatic sizing balloon A short tipped, stiff exchange lengthguide wire is positioned across the defect and into a leftupper pulmonary vein similarly to the delivery of otherASD occlusion devices A large, long sheath/dilator thatwill accommodate the delivery balloon with the coveringpatch is advanced over a wire to the area of the rightatrium, the dilator alone is removed and the sheath iscleared passively of air/clot and placed on a continuousflush The special balloon catheter carrying the collapsedpolyurethane “patch” on the deflated latex balloon is

run-C H A P T E R 3 2 Innovative, new therapeutic procedures

introduced over the wire, into the large, long sheath,

advanced out of the sheath and into the left atrium over the

wire The two ends of the long suture, which is attached

to the “patch” material, extend back through the long

sheath, along the side of the shaft of the balloon catheter

and out of the proximal end of the long sheath The distal

balloon with the “patch” covering it is inflated to a

dia-meter “several” millidia-meters larger than the measured

diameter of the defect The inflated distal balloon, which is

covered with the “patch”, is pulled back against and into

the defect by withdrawing the balloon catheter while

observing the balloon and septum on TEE or ICE If the

balloon/patch pulls through the defect, the balloon is

deflated, re-advanced into the left atrium, refilled with

slightly more fluid and repositioned back against/into the

septal defect The position and degree of occlusion are

confirmed with TEE/ICE If there still is leakage around

the balloon, the balloon is inflated even further Once

the distal balloon is against the septum and completely

occluding the defect, the second, more proximal balloon is

inflated This balloon inflates in the right atrium and helps

to “stabilize” the distal, left atrial balloon with the “patch”

against the rim of the defect The “patch” material, which

is covering the distal balloon, now should be in firm

con-tact with the entire rim of the atrial septal defect The

polyurethane sheet of material is wrapped around the

balloon and the catheter, but not fastened to the shaft of

the catheter Because of the extensive stretchability of the

polyurethane foam and of the latex balloons, only three

sizes of balloon/patch combinations reportedly are

suit-able for all defects

The constant pressure of the polyurethane against

the septum, which is necessary for the fixation of the

polyurethane “patch”, is accomplished by continual

ten-sion against the distal balloon, which is maintained on the

shaft of the balloon catheter by fastening the proximal shaft

of the catheter against the skin “outside” of the

vascula-ture system for 48 hours! The second large latex balloon,

which is inflated on the right side of the septum, helps to

stabilize the “patch” in position against the rim of the

atrial septal defect for the 48 hours, but does not hold the

distal balloon against the septum

Enough traction is applied to the balloon/delivery

catheter at the skin surface to maintain the distal (left

atrial) balloon against, and partially into, the atrial defect

without pulling the balloon through the defect The

bal-loon catheter is fixed securely against the patient’s leg at

the puncture site with several sutures in order to maintain

the “traction” on the catheter/balloon against the atrial

septum The patient is returned to the hospital ward but is

kept at strict bed rest with their leg extended straight for 48

hours All of this time the two balloons are inflated within

the heart and the proximal end of the balloon catheter

extends out of the femoral puncture site under some

tension! The patient is returned to the catheterization laboratory in 24 hours to check the balloons’ position andstability When the distal balloon remains in its properposition, it moves only in synchrony with the atrial septalmotion and should not be “bobbling” in the left atrium.After 48 hours the patient is returned to the catheteriza-tion laboratory The tension is released from the catheter

at the skin puncture site and the left atrial balloon, which

is covered with the “patch”, is deflated This allows theoriginally spherical patch material to collapse and shrinkinto a flat, but crumpled “patch” across the atrial defectwhile the deflated and collapsed balloon now is posi-

tioned on the right atrial side of the patch The area is

inter-rogated by TEE for any residual leak or displacement

of the patch When comfortable with the position andfixation of the patch, the more proximal balloon is deflatedand the balloon catheter with the two deflated balloons iswithdrawn very gently away from the septum The sep-tum and the now free “patch” again are interrogated withthe TEE/ICE for security on the septum, position and anyleak When satisfied with the implant, the long “retain-ing” suture is withdrawn slowly and carefully from the

“patch” material by pulling one end while releasing theopposite end of the suture

Because the “patch” material is pushed against theinner edge of the atrial defect and adheres to the septum

by that contact, theoretically, atrial defects that have norim and which are very large, can be occluded with this device Further multicenter, monitored trials of thisdevice with controlled rigid follow-up are necessary toestablish the utility of this very innovative but radicalapproach to ASD closure

Frameless VSD patch

The same “frameless” patch concept has been reported forthe closure of perimembranous ventricular septal defects(VSD) The patch is similar (identical?) to the framelesspatches for atrial septal defects (Pediatric CardiologyCustom Medical Devices, Athens, Greece) The ventricu-lar septal defect is crossed from the left ventricle into theright ventricle and a through-and-through wire “rail” cre-ated exactly as described for other techniques for per-imembranous ventricular defect closures (Chapter 30).Once the “rail” is created, the frameless VSD device,which is mounted on the latex balloon, is deliveredthrough a long sheath introduced from the femoral veinand pre-positioned across the VSD In the report on theVSD patches, the patches are pre-soaked in the patient’sblood, which accelerates the development of adhesions,and the duration of the traction against the patch neces-sary to fix the patch in place is only 23 hours The frame-less patch has been used with reported success in anumber of patients outside of the United States19 This is

C H A P T E R 3 2 Innovative, new therapeutic procedures

another innovative concept with some very favorable

points, but like the frameless ASD patch, the VSD patch

also requires a well controlled trial before it becomes an

accepted procedure

Frameless PDA patch

The same concept used for the frameless ASD and VSD

patches has been applied successfully to occlude the large

patent ductus arteriosus (PDA)20 Like the VSD patch, the

PDA patch is pre-clotted and only requires 23–24 hours of

balloon fixation before the implanting/fixation balloons

can be removed Also, like the other devices, the PDA

frameless patch has not been used in the United States or

in any regulated and/or controlled clinical trials

Dr Sideris has been experimenting with several

“sur-gical glues” in addition to the pre-clotting to enhance and

accelerate fixation of the patches to the tissues, which in

turn would eliminate the undesirable relatively long

period of fixation and immobilization of the patients The

frameless patches certainly are imaginative and possibly

indicative of the potential for transcatheter occlusion

ther-apy in the future

The future of interventional/therapeutic

catheterizations

The various procedures and devices described in this

chapter provide a glimpse into the future of transcatheter

therapeutic procedures for pediatric and congenital heart

patients Although all of these ideas may not evolve into

clinically useful procedures, they do illustrate the

con-tinued imagination and innovation of the current

pedi-atric/congenital interventionists and provide a challenge

for the future Patient care certainly will continue to be

improved, not only by procedures performed by

catheter-ization rather than surgery, but also by collaborative

and/or “hybrid” surgical/catheterization procedures21

References

1 Bonhoeffer P et al Percutaneous replacement of pulmonary

valve in a right-ventricle to pulmonary-artery prosthetic

con-duit with valve dysfunction Lancet 2000; 356(9239): 1403–1405.

2 Khambadkone S et al Percutaneous pulmonary valve

implantation for right ventricular outflow tract lesions after

congenital heart surgery Cardiol Young 2003; 13(Suppl 1

(Abstracts ’03 AEPC) ): 32 (Abstract #92).

3 Boudjemline Y et al Percutaneous pulmonary valve

replace-ment in large right ventricular outflow tract: an experireplace-mental

study Cardiol Young 2003; 13(Suppl 1 (abstracts of ’03 AEPC

meeting)): 30 (Abstract #84).

4 Boudjemline Y et al Percutaneous pulmonary valve

replace-ment in a large right ventricular outflow tract: an

experimen-tal study J Am Coll Cardiol 2004; 43(6): 1082–1087.

5 Boudjemline Y and Bonhoeffer P Percutaneous implantation

of a valve in the descending aorta in lambs Eur Heart J 2002;

23(13): 1045–1049.

6 Boudjemline Y et al Percutaneous implantation of a gical valve in the aorta to treat aortic valve insufficiencyaa

biolo-sheep study Med Sci Monit 2002; 8(4): BR 113–116.

7 Cribier A et al Percutaneous transcatheter implantation of an

aortic valve prosthesis for calcific aortic stenosis: first human

case description Circulation 2002; 106(24): 3006–3008.

8 Richens T et al Interventional treatment of lateral tunnel

dehiscence in a total cavopulmonary connection using a

balloon expandable covered stent Catheter Cardiovasc Interv

precon-Heart 1996; 75(4): 403–409.

11 Diethrich EB AAA stent grafts: current developments

J Invasive Cardiol 2001; 13(5): 383–390.

12 Chigogidze NA, Avaliani MV, and Cherkasov VA New

per-cutaneous technology of vascular shunting Cardiol Young

2003 13(Suppl 1 (abstracts of ’03 AEPC meeting)): 30

(abstract #86).

13 Mitchell MB et al Mechanical limitation of pulmonary blood

flow facilitates heart transplantation in older infants with

hypoplastic left heart syndrome Eur J Cardiothorac Surg 2003;

23(5): 735–742.

14 Sigwart U Non-surgical myocardial reduction for

hyper-trophic obstructive cardiomyopathy Lancet 1995; 346(8969):

211–214.

15 Sideris EB et al From disk devices to transcatheter patches: the evolution of wireless heart defect occlusion J Interv

Cardiol 2001; 14(2): 211–214.

16 Sideris EB et al Transcatheter patch occlusion of

experimen-tal atrial sepexperimen-tal defects Catheter Cardiovasc Interv 2002; 57(3):

404–407.

17 Sideris EB et al Transcatheter atrial septal defect occlusion

in piglets by balloon detachable devices Catheter Cardiovasc

Interv 2000; 51(4): 529–534.

18 Sideris A et al Transcatheter patch correction of atrial septal

defects: experimental validation and early clinical

experi-ence Cardiol Young 2000; 10: 13.

19 Sideris EB et al Transcatheter patch occlusion of branous ventricular septal defects J Am Coll Cardiol 2003;

perimem-41(6 Suppl B): 473.

20 Sideris A et al Accelerated transcatheter patch occlusion of

large patent ductus arteriosus Cardiol Young 2003; 13(Suppl

1 (Abstracts of ’03 AEPC)): 35 (abstract #99).

21 Bacha EA et al New Therapeutic Avenues with Hybrid

Pediatric Cardiac Surgery Heart Surg Forum 2004; 7(1):

33–40.

Transcatheter endomyocardial biopsies are utilized to

obtain specimens of myocardium from hearts that are

sus-pected of being diseased and/or damaged Transcatheter

biopsies have replaced open and direct transthoracic

punc-ture of the myocardium Biopsies using catheter techniques

were introduced over four decades ago, and although

the equipment has been refined, the procedure is little

changed1 Biopsies are performed to establish the

diagno-sis of myocarditis2,3, to monitor the course of treatment of

myocarditis4, to differentiate different types of

cardiomy-opathies5,6, to confirm cardio-toxicity of drugs7, to follow

the course of therapy and/or to detect rejection in cardiac

transplant patients8and even to obtain specimens of very

specific, localized tissues9 With the frequency of pediatric

transplants, endomyocardial biopsy has become one of

the more frequent procedures performed in major

pedi-atric/congenital catheterization laboratories

Because endomyocardial biopsies are performed so

fre-quently, they often are considered “routine” or “minor”

procedures and often are taken “lightly” by the operators

and catheterization laboratory staff In reality,

endomyo-cardial biopsy potentially is one of the more dangerous

procedures performed in the cardiac catheterization

labo-ratory With each biopsy sample, the forceful mechanical

jaws of the bioptome catheter purposefully “bite” into the

myocardium, each time with the potential of “biting” all

of the way through the muscle, through the wall of the

heart or through a chorda of the tricuspid valve! In

addi-tion, the patients who are undergoing biopsy frequently

are the sickest of the patients brought to the

catheteriza-tion laboratory The patients undergoing biopsy often

have obstructed systemic venous routes to the heart as a

result of numerous previous indwelling lines and/or

pre-vious catheterizations/biopsies As a consequence, the

venous access for the biopsy can be complicated or often

totally obstructed so that, because of the vascular access,

the endomyocardial biopsy becomes one of the more lenging and time-consuming procedures in the cardiaccatheterization laboratory

chal-A myocardial biopsy usually is accomplished in the cardiac catheterization laboratory and accompanied by atleast a minimal hemodynamic evaluation, which includesestimates of cardiac output by Fick and/or thermo-dilution determinations The hemodynamic data are usu-ally obtained before the tissue biopsies are performed.Transplant patients also undergo a complete angiographicstudy of their coronary arteries at least on an annual basis.The coronary arteriography usually is performed after thetissue samples are obtained

Some institutions perform the biopsies using onlyechocardiographic guidance10, in which case the biopsiescan be performed in a specific procedure room that doesnot contain X-ray equipment, in the intensive care unitand/or even in the patient’s hospital room11 When thebiopsy is performed in other than the catheterization laboratory and echo only guidance is used, the jugularapproach using special sheaths, which are long enough toreach the ventricle but not as long as the standard longtransseptal sheaths, becomes the preferred approach12.Like the performance of a balloon atrial septostomyusing echo guidance only, the manipulation of the biop-tome into the ventricle is more difficult, but once the biop-tome is in the desired chamber, the localization of the jaws

of the forceps on a specific area of the myocardial surfaceand the visualization of the tissues that are immediatelyadjacent to the forceps are more precise When not per-formed in the catheterization laboratory, the accuratehemodynamic assessment and/or the coronary angiogra-phy cannot be obtained during the same procedure Inaddition, in the rare event of a cardiac perforation duringthe biopsy, the facilities for complex resuscitations includ-ing a pericardiocentesis and/or the rapid placement of apericardial drain usually are not as available The perform-ance of a biopsy in the catheterization laboratory does notpreclude the use of the echo simultaneously!

33 Endomyocardial biopsy

C H A P T E R 3 3 Endomyocardial biopsy

Equipment for endomyocardial biopsy

A biplane X-ray system is recommended, if not essential,

for fluoroscopic-guided endomyocardial biopsies In

order to localize the tip of the bioptome catheter spatially

within the heart in “three dimensions” the two planes of

fluoroscopy are necessary A single-plane only, X-ray

sys-tem can be used for myocardial biopsies, but only with the

capability of rapidly rotating the X-ray tube at least 90°

around the thorax in order to obtain the perpendicular

plane for the precise positioning of the bioptome jaws

Even with the rotation capability, a single-plane system is

far less than satisfactory If, in the rotated (angled)

posi-tion of the X-ray tube, the bioptome is not in a satisfactory

position and it is repositioned while the X-ray tube is in

the rotated position, then the position of the tip of the

bioptome has changed relative to the original position of

the X-ray tube The positioning of the bioptome must be

started all over! Without actually viewing the bioptome in

two views, the precise location of the bioptome jaws in the

plane perpendicular to the one visualized is only a guess

Although there is some directional control over a

curved bioptome catheter and/or long sheath, the

resist-ance to torque within the vascular system prevents a true

one-to-one relationship between the degree of rotation

of the shaft of the sheath/bioptome to the degree of

rota-tion of the distal tip of the bioptome The final,

three-dimensional spatial position of the tip of a curved sheath

and/or bioptome catheter is determined by visualizing

the catheter tip in two, roughly perpendicular, X-ray

planes and extrapolating the “three-dimensional” position

within the cardiac chamber from the two planes

For added safety, and particularly in very high-risk

cases, either transthoracic echo (TTE) or transesophageal

echo (TEE) can be used in conjunction with the

fluoro-scopy to guide the forceps of the bioptome within the

specific cardiac chamber while the samples are being

obtained As mentioned previously, some centers even

perform the biopsies at the patient’s bedside using only

TTE to guide the bioptome to the site of biopsy13,14 These

biopsies have been carried out without complications

with the echocardiogram providing a clear image of the

endocardial surface and of all immediately adjacent

struc-tures once the bioptome catheter is positioned in the ventricle.

All bioptome catheters that are used currently are single

use, disposable catheters Many companies, including

Argon Medical Inc., Athens, TX, Cook Inc., Bloomington,

IN, CERES Medical Systems, L.L.C., Stafford, TX and

Cordis Corp., Miami Lakes, FL manufacture disposable

bioptome (biopsy forceps) catheters, and several sizes of

bioptome are available from most of the manufacturers

Each bioptome “catheter” consists of a small, articulated

pair of jaws at the distal end of the bioptome with a

flexible “cable catheter” connecting the jaws to an

“activating handle” at the proximal end The jaws on thebioptome open to approximately 180° by moving the twosliding, side rings on the handle forward and away fromthe central fixed ring on the central shaft of the handle.Standard bioptome catheters are available in 5- through 7-French sizes and most are at least 100 cm long

There is a very tiny, 3-French bioptome with a totallydifferent “activating handle” available from Cook Inc.,Bloomington, IN The smaller the French size of the biop-tome catheter, the smaller are the “jaws” of the bioptomeand, in turn, the smaller the possible “bite” and/or thespecimen, which is acquired Because of this, the 3-Frenchsized bioptome is used for myocardial biopsies almostexclusively in very small infants

Although initially almost all biopsies were performedfrom the jugular approach, most pediatric and congenitalcardiac catheterization laboratories are arranged physi-cally for optimal access to the patient’s vascular system

from the inguinal area As a consequence, for a myocardial

biopsy performed in the pediatric/congenital cardiaccatheterization laboratory, the usual and preferred ap-proach is from a femoral vein The femoral approach notonly is more convenient for the operators, but certainly ismore comfortable and less frightening for the sedatedpatient than a jugular venous approach Although thedesirable approach and majority of biopsies are per-formed from the femoral vein, a catheterization laborat-ory that performs myocardial biopsies must be prepared

to utilize a jugular vein, a brachial vein, a systemic artery

or even a transthoracoabdominal puncture into the atic veins when both the iliofemoral and the cephaladvenous systems are occluded

hep-The bioptome forceps is delivered to the ventricular site for the biopsy through a special, long, pre-curved,transseptal type sheath, which has a back-bleed valvewith a flush side port Delivering the bioptome through along sheath, which is positioned initially in the ventricle,eliminates the cumbersome, repeated and often unsuc-cessful maneuvering of the bioptome catheter alone,reduces the chance of perforation with the stiff bioptomecatheter, and lessens the chance of the bioptome forcepscatching on vital intraventricular structures when the

“jaws” are opened freely in the ventricle

The use of the long sheath/dilator for the delivery of thebioptome is similar to the guiding catheter system ori-ginally developed by Lurie for delivering the bioptomedirectly to the ventricular cavity15 The sheath for a biopsymust be long enough to reach the site of the biopsy (vent-ricle) but usually does not have to be as long as a standardtransseptal sheath, and definitely must be shorter than thebioptome catheter being used A radio-opaque markerband at the distal tip of the sheath is useful, if not essential.The radio-opaque band helps to visualize the exact

C H A P T E R 3 3 Endomyocardial biopsy

position of the tip of the sheath especially when the

biop-tome catheter is positioned within the sheath The

im-proved visibility of the tip of the sheath provided by the

radio-opaque band reduces the fluoroscopy time The

long sheath used to deliver the biopsy catheter must be

fairly “kink resistant”, since some manipulations of the

sheath itself are required within the ventricle Several

manufacturers now provide sheaths of special lengths, in

a variety of diameters specifically for biopsies from the

usual femoral vein approach These include Cook Inc.,

Bloomington, IN, Cordis Corp., Miami Lakes, FL and Daig

Corp., Minnetonka, MN

All except the most stoical patients require some

seda-tion in order to undergo a myocardial biopsy procedure

The standard premedication/sedation/anesthesia that is

used in the particular catheterization laboratory along

with the liberal use of local anesthesia at the introductory

site for the catheter usually is sufficient for a myocardial

biopsy performed from the femoral approach Since most

of these procedures require only a relatively short time in

the vessels and with the greater than usual chance of

caus-ing a cardiac perforation, extra, systemic heparin usually

is not utilized In patients who are undergoing evaluation

of the coronary arteries along with the biopsy, the biopsy

is performed first and then systemic heparin is added after

the biopsy samples are obtained, but before the extensive

systemic arterial catheter manipulation

Although the biopsy procedures usually are relatively

short, a small indwelling arterial line often is introduced

for more precise monitoring of the patient during these

procedures, particularly when access for the biopsy is a

problem and/or the patient’s clinical status is precarious

In most catheterization laboratories, when meticulous

technique and a 21- or 20-gauge teflon cannula is used for

the indwelling arterial line, the introduction of a small

femoral arterial cannula is a straightforward and very

benign procedure without complications At the same

time, since the potential for cardiac perforation is greater

with myocardial biopsy than any other procedure in the

catheterization laboratory, the continually monitored and

visualized curve of the arterial pressure from the

in-dwelling arterial line provides a very early predictor of

impending trouble compared to an intermittently

sam-pled blood pressure obtained with an extremity cuff,

which will provide only a late indicator of serious trouble

that had begun significantly earlier When a perforation

does occur, the arterial line becomes essential for

monitor-ing the patient durmonitor-ing the resuscitation It also is far better

to have the arterial line in place before the event occurs

and/or while preventing further hemodynamic

deterio-ration than attempting to obtain arterial access with the

patient in shock! When an arterial line is not used, the cuff

blood pressure should be monitored more frequently and

much more attention must be paid to each of the readings

from the cuff blood pressure, to the monitored heart rate,and to the displayed electrocardiogram for any even sub-tle changes that might indicate a perforation and/or theaccumulation of a pericardial effusion

Transthoracic echo (TTE) guidance is used by some ters either alone or in conjunction with fluoroscopy for thepositioning of the bioptome jaws within the ventricle for each “bite” Even bedside biopsies from the jugularapproach using TTE guidance alone have been advocated.The echo theoretically demonstrates more clearly if thejaws are against a thin or otherwise “wrong” area of myo-cardium and/or entangled on interventricular structuressuch as the tricuspid valve apparatus and chordae Theperformance of the biopsy at the bedside from the jugularapproach and using “echo only” almost prohibits the con-comitant use of a long pre-curved sheath pre-positioned

cen-in the ventricle for the cen-introduction of the bioptomecatheter In a “bedside environment”, it is very difficult

to maintain the sterility of the longer sheath extendingfrom the neck and to manage the clearing and adequateflushing of the sheath When the jugular route is used, thebioptome frequently is delivered directly into the vent-ricle from a short sheath fixed in the jugular introductorysite, which eliminates the direct course to the ventricle and the protection of the ventricular structures provided

by the long sheath Bedside biopsies also preclude thesophisticated monitoring that is available routinely in thecatheterization laboratory

Even if the echo machine is not used during the actualtissue sampling, an echo machine always should be avail-able in the catheterization laboratory In the event of anyinstability in the patient’s condition, a pericardial effusioncan be ruled out or documented definitively and immedi-ately and, in turn, treated rapidly, depending on the echo findings

Preparing the sheath and bioptome catheter for the biopsy

The distal end of the long sheath is pre-curved outside ofthe body and before the sheath is introduced into the

patient into a three-dimensional curve which conforms to the proposed course of the sheath from the particular vas-

cular access site (in a vein or peripheral artery), into the

desired ventricle and to the thickest area of the cardium within the accessed ventricle These “three-dimensional” curves that are formed are similar to thosedescribed by Lurie for his special bioptome and deliverycatheters (Cordis Corp., Miami Lakes, FL)16 The curvesthat are formed on the sheath vary for each patient accord-ing to the size of the patient, the size and “location” of the heart, the introductory (vascular access) site for thesheath and the desired area of the myocardium that is to

myo-be biopsied As a consequence, the specific curves that are

C H A P T E R 3 3 Endomyocardial biopsy

necessary for each patient/procedure are not

commer-cially available and must be formed individually for each

biopsy procedure A curve that is “tighter” than actually

desired to direct the bioptome to the site for biopsy, is

formed on the sheath/dilator in order to allow for some

straightening of the sheath when it is in the warm

circula-tion and when the shaft of the bioptome catheter is

intro-duced into the sheath

When forming the curves on the sheath/dilator outside

of the body and when manipulating the sheath within the

vascular system, extra precautions must be taken not to

kink the sheath The curves on the sheath are formed

and/or changed only with the long dilator still positioned

completely within the sheath To form the curves, the

sheath/dilator combination is “softened” either by

heat-ing the sheath/dilator combination in sterile boilheat-ing

water or in a jet of hot air from a “heat gun” Once the

sheath/dilator is “softened” in the heat, the

sheath/dila-tor manually is shaped into the desired curves and then

immersed in cold flush solution to “fix” the curves on the

sheath/dilator combination Minor curves can be formed

on the sheath/dilator by repeatedly “cold pulling” the tip

of the sheath/dilator combination between the thumb

and forefinger while simultaneously forming the desired

curve The “cold-pulled” curves usually cannot be formed

as tight as the curves formed after heating the sheath/

dilator Once the curves on the combined sheath/dilator

are formed, the dilator temporarily is withdrawn from the

sheath outside of the body in order to verify that the exact

desired curves have been formed specifically on the sheath

and not just on the dilator

Curves that correspond to the “three-dimensional”

curves on the sheath are also formed on the distal end of

the shaft (or “cable”) of the bioptome catheter The curves

on the distal shaft of the bioptome catheter (cable) are

formed by manual, gradual and smooth bending (but

not pulling!) of the shaft of the cable of the bioptome

“catheter” in the areas where the curves are desired Like

the curves on the sheath, in order to compensate for some

straightening within the body, the curves on the cable are

formed slightly tighter than the expected curved course

through the intravascular route to the site for the biopsy

At the same time, care must be taken not to create any

sharp “angles” in the woven, wire shaft of the bioptome

cable and not to “over-curve” the “cable” of the bioptome

to the point that the jaw mechanism of the bioptome no

longer will function Continued, adequate function of the

jaws only is assured by testing the jaw mechanism after

only partially forming an initial very slight bend of the

ultimately desired curve and then retesting the jaws

each time before tightening the curve any further This

sequence is repeated until either the desired curves are

formed or until there is even the slightest resistance to the

smooth function of the jaws Once the cable of the shaft of

the bioptome catheter is pre-curved, the operation of the jaws is retested several times while manually formingdifferent temporary bends on the more proximal catheter

A slight “over-curving” or kinking in the shaft of the bioptome catheter shaft can prohibit the opening and/orclosing of the jaws

Technique of myocardial biopsy from the femoral vein approach

For a right ventricular biopsy from the femoral veinapproach, the curves on both the sheath and the bioptomeare formed as visualized in the posterior–anterior projec-tion first to correspond to the smooth curve of approx-imately 90° from the inferior vena cava, through the tricuspid valve and into the right ventricle In the body,

this curve passes from the patient’s right toward the

patient’s left side The second (three-dimensional) curve

is formed at the very distal end of the first curve on boththe sheath/dilator and on the distal shaft of the biopsycatheter This secondary curve is formed to direct the tip posteriorly and toward the interventricular septum inthe right ventricle, which with the curved sheath or

catheter tip facing away from the operator will be a relatively sharp curvature to the left of the tip of the sheath (and

the operator)

Once the desired hemodynamics are obtained, an hole catheter is positioned in the pulmonary artery, anexchange length guide wire is introduced through theend-hole diagnostic catheter, and the catheter is with-drawn over the wire If a closed-ended angiographiccatheter was used for the diagnostic catheterization, thecatheter is withdrawn, the original catheter is replacedwith an end-hole catheter and the end-hole catheter andthen the wire are advanced through the right ventricle andinto the pulmonary artery Once the wire is in place, theend-hole catheter and the short sheath are removed The long sheath/dilator that has been pre-curved for thebiopsy is introduced over the wire With the wire posi-tioned in the pulmonary artery, the sheath/dilator isadvanced over the wire until the tip of the dilator is wellinto the right ventricle or even into the pulmonary artery

end-The sheath is advanced over the dilator until the tip of the

sheath and the tip of the dilator are together While ing the tip of the sheath securely in the right ventricle, thedilator and then the wire are withdrawn out of the sheath.Once the wire and the dilator have been removed, thesheath is allowed to bleed back passively through the sideport, paying particular attention that all entrapped airand/or clot is removed from the back-bleed valve appar-atus itself Usually blood is “pumped” vigorously fromthe right ventricle, which both verifies the location of thetip of the sheath and thoroughly clears the long sheath.Once cleared of all air (and clots!) the side port of the

keep-C H A P T E R 3 3 Endomyocardial biopsy

sheath is attached to a flush/pressure system, the sheath

is flushed thoroughly and then placed on a slow

continu-ous flush Except for intermittent, short checks of the

pres-sure through the sheath, the sheath is maintained on a

steady slow flush

A less desirable and slightly more precarious way of

introducing the sheath into the right ventricle is to

advance the exchange wire into the superior vena cava

instead of the pulmonary artery and then initially to

advance the pre-curved biopsy sheath/dilator into the high

right atrium The wire is removed and the dilator is cleared

of air and clot In the right atrium, passive bleeding back

through the dilator is not as brisk as from the right

vent-ricle, and gentle suction on the hub of the dilator may be

necessary to obtain blood return through the dilator Once

cleared of air and/or clot, the dilator is attached to the

flush/pressure system and the combination

sheath/dila-tor withdrawn from the SVC through the right atrium

while gently rotating the tip anteriorly and to the patient’s

left When adequate curves have been formed at the distal

end of the sheath/dilator, the combination “falls” almost

automatically from the right atrium into the right

vent-ricle as the tip of the sheath/dilator is withdrawn through

the right atrium When the tip of the dilator drops into the

right ventricle as confirmed by the appearance of a right

ventricular pressure through the dilator, the dilator is

fixed in position while the sheath is advanced over the

dilator to the tip of the dilator The dilator is withdrawn

slowly from the sheath and the sheath is cleared passively

of air and clot as described above

If the sheath/dilator combination does not “fall” into

the ventricle as the combination is withdrawn from the

high to the low right atrium, no further attempt is made

to maneuver the combination of sheath/dilator into the

ventricle The sheath/dilator combination is stiff and the

dilator has a sharp distal tip, which easily can

per-forate myocardium if pushed excessively When the tip

of the dilator does not “fall” into the ventricle during

withdrawal from the superior vena cava, the dilator is

withdrawn slowly from the sheath and the sheath

meticu-lously cleared of air and/or clot If the venous pressure is

low and/or particularly if there is any airway obstruction,

there is significant danger of the patient sucking air into

the sheath rather than blood flowing freely from the

sheath when the tip of the sheath is in the right atrium

The stopcock on the side port of the sheath is opened very

cautiously with the anticipation of having to close it

instantaneously if there is negative pressure and any

sug-gestion of fluid/air being drawn into the side arm/flush

port of the sheath When there is any negative pressure

from within the vascular space and there is any tendency

for air to be sucked into the side arm/sheath, the side port

is kept closed and capped with a syringe The end (valve)

of the sheath is covered very tightly with a gloved

finger-tip, the side port stopcock is opened to the syringe and

very gentle suction is applied intermittently to the side port

with the syringe When a vacuum is created and no blood

is aspirated, the suction on the syringe is released slowly.The sheath is rotated and/or withdrawn slightly andwhile still covering the back-bleed valve tightly, gentlesuction again is applied to the syringe on the side portuntil blood flow through the side port is obtained easily

aall of the time keeping the valve at the end of the sheath

covered tightly with the finger Once the sheath is clearedcompletely of air/clots, it is attached to the pressure flushsystem and placed on a continuous flush

From the right atrium, a very brief attempt is made attorquing and advancing the cleared sheath alone, very

slightly and very gingerly into the right ventricle The

sheath, alone, very easily can be kinked, particularlywhen the tip of the sheath impinges against any structurewithin the heart, and/or any forward pressure is appliedconcomitantly to the sheath against even minimal resis-

tance Again, unless the sheath “falls” easily into the

ventri-cle, it generally is more judicious to introduce an end-holecatheter that is the same French size as the sheath and to

maneuver the sheath/catheter combination into the ricle than it is to attempt any significant maneuvers into

vent-the ventricle with vent-the sheath alone

The catheter is maintained on a continuous slow flush

as it is introduced into the sheath and until it advances

well beyond the tip of the sheath An active tip deflector

wire (Cook Inc., Bloomington, IN) or a static Mullins™deflector wire (Argon Medical Inc., Athens, TX) can beused within the catheter to deflect the tip of the catheter,which is beyond the tip of the sheath, toward the rightventricle The deflector is bent approximately 90° and thecatheter is rotated to point anteriorly and to the patient’sleft (toward the tricuspid valve) Occasionally the sheathmust be rotated simultaneously with the catheter in order

to “aim” the tip of the catheter at the tricuspid valve Oncethe tip of the catheter is aimed toward the tricuspid valve,the deflector wire is held in place, the catheter is advancedfurther out of the sheath, off the still deflected wire andinto the right ventricle Once the catheter is secured withinthe ventricle, the sheath is advanced over the catheter tothe desired position in the ventricle Occasionally, both thesheath and catheter advance together over the wire

and into the right ventricle Once the tip of the sheath is in

the ventricle, the preformed curve on the sheath will help

to maintain the tip of the sheath in the correct position inthe ventricle for the biopsy The deflector wire and thenthe catheter are withdrawn from the sheath and the sheathagain carefully cleared passively of air/clots

Once within the ventricle, the pre-curved sheath is

maneuvered with fluoroscopic and/or echo visualization

very cautiously into the desired position against the

pre-sumed thicker areas of the ventricular myocardium The

C H A P T E R 3 3 Endomyocardial biopsy

precise thickness of the area of the myocardium can be

visualized with echo When the “squared-off” single

opening of the tip of the sheath is positioned against the

ventricular myocardium, it may not be possible to

with-draw blood, fluid or any entrapped air from the sheath,

and as a consequence it is important that the sheath is

cleared passively and completely before being

maneu-vered against the myocardium of the ventricle for the

introduction of the bioptome A large, long sheath can

hold as much as 8–10 ml of air! The introduction of a

significant amount of air during a myocardial biopsy is an

additional risk to the procedure, which is second only to

the risk of perforation Once cleared of air, the sheath is

kept on a slow flush during all of the subsequent

position-ing within the ventricle

The pre-curved bioptome with the jaws of the bioptome

closed is introduced into the positioned and

pre-curved sheath and advanced under continual

fluoro-scopic observation to just within the tip of the sheath The

sheath is kept on a slow but continuous flush through the

side port as the bioptome is introduced into and advanced

within the sheath As the stiffer (often straighter!)

biop-tome catheter is advanced within the sheath, the tip of the

sheath often is seen on fluoroscopy to move away from

the original position on the myocardial surface As this

occurs, the sheath is allowed to retract away from the

myocardium by relaxing the forward push on the sheath,

and once the bioptome reaches the tip of the sheath, the

combination of the sheath and bioptome is re-advanced

against the myocardial surface Again the position against

the endocardium and the thickness of the myocardium

in front of the bioptome can be verified with echo This is

particularly important in patients who have any

malposi-tioning of the cardiac silhouette and/or those who have

had multiple prior biopsies The handle mechanism of

the bioptome is activated to the “open” position with

the “jaws” at the very tip, but still within the tip of the

sheath This activation of the jaws of the bioptome also

tends to withdraw the tip of the sheath slightly The jaws

of the bioptome themselves, while still within the tip of the

sheath do not open, but, as the bioptome jaws are

advanced out of the tip of the sheath, the “pre-activation”

of the handle results in the jaws opening fully while the

jaws are immediately adjacent to the tip of the sheath

and just as the jaws exit the tip of the sheath With the

tip of the sheath pre-positioned adjacent to the

myo-cardium, the open jaws immediately dig into the

endo-cardium, which is adjacent to the tip of the sheath, without

passing through any of the cavity of the ventricle This

technique allows the jaws to be directed to very precise

sites on the myocardium, and since the open jaws are

not advanced any distance through the cavity of the

vent-ricle, the possibility of “biting” unwanted (and

pos-sibly vital) structures such as the chordae of the tricuspid

valve is reduced by this technique of pre-positioning the sheath Adjacent and/or trapped structures can usu-ally be visualized on echo

The bioptome with the jaws wide open together withthe sheath is pushed forward against the endocardiumwithin the ventricle and the jaws of the bioptome areclosed tightly on the tissue When the jaws are in adequateapproximation to the tissues, some resistance is felt to theclosure of the jaws The bioptome catheter is withdrawn

as the sheath simultaneously is maintained or advancedslightly against the myocardium by a slight forward push

on the sheath There usually also is some resistance feltand then a sudden jerk backwards of the shaft of the biop-tome catheter as the closed bioptome jaws are withdrawnaway with the grasped endomyocardial tissue With thesheath still on a slow flush and the jaws of the bioptomemaintained tightly closed, the bioptome is withdrawnslowly and completely out of the sheath The sheath ismaintained on a flush while keeping it in the same posi-tion in the ventricle

Once out of the sheath, the closed jaws of the bioptomeare positioned over a sterile Petri dish and the jaws areopened The sample of tissue from the “bite” is removedfrom the bioptome jaws and flushed onto the sterile Petridish using a “jet” of flush solution squirted through a needle attached to a syringe full of flush solution Depend-ing upon the particular laboratory and the studies desired,

five to seven good tissue samples are required for each

biopsy study17 Once the bioptome is removed after each

“bite”, the sheath is repositioned slightly to a different site

on the myocardium by careful, gentle torque and imal, to-and-fro motion of the sheath alone within theventricle while, at the same time, being very careful not topush the sheath forward too forcefully Once the sheath

min-is in a new and satmin-isfactory position as vmin-isualized onfluoroscopy and/or echo, the bioptome is reintroducedand the tissue sampling repeated in a similar fashion

If the sheath alone cannot be repositioned adequatelywithin the ventricle there are several helpful procedures

to achieve a new, different position Once the bioptomecatheter is reintroduced into the sheath, the sheath and thebioptome catheter together can be maneuvered more lib-erally within the ventricle The extra support provided bythe bioptome within the sheath allows more control overthe movement, and the bioptome cable provides someresistance to the kinking of the sheath

When the sheath/bioptome catheter together cannot

be maintained in an adequate position, a fine, preformed,0.017″ Mullins static, deflector wire (Argon Medical Inc.,Athens, TX) can be used to help reposition the sheathmore selectively The lumen of the pre-curved bioptomesheath, which already is in the ventricle, must be suf-ficiently larger than the shaft of the bioptome catheter inorder to allow the wire and the shaft of the bioptome to

C H A P T E R 3 3 Endomyocardial biopsy

have room side by side within the long sheath The 0.017″

Mullins™ deflector wire is pre-curved outside of the body

similar to the curving of the bioptome cable to conform to

the desired “three-dimensional” course from the venous

entry site to the new site that is desired for the biopsy The

distal “RA to RV” and “posterior” curves are formed on

the wire significantly “tighter” than the actually desired

curves to allow for straightening of the wire by the

sheath/bioptome The wire is introduced adjacent to

the bioptome catheter through the back-bleed valve of the

sheath The wire can be introduced into the sheath after a

bioptome catheter already is in place within the sheath or

the bioptome can be introduced after the wire is in place

and has “repositioned” the sheath An “active deflector

wire” (Cook Inc., Bloomington, IN) can also be used to

deflect the sheath; however, an even larger sheath is

nec-essary to accommodate the larger “gauge” of the active

deflector wire In addition, with an active deflector wire,

the deflection only can be created in a single dimension

and only in the direction of the concavity of the curve from

the right atrium to the right ventricle A final method of

repositioning the sheath is to replace the bioptome in

the sheath with a standard catheter that is the same size as

the sheath and then to use one of the deflector wires

within the catheter to reposition the tip of the sheath Once

the sheath is repositioned, the catheter is removed and the

bioptome is reintroduced, both very carefully Unless the

curves on the bioptome are re-formed, the bioptome

eas-ily can displace the sheath once again as the stiffer

biop-tome is reintroduced

Right ventricular biopsy from the jugular

approach

Biopsies from the neck were routine during the early

development of biopsy techniques The jugular approach

is preferable when the biopsy is performed at the patient’s

bedside using echo guidance only The jugular approach

is still used electively in the catheterization laboratory

in many centers and the jugular approach becomes

absolutely necessary when the femoral venous access is

occluded and/or when a particular site is desired in the

ventricle for the biopsy The approach from the neck is

less convenient for the catheterizing physicians in most

catheterization laboratories because of the physical

arrange-ment of the X-ray equiparrange-ment, and the neck approach is

more uncomfortable for the patient during and after the

procedure At the same time, some physicians in the

cathe-terization laboratory prefer the jugular venous approach

for routine biopsies in spite of these disadvantages

Unless the patient is very stoical and extremely

coopera-tive, general anesthesia and/or very heavy “conscious

sedation” is used when biopsies are performed from the

neck in pediatric and congenital patients When the neck

approach is used, the patient’s head must be maintainedturned away (restrained) from the venous entrance site,much of the “activity” of the biopsy catheter manipulation

is performed immediately adjacent to the patient’s faceand the face and head must be kept covered during thewhole procedure

Once the jugular vein is entered, the approach to the

tri-cuspid valve and the ventricle itself is “straighter”, more

direct and more “controllable” than the approach fromthe groin The major differences are the distance from theskin to the right ventricle, the greater danger of air aspira-tion through the sheath because of this shorter distanceand the different “pre-curves” that are formed at the distalends of the biopsy sheath and biopsy catheter The curves

on the sheath and/or bioptome catheter are somewhat of

a “mirror image” to the curves when coming from the

groin, but in order to approach the septal wall of the right ventricle from the superior vena cava, the angle within the

ventricle is more acute The initial curves formed on thesheath and bioptome catheter, in turn, are more acute Tocorrespond to the course from the neck/right atrium intothe mid right ventricle, a 150–180° curve is formed initially

at the distal end of the sheath/dilator This curve is similar

in shape to the standard “transseptal” curves provided bythe manufacturers on the long MTS™ sheaths (UnitedStates Catheter, Inc [USCI] Angiographics, Billerica, MA;Cook Inc., Bloomington, IN), but always must be “tight-ened” to a more acute curve compared to the manufac-turer’s curves The secondary or “third-dimensional curve”,which is formed at the end of the initial curve in order todirect the tip posteriorly in the ventricle, is formed in theopposite direction of the curve formed on the sheath whenthe bioptome is introduced from the inferior vena cava.When the distal end and tip of the initial curve of thesheath/dilator and/or bioptome are pointing away fromthe operator, the secondary curve should direct the tip ofthe sheath posteriorly toward the septal surface of theright ventricular cavity i.e., when the tip of the long sheath

is facing away from the operator and toward the operator’s

left, the secondary curve is formed directed posteriorly ordorsally in the chest

In spite of entering the right atrium from the oppositedirection, the sheath that is introduced from the superiorvena cava is introduced or maneuvered into the right vent-ricle over a pre-positioned wire similarly to when thesheath is introduced from the femoral vein/inferior venacava The wire is pre-positioned in the pulmonary arterythrough a separate end-hole catheter introduced from thejugular vein and advanced into the pulmonary artery Thelong sheath/dilator combination or the sheath introducedover an end-hole catheter of the same French size isadvanced over the wire until the tip of the dilator orcatheter is well within the right ventricle or into the pul-monary artery The tip of the sheath is advanced to the tip

C H A P T E R 3 3 Endomyocardial biopsy

of the dilator or catheter The sheath is fixed in position

and the dilator or catheter is withdrawn from the sheath

followed by the wire The sheath is cleared passively of

all air and/or clot similarly to the introduction from the

femoral approach

Rarely, the end-hole catheter and then the wire from

the jugular vein are advanced through the atrium and into

the inferior vena cava The pre-curved sheath/dilator or

sheath/catheter is advanced over the wire into the inferior

vena cava and the pre-curved sheath “withdrawn” into

the right ventricle from there The dilator or catheter and

wire are withdrawn from the sheath The sheath is cleared

of air and/or clot while in the inferior vena cava This may

require gentle suction on the side port of the sheath while

sealing the valve of the sheath with a gloved finger Once

cleared and on a continuous flush, the pre-curved sheath

alone is withdrawn from the inferior vena cava until the

tip of the curved sheath “flips” into the right ventricle

With any or all of these maneuvers performed from the

jugular vein, extreme care is necessary to prevent air entry

into the delivery system because of the shorter distance

and more direct transmission of negative pressures from

the heart to the venous entrance site

Even the standard, special biopsy sheaths are

unneces-sarily long for the approach from the jugular vein As a

consequence, manipulation of the sheath and bioptome

catheter by the catheterizing physician is necessarily from

a very awkward position The proximal end of the long

sheath will be significantly cephalad to the patient’s head,

well beyond the cephalad (head) end of the

catheteriza-tion table, frequently immediately adjacent to the

(unster-ile) suspension arms of the X-ray system and with no

place to “rest” or even temporarily to release the proximal

end of the sheath from the operator’s grip Without

spe-cially manufactured shorter sheaths, this requires at least

two very well coordinated catheterizing physicians

work-ing together in this area to prevent contamination of the

catheters, sheaths and site as well as to prevent the

intro-duction of air into the system

Left ventricular biopsy

Usually, the right heart biopsies are sufficient for tissue

diagnosis17 Occasionally, because of unique myocardial

problems, a left heart biopsy is desired This is

accom-plished preferably by a prograde approach through an

atrial transseptal puncture or alternatively and rarely,

when there is no reasonable access to the venous system,

from the retrograde arterial approach

For the prograde, atrial transseptal approach, a

stand-ard Mullins Transseptal Set™ is used The transseptal

sheath should have an internal diameter large enough to

accommodate the bioptome catheter plus some type of

deflector wire(s) adjacent to the bioptome The sheath,

bioptome and any deflector wires are pre-curved with a

tighter than normal, 270°, “transseptal curve” plus a short,

relatively sharp anterior curve at their tips The curves onall of the items are formed in proportion to the patient’ssize, the cardiac size and the cardiac position within thethorax The anterior curve is formed on the distal end ofthe exaggerated “transseptal” curve of the sheath bybending (forming) the distal tip anterior when the tip ofthe sheath is facing away from the operator and curving

to the operator’s right (anteriorly when the proximal

“transseptal” curve is facing the patient’s left whenapproached from the femoral area) The exaggeratedmanufactured “transseptal curve” directs the sheath/bioptome into the left ventricle and medially while theanterior curve deflects the sheath/bioptome toward theseptal wall of the left ventricular cavity

For operators who are comfortable with the atrialtransseptal procedure, the prograde transseptal approach

to the left ventricle for a myocardial biopsy is no moredifficult or significantly more hazardous than the stand-ard right ventricular biopsy from a venous approach.There are, in fact, several advantages of a left ventricularbiopsy from the atrial transseptal approach to the left vent-ricle compared to the “routine” right ventricular biopsy.Generally, the myocardium of the left ventricle is thickerand it is easier to position the bioptome against an area ofthe myocardium that is away from vital intraventricularstructures in the left ventricle than it is in the right ven-tricle From the venous and atrial transseptal approach,large bioptome catheters can be used in conjunction with adeflector wire without compromise of an artery by thelarge sheath All of the necessary curves to the biopsy site

from the femoral venous approach essentially are concave

curves This allows the use of active deflector wires within

the sheath adjacent to the bioptome to help position thebioptome more precisely The curved bioptome cathetersare easier to control with all concave curves and with thestatic deflector wires than when there is an associatedcomplex curve in the “reverse” direction

The technique for acquiring the samples during leftventricular biopsies is similar to the right ventricularbiopsy Because of the longer sheaths, the transseptal pro-cedure itself and the more precise preformed curves nec-essary to create a firm apposition against the left ventriclewalls, transseptal left ventricular biopsies often are con-sidered more difficult Left ventricular biopsies do requiremore stringent precautions for clearing the sheaths andcatheters of even infinitesimal amounts of air and/or clotsince all of the maneuvering of the catheters, sheathsand/or bioptomes will be within the systemic circulation.Particular attention must be paid to prevent the introduc-tion of air into the sheath each time a sample is withdrawnthrough, and out of, the back-bleed valve of the long

sheath Fortunately, as long as the tip of the sheath bounces

C H A P T E R 3 3 Endomyocardial biopsy

freely and away from the endocardium even intermittently, the

high pressure in the left ventricle usually pumps the sheath

free of air and/or clot

Once the sheath/dilator has entered the left atrium

through the transseptal puncture, the special preformed

curve almost automatically directs the set into the left

ven-tricle and toward the septal wall of the left venven-tricle If the

sheath/dilator set does not advance easily into the left

ventricle, the dilator is withdrawn, the sheath, which is in

the left atrium, is cleared of air and/or clots and placed on

a continuous flush An end-hole catheter that is the same

French size as the sheath/dilator is placed on a

continu-ous flush through a wire back-bleed device, advanced

through the sheath and, with the catheter extending

beyond the tip of the sheath, the catheter is maneuvered

into the left ventricle using either a torque-controlled

guide wire or with the use of deflector wires, as described

in Chapter 8 Once the catheter is in the left ventricle, the

tip of the catheter, still on a flush, is deflected against the

ventricular wall to a position where the biopsy can be

obtained This is accomplished with an active or a static

deflector wire Once the catheter is in position, the

cath-eter is maintained on a vigorous flush and the sheath, also

still on a flush, is advanced over the catheter to the end

of the catheter and against the endocardial surface With

the catheter and sheath still on a vigorous flush, first the

catheter and then the deflector wire are withdrawn from

the sheath

When the tip of the sheath is pressed tightly against

the endocardium there can be no passive bleeding back

from the sheath and nothing can be withdrawn through

the sheath to “clear” it, however, when the catheter and

sheath were being maintained on a vigorous flush during

the previous maneuvers, the sheath would be full of flush

and contain no air or clots The side arm of the sheath is

maintained on a flush while an appropriately pre-curved

bioptome catheter is introduced into the sheath and

advanced to the endocardial surface of the left ventricle

The biopsy is carried out identically to the right

ventricu-lar biopsies but the sheath is kept on a continuous flush

during both the introduction and withdrawal of the

biop-tome catheter between samples

When the sheath needs to be redirected slightly to a

dif-ferent location on the endocardial surface, this is

accom-plished using a deflector wire introduced into the sheath

adjacent to the bioptome catheter If a more significant

readjustment of the position is necessary, the sheath is

withdrawn back into the ventricular cavity, the

end-hole catheter is reintroduced and the catheter is

maneu-vered to the new location using some combination of

deflector wires Once the desired position is achieved

with the tip of the catheter, the long sheath is re-advanced

over the catheter exactly as with the initial positioning All

of the time when there is no passive back bleeding, the

sheath and/or catheter must be maintained on a vigorousflush

Retrograde arterial approach for myocardial biopsy

The retrograde approach for a myocardial biopsy is ized only when there is no venous access at all or, pos-sibly, when a left ventricular biopsy is desired and there

util-is no femoral venous access Whenever venous access

is available to the right ventricle and/or to an atrial transseptal puncture, the venous route is employed formyocardial biopsies

For the retrograde approach, a significantly longersheath is necessary to delivery the bioptome catheter fromthe femoral artery, around the aortic arch, across the aorticvalve and into a very secure position against the septalwall within the left ventricle In order not to compromisethe artery any more than necessary, usually a smallerbioptome is used for biopsies performed through the retrograde arterial approach At the same time, whenusing the retrograde approach, the use of a rigid (static)deflector wire will usually be necessary and, as a con-sequence, the sheath must be one or two French sizeslarger than the bioptome that is to be used, in order to

accommodate a deflector wire adjacent to the bioptome

catheter within the sheath

The sheath/dilator, static deflector wires and distal end

of the bioptome catheter, all are pre-curved before duction into the artery to correspond to the course aroundthe arch, into the left ventricle and with a separate verydistal curve in order to approximate the appropriate wall

intro-of the left ventricle intro-of each individual patient Thesecurves are formed outside of the body and again, are pre-formed “tighter” than the visualized curves within thebody The distal end of an extra long (75 or 85 cm) MTS™sheath/dilator set first is straightened A fairly tight, 180°curve is formed on the sheath/dilator 4–10 cm proximal

to the tip of the sheath (depending on the height of the

patient and the length of the patient’s ascending aorta),which leaves the distal 4–8 cm of the sheath straight Thisallows the 180° curve to be positioned at the top of the aor-tic arch while the more distal, straightened end of thesheath extends through the ascending aorta to a positionwell into the cavity of the left ventricle The tightness ofthis 180° curve and the length of the straightened segmentare determined according to the size of the patient and thelength of the ascending aorta in each individual patient

In order to obtain samples from the medial or septalsurface of the left ventricle, a second, relatively acute “out-

ward” curve (on the outer or convex side of the more

prox-imal curve) is formed at the tip of the straight portion atthe distal end of the sheath The second curve then will bedirected away from the primary 180° concave curve on

C H A P T E R 3 3 Endomyocardial biopsy

the sheath This distal curve gives the sheath/dilator a

“shepherd’s crook” configuration and functions to deflect

the tip of the sheath away from the cavity and toward the

septal wall of the ventricle once the dilator is removed.

A similar but slightly “tighter” combination of the same

curves with the same compound “shepherd’s crook” type

of distal configuration is formed on the distal end of the

bioptome catheter The opening and closing of the

biop-tome jaws must be tested several times as the compound

curves are formed on the bioptome catheter Any static

deflector wire that is to be used during the retrograde

biopsy also has similar, but slightly tighter curves formed

on it The more precise the curves that are preformed on

the sheath, bioptome catheter and static deflector wires,

the more readily and precisely the sheath with the

biop-tome will “engage” on the desired area of the left

ventricu-lar myocardium “Active” deflector wires are not suitable

to assist in the positioning of the sheath during the

retro-grade approach unless the biopsy is to be obtained from

the posterolateral wall of the ventricle

To perform a retrograde left ventricular biopsy, first an

end-hole catheter is advanced retrograde from a femoral

artery entry site, around the aortic arch and into the left

ventricle A stiff, exchange length spring guide wire with

a long floppy tip (Medi-Tech, Boston Scientific, Natick,

MA) is passed through the catheter and positioned

securely in the left ventricular cavity with the floppy tip

looped back on itself toward or into the left ventricular

outflow tract The end-hole catheter and the short

intro-ductory sheath are removed over the wire and the

pre-formed long sheath/dilator combination for the biopsy is

advanced over the exchange wire as far as possible into

the ventricle The sheath is advanced to the tip of the

dila-tor The wire is withdrawn slowly from the diladila-tor The

dilator is allowed to bleed back passively to clear it of any

air and/or clot and then the dilator is withdrawn slowly

out of the sheath The sheath is allowed to bleed back

passively through the side port of the back-bleed valve.

Usually, because of the left ventricular pressure, this

“back bleeding” is very brisk Occasionally, when the tip

of the pre-curved, end-hole only sheath is positioned

tightly against the wall of the ventricle, it will be occluded

against the wall and there is no passive back bleeding

When the tip of the sheath is occluded and not recognized,

a “vacuum” is created in the sheath and dilator as the

dila-tor is withdrawn When the diladila-tor does not bleed back

during the withdrawal, it allows a large column of air to

be sucked through the dilator into the sheath as the dilator

is withdrawn Under this circumstance the sheath never

should be flushed and/or should anything be introduced

into the sheath until there is free back bleeding of blood

only from the side arm of the sheath! If there is no passive

back bleeding from the sheath, the sheath must be

with-drawn and/or rotated very slightly until vigorous back

bleeding occurs Only when there is a free flow of bloodfrom the proximal end of the sheath is the sheath attached

to the flush/pressure system and placed on a slow flush

To avoid this problem with air in the sheath, both thesheath and dilator are placed on a vigorous flush beforebeing introduced into the artery over the wire The flush

is continued on both the sheath and the dilator but tinued very vigorously on the dilator as the wire and thenthe dilator are withdrawn very slowly This techniqueshould keep the sheath full of fluid and prevent the vacuum as the dilator is withdrawn

con-The preformed bioptome catheter is advanced throughthe long sheath into the left ventricle with the sheathmaintained on a continuous flush Just as the jaws of thebioptome approach the tip of the sheath, the openingmechanism is activated so that just as the jaws areadvanced beyond the tip of the sheath, they open immedi-ately adjacent to the tip of the sheath The jaws are pushedinto the endocardium by continuing to advance the pre-curved sheath/bioptome catheter forward together Oncethe open jaws are forced against the tissues, the jaws areclosed, withdrawn slowly back into the tip of the sheathand then completely out of the sheath to remove the sam-ple The sheath is maintained on a continuous flush dur-ing the entire acquisition of the tissue samples as well asduring the introduction and withdrawal of the bioptomecatheter In addition, the sheath is allowed to bleed backaround the bioptome each time the catheter is withdrawnand then the flush is continued as the bioptome is intro-duced into the sheath

Post-biopsy care

Once the necessary hemodynamic/anatomic informationand the biopsy specimens have been obtained, the cath-eters are removed and hemostasis achieved by select-ive pressure over the catheter introductory site(s) Thepatient is observed in the catheterization laboratory for atleast 15 minutes, which usually corresponds to the timenecessary to obtain hemostasis Even when the patientremains absolutely stable hemodynamically during thistime, it is desirable to perform a quick, screening,transthoracic echo of the pericardial space before thepatient leaves the catheterization laboratory It always ismore expedient to treat a perforation/pericardial effusionearly and in the catheterization laboratory than later afterthe patient has left the laboratory Except when either aretrograde left heart biopsy was performed, or very largesheaths were used in the veins, or when there is an extens-ive left heart coronary study, or, of course, unless there is

a known complication, the biopsy patient usually can bedischarged after 6–8 hours of in-hospital observation.This usually corresponds to the time when the biopsy

C H A P T E R 3 3 Endomyocardial biopsy

reports are available and the patient’s medications are

adjusted accordingly

Complications of myocardial biopsy

Although complications rarely occur during myocardial

biopsies, any complication of cardiac catheterization can

occur with a myocardial biopsy procedure Because of the

repeated withdrawal and reintroduction of the bioptome

catheter into the long biopsy sheaths, the introduction of

air and/or clot through the sheath is very easy and, as

described, extreme attention must be paid to prevent this

problem, particularly during left heart biopsies

The most obvious, very serious complication of a

myocardial biopsy is perforation of the myocardium

along with cardiac tamponade and all of the other

pos-sible consequences of cardiac perforation, including shock,

central nervous system damage and even death As with

all complications, prevention is the best treatment and

with biopsies, prevention is accomplished best by strict

attention to the meticulous details of the technique

Unfortunately, when “purposefully and repeatedly

chew-ing” into the myocardium and when repeated enough

times in any one patient or by any one operator, a

perfora-tion eventually is almost inevitable, regardless of the care

and precision of the technique The next best treatment to

prevention is the continual expectation and anticipation

of a perforation with rapid recognition and immediate

therapy of the perforation when it does occur, preferably

before the long sheath for the biopsy has been removed

An indwelling arterial pressure line during the procedure

provides the very earliest indication of a perforation and

cardiac tamponade A perforation should be considered

whenever there is any deterioration in the patient’s

hemo-dynamic status during or immediately after the

proced-ure, and can be diagnosed rapidly with a transthoracic

echocardiogram in the catheterization laboratory

Treatment is to secure (or re-establish if the biopsy line

was removed!) a large venous access line while the

peri-cardium is being tapped and drained with the insertion of

a large size pericardial drain Circulating volume

replace-ment is initiated with normal saline or lactate (not the

flush solution containing heparin!) and plasma expanders

until whole blood is available When the

hemoperi-cardium is large and/or continues to accumulate, the

blood from the pericardial drainage is filtered and

auto-transfused to the patient while fresh whole blood is

obtained and the patient is prepared for surgery If

recog-nized immediately and treatment is begun early, usually

the patient’s vital signs can be maintained until the

per-foration can be closed definitively

Damage to the tricuspid valve apparatus with the

cre-ation of a flail tricuspid valve leaflet has been reported in

patients undergoing transcatheter myocardial biopsies in

as many as 6–10% of procedures, although actual damage

to the valve structures during a procedure are reportedvery rarely18,19 There appears to be a decrease in the incid-ence of tricuspid valve damage when the bioptome isdelivered to the right ventricle through a pre-curved long sheath that is pre-positioned in the ventricle andwhen using echocardiography to guide the bioptome10,20.Certainly, prevention of tricuspid valve/valve apparatusdamage is the only effective treatment Prevention isaccomplished most effectively by the very precise posi-tioning of the bioptome forceps, being sure that the for-

ceps are against the myocardium during each and every

“bite” The combination of both biplane fluoroscopy andechocardiography provides the most accurate position-ing, but does add to the expense and complexity of theprocedure

References

1 Sakakibara S and Konno S Endomyocardial biopsy Jpn

Heart J 1962; 3: 537–543.

2 Fenoglio JJ Jr et al Diagnosis and classification of myocarditis

by endomyocardial biopsy N Engl J Med 1983; 308(1): 12–18.

3 Schmaltz AA and Kandolf R Myocarditis in childhood:

results of a decade’s researchabiopsy studied Klin Padiatr

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4 Mason JW, Billingham ME, and Ricci DR Treatment of acute inflammatory myocarditis assisted by endomyocardial

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5 Ferrans VJ et al Ultrastructural studies of myocardial

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car-diomyopathy Recent Adv Stud Cardiac Struct Metab 1973; 2:

8 Caves PK et al Percutaneous transvenous endomyocardial

biopsy in human heart recipients Experience with a new

technique Ann Thorac Surg 1973; 16(4): 325–336.

9 Colvin EV, Lau YR, and Samdarshi TE Vegetation biopsy using transesophageal echocardiography guidance: a tech- nique to aid in diagnosis of culture-negative endocarditis.

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10 Miller LW et al Echocardiography-guided endomyocardial

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III99–102.

11 Appleton RS et al Endomyocardial biopsies in pediatric

patients with no irradiation Use of internal jugular venous

approach and echocardiographic guidance Transplantation

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C H A P T E R 3 3 Endomyocardial biopsy

13 French JW, Popp RL, and Pitlick PT Cardiac localization of

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echocardiogra-phy Am J Cardiol 1983; 51(1): 219–223.

14 Weston MW Comparison of costs and charges for

fluoroscopic- and echocardiographic-guided

endomyo-cardial biopsy Am J Cardiol 1994; 74(8): 839–840.

15 Lurie PR, Fujita M, and Neustein HB Transvascular

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description of a new technique Am J Cardiol 1978; 42:

453–457.

16 Lurie PR Revision of pediatric endomyocardial biopsy

tech-nique Am J Cardiol 1987; 60(4): 368–370.

17 Baandrup U, Florio RA, and Olsen EG Do endomyocardial

biopsies represent the morphology of the rest of the myocardium? A quantitative light microscopic study of sin-

gle v multiple biopsies with the King’s bioptome Eur Heart J

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18 Braverman AC et al Ruptured chordae tendineae of the

tri-cuspid valve as a complication of endomyocardial biopsy in

heart transplant patients Am J Cardiol 1990; 66(1): 111–113.

19 Huddleston CB et al Biopsy-induced tricuspid regurgitation

after cardiac transplantation Ann Thorac Surg 1994; 57(4):

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car-diac transplantation Echocardiography 1997; 14(2): 111–118.

Phlebotomy (“exchange phlebotomy”,

erythrophoresis)

Cyanotic congenital heart patients with polycythemia

often require a phlebotomy during and/or separate from

a cardiac catheterization The large majority of patients

with polycythemia have complex cardiac defects and/or

an Eisenmenger’s complex with significant right to left

shunting and with moderate to marked desaturation The

human body’s physiologic response to systemic

desatura-tion is to increase the oxygen carrying capacity of the

blood This it does by producing more red blood cells An

increased number of red cells does deliver more oxygen to

the tissues, but at the same time increases the viscosity of

the blood which, then, slows the velocity of blood flow

When the hematocrit increases to more than 65%, the

vis-cosity of the blood begins to increase exponentially with

the blood flow through the vessels and to the tissues

slowing proportionately to the increase in hematocrit

The slowing in the blood flow is far out of proportion to

any gain in oxygen carrying capacity by the increased

red cell mass so that the net oxygen delivery to the tissues

is reduced

When patients become significantly polycythemic, they

develop increased cyanosis, increasing fatigue, dyspnea,

listlessness and headaches The level of the hematocrit at

which these signs and symptoms develop varies from

patient to patient, but in any one patient, it often is a very

reproducible level Older patients often can determine

when their hematocrit has increased to the level that they

need therapy even before the hematocrit is measured

At a hematocrit over 70%, the blood flow becomes very

sluggish and prone to thrombosis In the presence of this

lowered threshold for intravascular thrombosis from the

polycythemia, even a slight degree of dehydration further

aggravates the viscosity and can precipitate major

intra-vascular thrombotic events In addition to the changes in

blood flow, many clotting factors in the blood become

deranged because of the proportionate decrease in plasmavolume As a treatment for the multiple adverse effects ofsignificant polycythemia, polycythemic patients are treated

by a phlebotomy with a volume replacement with an

equal volume of iso-osmotic colloidal solution The colloid

replacement usually is either a 5% solution of pooledhuman albumin in normal saline, a 5% solution of pooledhuman plasma proteins, or Hetastarch The albumin isavailable as Buminate 5% solution, Plasbumin-5 orAlbuminar-5 The pooled plasma proteins are available asPlasmanate™ The albumin solutions and the plasma pro-tein solutions both are iso-osmotic with human plasma.This treatment is offered when the patient’s spun venoushematocrit approaches 65–70% and/or when the patientsexhibit signs or symptoms from their polycythemia.The amount of whole blood to be withdrawn during aphlebotomy is determined by the formula:

Vol= {(Hct1− Hct2)/Hct1}× TBVwhere Vol = the volume of blood to be removed, Hct1=the initial hematocrit, Hct2= the desired hematocrit and TBV = estimated blood volume of the patient (90–

100 ml/kg of body weight) The exact volume of bloodwithdrawn from the patient is replaced, ml for ml with a

colloidal volume replacement fluid, using either plasma,

albumin, Plasmanate or Hetastarch Hetastarch is the onlynon-blood product colloidal replacement fluid

Normal saline and/or Ringer’s lactate has been used toreplace the removed blood volume during a phlebotomy,but these isotonic fluids are diuresed so rapidly that

the circulating volume cannot be maintained adequately,

nor is the circulating volume sustained for any period oftime Many patients who had the blood replaced withonly normal saline or Ringer’s lactate, developed acutesystemic hypotension with an aggravation of their right

to left shunting, further desaturation, the development ofacidosis, shock, cardiovascular collapse and even death.This sequence of events gave the “phlebotomy” proced-ure itself a very bad reputation with many “authorities”

34 Phlebotomy, pericardial and

pleural drainage

C H A P T E R 3 4 Phlebotomy, pericardial and pleural drainage

actually declaring the procedure too dangerous and

contraindicated

A phlebotomy does not have to be performed in a

car-diac catheterization laboratory, although if the laboratory

is available and/or the patient is undergoing a

catheter-ization anyway, it is the ideal and most convenient

location to perform the procedure If not performed in a

cardiac catheterization laboratory, the phlebotomy must

be performed in a “special procedure” area where full

monitoring and full resuscitation equipment are available.

The patient undergoing a phlebotomy requires

monitor-ing with an electrocardiogram, saturation monitormonitor-ing

with a pulse oximetry and frequent blood pressures with

at least a frequently cycled, cuff blood pressure apparatus

or in more precarious cases, an indwelling arterial line

The “phlebotomy” with colloid replacement represents

an “exchange transfusion” involving the withdrawal of

thickened whole blood and replacing the blood that is

removed, with an equal volume of the colloidal fluid A

large bore intravenous cannula/catheter is introduced

into at least one large vein Since all of these patients have

significant right to left shunting, very meticulous

precau-tions are necessary to prevent the introduction of even

minute amounts of air and/or the development of clots

during the entire phlebotomy procedure Unfortunately,

the volume and rate of blood/fluid exchanged is too great

to allow the use of air filters in the intravenous lines The

blood withdrawal and the colloidal fluid replacement can

be performed through a single intravenous line, and, in

fact, there are special phlebotomy/exchange “sets” now

commercially available These sets have a series of either

two or three, three-way stopcocks attached to the

“with-drawal” syringe This creates a closed system with a port

into a sealed container for the “discard” blood, a port for

the inflow of the plasma/colloid from a sealed and

“de-aired” reservoir, and an optional third port from a sealed

reservoir to introduce flush solution The flush solution is

isotonic saline or Ringer’s lactate, without dextrose and

with 3 units of heparin/ml added to the flush solution

Once the “set” or a self-fabricated, similar system is set

up and thoroughly cleared of air, the most distal stopcock

is attached to a common line going from the stopcocks to

the patient

The larger the vein and the larger the intravenous

can-nula, the more effective is the blood

withdrawal/replace-ment The procedure becomes even more efficient when

two separate, large, vascular lines can be accessed With

the use of two separate lines, the colloid fluid is

intro-duced through one line while the blood is withdrawn

simultaneously through the other line With two separate

lines, there is no “mixing” and/or diluting of the discard

(withdrawn) blood and the introduced (colloid) fluid in

the “common line” during each exchange of an increment

of blood out and fluid in Theoretically, there is more

uniform mixing within the patient’s circulation of thefluid introduced through two separate lines, with lesschance of the just introduced colloid fluid being with-drawn undiluted from the single vessel In patients whoundergo a phlebotomy during and/or in conjunction with

a heart catheterization, optimal efficiency is achieved bywithdrawing the blood from the indwelling arterial linewhile introducing the colloidal replacement fluid through

a large venous catheter

The amount of blood withdrawn/replaced with each

syringe withdrawal/fluid infusion varies with the size of

the patient and the status of the patient The blood isexchange in 5–10 ml increments in very small patientsand/or patients who are in “heart failure”, while it can beexchanged in as much as 50 ml increments in adult sizedpatients who are very stable In patients where the poly-cythemia is secondary to obstruction to pulmonary flow(“tetralogy” type physiology or pulmonary vascular dis-ease), the exchange of blood also is performed at a slowerrate In those patients, as the thicker blood is diluted, thesystemic resistance drops faster than the comparableincrease in the pulmonary blood flow

As the blood is withdrawn and the fluid is replaced, aseparate nurse or technician maintains an accurate tabula-tion of the number of syringes of blood withdrawn andthe number of syringes of fluid reintroduced This is crit-ically important, particularly when two separate lines arebeing used and there is a greater chance of the withdrawalgetting ahead of the re-infusion or vice versa

Once the phlebotomy/exchange is completed, the patient

is observed with heart rate, ECG, blood pressure andpulse oximetry monitoring for at least four hours beforebeing discharged During this time the patient is ambu-lated purposefully several times while under close obser-vation to be sure there is no aggravation of posturalhypotension by the dilution of the blood volume It oftentakes hours for the circulating hemoglobin/hematocrit toequilibrate following a phlebotomy with colloid exchange

so that a repeat hematocrit immediately after the procedure

is of little use Some older, cyanotic patients require aphlebotomy as often as every three months althoughmany go 6–12 months between phlebotomies

Pericardial drainage

A pericardiocentesis often is not considered a tion laboratory procedure Pericardial drainage can be apurely elective procedure, or, at the opposite extreme, avery acute emergency procedure The urgency of the peri-cardiocentesis depends upon the etiology of the effusionand the presentation of the patient Patients with pericar-dial effusions can present with the effusion as an “inciden-tal” finding with a large heart on chest X-ray or non

catheteriza-C H A P T E R 3 4 Phlebotomy, pericardial and pleural drainage

specific S-T changes on an echocardiogram, with or

without vague symptoms related to low cardiac output

and/or chest discomfort At the opposite extreme,

peri-cardial effusions present with signs and symptoms of

acute cardiovascular collapse due to cardiac tamponade

In any situation, a pericardial tap and drainage is a serious

procedure with definite inherent risks In all circumstance,

it involves inserting a needle, relatively blindly, through

the chest wall into the often relatively narrow and/or

iso-lated pericardial space surrounding the heart When the

puncture is over the area of the right atrium, the heart wall

is very thin below the site of the needle puncture In

addi-tion to the underlying thin wall of the right atrium, the

puncture can be over (and potentially into) the right or

left ventricle, and/or the coronary arteries can lie on the

epicardial surface of the heart just beneath the visceral

pericardium

When the heart is in a normal position, has a normal

ori-entation and is in a patient of “normal” size and “habitus”,

the site for the usual pericardiocentesis is at the left

chon-droxiphoid junction The goal is to enter the anterior–

inferior pericardium over the area of the right ventricle

Occasionally pericardial punctures for loculated inferior

and/or posterior effusions are made over the apical area

of the cardiac silhouette or, in extreme cases, from

poster-ior Malpositions of cardiac chambers due to individual

chamber enlargement, mesocardia and dextrocardia, of

course, require a different approach to suit the anatomy

and the location of the effusion

Although not absolutely necessary in all situations, a

pericardiocentesis is performed most safely and most

expeditiously in the cardiac catheterization laboratory The

environment of the cardiac catheterization laboratory

intrinsically is sterile In addition, acute pericardial

effu-sions, with or without tamponade, unfortunately do occur

as a complication of a cardiac catheterization secondary to

cardiac perforation As a consequence, the catheterization

laboratory “automatically” is totally prepared for a

peri-cardiocentesis both in equipment and “experience” and

under all circumstances

Of equal importance, biplane fluoroscopic equipment is

available in the catheterization laboratory to provide

actual visualization of the cardiac silhouette and the

course of needles, wires and catheters toward and within

the cardiac silhouette The necessary disposable

equip-ment for a pericardiocentesis is available readily and

immediately in the catheterization laboratory

Monitor-ing and emergency equipment for any type of

cardiovas-cular emergency including even opening the chest, along

with personnel experienced with the use of this

equip-ment are also available immediately in the

catheteriza-tion laboratory Most catheterizacatheteriza-tion laboratories have

echocardiographic equipment present in the laboratory

and with most pediatric cardiologists, this results in

echocardiographic support being available automaticallyand immediately

Another factor favoring the catheterization laboratoryfor pericardiocentesis in that the catheterization laborat-ory personnel are accustomed to moving expeditiouslywhen it is required in an emergency procedure It usually

is more expedient to move a sick patient with an effusion

to the catheterization laboratory to perform the procedurethan it is to arrange for all of the support and equipmentnecessary for the procedure to be moved to the area wherethe patient happens to be “residing”

Although most modern catheterization tables do nothave the capability of tilting of the catheterization tableitself cranially or caudally, usually various “wedge” cush-ions, which are used otherwise to create unusual patientpositions on the table, are available in the catheterizationlaboratory A tall “pillow” or wedge is placed under thehead, neck and thorax of the patient to position the patientinto a steep, “semi-sitting” position This position helps toboth “lower” the cardiac mass caudally in the thorax and

to “float” the heart more cephalad in the pericardial fluidand away from the area of puncture (Figure 34.1) Oncethe patient is secured in the “sitting” position, the posterior–anterior (PA) X-ray tube is angled caudally to

an angle perpendicular to the anterior chest wall The ray image then will correspond to the straight PA vieweven thought the patient is in the “sitting” position This,

X-in turn, provides an accurate equivalent of a straight PAX-ray view of the thorax and cardiac silhouette At the same time, the lateral X-ray tube can be raised to provide

a simultaneous lateral view of the chest and cardiac silhouette

Expendable equipment

There must be the capability of creating a large and securesterile field around the proposed area of puncture.Disposable, single-hole, paper drapes with the adhesive

Figure 34.1 The position of the cardiac silhouette in the thorax comparing

the supine to the erect position of the patient M, the manubrium; X, the xyphoid; the numbers 2 & 5 indicate the respective ribs.