Giáo trình Phẫu thuật đướng tiết niệu 2008

Giáo trình Phẫu thuật đướng tiết niệu 2008

Edited by Drogo Montague Inderbir Gill Kenneth Angermeier Jonathan H Ross

Textbook of

REconsTRucTIvE uRoloGIc suRGERy

In recent years, athough open reconstructive urologic procedures have continued to evolve and remain

the main choice of urologists, newer laparoscopic and robotic approaches to reconstructive urology are

becoming ever more popular and challenging the open method as the technique of choice for the urologic

surgeon The Textbook of Reconstructive Urologic Surgery presents a totally comprehensive approach to open,

laparoscopic, endourologic, robotic, microsurgical, and prosthetic reconstructive techniques

Superbly edited by the Glickman Urological and Kidney Institute’s editorial team, the emphasis has been

to bring together an outstanding contributor team of the world’s leading urologists The result is a truly

landmark text which provides detailed illustrations of all reconstructive procedures along with diagnostic

considerations, surgical indications, pre and postoperative care instructions, and discussions

of complications Superbly illustrated with specially commissioned anatomical and surgical line drawings,

the topics covered are split into 9 sections, including:

Renal Reconstruction • Ureteral Reconstruction • Bladder Reconstruction • Urinary Diversion

• Male Urethral Reconstruction • Urogynecologic Reconstruction • Reconstruction of the Penis

and Scrotum • Future Considerations

Functioning as a definitive reference and surgical text, the Textbook of Reconstructive Urologic Surgery,

with its clearly structured format, will prove to be an indispensable tool for any urologic surgeon involved in

the diagnosis and surgical management of a whole range of urologic malignancies

uRoloGIc suRGERy

www.informahealthcare.com

Edited by

Drogo Montague Inderbir Gill Kenneth Angermeier Jonathan H Ross

Cover artwork supplied with permission of The Cleveland Clinic

Center for Medical Art & Photography © 2008

TEXTBOOK OF RECONSTRUCTIVE

UROLOGIC SURGERY

TEXTBOOK OF RECONSTRUCTIVE

UROLOGIC SURGERY

Editors Drogo K Montague MD

Professor of Surgery Cleveland Clinic Lerner College of Medicine Case Western Reserve University and Director, Center for Genitourinary Reconstruction Glickman Urological and Kidney Institute

Cleveland Clinic Cleveland, OH, USA

Indebir S Gill MD MC h

Vice Chairman Glickman Urological and Kidney Institute

Director Center for Laparoscopic and Robotic Urology

Professor of Surgery Cleveland Clinic Lerner College of Medicine Case Western Reserve University

Cleveland Clinic Cleveland, OH, USA

Kenneth W Angermeier MD

Center for Genitourinary Reconstruction Glickman Urological and Kidney Institute

Cleveland Clinic Cleveland, OH, USA

Jonathan H Ross MD

The Cleveland Clinic Lerner College of Medicine

Case Western Reserve University Section of Pediatric Urology Glickman Urologic and Kidney Institute

Cleveland Clinic Cleveland, OH, USA

© 2008 Informa UK Ltd

First published in the United Kingdom in 2008 by Informa Healthcare, Telephone House, 69–77 Paul Street, LondonEC2A 4LQ Informa Healthcare is a trading division of Informa UK Ltd Registered Office: 37/41 Mortimer Street,London W1T 3JH Registered in England and Wales number 1072954

of any licence permitting limited copying issued by the Copyright Licensing Agency, 90 Tottenham Court Road,London W1P 0LP

Although every effort has been made to ensure that all owners of copyright material have been acknowledged inthis publication, we would be glad to acknowledge in subsequent reprints or editions any omissions brought to ourattention

Although every effort has been made to ensure that drug doses and other information are presented accurately in thispublication, the ultimate responsibility rests with the prescribing physician Neither the publishers nor the authorscan be held responsible for errors or for any consequences arising from the use of information contained herein Fordetailed prescribing information or instructions on the use of any product or procedure discussed herein, please con-sult the prescribing information or instructional material issued by the manufacturer

A CIP record for this book is available from the British Library

Library of Congress Cataloging-in-Publication Data

Data available on application

ISBN-10: 1–84184–644–9

ISBN-13: 978–1–84184–644–6

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Dennis LL Cochlin

Keith L Lee and Marshall L Stoller

Maria Siemionow and Serdar Nasir

Gerald H Jordan

Michael E Moran

Alireza Moinzadeh and Antonio Finelli

Kamal Mattar, Alireza Moinzadeh, and Antonio Finelli

Hillary Copp and Craig A Peters

Patrick E Davol, Brant R Fulmer, and Daniel B Rukstalis

Jack W McAninch

Andrew C Novick

Burak Turna, Monish Aron, and Inderbir S Gill

Amr F Fergany and Andrew C Novick

Michael A Geisinger

Stuart M Flechner and Alain Duclos

Carlos R Estrada and Alan B Retik

Kristofer R Wagner and Thomas W Jarrett

18 Ureteroscopic endopyelotomy for the treatment

Brent Yanke and Demetrius Bagley

19 Percutaneous management of ureteropelvic junction obstruction 167

Robert J Stein and Mihir M Desai

Rodrigo Frota, Robert J Stein, Monish Aron, and Inderbir S Gill

James C Ulchaker and Bashir R Sankari

Alison M Lake and J Stuart Wolf Jr

23 Endoscopic and open surgical management of ureterocele and ectopic ureter 192

Una J Lee and Jeffrey S Palmer

Thomas HS Hsu and Tatum Tarin

Jason Wilson and Laurence S Baskin

26 Injectables in pediatric urology: reflux, bladder neck, and stomas 213

Wolfgang H Cerwinka and Andrew J Kirsch

27 Surgical management of primary vesicoureteral reflux and megaureters 226

William Robert DeFoor Jr and Curtis A Sheldon

J Todd Purves and John P Gearhart

Martin A Koyle and Jane F Peterson

Jack S Thomas and John C Elder

Raymond R Rackley, Jonathan H Ross, and Joseph Abdelmalak

Ginger Isom-Batz and Philippe E Zimmern

Amr Mahmoud Abdel Hakim

Richard E Hautmann

Nivedita Bhatta Dhar and Urs E Studer

John P Stein

Ludger Franzaring, Joachim W Thüroff

41 Left colon neobladder 345

Pratap K Reddy and Avinash K Reddy

Stephen Boorjian and Michael L Blute

Amit R Patel and Amr Fergany

Hassan Abol-Enein and Mohamed A Ghoneim

Matthew N Simmons and Steven C Campbell

Rudolf Hohenfellner

Drogo K Montague

Bradley A Erickson and Anthony J Schaeffer

Douglas Canning and Andy Chang

Jonathan H Ross

Michael C Carr

Jack W McAninch and Jill Buckley

Neil H Grafstein and George D Webster

54 Anterior urethral reconstruction: excision with primary anastomosis 453

Michael B Williams and Steven M Schlossberg

Kenneth W Angermeier

Guido Barbagli and Massimo Lazzeri

Jeremy B Myers and Allen Morey

Charles L Secrest

D E Andrich and Anthony R Mundy

60 Combined use of fasciocutaneous, muscular

and myocutaneous flaps and graft onlays in urethral reconstruction 487

Leonard N Zinman

Leonard N Zinman

Jacob M Patterson, Sheila MacNeil, and Christopher R Chapple

Abdel W El-Kassaby

Neil H Grafstein and George D Webster

SECTION 7 UROGYNECOLOGIC RECONSTRUCTION

Christian O Twiss, Veronica Triaca, Ramdev Konijeti, and Shlomo Raz

Rufus Cartwright and Linda Cardozo

Melissa C Davies and Sarah M Creighton

Sandip P Vasavada

Courtenay K Moore

Sarah E McAchran and Howard B Goldman

Edward J McGuire and Rebecca U Margulies

72 Reconstructive procedures for male-to-female gender reassignment 589

Carolina R Alvayay and Arnold Melman

Jeffrey A Leslie and Richard C Rink

74 Laparoscopic surgery for stress urinary incontinence and pelvic organ prolapse 612

Chi Chiung Grace Chen and Marie Fidela R Paraiso

Rene Sotelo and Anthony Finelli

Jonathan P Jarow

William O Brant, Anthony J Bella, and Tom Lue

Matthew K Tollefson and Ajay Nehra

Genoa G Ferguson and Steven B Brandes

Nicholas Watkin

Jennifer Lawson Bepple and Kurt A McCammon

Kenneth W Angermeier

Gerald H Jordan and Ramon Virasoro

84 Correction of Peyronie’s disease: plaque incision and venous grafting 694

Anthony J Bella, William O Brant, and Tom Lue

Dudley Atkinson and Wayne JG Hellstrom

A Nim Christopher and David J Ralph

W Scott McDougal

88 Management of the non-palpable testicle 723

Marc C Smaldone, Derek J Matoka, Michael C Ost, and Steven G Docimo

Edmund S Sabanegh Jr

Anthony Atala

Arnold Melman and Kelvin Davies

Georges-Pascal Haber, Jose R Colombo Jr, and Inderbir S Gill

Arthur L Burnett

Shahin Tabatabaei, Mukesh Harisinghani, and W Scott McDougal

Section of Voiding Dysfunction and Female Urology

Glickman Urological and Kidney Institute

Center for Genitourinary Reconstruction

Glickman Urological and Kidney Institute

Cleveland Clinic

Cleveland, OH

USA

Monish Aron

Section of Laparoscopic and Robotic Surgery

Glickman Urological and Kidney Institute

Wake Forest Institute for Regenerative Medicine

Wake Forest University School of Medicine

Winston Salem, NC

USA

Department of UrologyTulane University Medical CenterNew Orleans, LA

USA

UrologyThomas Jefferson UniversityPhiladelphia, PA

USA

HeadCenter of Reconstructive Urethral SurgeryArezzo

Italy

ChiefPediatric UrologyProfessor of Urology and PediatricsUCSF Children’s Hospital

San Francisco, CAUSA

Associate ProfessorDivision of Urology, Department of Surgeryand Department of Neuroscience

University of OttawaOttawa

Canada

Department of UrologyUniversity Hospital BernBern

Washington University School of Medicine

Division of Urologic Surgery

Professor of Surgery and

Director, Residency Program

Section of Urologic Oncology

Glickman Urological and Kidney Institute

Cleveland Clinic

Cleveland, OH

USA

Douglas A Canning

Professor and Director, Urology

The Childrens Hospital of Philadelphia

UK

Professor and ChairmanUniversity of LouisvilleDepartment of UrologyLouisville, KY

USA

Fellow in Pediatric UrologyChildren’s Healthcare of AtlantaEmory University School of MedicineAtlanta, GA

USA

Andy Chang

Assistant ProfessorDivision of Pediatric UrologyChildren’s Hospital Los AngelesKeck School of MedicineUniversity of Southern California, CAUSA

Department of Reconstructive UrologyFemale Urology and UrodynamicsRoyal Hallamshire HospitalSheffield

UK

St Peter’s Andrology CentreThe London Clinic

LondonUK

Consultant RadiologistUniversity Hospital of WalesCardiff

UK

Jose R Colombo Jr

FellowCenter for Laparoscopic and Robotic SurgeryDepartment of Urology

Glickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Hillary Copp

Harvard Medical School

Children’s Hospital Boston

Institute of Women’s Health

Elizabeth Garrett Andersin Hospital

Division of Pediatric Urology

Cincinnati Children’s Hospital Medical Center

Division of Pediatric Urology

The Children’s Hospital of Pittsburgh

USA

Harvard Medical School Children’s Hospital BostonBoston, MA

USA

Section of Oncology, Laparoscopy and RoboticsGlickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Washington University School of MedicineDivision of Urologic Surgery

St Louis, MOUSA

Princess Margaret HospitalUniversity Health NetworkToronto, ON

Canada

Professor of SurgeryCleveland Clinic Lerner College of MedicineGlickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

James Whitcomb Riley Hospital for Children

Indiana University School of Medicine

Indianapolis, IN

USA

Brady Urological Institute

Johns Hopkins Hospital

Center for Laparoscopic and Robotic UrologyProfessor of Surgery

Cleveland Clinic Lerner College of MedicineCase Western Reserve University

Cleveland ClinicCleveland, OHUSA

Section of Voiding Dysfunction and Female UrologyGlickman Urological and Kidney Institute

Cleveland ClinicCleveland, OHUSA

Glickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Associate Professor of UrologyDepartment of UrologyUniversity of Washington School of Medicine Director, Clinical Research

Division of Pediatric UrologyChildren’s Hospital and Regional Medical CenterSeattle, WA

Georges-Pascal Haber

FellowCenter for Laparoscopic and Robotic SurgeryDepartment of Urology

Glickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Stanford Cancer Center

Stanford University School of Medicine

Brady Urological Institute

Johns Hopkins University School of Medicine

Eastern Virginia Medical School

Devine Center for Genitourinary Reconstructive

USA

University of CaliforniaLos Angeles School of MedicineLos Angeles, CA

USA

Department of UrologyThe Children’s HospitalDenver, CO

USA

Clinical Professor of UrologyChildren’s Healthcare of AtlantaEmory University School of MedicineAtlanta, GA

USA

Department of UrologyUniversity of MichiganAnn Arbor, MI

USA

Eastern Virginia Medical SchoolDevine-Tidewater UrologyVirginia Beach, VAUSA

Department of UrologyCasa di Cura Santa Chiara FirenzeFlorence

Italy

Department of UrologyUniversity of California San FranciscoSan Francisco, CA

USA

Una J Lee MD

Director Minimally Invasive Pediatric Urology

Cleveland Clinic Children’s Hospital and

Associate Professor of Surgery and Pediations

Department of Urology, Pediatric Section

University of Texas Health Science Center

Tissue Engineering Group

Department of Engineering Materials

and Division of Biomedical Sciences and Medicine

Kroto Research Institute

Sheffield

UK

Department of Obstetrics and Gynecology

The University of Michigan

MI

USA

Division of Pediatric Urology

Children’s Hospital of Pittsburgh

USA

Eastern Virginia Medical SchoolDevine-Tidewater Urology,Virginia Beach, VA

USA

Department of UrologyMassachusetts General HospitalBoston, MA

USA

Professor of UrologyThe University of MichiganAnn Arbor, MI

USA

Arnold Melman

Monefiore Medical CenterDepartement of UrologyBronx, NY

USA

Kelvin Melman MD

Associate ProfessorDepartment of UrologyAlbert Einstein college of MedicineBronx, NY

USA

Lahey ClinicInstitute of UrologyRobotic and Laparoscopic SurgeryBurlington, MA

USA

Professor of SurgeryCleveland Clinic Lener College of MedicineCase Western Reserve University

DirectorCenter for Genitourinary ReconstructionGlickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

University of Colorado Hospital

Department of Surgery Division of Urology

and Professor of Surgery

Cleveland Clinic Lerner College of Medicine

USA

DirectorMinimally Invasive Pediatric UrologyCleveland Clinic Children’s Hospital andAssociate Professor of Surgery and PediationsCleveland Clinic Lerner Coluege of MedicineCase Western Reserve University

Cleveland, OHUSA

HeadCenter of Urogynecology and ReconstructivePelvic Surgery

andCo-DirectorFemale Pelvic Medicine and Reconstructive SurgeryDepartment of Obstetrics and Gynecology

Glickman Urological and Kidney InstituteCleveland, OH

USA

The University of Colorado atDenver and Health Sciences CenterDenver, CO

USA

J Todd Purves

Fellow in Pediatric Urology

Brady Urological Institute

Johns Hopkins Hospital

Baltimore, MD

USA

The Cleveland Clinic Lerner College of

Medicine at Case Western Reserve University

Section of Voiding Dysfunction and Female Urology

Glickman Urological and Kidney Institute

Cleveland Clinic

Cleveland, OH

USA

St Peter’s Andrology Centre

The London Clinic

Robert A Garret Professor of Pediatric Urology and

Chief

Pediatric Urology

James Whitcomb Riley Hospital for Children

Indiana University School of Medicine

Cleveland, OHUSA

Director of UrologyDepartment of UrologyGeisinger Medical CenterDanville, PA

USA

Center for Male FertilityGlickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Glickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Northwestern UniversityFeinberg School of MedicineDepartment of UrologyChicago, IL

Division of Pediatric UrologyCincinnati Children’s Hospital Medical CenterCincinnati, OH

USA

University of Southern California

Department of Urology,

Los Angeles, CA

USA

Robert J Stein

Section of Laparoscopic and Robotic Surgery

Glickman Urological and Kidney Institute

USA

Jack S Thomas

Division of Pediatric UrologyChildren’s Hospital at Vanderbilt Nashville, TN

USA

Joachin W Thüroff

Department of UrologyJohannes Gutenberg UniversityMainz

Germany

Department of UrologyMayo Clinic

Rochester, MN USA

University of CaliforniaLos Angeles School of MedicineLos Angeles, CA

University of California,Los Angeles School of MedicineLos Angeles, CA

USA

Co-Director of Prostate CenterGlickman Urological and Kidney InstituteCleveland Clinic

Cleveland, OHUSA

Endourology and LaparoscopyThomas Jefferson UniversityPhiladelphia, PA

USA

Department of UrologyThe University of Texas Southwestern Medical CenterDallas, TX

Reconstructive urology has made many advances in the

past ten to fifteen years primarily as a result of significant

progress in minimally invasive surgery This is the first

major text to examine adult and pediatric reconstructive

procedures from the standpoint of open, laparoscopic,

endourologic, microsurgical, prosthetic, tissue engineering

and robotic approaches An internationally renowned set

of contributions have graced us with their wisdom

Drogo K Montague

To our families who have supported us while patiently

enduring our absences, to our mentors and colleagues

from whom we have learned, to our residents and

fellows who give us more than we give them, and lastly,

to our patients who make this all meaningful

Acknowledgment

There are a number of imaging methods that can be

used in the genitourinary tract Whole texts have been

written on the subject and this is but a single chapter

What follows is therefore not a comprehensive

account but an overview of different imaging

modali-ties with an indication of their use in the genitourinary

system In some cases they are alternatives to each

other, while in others they complement one another

Examples are shown which include genitourinary

pathology, not all of which is necessarily directly

rele-vant to reconstructive surgery, and some are supplied

simply as examples

THE INTRAVENOUS UROGRAM

The intravenous urogram (IVU, intravenous

pyelo-gram [IVP]) has largely been superseded in many cases

by ultrasound and computed tomography (CT) or less

frequently by magnetic resonance imaging (MRI).1,2

Nevertheless, the IVU is still in relatively widespread

use Even if this changes in the future, patients’

previ-ous investigations may be in the form of an IVU For

this reason a brief discussion of the technique follows

The IVU consists of a plain (control or scout) film

obtained before intravenous contrast is administered

This is to detect radio-opaque calculi that may not be

visible on the contrasted films as they are of similar

radiodensity to the contrast that fills the collecting

sys-tem Intravenous iodinated contrast is then given as a

bolus injection This is initially contained within the

intravascular space but soon passes through the

glomeruli into the tubules A film taken in the first few

minutes after contrast is given opacifies the renal

parenchyma, the nephrographic phase This provides

an image of the renal outlines These outlines are often

poorly seen and partly obscured by overlying bowel

After about 5 minutes the calyceal systems are filled

with contrast By 10–15 minutes the calyces, ureters,

and bladder are filled, though excretion is delayed,

often considerably, in an obstructed system

The calyces are seen with varying clarity depending

on how well the contrast is excreted and to what degree

they are obscured by bowel contents Only portions of

the ureters are usually seen on a single film depending

on the position of the peristaltic wave Contrast in thebladder shows the outline but is so dense that it willobscure small lesions within the bladder (Figure 1.1).Before good quality ultrasound, CT, and MRI wereavailable, almost total reliance had to be placed on theIVU Various methods were used to improve its diag-nostic quality Bowel preparation in the form of laxa-tives was given to minimize the problem of overlyingbowel contents Patients were dehydrated to improvecontrast excretion Relatively high doses of contrastwere used, particularly in patients with poor renalfunction, despite the nephrotoxicity of the contrast.The older, less well tolerated ionic contrast agent wasexcreted better than newer non-ionic contrast agents.Multiple films were often taken including obliqueviews, tomograms, delayed films, and fluoroscopicscreening Some older clinicians bemoan the fact thatthe quality of the IVU has deteriorated in recent years

It is well to remember that the high quality of the oldIVU came at a price At best there was greater patientdiscomfort, at worst actual morbidity and mortality It

Dennis LL Cochlin

Figure 1.1 Intravenous urogram (IVU) This demonstrates how an IVU may show altered anatomy The ureters drain into a neobladder.

is right that centers where the IVU is still used accept

the limitations of a simpler and safer technique

know-ing that they can gain whatever information is not

obtained by other secondary imaging methods

CLINICAL APPLICATIONS

Perhaps the most common use of the IVU now is in

sus-pected ureteric colic In many centers, however, the IVU

is being replaced in this indication by low dose

uncon-trasted CT Many studies show that CT is virtually as

sensitive and specific as an IVU Some show it to be

sig-nificantly more sensitive More importantly, CT, even

low dose CT, detects significantly more pathology that

mimics ureteric calculus colic CT is safer as no contrast

is given The only disadvantages are a higher radiation

dose (3.5 mSv for CT versus 1.5 mSv for IVU), and that

no physiologic information is obtained.3,4

It is also arguable that the IVU may still have a place

in the investigation of macroscopic hematuria Renal

cell cancers and large bladder tumors are excluded by

ultrasound, small bladder lesions are excluded by

cys-toscopy The problem lies in the detection of upper tract

transitional cell cancers The percentage of cases of

macroscopic hematuria that are due to upper tract

tran-sitional cell cancers is, however, small, and by no means

all of those tumors present will be detected by an IVU

Because of this some argue that ultrasound and

cys-toscopy are sufficient, some would still add an IVU, and

others use a CT with delayed secretory phase imaging.5

The IVU may still be used to outline the anatomy of

the urinary tract This is often necessary if the patient is

thought to have anomalies or has had previous surgery

the details of which are not known (Figure 1.1) The

same information may, however, be obtained by CT and

with modern reconstructive methods CT often gives

superior information

COMPUTED TOMOGRAPHY

Ultrasound and CT are now the mainstay of urologic

imaging Multislice CT with a 64-slice system can now

achieve isotropic imaging That is to say that the

vox-els that make up the image are the same thickness in

all three dimensions This means that a reconstructed

image in any plane has the same resolution as the axial

plane used for primary acquisition (Figure 1.2) This

makes CT a very powerful imaging tool

The spatial resolution of a modern multislice system

is impressive with a voxel size of down to 0.6 mm This

resolution, however, comes at the cost of relatively highradiation A typical high resolution scan of the renalsystem carries a radiation dose of about 8 mSv for a twophase scan, about 16 times that of a plain abdominalfilm The scan may be performed in several phases,such as, pre-contrast, arterial phase, venous phase, andexcretory phase If several or all of these are performedthe dose is multiplied Such extended studies are some-times necessary and in these cases the radiation isaccepted In most cases, however, the informationrequired may be obtained in one or two phases Insome circumstances high resolution is not necessary.For instance, renal calculi Even those not visible on aplain film, are significantly more radiodense than softtissue If a CT is being performed for the detection orfollow-up of calculi, a far lower dose technique may beused by lowering the mA and acquiring thicker slices.This method reduces the dose by a factor of two toabout 2 mSv for a single phase.6–10The signal to noiseratio is reduced and the resulting image is not pleasing

to look at but is diagnostic (Figure 1.3) Calculus ease is an obvious example of when a reduced dosetechnique can be used but there are others where thetechnique can be used This is particularly desirablewhen follow-up scans are needed

dis-Uncontrasted computed tomography

CT without intravenous contrast demonstrates thekidneys but with little or no tissue contrast betweennormal parenchyma and pathologic tissue such astumor (Figure 1.4) The ureters are well shown thoughthey are difficult to follow on a set of hard copy films.They are far easier to follow on a workstation byscrolling through the images Bladder anatomy isshown though contrast resolution between tumor andbladder wall is poor The main use of uncontrasted CT

is to detect calculi (a low dose technique is usual).Uncontrasted CT is also sometimes used if contrast iscontraindicated

Contrast enhanced computed tomography

Contrast enhanced CT involves the intravenous tion of iodinated contrast (identical to that used in theIVU) that is excreted by the kidneys Use of iodinatedcontrast in patients with impaired renal function or inpatients taking metformin may worsen their condition.Use of iodinated contrast in such cases is not totallycontraindicated but if used it must be clear that the

injec-Figure 1.2 Computed tomography (CT) scan This CT study demonstrates how CT may show anatomy Between the images ((A) and (B) reconstructed coronal views, (C) and (D) sagittal views) the dilated ureters can be seen passing into an ileal conduit Note also that the right ureteric wall is contrasted indicating ureteritis.

(C)

(D)

Figure 1.3 Low dose uncontrasted CT for the demonstration of calculi (A) Axial view (B) Coronal view Although the images are very noisy (low signal to noise ratio) the calculus in the mid-ureter is clearly seen.

Figure 1.4 Uncontrasted CT scan (A) Axial plane (B) Recontructed coronal plane Although the kidneys and bladder are clearly seen, there is little parenchymal detail For instance, there is no differentiation between cortex and medulla (though the left renal calculus is seen).

potential benefits of the study outweigh the possible

morbidity.11There are also other relative

contraindica-tions to contrast including a previous contrast reaction,

allergies, or asthma

Image acquisition may be performed at any phase of

the passage of contrast through the system The phases

used are principally the arterial, nephrographic, venous,

and excretory phases Although imaging in multiple

phases may be performed in a single examination, theradiation dose is high and it is more common to con-fine the examination to one or two phases depending

on the information required By careful timing, varying

or splitting the contrast dose, two phases, usually thenephrographic and excretory phase may be combined.The timing of the sequences is made more accurate by

‘smart’ scanning where the CT scanner constantly

scans at low dose and detects when the bolus of

contrast arrives at an appropriate artery The start of

the scan may therefore be set at an appropriate time

interval after this event.12,13

Arterial phase

The arterial phase demonstrates the arterial tree from

the aorta to the interlobar arteries With high resolution

scanning the resolution of the larger vessels approaches

that of a catheter angiogram (Figure 1.5), though the

catheter angiogram still has better resolution in small

vessels (see Figure 1.29) The CT image may be

recon-structed in any plane or a pseudo three-dimensional

image may be constructed14,15(Figure 1.6) Some digital

catheter angiography systems also have this capability

The technique is, however, rarely used as now most

or all diagnostic angiograms are performed by CT

angiography, catheter angiograms being reserved forinterventional procedures

Arterial phase CT angiography is most often usedfor suspected renal artery stenosis It has other appli-cations, however, including assessment of potential livekidney donors and for mapping the vessels when plan-ning for procedures such as partial nephrectomy.16

Parenchymal or venous phase

The parenchymal and venous phases overlap and may

be regarded together It is this phase that gives the bestcontrast resolution between normal renal parenchymaltissue or bladder wall and pathologic tissue such astumor (Figure 1.7) As there is contrast in the veins,the venous system can also be mapped The most com-mon reason for studying the veins is to assess whether

a renal tumor has invaded the vena cava in order to

Figure 1.5 Arterial phase CT scan (A) Axial view showing the right renal artery leaving the aorta Because the vessels are not straight multiple images or ideally a workstation is needed

to follow the vessels (B) Images can be reconstructed in other planes or (C) a three-dimensional reconstruction can be produced which can be rotated on a workstation.

(B)

Figure 1.6 Three-dimensional reconstruction (A) and (B) Still views of a reconstructed image from a potential live kidney donor, clearly showing the vascular anatomy On a workstation these images can be rotated and viewed from different angles The color rendering, although attractive, adds no diagnostic information.

Figure 1.7 Parenchymal phase CT scan (A) The urethra and the bladder are clearly shown in the sagittal plane (B) The urethra is shown in the axial plane (C) Coronal axial and sagittal views In this phase the cortex and medulla are clearly differentiated There is also clear identification of the tumor in the upper pole of the left kidney This is an oncocytoma with a central scar.

(A)

(B)

(C)

plan surgery; however, MRI may be preferable17

(Figure 1.8) The calyceal system and ureters are not

opacified at this stage and appear similar to their

image on an uncontrasted scan It is possible to reduce

the dose of contrast in this phase to a level where the

parenchyma is contrasted but not to a degree that

obscures renal calculi

Late or excretory phase

In the late or excretory phase contrast fills the

pelvica-lyceal system, ureters and bladder Similar information

is given to that provided by an IVU.18This phase is

useful for mapping anatomy The image may be

recon-structed in any plane The most common planes used

are coronal and sagittal (Figure 1.9), though other

planes, including curved planes may be constructed In

practice, however, reconstructed images give no more

information than is obtained by scrolling through

stan-dard image planes on a workstation This phase may

also identify uroepithelial tumors in the calyceal

sys-tem or ureters, though sensitivity is relatively low

Small bladder tumors may be obscured by contrast in

this phase Bladder tumors are best assessed in the

arterial phase when the wall is contrasted and the

lumen is not opacified (Figure 1.10)

MAGNETIC RESONANCE IMAGING

MRI has relatively poor spatial resolution compared

with CT, is more prone to artifacts, and more expensive

than CT It is therefore used less often in the genitourinarytract It does, however, involve no radiation and so may

be used in pregnancy or when multiple repeat scansare needed.19,20It does not require iodinated contrast

so may be used in patients with renal failure, contrastallergies, or asthma

The physical principles of MRI5are extremely esting but are not discussed further in this chapter.Nor is an understanding of the physical principlesabsolutely essential to interpretation of the images.Suffice it to say that MRI produces its images by caus-ing magnetic excitation of the protons and then col-lecting the signals that they emit when they relax Asprotons are most abundant in hydrogen, MRI imagesare based on the distribution and density of hydrogenatoms This distribution and density varies in differenttissues and also in disease states.21,22

inter-MRI images may be produced in a large number ofdifferent ways or sequences There are four basicsequences that are commonly used and the others arevariations on these These sequences are T2 weighted,T1 weighted, fat suppressed, and contrast enhancedimages.23–25There is insufficient space here to explain

in detail what these images entail or how they are duced The reader is referred to one of the many excel-lent MRI texts that are available.21,22 Only briefdiscussions follow

pro-T2 weighted images

T2 weighted images strongly reflect hydrogen density

As hydrogen density is highest in water, aqueous fluidsproduce a strong signal and appear white on theimage Fat also appears white or pale gray Manypathologic tissues are edematous These tissues, as theycontain more water, have a higher signal than healthytissue (Figure 1.11)

T1 weighted images

T1 weighted images are the images that traditionallywere used to demonstrate anatomy As higher mag-netic field strengths have become available, however,T2 weighted images that show pathology well alsodemonstrate the anatomy well In many cases there-fore only T2 weighted images are needed T1 weightedimages are reserved for those cases where a compari-son of the T1 and T2 tissue signal helps in tissue diag-nosis (Figure 1.12)

Figure 1.8 Venous phase CT scan Contrast is seen in the

right renal vein and part of the inferior vena cava (IVC).

Because of this the tumor thrombus in the left renal vein is

outlined.

Figure 1.9 Excretory phase (late phase) CT scan (A–D) Show there is contrast in the ureter Only small portions are shown in each single image but on a workstation the ureters can be easily followed.

(A)

(B)

(C)

(D)

Fat suppressed images

Fat suppressed images as the name implies suppress

signals from fat on a T2 weighted scan This may be

achieved in a number of ways but whatever method is

used the effect is the same Fat loses its signal and

therefore appears dark on the image while other

tis-sues with high hydrogen content remain high signal In

some instances the reason for fat suppression images is

to differentiate pathologic tissue from fat, while in

other cases it is to show that fat is present in a lesion,

for example, for the characterization of an

angio-myolipoma The image is often low grade which needs

to be viewed alongside the corresponding T2 weighted

image for interpretation (Figure 1.12)

Contrast enhanced images

The contrast agents used in the vast majority of contrastenhanced MRI studies are gadolinium based agents.These are nephrotoxic, but not to a sufficient degree tocause concern Until recently they were regarded as oth-erwise safe In the last year however a condition hasbeen described that has been labeled nephrogenic scle-rosing fibrosis This is a multi-system disorder affectingpatients in renal failure It is characterized by fibroticskin lesions, sometimes leading to contractures In somecases fibrosis of multiple organs has been described anddeaths have occurred from the condition There is noeffective treatment It has further been found that many

of the patients with this condition have had gadoliniumbased contrast agents prior to the onset of the disease.Gadolinium has been detected in the fibrous lesions It

is likely therefore that gadolinium is implicated in thedisease process Because of this it is currently recom-mended that gadolinium contrast agents should not begiven to patients with severely impaired renal functionand perhaps also not to those with moderately impairedrenal function This remains prudent advice until more

is known about the condition

Contrast enhanced images utilize the fact that MRcontrast agents, although not visible themselves onMRI, change the state of the adjacent protons so thattheir T1 and T2 states and therefore the signals thatthey emit are altered This has an effect on the imagesimilar to contrasted CT, though the physical principlesare quite different The main contrast used is gadolin-ium This is initially contained within the intravascularspace MR angiography images may therefore beobtained While these images have less spatial resolutionand more artifacts than a contrasted CT image, they can

Figure 1.10 Arterial phase CT scan of the bladder The wall of the bladder is enhanced outlining the tumor in the left wall.

Figure 1.11 T2 weighted magnetic resonance image

(MRI) scan This clearly shows the anatomy of the left

kidney The large tumor in the right kidney is also clearly

demonstrated.

nevertheless be diagnostically useful26 (Figure 1.13).

Angiographic MRI images may also be obtained

with-out the use of intravenous contrast The sequences used

may utilize the fact that moving blood has an altered

signal, or in another method the fact that the blood is

moving within the vessels If the blood contained within

an MR slice is excited but has moved on by the time the

signal is detected, then the excited blood is replaced by

non-excited blood which is seen as a signal void There

are other more complex methods These methods,

how-ever, while novel and not requiring contrast, lack the

resolution of a gadolinium enhanced angiogram and are

now little used

Contrast perfusion

Gadolinium enhanced images may also be used to

pro-duce studies which reflect tissue perfusion (Figure 1.14)

As with any contrast agent the change in tion of gadolinium in a tissue may be plotted againsttime This may be used to distinguish normal fromabnormal tissue Such studies, while possible, are timeconsuming and have not proved so far to be suffi-ciently sensitive or specific to be useful in routine clin-ical practice Gadolinium is also excreted by thekidneys; however, this feature is seldom utilized in MRimaging.27,28

concentra-Tissue specific contrast agents

MRI contrast agents have been and are being oped that are taken up by specific tissues, enablingstudy of the tissues.29An example is small particle ironoxide (SPIO) Iron oxide particles are taken up by thereticuloendothelial cells Where present, they causelow signal, as they are paramagnetic This can be used

devel-Figure 1.12 Series of MRI sequences This series demonstrates how different sequences can categorize lesions, in this case in a patient with von Hippel-Lindau disease (A) T2 weighted image, (B) T1 weighted image, (C) fat saturation image, and (D) fat saturation image with contrast This sequence shows that the larger lesion in the right kidney has a high T2 signal, medium T1 signal, contains no fat as shown on the fat saturation image, and enhances with contrast This characterizes it as a renal cell cancer.

(A)

(C)

Figure 1.13 Gadolinium enhanced MR angiogram The

vascular pattern is clearly demonstrated, as is the left renal artery

stenosis (A–C) Different angulations can be used to effect.

(A)

(C) (B)

for tissue characterization, for instance, to distinguish

normal, infected, or reactive lymph nodes that contain

reticuloendothelial tissue from malignant nodes where

the reticuloendothelial tissue has been replaced by

tumor

MR spectroscopy

MR was originally developed as a tool for the troscopic analysis of chemical compounds MRIdepends almost entirely on hydrogen density as thisproduces the strongest signal Nevertheless, spectro-scopic analysis of the other elements within a smallvolume or multiple volumes of tissue within an MRIslice is possible This has found a number of uses, forinstance, in the measurement of citrate and cholinepeaks in the prostate gland.30,31The normal ratio isreversed in prostate cancer, making tissue differenti-ation theoretically possible (Figure 1.15) Initialenthusiasm for this very exciting technique has beentempered by disappointing results in subsequentstudies The current trend towards higher power clin-ical MRI machines, principally 3 T as opposed to thecommon 1.5 T magnet strength now in use, mayimprove the technique

spec-MR urogram

T2 weighted images produce high signal fromaqueous fluid including urine A heavily T2 weightedimage therefore makes the calyceal system, ureters,and bladder very bright compared to the surroundingtissue Such an image often viewed in thecoronal plane is termed an MR urogram (MRU)32

5815MR Units

1 Ch/Cr :2.24

Ci :1156 CC/Ci :1.83

GEMEDICAL SYSTEMS

Figure 1.15 MR spectroscopy This is a study of a prostate gland for suspected cancer (A) A small volume of the peripheral zone has been selected This is outlined by the smaller box (B) Spectral analysis, the two larger peaks representing citrate and choline.

Figure 1.16 MR urogram This heavily T2 weighted study

shows fluid filled structures The hydronephrotic left kidney

and hydroureter are well demonstrated as is the normal right

upper ureter and the bladder The central structure is

cerebrospinal fluid in the spinal canal.

MR urethrography

A technique has recently been described in which the

urethra is filled with aqueous gel and T2 weighted

MRI is then performed.33This outlines the urethra in

a similar way to a contrast urethrogram It has the

added advantage that the tissues around the urethra

are also demonstrated (Figure 1.17) MRI is also

prob-ably the best method of imaging the female urethra

(see also the Imaging of the urethra section below)

ULTRASOUND

As with CT and MRI a detailed account of the cal principles of ultrasound is outside the scope of thischapter Many good accounts are available.34It is rele-vant, however, to discuss briefly recent developments

physi-in ultrasound.35

The first ultrasound machines transmitted beams ofhigh frequency sound that were reflected at tissueinterfaces The reflected beams were received by thesame transducer and analysed Depending on the timetaken for the echo to return a dot could be placed onthe image screen that represented an interface Otherinterfaces at different depths were represented byother dots along the line, their brightness representingthe strength of the reflection from the interface Whenmany of these lines were displayed side by side then atwo-dimensional image was created

Modern machines use exactly the same basic nique; however, more complex principles are superim-posed Over the years improvement in the basic design

tech-of transducers and receivers, and the superimposition tech-ofother methods of image processing have achieved a grad-ual but dramatic increase in image quality This improve-ment has led to the survival of ultrasound alongside themore recent developments of CT and MRI

Real-time imaging

Ultrasound systems operate in real time This meansthat the operator sees a moving image reflecting thecontinuously changing planes as the transducer ismoved With experience, hand–eye co-ordinationbecomes such that the transducer movement is intu-itive There are many controls that alter the image Anexperienced operator will continuously adjust these tooptimize the information obtained It is important torealize that although a good operator will obtain a set

of still images that display the examination andpathology found as clearly as possible, these cannotfully reflect the real-time information obtained by theoperator This makes ultrasound the most operatordependent modality in use Modern PACS (picturearchiving and communications system) systems cansupport video clips but in some cases trust must beplaced on the interpretation of the operator

IMPROVEMENTS IN BASIC DESIGN

A major part of the increase in image quality has beenthe development of more efficient transducers These

Figure 1.17 MR urethrogram This is a heavily T2

weighted study performed with gel in the urethra (A) The

urethra and the bladder are clearly shown in sagittal plane.

(B) The urethra is shown in the axial plane.

(A)

(B)

produce a more evenly focused ultrasound beam

nearer to the theoretical ideal narrow parallel beam

than produced by older machines Modern transducers

also function at a wide range of frequencies This is

essential to some of the other improvements discussed

later The image processing is complex and a thorough

understanding is not essential to the user of ultrasound

equipment Many of the functions are programmed

into the machine and the operator has little or no

con-trol over them Some, however, are under operator

control and these need to be understood in order to

optimize the examination

Tissue harmonic imaging

Tissue harmonic imaging is a fairly recent innovation

It was found that when an ultrasound beam strikes

tis-sue, not only is it reflected at the interfaces, but also

the pressure of the beam causes the tissues to vibrate

This vibration occurs not only at the frequency being

transmitted, but also in a wide band of frequencies

both above and below With a broadband transducer,

all these frequencies may be received Although these

non-fundamental frequencies are weaker than the

fun-damental frequency, if they are selectively used to

pro-duce the image, then the image is subtley changed

from the fundamental image In modern high range

machines the image may be switched from

fundamen-tal to tissue harmonic and in some cases a fused image

of both may be displayed

The theoretical advantage of tissue harmonic

imag-ing is that when an ultrasound beam is passed through

tissue it is not only reflected but also diffracted This

diffraction degrades the image With fundamental

imaging the beam that produces the image passes

through the tissues twice, with tissue harmonics only

the beam from the excited tissue produces the image

so that there is only one passage Tissue harmonic

imag-ing therefore, theoretically produces a less degraded

image particularly in deeper structures; however, it is

clear from clinical use that this is an oversimplification

Different patients and different tissues react differently

so that in some cases the tissue harmonic image may be

clearer, while in others the fundamental image is

clearer Interestingly, the echo pattern of some

patho-logic tissues differs in both methods This may have

potential in tissue characterization

Compound imaging

Spatial compounding is a technique that started with

the original non-real-time compound B scanners

Experienced operators would pass the probe across

the patient’s skin not in a single even sweep but using

a number of oscillations along the path Modern ners may achieve the same thing by electronic steering

scan-of the beam The result is that the image is viewedfrom several different angles Combining these into asingle image increases spatial resolution

Frequency compounding is achieved by combiningthe image obtained from a number of different fre-quencies In general, higher frequencies give better spa-tial resolution but poor depth quality, and lowerfrequencies the reverse Machines constantly changefrequencies with depth to optimize these qualities.There are, however, other differences in the image withdifferent frequencies If the images produced by differ-ent frequencies are fused this has some advantages.While both types of compounding may improveimage quality they also cause artifacts It would there-fore be inappropriate to have them switched on at alltimes In practice, the operator will switch betweencompounded and non-compounded images to gainmaximum information

Clinical applications of gray scale imaging

Diagnostic ultrasound is safe, cheap, easily available, andgives a great deal of information about the urogenitaltract It is the imaging modality that is used almostexclusively in the scrotum (MRI may rarely be used) Formany urogenital pathologies it is the initial and often theonly modality used; however, it does have significant lim-itations It is far more operator dependent than otherimaging modalities, though with experienced operatorsthis should not be a major problem The image quality isdegraded in large patients though top of the rangemachines may largely overcome this The main limita-tion in the urinary system is that the non-dilated pelvi-calyceal system and ureters are only poorly seen.36

Ultrasound demonstrates the kidneys as mediumechodensity structures with the renal pyramids shownwith varying clarity as rounded triangular structures oflower echodensity than the cortex The pelvicalycealsystem together with the paracalyceal fat is seen as ahyperechoic white complex structure lying centrally.The pelvicalyceal system may be seen as an anechoicstructure as may the renal pelvis The non-distendedsystem is seen with varying clarity, certainly not suffi-ciently well to exclude uroepithelial tumors (thoughthey are often detected) or even to detect most duplexsystems with certainty The distended system is moreclearly seen (Figure 1.18)

The ureters may be seen at their upper ends byscanning through the lower pole of the kidneys.The lower ureters may be seen by scanning through a

reasonably full but not over full bladder The mid-part

of the ureters may often be seen as they cross the iliac

vessels The rest of the ureters unless distended are

poorly seen or not seen at all (Figure 1.19) There are

some recent studies that suggest that real-time dimensional ultrasound, often referred to as ‘4D’, maymore successfully map the distended ureters and maydisplay the cause of obstruction The technique is,however, still significantly inferior to CT, MRI, or IVU.Technical advances in volume acquisition 4D maychange this situation in the future

three-The retroperitoneum is in general poorly visualized

by ultrasound, although retroperitoneal structuresmay be well seen in some, particularly in slim patients.Some areas are often obscured by bowel gas Largetumors or pathology may be seen but for instance theretroperitoneal lymph nodes are certainly not suffi-ciently well seen to stage urologic tumors

The bladder is reasonably well visualized by sound The shape and size is well demonstrated andbladder volume may be estimated sufficiently accu-rately to study bladder emptying Structural anomaliessuch as diverticula and ureteroceles are well demon-strated The augmented or reconstructed bladder isadequately assessed by ultrasound (Figure 1.20).Thickness of the bladder wall can be assessed Theserosal, muscularis, and mucosal layers can be distin-guished with good quality equipment though not suf-ficiently reliably to stage bladder tumors for whichMRI is the best modality, and CT second best.Most bladder tumors can now be detected by ultra-sound (Figure 1.21) though cystoscopy remains thegold standard and has the advantage of the facility tobiopsy any lesions seen

ultra-Doppler imaging

Doppler imaging is a method of displaying moving tures or tissue (principally flowing blood) and measuringtheir velocity It utilizes the Doppler principle that abody moving in relation to a sound source will alter thefrequency of the reflected sound to a degree propor-tional to its velocity In diagnostic ultrasound systems thefrequency altered signals can be displayed by a colormap (color Doppler) (Figure 1.22), or in the form of agraph plotting frequency shift, which is proportional tovelocity against time (spectral Doppler) (Figure 1.23).Power Doppler is a technique that processes thealtered signal in a power domain rather than a fre-quency domain It is more sensitive and less dependent

struc-on the angle of the vessel in relatistruc-on to the ultrasoundbeam It does not give directional information Althoughpower Doppler is theoretically more sensitive, fre-quency domain Doppler systems have improved tosuch an extent that there is now little difference Insome systems the two modalities can be combined

Figure 1.18 Renal ultrasound (A) Normal kidney

demonstrating the clear differentiation between cortex,

medulla, and central complex By contrast (B) shows a case

of acute renal failure where the cortical medullary

differentiation is lost and there is perinephric fluid (C)

There is a loss of corticomedullary differentiation in this case

of chronic renal failure.

(A)

(B)

(C)

Some machines can produce a color flow map

sim-ilar to a color Doppler image that does not use the

Doppler principle but compares several consecutive

frames and detects the change in pixels from moving

structures This produces a cleaner image with no

color bleed outside the vessels

In practice, none of these techniques has an overalladvantage and where available each is used appropriately.Ultrasound contrast agents in the form of stabilizedmicrobubbles injected intravenously greatly enhance theDoppler signal This is sometimes, though infrequently,necessary for straightforward Doppler studies but the

Figure 1.20 Ultrasound studies of the bladder (A) The

layers of the bladder wall are clearly seen on the anterior and

posterior wall but not laterally There is a very small

papilloma on the left wall (B) and (C) Axial and sagittal

views of a cecocystoplasty showing how ultrasound can

demonstrate a reconstructed bladder.

Figure 1.21 Ultrasound studies of bladder tumors (A) The tumor on the posterior wall is clearly seen (B) There is a tumor in a bladder diverticulum which extends through the neck into the bladder.

Figure 1.22 Color Doppler study The intrarenal vessels are clearly demonstrated.