Handbook of Advanced Interventional Cardiology - part 5 potx

However, treatment of branch vessels with severe ostial lesions may, at times, result in compromise of the main vessel, requiring bifurcation intervention.. In our laboratory, we studied

Rescue angioplasty for failed thrombolysis: Since

clinical signs and electrocardiographic data of reperfusion are not precise, the guidelines of the ACC/AHA task force suggest that catheterization be performed in any thrombolytic patients with ongoing chest pain or hemodynamic instability,

or in asymptomatic patients who are less than 12 hours of symptom onset with persistent ST elevation, after 90 minutes

of thrombolytic therapy.37 However, the patients who require rescue angioplasty due to failed thrombolysis remained at increased risk for reocclusion, because they possibly had higher resistance to pharmacologic reperfusion, large throm-bus burden or platelet-rich thrombi, factors unfavorable to the performance of mechanical intervention

Rescue PCI should be performed on high-risk lesion (>75%) with TIMI of 2 or less The mortality of patients who failed rescue PTCA was high, in the 30% range, while it was only 7–11% in patients with persistent occluded IRA treated conservatively There was no indication for PCI of the IRA if the TIMI fl ow is 3 following lytic treatment However, there are exceptions, which include the patients with high risk of reocclusion or severe complications if there is occlusion of the IRA, and patients with >90% residual stenosis, prior MI, decreased LV ejection fraction, or multivessel disease

Non-IRA lesion: Stenosis of non-IRA vessels should

not be treated by emergent PCI unless there is evidence of persistent ischemia or cardiogenic shock after adequate re-perfusion of the IRA

PCI for saphenous vein graft: Patients with prior

coro-nary artery bypass grafting who present with AMI are equally likely to occlude native vessels and bypass grafts, although LIMA grafts have a lower rate of stenosis AMI after CABG usually affects smaller territories and presents with milder symptoms.36 In comparison to native vessels, SVG thrombo-sis typically has a suboptimal response to fi brinolytic therapy Vein grafts lack side branch vessels that would normally de-liver the fi brinolytic agent to the site of occlusion.37 In the case

of mechanical intervention, because of the large size of the SVGs and high thrombotic burden, there is a signifi cant risk

of distal embolization In the PAMI-2 trial the overall pital and 6-month mortality of patients with prior CABG was higher compared with patients without prior CABG Patients with CABG had lower rates of TIMI-3 fl ow after PCI, and mechanical intervention was less frequently attempted.38Recently, catheter-based fi lter devices were found to be effective in preventing distal embolization in primary PCI of SVG lesions

in-hos-Left main PCI in AMI: In a small study by Marso et al., in

which 40 patients with AMI due to LM occlusion were treated with emergent PCI, the angiographic success rate was 88% In-hospital mortality was 55%, and CABG was performed in 10% of patients The 12-month mortality after left main PTCA

with stenting was high (58%) but substantially lower than PTCA without stenting (78%; P <0.05).39 All hospital deaths were a result of cardiogenic shock Therefore, although PCI strategy for AMI from left main disease is feasible, short- and long-term mortality is high.40 If LM occlusion is a result of aortic dissection, then PCI of the LM may be performed as a bridge toward hemodynamic stability before proceeding with defi ni-tive surgery.41

CONCLUSION

Despite numerous advances in management of STEMI, the treatment goal remains unchanged: prompt restoration of patency in the infarct-related artery (IRA) can reduce myo-cardial infarct size, minimize myocardial damage, preserve ventricular function, and signifi cantly reduce mortality The dominant and benchmark reperfusion strategy worldwide remains fi brinolytic therapy However, rapid restoration of pa-tency by catheter-based percutaneous intervention can result

in excellent outcomes,42 and the use of an early interventional strategy continues to increase

If experienced operators are available at an institution with a large procedure volume, and if the interval between door and balloon (reperfusion) is less than 120 minutes, pri-mary PCI has been shown to be superior to pharmacologic re-perfusion, mostly by virtue of reducing recurrent MI and ICH This benefi t is mitigated by a number of factors and adjunct therapies, including glycoprotein 2b3a receptor antagonists, antithrombotics and antiplatelet agents, and low-dose fi brino-lytics These agents help to increase the opening rate of the IRA, increase tissue perfusion, and sustain patency after the acute event.43 Female sex, age >65, presence of left bundle branch block, and advanced time of presentation (>12 hours) represent high-risk factors, and early mechanical intervention should be considered in these patients even in the absence of chest pain In subgroups where PCI is comparable to throm-bolysis in reducing mortality, mechanical reperfusion may still have an important role in prevention of ventricular remodeling, dilatation, and dysfunction that could impact the long-term prognosis of patients with AMI

REFERENCES

1 Keyt BA, Paoni NF, Refi no CJ et al A faster-acting and more potent form of tissue plasminogen activator Proc Natl

Acad Sci USA 1994; 91: 3670–4.

2 Single-bolus tenecteplase compared with front-loaded alteplase in acute myocardial infarction: the ASSENT-2 double-blind randomised trial Assessment of the Safety and

Effi cacy of a New Thrombolytic Investigators Lancet 1999;

4 The TIMI Study Group The Thrombolysis in Myocardial

In-farction (TIMI) trial Phase I fi ndings N Engl J Med 1985; 312.

5 Gibson CM, Cannon CP, Daley WL et al TIMI frame count:

a quantitative method of assessing coronary artery fl ow

Cir-culation 1996; 93: 879–88.

6 Cannon CP, Braunwald E GUSTO, TIMI and the case for

rapid reperfusion Acta Cardiol 1994; 49 : 1–8.

7 Gibson CM, Murphy SA, Rizzo MJ et al Relationship

between TIMI frame count and clinical outcomes after bolytic administration Thrombolysis In Myocardial Infarction

throm-(TIMI) Study Group Circulation 1999; 99 : 1945–50.

8 Gibson CM, Cannon CP, Murphy SA et al Relationship of

TIMI myocardial perfusion grade to mortality after

administra-tion of thrombolytic drugs Circulaadministra-tion 2000; 101: 125–30.

9 Gibson CM, Murphy SA, Barron HV Relation of epicardial blood fl ow and myocardial perfusion to long term outcomes

2 years following thrombolysis in AMI: A TIMI 10B substudy

Circulation 2000; 102 : 435.

10 Gibson CM How to do the Corrected TIMI Frame Count

Instruction to the investigators of the TIMI trials www.timi.tv

13 Beran G, Lang I, Schreiber W et al Intracoronary

throm-bectomy with the X-Sizer catheter system improves epicardial

fl ow and accelerates ST-segment resolution in patients with acute coronary syndrome: a prospective, randomized, con-

trolled study Circulation 2002; 105: 2355–60.

14 Ross AM, Coyne K, Reiner J Very early PTCA of IRA with

TIMI fl ow is associated with improved clinical outcomes J Am

Coll Cardiol 2000; 35: 403.

15 Lansky A, Stone G, Mehran R Impact on baseline TIMI

fl ow on outcome after primary stenting versus primary PTCA

in AMI: Results of the PAMI trials J Am Coll Cardiol 2000; 35:

hospitals without cardiac surgery J Am Coll Cardiol 1999; 33:

1257–65

17 Grines CL, Cox DA, Stone GW et al Coronary angioplasty

with or without stent implantation for acute myocardial tion Stent Primary Angioplasty in Myocardial Infarction Study

infarc-Group N Engl J Med 1999; 341: 1949–56.

18 Stone GW, Marsalese D, Brodie BR et al A prospective,

randomized evaluation of prophylactic intraaortic balloon counterpulsation in high risk patients with acute myocardial infarction treated with primary angioplasty Second Primary Angioplasty in Myocardial Infarction (PAMI-II) Trial Investiga-

tors J Am Coll Cardiol 1997; 29 : 1459–67.

19 Quinn MJ, Plow EF, Topol EJ Platelet glycoprotein IIb/IIIa

inhibitors: recognition of a two-edged sword? Circulation

(PRISM) N Engl J Med 1998; 338: 1498–505.

22 The PRISM-PLUS Investigators Inhibition of the platelet glycoprotein IIb/IIIa receptor with tirofi ban in unstable angina and non-Q-wave myocardial infarction Platelet Receptor In-hibition in Ischemic Syndrome Management in Patients Lim-ited by Unstable Signs and Symptoms (PRISM-PLUS) Study

Investigators N Engl J Med 1998; 338: 1488–97.

23 The PURSUIT Trial Investigators Inhibition of platelet glycoprotein IIb/IIIa with eptifi batide in patients with acute coronary syndromes The PURSUIT Trial Investigators Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor

Suppression Using Integrilin Therapy N Engl J Med 1998;

339 : 436–43.

24 Simoons ML Effect of glycoprotein IIb/IIIa receptor

block-er abciximab on outcome in patients with acute coronary dromes without early coronary revascularisation: the GUSTO

syn-IV-ACS randomised trial Lancet 2001; 357: 1915–24.

25 The PARAGON Investigators: Platelet IIb/IIIa nism for the Reduction of Acute coronary syndrome events

Antago-in a Global Organization Network International, randomized, controlled trial of lamifi ban (a platelet glycoprotein IIb/IIIa in-

hibitor), heparin, or both in unstable angina Circulation 1998;

97: 2386–95.

26 Topol EJ Reperfusion therapy for acute myocardial farction with fi brinolytic therapy or combination reduced fi bri-nolytic therapy and platelet glycoprotein IIb/IIIa inhibition: the

in-GUSTO V randomised trial Lancet 2001; 357: 1905–14.

27 Escobar J, Marchant E, Fajuri A Stenting could decrease coronary blood fl ow during primary angioplasty in acute myo-

cardial infarction J Am Coll Cardiol 1999; 33: 361A.

28 Lincoff AM, Topol EJ Illusion of reperfusion Does one achieve optimal reperfusion during acute myocardial

any-infarction? Circulation 1993; 88: 1361–74.

29 Gibson CM, Ryan KA, Murphy SA et al Impaired

coro-nary blood fl ow in nonculprit arteries in the setting of acute myocardial infarction The TIMI Study Group Thrombolysis in

myocardial infarction J Am Coll Cardiol 1999; 34: 974–82.

30 Garbo R, Steffenino G, Dellavalle A, Russo P, Meinardi F Myocardial infarction with acute thrombosis of multiple major coronary arteries: a clinical and angiographic observation in

four patients Ital Heart J 2000; 1: 824–31.

31 Leosco D, Fineschi M, Pierli C et al Intracoronary rotonin release after high-pressure coronary stenting Am J

se-Cardiol 1999; 84: 1317–22.

32 Mahaffey KW, Puma JA, Barbagelata NA et al

Adenos-ine as an adjunct to thrombolytic therapy for acute myocardial infarction: results of a multicenter, randomized, placebo-con-trolled trial: the Acute Myocardial Infarction STudy of ADenos-

ine (AMISTAD) trial J Am Coll Cardiol 1999; 34: 1711–20.

33 Late breaking trials: AMISTAD-2 In: Scientifi c Session of the American College of Cardiology Atlanta, GA; 2002

34 Platelet glycoprotein IIb/IIIa receptor blockade and dose heparin during percutaneous coronary revasculariza-

low-tion The EPILOG Investigators N Engl J Med 1997; 336:

1689–96

35 The ASSENT 3 Investigators Effi cacy and safety of necteplase in combination with enoxaparin, abciximab, or un-fractionated heparin: the ASSENT-3 randomised trial in acute

te-myocardial infarction Lancet 2001; 358: 605–13.

36 Grines CL, Booth DC, Nissen SE et al Mechanism of

acute myocardial infarction in patients with prior coronary

artery bypass grafting and therapeutic implications Am J

Cardiol 1990; 65: 1292–6.

37 Reiner JS, Lundgren CF, Kopecky SL Ineffectiveness

of thrombolysis for AMI following vein graft occlusion (abst)

Circulation 1996; 94: I-570.

38 Stone GW, Brodie BR, Griffi n JJ et al Clinical and

angio-graphic outcomes in patients with previous coronary artery bypass graft surgery treated with primary balloon angioplasty for acute myocardial infarction Second Primary Angioplasty

in Myocardial Infarction Trial (PAMI-2) Investigators J Am

Coll Cardiol 2000; 35: 605–11.

39 Marso SP, Steg G, Plokker T et al Catheter-based

re-perfusion of unprotected left main stenosis during an acute myocardial infarction (the ULTIMA experience) Unprotected

Left Main Trunk Intervention Multi-center Assessment Am J

41 Barabas M, Gosselin G, Crepeau J, Petitclerc R, Cartier

R, Theroux P Left main stenting – as a bridge to surgery – for acute type A aortic dissection and anterior myocardial infarc-

tion Cathet Cardiovasc Interv 2000; 51: 74–7.

42 Timmis G, Timmis S The restoration of coronary blood

fl ow in acute myocardial infarction J Interv Cardiol 1998; 11:

S9-S17

43 Smith SC Jr, Dove JT, Jacobs AK et al ACC/AHA

guide-lines for percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the

1993 Guidelines for Percutaneous Transluminal Coronary

Angioplasty) J Am Coll Cardiol 2001; 38: 2239i.

*Basic; **Advanced; ***Rare, exotic, or investigational

From: Nguyen T, Hu D, Saito S, Grines C, Palacios I (eds), Practical

Handbook of Advanced Interventional Cardiology, 2nd edn © 2003

Futura, an imprint of Blackwell Publishing

Balloon angioplasty (PTCA)

**Double balloon angioplasty

**Selection of guides in double balloon technique

**Which branch to wire fi rst?

Directional coronary atherectomy (DCA)

The CAVEAT trial

**Indications and contraindications

**Selection of cutter and guide for DCA

**Stenting of main vessel alone

**Interventions of side branch

**Crossing a stent at its side strut

GENERAL OVERVIEW

Bifurcation lesions present some of the most diffi cult lenges in percutaneous coronary interventions Treatment of such lesions is associated with reduced procedural success and increased complications as well as increased restenosis risk Several factors are likely to contribute to these poorer outcomes Plaque and endothelial characteristics of ostial lesions appear to lead to increased recoil and increased risk

chal-of dissection with compromise chal-of side branches and/or main vessel Intervention in either branch of a bifurcation lesion fre-quently leads to “snow plowing” with shifting of plaque, com-promising the opposing branch Because of these concerns, such lesions are often treated less aggressively, leading to greater residual stenosis and therefore greater restenosis

TECHNICAL CONSIDERATIONS

True bifurcation lesions are generally considered to be those in which a single lesion involves both main vessel and branch vessel with greater than 50–70% stenosis in both Lesions in which a side branch originates from within a signifi -cant lesion in the main vessel, but without apparent signifi cant disease in the branch itself, may also be considered as bifur-cation lesions since the branch vessel may require treatment

as well Situations in which a branch without apparent disease originates near, but not within, a lesion in a main vessel rarely require treatment of the branch vessel However, treatment

of branch vessels with severe ostial lesions may, at times, result in compromise of the main vessel, requiring bifurcation intervention

Because treatment of bifurcation lesions with balloon angioplasty alone frequently gives suboptimal results, ex-perience has developed in the use of other technologies, including directional coronary atherectomy (DCA), rotational atherectomy, and stenting These newer devices generally provide improved procedural results, though with the potential

of increased complications, with continuing uncertainty as to the long-term outcomes In our laboratory, we studied 70 con-secutive patients with true bifurcation lesions, 30 treated with conventional PTCA alone and 40 with either DCA or rotational atherectomy with adjunctive PTCA.1 Use of atherectomy re-sulted in lower immediate residual stenosis in both the main and the branch vessels and a decreased 1-year target vessel revascularization (TVR) (28% vs 53%) Independent predic-tors of need for TVR were side branch diameter >2.3 mm, le-sion length, and treatment with PTCA alone This experience suggests that more aggressive debulking techniques should

be considered for larger side branches, although they may be

of no benefi t for smaller ones

BALLOON ANGIOPLASTY (PTCA)

Dilatation of main vessel only: A strategy of dilatation of

the main vessel only may be suitable if the side branch has no apparent ostial disease, or if there is no more than moderate disease that does not require treatment, with the side branch originating adjacent to, but not within, the main vessel lesion Under these circumstances, risk of side branch compromise

is minimal, and if it occurs, it can be easily treated.2 This egy may also be suitable if an involved side branch is of small caliber and diffusely diseased such that loss would have little,

strat-if any, clinical signstrat-ifi cance Loss of septal branches, except those of very large caliber, rarely results in adverse clinical outcomes, probably because of collateral septal supply Unless the artery is very large with excellent fi nal MLD after POBA, it is diffi cult to justify POBA alone because of lower restenosis rates with atherectomy and bare stenting

Treatment of main vessel and side branch using a double wire technique: If a branch arises from within the le-

sion in the main vessel, there is an increased risk of branch clusion with dilatation of the main vessel alone, with a reported incidence of 38–41% if there is greater than 50–70% stenosis

oc-of the branch origin.2–4 This may occur as a result of plaque shifting, dissection involving the branch origin, or emboliza-tion Therefore, side branches considered to be clinically important, and particularly those with ostial disease, should

be treated as well as the main vessel Follow-up of patients treated with PTCA of both branches have been reported as having an angiographic restenosis rate at 6 months of 37%5and a clinical restenosis rate of 42%.4

TECHNICAL TIPS

**Double balloon angioplasty: When treatment of the

side branch is anticipated, a double wire technique should

be used with a guidewire advanced into each branch, ing careful that the wires do not twist during manipulation Although some operators use a triport hemostasis valve, both wires and balloons can be easily advanced through the same opening of a single hemostasis Y adaptor The main vessel and side branch can be sequentially dilated using either rapid exchange or over-the-wire dilating catheters Sequential dilatations will permit the use of a smaller guid-ing catheter, but this strategy frequently results in shifting of plaque toward the undilated vessel with failure to achieve optimal results in both vessels A more optimal result can usually be obtained using a “kissing balloon” strategy with simultaneous dilatations in both branches (Figure 13-1) Since both balloons will infl ate together in the main vessel proximal to the bifurcation, it is important that these bal-loons not be oversized for the vessel diameter or infl ated

be-to high pressures The dilating diameter of the two balloons together will be less than the nominal diameters of the bal-loons individually, depending on balloon and vessel compli-ance and infl ation pressure, and this must be considered subjectively This technique may, therefore, not be suitable

if the proximal vessel diameter is not larger than that of the branches involved In this case, both branches may be di-

Figure 13-1: Severe lesion in proximal LAD involving fi rst

diagonal branch PTCA of LAD alone would likely have promised the diagonal A 3.5-mm balloon in the LAD and a 3.0-mm balloon in the diagonal were infl ated simultaneously,

com-giving a good fi nal result in both branches (Continued)

lated more aggressively sequentially with a fi nal sure kissing dilatation to limit plaque shifting Unfortunately, many ostial side branch lesions, because of their plaque characteristics, are poorly dilatable, resulting in a signifi cant residual stenosis Cutting balloon (CB) angioplasty can give better acute results without plaque shifting.

low-pres-**Selection of guides in double balloon technique:

It is important that the guide has a suffi ciently large lumen

to permit passage of both balloons simultaneously with equate vessel visualization Required minimal guide lumen diameter may be calculated by adding 0.006" to the com-bined diameters of the largest portion of the shafts of the two dilating catheters With presently available low-profi le balloon catheters, this can be accomplished with a large lu-men 8F guide with most over-the-wire catheters and with a large lumen 7F guide with some rapid exchange catheters The guide must also be carefully selected to provide the best possible support for device delivery

ad-**Which branch to wire fi rst? To avoid wire crossing,

the most diffi cult branch should be wired fi rst Usually, it is the SB which needs more manipulation Then the second wire can be inserted to cross the lesion with gentle torqu-ing An easy way to identify the wire is by having a steering device of a different color on each wire

DIRECTIONAL CORONARY ATHERECTOMY (DCA)

The removal of plaque with DCA has potential

advantag-es in treatment of bifurcation ladvantag-esions in decreasing the amount

Figure 13-1 (Continued)

of plaque shifted toward side branches, possibly decreasing the incidence of dissection, and providing a larger, smoother lumen that could decrease restenosis without the necessity of stenting with its technical challenges.6

EVIDENCE-BASED MEDICINE APPLICATIONS

The CAVEAT trial: Analysis of data from the CAVEAT I trial

indicated a larger post-procedure lumen in main vessels in bifurcation lesions treated with DCA as opposed to PTCA, but with an increased risk of side branch occlusion associ-ated with an increase in small non-Q myocardial infarction with no difference in restenosis at 6 months.7

TECHNICAL TIPS

**Indications and contraindications: DCA may be

par-ticularly benefi cial in larger vessels, with side branches

>2.5 mm diameter, and with bulky and eccentric lesions Its use may provide a lumen as large as that obtained with stenting without the technical diffi culties of bifurcation stenting In addition, when stenting becomes necessary because of an unsatisfactory result with DCA alone, the initial treatment with DCA may decrease the amount of plaque shifted into a side branch DCA should be avoided with heavily calcifi ed lesions and in situations where use of

a 10F guide is not feasible DCA of side branches is unlikely

to be successful with side branches of >2.5 mm diameter,

in those severely diseased, or with an acute takeoff angle from the main vessel

**Selection of cutter and guide for DCA: It is important

that there is good guide support prior to beginning tion treatment The older DCA cutters require a 10F guide The newer Flexicut cutters can be used with 8F guides with

bifurca-an inner diameter of at least 0.087" A 6F DCA cutter or a small fl exicut cutter should be used for treatment of vessels 2.5–2.9 mm diameter, a 7F device or a medium Flexicut cutter for vessels 3.0–3.4 mm diameter, with consideration

of a 7F graft cutter or a large Flexicut cutter for vessels larger than 3.5 mm

**Wiring technique: A wire is fi rst passed beyond the

le-sion in the main vessel Use of an extra support wire will frequently help in delivery of the device

The double wire technique, which uses Nitinol wires placed in both branches with both wires left in place while DCA is performed fi rst in the main and then in the branch vessel, has been described.8 This technique has the po-tential risk of the guidewire becoming trapped in the cutter

during operation and is rarely required since side branch access with a guidewire is rarely diffi cult.

**Cutting technique: Cuts should be made as in routine

DCA in the direction of plaque At least some cuts in the direction of the bifurcation may be helpful in maintaining branch patency and providing access with a wire into the branch Side branch occlusion with DCA has been as-sociated with branches originating within the main vessel lesion and having greater than 50% branch ostial disease,

as well as branches located on bends, within long lesions,

or involved in dissection.7,9 In our laboratory, there is an increased incidence of side branch occlusion with DCA as compared to PTCA,1 but with aggressive management by experienced operators it is rare not to obtain a fi nal good result in both branches of the bifurcation

**DCA in side branch: When a satisfactory result has

been obtained, the DCA device is removed from the nary artery and the wire removed from the main vessel and repositioned in the branch vessel This is generally not dif-

coro-fi cult even if a side branch occlusion has occurred DCA is then performed in the branch vessel using an appropriate sized cutter If the side branch is small, it may be appropri-ate to treat this with PTCA rather than DCA, although as previously noted, ostial lesions may not dilate satisfactorily

If an excellent result is obtained in both branches with DCA alone, adjunctive fi nal balloon dilatation may not be neces-sary, but generally a smoother, larger lumen is obtained if the procedure is completed with a low-pressure “kissing” balloon dilatation

ROTATIONAL ATHERECTOMY

Lesion debulking with rotational atherectomy rather than DCA may be of particular benefi t in smaller vessels, vessels that are heavily calcifi ed, and those with signifi cant ostial side branch lesions Use of rotational atherectomy may decrease the incidence of dissection and side branch loss As with DCA, rotational atherectomy followed by adjunctive PTCA may pro-vide a satisfactory smooth lumen and thus avoid the need for bifurcation stenting or decrease the incidence of side branch occlusion if main vessel stenting alone is performed (Figure 13-2)

TECHNICAL TIP

**Strategies for rotational atherectomy: A guiding

catheter of suffi cient size to permit passage of the est anticipated burr should be used A Rotablator wire is

larg-generally passed fi rst across the lesion in the main vessel into the distal vessel and rotational atherectomy with the smallest burr to be used performed in the main vessel le-sion If the branch lesion is much more severe than that

in the main vessel and it is anticipated that wire access in the main vessel will not be diffi cult, initial treatment of the branch lesion may be done As each branch is treated, the wire must be removed from the opposing branch With

Figure 13-2: Severe LAD/diagonal bifurcation lesion

Because of severe ostial involvement of the diagonal, tional atherectomy was fi rst performed with a 1.75-mm burr, followed by “kissing” balloon infl ations with a 2.5-mm balloon

rota-in the diagonal and a 3.5-mm balloon rota-in the LAD, followed by placement of a 3.5-mm stent in the LAD Because of the initial atherectomy treatment of the branch, there was no compro-mise of this following stenting in the LAD

progressive increases in burr size, it is generally preferable

to treat fi rst one branch and then the other with the same burr, redirecting the guidewire from one branch to the other

In some situations in which it is felt that access to the side branch with the guidewire will not be diffi cult, the main vessel may be treated fi rst with progressively increasing burr sizes with subsequent treatment of the side branch Wire bias resulting in dissection and/or perforation are of particular concern in side branches with an acute angle of takeoff This may be reduced by use of a small burr and careful attention to wire bias Since rotational atherectomy alone usually results in a suboptimal lumen, the procedure

is generally completed with a “kissing” balloon infl ation that can usually be accomplished with low-infl ation pressures (Figure 13-3)

Figure 13-2 (Continued)

There is now increasing experience with stenting of bifurcation lesions Stenting may be performed as an initial

Figure 13-3: Severe ostial stenosis of the circumfl ex artery

with ostial involvement of a large marginal branch (not well seen) PTCA alone or stenting into either branch would likely have compromised the opposing branch Because of the ostial location of the lesion, PTCA would have given a sub-optimal result and the angle of origin was into both circumfl ex branches, followed by a low-pressure balloon infl ation, giving

a good fi nal result

strategy or used as a “bail-out” if the previously described techniques fail to provide a satisfactory result When stenting

is planned, adjunctive initial use of debulking techniques may permit a better stenting outcome (Figure 13-2) Numerous techniques have been devised, all with technical challenges and often less than optimal results and uncertain long-term outcomes.10,11 In a recently reported series of 70 patients hav-ing bifurcation stenting, the simplest strategy of stenting a main vessel across the side branch with rescue of the branch

as needed was compared with several complex stenting strategies Procedural outcomes were similar but a greater frequency of long-term adverse coronary events was seen in patients undergoing complex stenting.12 Available stents and operator experience with new techniques may improve stent-ing outcomes in the future

TECHNICAL TIPS

**Stenting of main vessel alone: The simplest stenting

strategy involves deployment of a stent in the main vessel lesion, resulting in “jailing” of the side branch Predictors of side branch occlusion are similar to those found with PTCA and atherectomy and include side branches arising within the main vessel lesion and having ostial lesions >50% Side branch occlusion most commonly occurs during high-pressure infl ation with stent deployment Late occlusion or progression of disease at the side branch origin appears

to be rare and some occluded side branches may actually reopen with time.13,14

**Interventions of side branch: Compromise of small

side branches of <2 mm diameter is frequently of no clinical signifi cance and may require no particular treatment With loss of a larger side branch, a second guidewire can usually

be passed through the stent into the compromised branch This can usually be accomplished with any wire, although

in diffi cult situations, success is sometimes greater with a wire having a stiffer tip or a hydrophilic coating (Choice PT, Scimed, Minneapolis, MN and Shinobi, Cordis Miami, FL) Some operators leave a guidewire in the side branch at the time of stent deployment as a marker for the site of origin of the branch The wire may occasionally, however, become entrapped with stent deployment and this technique is usu-ally not necessary in locating the origin of the branch occlu-sion Care must be taken to avoid passing the wire behind the stent rather than through a cell into the side branch Proper positioning of the wire within the stent lumen is con-

fi rmed by easy, unobstructed passage beyond the stent Positioning of the wire under the stent may be indicated by inability to advance a balloon catheter A balloon catheter can usually be easily advanced over the wire across the

ostial lesion and dilatation performed Occasionally, use of

a fi xed wire balloon may be successful when an wire balloon fails to cross It is important to maintain the proximal shoulder of the balloon within the stent since pas-sage of the entire balloon into the side branch may result in entrapment If no balloon will cross into the side branch and treatment is felt necessary, or in the case of some severe side branch lesions seeming unlikely to respond to balloon dilatation, rotational atherectomy through the stent struts into the branch can be performed When this is done, a small burr should be used initially with slow advancing

over-the-to assure ablation of any stent struts and with gradual crease in burr size to prevent burr entrapment in the branch Frequency and severity of side branch compromise may be decreased by PTCA, rotational atherectomy, or DCA of the side branch prior to stent placement, although redilatation

in-is frequently required following stent deployment With a poor result in the branch despite these procedures, bail-out

T stenting as described below can be performed

**Crossing a stent at its side strut: With rescue of side

branches “jailed” within a stent, it is important to recognize differences in stent design and the result of dilatation of stent cells In slotted tube and repeating cell stents, the stent struts are stretched and displaced with side lumen dilatation, resulting in a progressively larger lumen as balloon size increases, although not all stents respond equally With the NIR stent (Boston Scientifi c), the side lumen increases little more than 2 mm until balloon size reaches approximately 4 mm, at which point strut rupture occurs This stent should, therefore, not be used with antici-pated need to dilate a side branch >2 mm diameter It has also been demonstrated that side branch dilatation through

a stent consistently results in narrowing of the main stent lumen immediately downstream from the side branch; this narrowing increases in severity with the increasing size of the balloon used for side branch dilatation Redilatation

of the main stent lumen then results in some reduction of size of the side lumen This problem can best be avoided

by ending the procedure with “kissing” balloon dilatation of both the main lumen and side branch, although with caution

to keep the proximal balloon margin within the stent and to avoid overdilatation of the proximal stent.15

**T stenting: In T stenting of bifurcation lesions, a

guide-wire is placed in both the main lumen and the side branch and a stent is deployed fi rst in the side branch with the proximal stent edge at the origin of the side branch, being careful this does not protrude into the main lumen The wire

is then removed from the side branch and a stent placed over the wire in the main lumen across the origin of the side

branch.10–12,16 It is probably then optimal to recross from the main lumen stent into the side branch and to dilate the os-tium to provide a larger cell opening into the branch.

An alternative approach to T stenting is to deploy the fi rst stent in the main lumen after prior treating with PTCA, DCA,

or rotational atherectomy If, after placement of the main lumen stent, results in the side branch are poor and appear

to require stenting, a wire is passed through the main lumen stent into the side branch, the origin dilated, and a stent

is then passed into the side branch and deployed with its proximal margin just at the origin of the branch

T stenting can provide excellent results when the side branch originates at a right angle from the main lumen (Figure 13-4 A) With other than a right angle takeoff, there will be either an unstented gap at the origin of the branch, or protrusion of a portion of the side branch stent into the main lumen (Figures 13-4 B,C) When the latter occurs, it may

be possible to advance a guidewire through the protruding stent struts and dilate these to the diameter of the main ves-sel lumen

**“Kissing” stents: “Kissing” stents may be placed in both

branches of a bifurcation with overlapping of the proximal stent portions.10,11,17 Guidewires are placed in both branches and, with or without predilation, stents are deployed in both branches with proximal overlap This may be done with ei-ther simultaneous stent deployment with equal pressure in both balloons or with sequential stent deployment followed

by fi nal simultaneous infl ations of both stent balloons ure 13-4 D) This provides good access to both branches of the bifurcation but should be used only in larger arteries and where the size of the proximal vessel will permit simultane-ous high-pressure balloon infl ations With this technique,

(Fig-a double-b(Fig-arreled lumen is cre(Fig-ated in the proxim(Fig-al vessel with a metallic carina not opposed to any vessel wall Al-though this procedure has been reported and used in our laboratory with procedural success, the long-term outcome

is uncertain

**V stenting: Guidewires are placed in both branches of the

bifurcation with predilation performed as necessary Stents are then sequentially deployed in each of the branches with the proximal stent margins carefully positioned so as not

to enter the bifurcation itself This should then be fi nished with a simultaneous “kissing” balloon infl ation (Figure 13-4 E) This technique provides good access into both of the branches but leaves uncovered any disease in the bifurca-tion itself or proximal to the bifurcation.10–12

Figure 13-4: Types of bifurcation stenting (A) T stenting with

the right angle takeoff of side branch providing good coverage

of lesion (B) T stenting with acute angle takeoff of side branch leaving an unstented gap at origin of branch (arrow) (C) T stenting with a similar acute angle takeoff of the side branch with coverage of origin but protrusion of the stent into the main

lumen (arrow) (Continued)

Figure 13-4: (D) “Kissing” stenting with stents in main vessel

and side branch and creation of double-barrel lumen in mal vessel (arrow) (E) V stenting, providing good coverage

proxi-of main lumen and side branch just beyond the bifurcation but leaving the bifurcation itself uncovered (F) Y stenting similar

to (E), but with placement of a third stent in the proximal sel, the bifurcation itself remaining unstented (arrow) (G)

ves-“Trousers stenting” with the third stent advanced over 2 loons into both distal branches overlapping the distal stents

bal-(Continued)

Figure 13-4: (H) “Culotte stenting” with placement of fi rst

stent in the most angulated branch, followed by (I) advancing a guidewire through this stent into the opposing vessel, (J) stent-ing this vessel through the fi rst stent after predilation, and fi nish-ing by (K) recrossing the initial stent with a guidewire and doing simultanenous “kissing” balloon dilatations in both branches

**Y or “trousers” stenting: V stenting, as described

above, is performed The wire is then removed from the branch vessel and a third stent advanced over the guide-wire in the main lumen and deployed with the distal stent margin just at the proximal border of the side branch origin

so as not to “jail” it This should again be fi nished with ing” balloon infl ations.10–12,18 This technique has the advan-tage of stenting disease proximal to the bifurcation but, of necessity, leaves a small unstented gap at the origin of the branch vessel (Figure 13-4 F)

“kiss-A further variation of this technique is “trousers” stenting in which a third stent is free mounted on the proximal portions

of two balloons with the distal portions of the balloons covered with stent.10–12 Guidewires are left in both branches following V stenting and over these wires the two balloons

un-on which the third stent are mounted are advanced until the distal portions of the balloons enter each of the side branches and the distal stent margin reaches the proximal margins of the previously placed V stents The third stent

is then deployed with simultaneous “kissing” balloon

in-fl ations (Figure 13-4 G) Although this technique permits coverage of the entire bifurcation, it is extremely technically diffi cult and requires a suffi ciently large proximal vessel to permit the simultaneous infl ations

**“Culotte” stenting: In “culotte” stenting, a stent is

placed in one branch with a second stent placed through a cell of the fi rst stent into the branch vessel with overlapping

of the proximal portions of both stents (Figures 13-4 H–K)) Guidewires are initially placed in both branches and predi-lation is performed, either sequentially or simultaneously

A stent is then placed in one vessel covering a segment proximal and distal to the bifurcation across the opposing branch Generally the larger, more important branch is stented fi rst, although consideration must also be given to angulation at the bifurcation If there is marked angulation,

it is preferable to stent the more angulated branch fi rst to permit easier access into the opposing branch Another guidewire is then advanced across the deployed stent into the unstented vessel as previously described Some oper-ators prefer leaving the initial guidewire in the branch vessel during stenting of the fi rst vessel as a guide to recrossing, although this has the disadvantage of possibly entrapping this wire Once the unstented branch has been crossed with a wire, this is dilated with a balloon to open the stent cell

in preparation for stenting of the branch The balloon is then removed and the second stent advanced over the branch wire and positioned so as to cover the branch lesion and widely overlap the proximal portion of the previously placed stent The guidewire in the fi rst branch, having been pulled

back prior to deployment of the second stent, is then vanced across the struts of both stents into the fi rst vessel and balloons advanced over both wires to fi nish with a “kiss-ing” balloon infl ation During this fi nal infl ation, it is impor-tant to be certain that both balloons are within the proximal stent and that they are infl ated at relatively low pressure, being careful not to oversize the overlapped balloons.This technique has the advantage of completely cover-ing the bifurcation and permitting access into both branch-

read-es A series of 50 patients treated in this manner resulted

in 94% procedural success and 12.5% target lesion cularization at 6 months if a fi nal “kissing” balloon infl ation could be performed, vs 44% if this was not possible.19

revas-**True bifurcated stents: True bifurcated stents are

cur-rently being developed but none are thus far available for general clinical use A single case using the Bard XT Carina stent (Bard, Galway, Ireland) has recently been reported.20This consists of a bifurcated stent mounted on a dual bal-loon delivery system Further developments of such a stent may lead to better coverage of true bifurcation lesions than any other technique presently available

PRACTICAL CONSIDERATIONS

Many bifurcation lesions may be treated with PTCA alone with satisfactory results, particularly if the branch vessel is small or not more than mildly diseased, with best results obtained by use of “kissing” balloon infl ation For branch vessels >2.5 mm in diameter with ostial involvement, and for longer lesions, debulking with DA or rotational atherectomy provides a better acute lumen gain and lower need for TVR Ostial lesions are particularly resistant to PTCA alone, and DA

or rotational atherectomy will provide more optimal results In many cases, stenting will result in a larger lumen in the main vessel, although with the risk of branch compromise This may

be treated with side branch “rescue” with PTCA or by various complex stenting techniques Regardless of approach to bifurcation lesions, it is critical to: (1) obtain optimal angio-graphic views to adequately defi ne the bifurcation anatomy, (2) choose a guiding catheter with an adequate lumen size and optimal backup support, (3) carefully plan an initial strat-egy most appropriate for vessel size and lesion morphology, and (4) consider the best subsequent options if the initial ap-proach fails to provide satisfactory results

1 Dauerman HL, Higgins PJ, Sparano AM et al Mechanical

debulking versus balloon angioplasty for the treatment of true

bifurcation lesions J Am Coll Cardiol 1998; 32 : 1845–52.

2 Meier D, Gruentzig AR, King SB et al Risk of side branch occlusion during coronary angioplasty Am J Cardiol 1984;

53: 10–14.

3 Boxt LM, Meyerovitz MF, Taus RH et al Side branch

oc-clusion complicating percutaneous transluminal coronary

angioplasty Radiology 1986; 161: 681–3.

4 Weinstein JS, Baim DS, McCabe CH, Lorell BH Salvage

of branch vessels during bifurcation lesion angioplasty: Acute

and long-term follow up Cathet Cardiovasc Diagn 1991; 22 :

1–6

5 Renkin J, Wijns W, Hanet C et al Angioplasty of coronary

bifurcation stenoses: Immediate and long-term results of the

protecting branch technique Cathet Cardiovasc Diagn 1991;

7 Brener SJ, Leya FS, Apterson-Hinsen C et al A

compari-son of debulking versus dilatation of bifurcation coronary

arte-rial narrowings (from the CAVEAT I tarte-rial) Am J Cardiol 1996;

78: 1039–41.

8 Lewis BE, Leya FS, Johnson SA et al Acute procedural

re-sults in the treatment of 30 coronary artery bifurcation lesions with a double-wire atherectomy technique for side-branch

protection Am Heart J 1994; 127: 1600–7.

9 Vaska KJ, Franco I, Whitlow PL Risk of side-branch clusion following directional coronary atherectomy (abstract)

oc-Circulation 1991; 84 (Suppl II): II-81.

10 Baim DS Is bifurcation stenting the answer? Cathet

Car-diovasc Diagn 1996; 37: 314–16.

11 Di Mario C, Columbo A Trousers-stents: How to choose

the right size and shape Cathet Cardiovasc Diagn 1997; 41:

197–9

12 Pan M, de Lezo JS, Medina A et al Simple and complex

stent strategies for bifurcated coronary arterial stenosis

involving the side branch origin Am J Cardiol 1999; 83:

1320–5

13 Aliabadi D, Tilli FV, Powers TR et al Incidence and

angiographic predictors of side branch occlusion following

high-pressure intracoronary stenting Am J Cardiol 1997; 80 :

994–7

14 Fischman DL, Savage MT, Leon MB et al Fate of related side branches after coronary artery stenting J Am Coll

lesion-Cardiol 1993; 22 : 1641–6.

15 Ormiston JA, Webster MWI, Ruygrok PN et al Stent

deformation following simulated side-branch dilatation: A

comparison of fi ve stent designs Cathet Cardiovasc Interv

1999; 47: 258–64.

16 Carrie D, Karouny E, Chouairi S, Puel J “T”-shaped stent placement: A technique for the treatment of dissected bifurca-

tion lesions Cathet Cardiovasc Diagn 1996; 37: 311–13.

17 Colombo A, Gaglione A, Nakamura S, Finci L “Kissing”

stents for bifurcational coronary lesion Cathet Cardiovasc

Diagn 1993; 30 : 327–30.

18 Teirstein PS “Kissing” Palmaz-Schatz stents for

coro-nary bifurcation stenoses Cathet Cardiovasc Diagn 1996;

37: 307–10.

19 Chevalier B, Glatt B, Royer T, Guyon P Placement of onary stents in bifurcation lesions by the “culotte” technique

cor-Am J Cardiol 1998; 82 : 943–9.

20 Carlier SG, van der Giessen WJ, Foley DP et al Stenting

with a true bifurcated stent: Acute and mid-term follow-up

re-sults Cathet Cardiovasc Interv 1999; 47: 361–9.

*Basic; **Advanced; ***Rare, exotic, or investigational

From: Nguyen T, Hu D, Saito S, Grines C, Palacios I (eds), Practical

Handbook of Advanced Interventional Cardiology, 2nd edn © 2003

Futura, an imprint of Blackwell Publishing

The VEGAS trial

The X-TRACT trial

The SAFER trial

The FIRE trial

**How to ensure there is total distal protection

**Long PCI with intermittent distal balloon occlusion

**No fl ow with distal fi lter devices

**Avoid distal occlusive device in SVG ostial lesion

**Double wire technique with distal occlusive device

***Improvised distal protection devices

Technical implications

**Guides for left bypass grafts

**Guides for right bypass grafts

**Balloon angioplasty for vein grafts

**Stenting for vein grafts

**Size and length of stent

CAVEAT: Mismatch and risk of dislodgment during PCI at

the insertion site

PCI of chronic total occlusion

**Guides for the left and right IMA graft

***Engaging a LIMA guide with a wire

***Engaging the RIMA with a pigtail catheter

TAKE-HOME MESSAGE: Management of patients with IMA graft

***Femoral or radial approach

**Cause of failure of PCI in LIMA graft

**PCI in the subclavian artery

Conclusions

GENERAL OVERVIEW

Patients who experience recurrence of ischemia after coronary artery bypass graft surgery (CABG) have lesions in diverse anatomic distributions (saphenous vein graft (SVG), native arteries, internal mammary, radial, gastroepiploic graft,

or proximal subclavian artery) The results of percutaneous coronary interventions (PCI) depend on the types of conduits (native artery, arterial or saphenous vein grafts) or the loca-tions on the conduits (proximal, mid-, distal or at the anasto-motic sites) and the age of the grafts.1 Despite the use of new interventional devices, SVG intervention was still associated with signifi cant in-hospital mortality (8%) and Q-wave myo-cardial infarction (MI) (2%).2 The clinical and technical prob-lems encountered during PCI of SVG are listed in Table 14-1

Early postoperative ischemia (<1 month): The most

common cause of ischemia within hours or days of surgery is acute vein graft thrombosis (60%) Other causes are incom-plete surgical revascularization (10%), kinked grafts, and fo-cal stenoses distal to the insertion site and at the proximal or distal anastomotic sites, spasm or injury, insertion of graft to a vein causing AV fi stula, or bypass of the wrong vessel (Figure

Table 14-1

Clinical and technical problems during PCI of SVG

Problem Corrective measure Adverse outcome

Diffuse disease Long stent High rate of

restenosis

Degenerated SVG Distal protection Distal embolizationRestenosis Drug-eluting stent

(DES)

?% restenosisBrachytherapy

(VBT)

?% restenosis after VBT

Problems without solution yet:

• Progression of disease in other areas of the graft

• Retrograde embolization during PCI of aorto-ostial lesions

• Distal protection in bifurcation lesions: one or two devices? Which branch?

14-1).3 The patients at increased risk for early postoperative ischemia include those undergoing technically demanding minimally invasive and “off-bypass” techniques.4

Early postoperative ischemia (1 month–1 year):

Re-current angina between 1 month and 1 year after the surgery

is most often due to peri-anastomotic stenosis, graft sion, or mid-SVG stenosis from fi brous intimal hyperplasia Recurrence of angina at about three months postoperatively

occlu-is highly suggestive of a docclu-istal graft anastomotic lesion and should, in most cases, lead to evaluation for PCI

Late postoperative ischemia (>3 years after surgery):

At this stage, the most common cause of ischemia is the mation, in vein grafts, of new atherosclerotic plaques which contain foam cells, cholesterol crystals, blood elements, and necrotic debris as in native vessels However, these plaques have less fi brocollagenous tissue and calcifi cation, so they are softer, more friable, of larger size, and frequently associ-ated with thrombus

for-Figure 14-1: LIMA to large cardiac vein: (A) The LIMA at its

origin (Continued)

A

INDICATIONS FOR REVASCULARIZATIONS 1

Indications for percutaneous interventions: PCI

of-fers a less invasive alternative for revascularization in tomatic post-bypass patients, including many who were not candidates for repeat surgery because of contraindications (pulmonary and renal failure, old age, malignancy) Other patients who can undergo PCI with acceptable risks are pa-tients with patent arterial grafts that would be jeopardized by reoperation, patients with relatively small amount of ischemic, symptom-producing myocardium, and patients with no arte-rial or venous conduit available for graft

symp-The status of the left anterior descending artery (LAD) and its graft signifi cantly infl uences the selection process be-cause of its impact on long-term outcome and lack of survival benefi t of repeat surgery to treat non-LAD ischemia.5 A patent left IMA (LIMA) to LAD improves the safety and so favors the selection of PCI in the right coronary artery (RCA) or left cir-cumfl ex artery (LCX) distributions Thus selection of lesions for PCI must be based on careful analysis of the probabilities

of initial success, complications, and for long-term safety and

Figure 14-1: (B) LIMA inserted into the large cardiac vein The

proximal vein was closed The distal vein (which is larger) was seen fl owing back to the left atrium

B

effi cacy compared with competitive surgical strategies and medical therapies.

Indications for surgical revascularization:

Reop-eration is frequently recommended for severe disease of vein graft to the LAD Multiple vessel involvement, small number of patent grafts, severe vein graft disease, and a damaged ven-tricle are factors more likely to lead to repeat surgery (Table 14-2).1 In the past, PCI was not preferred for bulky atheroma-tous lesions or thrombus-laden grafts With the advent of dis-tal protection devices, the acute results are more promising However, the long-term data on a large scale are still lacking

ic complications.1 Once a graft is thrombosed, opening of the native vessel is preferable However, if the native vessel is not

a reasonable target, balloon interventions on the graft are also effective if thrombus formation is not extensive Intracoronary thrombolytic therapy, although technically feasible, is re-ported only in rare cases, with one-third requiring mediastinal

Table 14-2

Anatomic factors infl uencing revascularization

decisions in post-bypass patients

Often lead to PCI Often lead to CABG

Patent arterial graft

(especially LAD)

Diseased SVG to LAD

≥ 2 patent grafts Ejection fraction: 25–35%1–3 culprit lesions >3 culprit lesions

Inadequate conduit Multiple SVG lesions

Near-normal left ventricle Available arterial conduitsDiffi cult surgical access

• Posterior lateral target vessel

• Mediastinal scarring secondary to radiation, infection, or pericarditis

• Prior muscle transfer closure of unhealed sternotomyFuture cardiac surgery anticipated

• In-situ prosthetic valve

• Mild to moderate aortic or mitral valve disease

drainage due to bleeding.6 Therefore, removal of thrombus

by a thrombectomy device is preferred In general, no PCI could ever be done without the patient being anticoagulated.7However, after removal of any obstruction, a good TIMI-3 fl ow may prevent any further thrombotic formation with an oral anti-platelet drug alone, without long-term anticoagulant

Native coronary interventions: 1 One year after bypass

surgery, patients begin to develop new atherosclerotic plaques

in the graft conduits or to show atherosclerotic progression in the native coronary arteries Whenever possible, native artery lesions are targeted fi rst because of their lower rate of reste-nosis Their procedural success is high (approximately 90%) Their outcome is quite favorable, with in-hospital mortality

of 1%, Q-wave myocardial infarction (MI) 1%, non-Q-wave infarction 4%, and emergency surgery 2.8%.1 Approaches to native vessel sites in post-bypass patients include the treat-ment of protected left main disease, recanalization of old total occlusion, or native artery via venous or arterial grafts

Saphenous vein graft interventions: One to three

years after surgery, patients begin to develop atherosclerotic

plaques in the SVG and, after 3 years, these plaques appear

with increased frequency At the early stage, dilation of the tal anastomosis can be accomplished with little morbidity and good long-term patency (80–90%) Dilation of the proximal and mid-segment of the vein graft was highly successful at 90%, with a low rate of mortality (1%), Q-wave MI, and CABG (2%) The rate of non-Q-wave MI was 13% The length of time since surgery was an important factor for restenosis, as was the location of the lesion The lowest target lesion revascular-ization (TLR) rate by bare stent [25% with plain angioplasty (POBA) and 14% with stenting] was noted for lesions that oc-curred at the distal anastomosis within one year of surgery.8There are no data on DES yet available

dis-When evaluating the SVG lesions for intervention, the interventional cardiologist must consider possible conse-quences of atheromatous embolism, considering that the en-tire lesion and accompanying thrombus may be fragmented, dislodged, and embolized If the risk of major atheroemboliza-tion, which could be decreased by distal protection devices,

is acceptable, compared with other therapeutic options, PCI may be appropriate.1 Also, the relatively high subsequent coronary event rate and restenosis potential must also be factored into this decision If the lesion is relatively bulky, pretreatment with diltiazem or verapamil in 200–300 µg incre-ments intracoronary up to 1 mg (or nitroprusside 40 µg bolus) seems to minimize slow and no-fl ow states, but these strate-gies are of limited effectiveness in preventing enzymatic leak compared with the distal protection devices.1

Intervention of the aorto-ostial lesion: There is not

much difference in the technique of PCI for aorto-ostial sion of the SVG However, because there is increased fi brotic

le-change and more spasm, there is a question about need of prior debulking followed by stenting or stenting alone of the

aorto-ostial lesion In a study by Ahmed et al for both groups

of patients with or without prior debulking, the TLR rate after one year was similar at 19% The technical concern during PCI of large and bulky aorto-ostial lesion is the antegrade and retrograde embolization There is distal protective device for antegrade embolization but there is none for retrograde em-bolization.9

Intervention in degenerated saphenous vein grafts:

The lesions that are bulky or associated with thrombus are considered to be high-risk The complications include distal embolization, no-refl ow, abrupt closure, and perforation So different approaches were devised because there is much to lose from the standpoint of distal embolization causing non-Q

MI and increasing long-term mortality In the case of tion of SVG, usually there is contained perforation rather than cardiac tamponade due to the extrapericardial course of the grafts and extensive post-pericardiotomy fi brosis

perfora-EVIDENCE-BASED MEDICINE APPLICATIONS

The Vein Graft AngioJet Study (VEGAS) Phase II Trial:

In this trial, the patients were randomized to have either cal infusion of urokinase or underwent thrombectomy with the AngioJet device (Possis Medical Inc, Minneapolis, MN)

lo-in SVG lesions with demonstrable thrombus or lo-in native teries.10 The results showed that the AngioJet was found to

ar-be superior for patients undergoing high-risk PCI with large thrombus burdens However, despite effi cient removal of thrombus as evidenced by lower angiographic thrombus score, the rate of signifi cant elevated CK-MB was still high

at 11%.10

EVIDENCE-BASED MEDICINE APPLICATIONS

The X-TRACT trial: This trial enrolled 800 patients who

had a target lesion in a native coronary artery with defi nite angiographic thrombus or a strong suspicion of thrombus,

or a lesion in any SVG with or without obvious thrombus At

30 days, there were no differences in cardiac death, MI, or TVR The overall, 30-day MACE rates were similar (17% of the X-Sizer group and in 17.4% of the control group) How-ever, large MIs, defi ned as CK-MB leak greater than 8 times normal limits, were reduced by 46% (8.3% in the control group compared to 4.5% in the X-Sizer group) There was one perforation in the X-Sizer group and four in the control group.11

In general, the X-Sizer system (EndiCOR Medical, Inc, San Clemente, CA) is more effective in removing thrombus and atheromatous debris while the AngioJet system was