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Pediatric Surgery, 7th Edition Sample chapter_ch120


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Focusing on the fetus as the patient, this new edition also brings together a new team of editors whose perspectives on tissue engineering & molecular biology will bring this well into the 21st century

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Pediatric Surgery, 7th Edition Sample chapter_ch120

  1. 1. HISTORICAL PERSPECTIVES The earliest account of bladder exstrophy can be found on As- syrian tablets, dating back to 2000 BC. Von Grafenberg first de- scribed the medical condition in 1597, and Mowat is credited with providing a complete description of bladder exstrophy in 1748. It was not until 1780, however, that Chaussier first coined the term “exstrophie.”1 Early management of bladder exstrophy included the application of an external urinary re- ceptacle to the surface of the exposed bladder,2 ureterosigmoi- dostomy,3 transplantation of the bladder trigone into the rectum,4 and coverage of the exposed bladder with lateral skin flaps.5 These methods were fraught with continued urinary incontinence and/or urosepsis. Contributions by Coffey, Nesbitt, Leadbetter, and Clarke improved the technique of ureterosigmoidostomy; however, associated morbidities in- cluded infection, electrolyte abnormalities, and malignancy.6 Complete urinary diversion into the colon or alternate conduit was preferentially used to provide continence and minimize infection, but the problems of anatomic reconstruction and sexual function persisted. Paralleling efforts to develop improved methods of urinary diversion were attempts at successful bladder closure. Trende- CHAPTER 120 lenburg described bilateral sacroiliac osteotomies and the ap- plication of a pelvic sling to support bladder and abdominal wall closure in 1892.7 The first case of successful closure and continence in a female patient with bladder exstrophyBladder and Cloacal was not reported until 1942 by Young.8 Michon subsequently reported successful reconstruction in a male patient 6 years later.9 Despite these accounts of functional closure, a 1970 re-Exstrophy view of 329 cases by Marshall and Muecke concluded that only 19% of patients undergoing total reconstruction had fair-to-satisfactory results.10 These unfavorable outcomesLynn L. Woo, John C. Thomas, and John W. Brock III were reported by others, spurring efforts to improve methods of surgical repair.11,12 EPIDEMIOLOGYThe authors would like to acknowledge Romano T. DeMarcoand James A. O’Neill, Jr. for their previous contributions to The incidence of bladder exstrophy is estimated at between 1this chapter. in 10,000 and 1 in 50,000 live births13 with a higher male- to-female ratio of between 2.3:1 and 4:1.14 Familial recur- rence is approximately 1 in 100.15 On the basis of a survey of 2500 indexed cases, familiar occurrence was found to beBladder Exstrophy 1 in 275.14 Multiple reports of bladder exstrophy among------------------------------------------------------------------------------------------------------------------------------------------------ identical twins have demonstrated variability in involvementBladder exstrophy is a rare midline defect and exists as part of of one or both twins. Subsequent siblings and the offspringa larger spectrum of abdominal-pelvic fusion abnormalities, of individuals with bladder exstrophy may be at increased riskknown collectively as the exstrophy-epispadias complex of being affected.14,15 However, no clear pattern of inheritance(EEC). Presentation of EEC can range from isolated glanular has been characterized and no specific genetic or environmen-epispadias to cloacal exstrophy, in which several other organ tal factor that predisposes to bladder exstrophy has yet beensystems may be affected. In the case of bladder exstrophy, the bladder can be seen everting through a lower abdominalwall defect. This is accompanied by epispadias, a widened pu- EMBRYOLOGYbic diastasis, and an anus that is anteriorly displaced. Over thepast 2 decades, continued improvements in the methods of The underlying embryologic defect shared by bladder exstro-functional bladder closure have dramatically increased recon- phy and other variants of the EEC is due to abnormal devel-structive success rates; however, achieving the ultimate goals opment of the cloacal membrane, a bilaminar structureof adequate bladder capacity, urinary continence, and a good composed of endoderm and ectoderm that overlies the cloacalcosmetic outcome remain challenging. cavity at the caudal end of the germinal disk.16 In normal 1515
  2. 2. 1516 PART VIII GENITOURINARY DISORDERS Mesonephric duct Allantois Primitive Bladder urogenital Phallus sinus Mesonephric Perineal Cloacal duct body membrane Ureteric bud Urorectal Hindgut Anorectal Urorectal septum Ureter A septum B canal CFIGURE 120-1 Division of the cloaca in the urogenital sinus and rectum. A, At the end of the fifth week. B, At 7 weeks. C, At 8 weeks. (Modified from SadlerTW: Langman’s Medical Embryology, 8th ed. Philadelphia, Lippincott Williams and Wilkins, 2000, p 316.)development, lateral ingrowth of mesoderm occurs between submucosal tunnel in the bladder wall.22 With continued ex-the two layers of the cloacal membrane during the fourth posure and chronic inflammation, the exstrophied bladderand fifth weeks of gestation. This results in formation of the becomes thickened and polypoid (Fig. 120-3). Long-termlower abdominal wall and pelvis. Subsequent caudal growth exposure may eventually result in a fibrotic, rigid bladderof the urorectal septum results in its fusion with the cloacal plate that is ultimately unsuitable for closure.membrane, thus fully separating the cloaca into the bladderanteriorly and the rectum posteriorly (Fig. 120-1). The paired GENITAL DEFECTS—MALEgenital tubercles, which will give rise to the phallus, migratemedially to fuse in the midline. Normal perforation of the clo- In the male infant, the open and everted urethral plate can beacal membrane occurs after fusion with the urorectal septum, seen joining the exposed bladder. The penis is characteristi-at approximately the sixth week, resulting in formation of cally short with a flattened, everted glans. The prepuce is lo-separate urogenital and anal openings.17 cated on the penile ventrum (Fig. 120-4). The ejaculatory Migratory failure of the lateral mesodermal folds and ab- ducts are typically normal and exit at the exposed verumon-normal overdevelopment of the cloacal membrane have both tanum in the posterior urethra. The base of the penis and scro-been proposed as potential causes of the prevention of normal tum are widely separated, with lateral displacement of themesodermal ingrowth to the cloacal membrane.16,18 The lack corporal bodies and neurovascular bundles. Historically itof adequate mesodermal reinforcement is thought to result in was believed that the individual corpora were of normal cal-premature rupture of the cloacal membrane, the timing of iber and appeared shortened because of their attachment towhich determines the extent of the abdominal wall defect the widened pubic diastasis and associated dorsal chordee.and degree/severity of urogenital tract involvement.19 Ruptureof the cloacal membrane after fusion with the urorectal sep-tum results in bladder exstrophy, whereas rupture before fu-sion gives rise to the more severe presentation of cloacalexstrophy (see later discussion).CLINICAL PRESENTATIONIn general infants with bladder exstrophy are born full term,without coexisting anatomic anomalies. At birth, an evertedposterior bladder plate of varying size is seen in the midlineof the lower abdomen. The mucosa of the exposed bladderin the newborn is typically smooth and pink. The umbilicalcord exits from the superior-most border of the bladder plate,and a small umbilical hernia may be present (Fig. 120-2). Inaddition, there is significant widening of the pubic symphysisand the anus is anteriorly displaced. The levator ani complexis also divergent, leading to an inherent weakness in the pelvicfloor and a tendency toward rectal prolapse and varying de-grees of fecal incontinence. Associated inguinal hernias arecommon and have been reported in 82% of boys and 10%of girls.20 The upper urinary tract is usually normal, thoughrenal anomalies including ectopic, horseshoe, hypoplastic,dysplastic kidneys, and megaureters may be observed.21 Vesi- FIGURE 120-2 Typical findings of classic bladder exstrophy in a new- born male. The bladder plate is small, and a small hernia is evident at itscoureteral reflux occurs in the vast majority of children after superior border. The penis is foreshortened, with widely splayed corporalbladder closure, secondary to an exaggerated lateral course bodies and glanular separation. The urethral plate is short and located onof the ureters within the pelvis and lack of adequate the anterior surface of the split phallus.
  3. 3. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1517 GENITAL DEFECTS—FEMALE The clitoris is bifid, with divergence of the mons pubis, labia, and clitoral halves (Fig. 120-6). The urethra and vagina are shortened, and the introitus is anteriorly displaced. The vag- inal orifice is often stenotic. The uterus and adnexa are typi- cally normal, though vaginal and uterine duplication have been reported.24,25 Uterine prolapse occurs commonly in female patients, secondary to the inherent weakness in pelvic floor support. PELVIC DEFECTS Some degree of widening of the pubic symphysis is present in all cases of bladder exstrophy and contributes to outward ro- tation and eversion of the pubic rami at their junctions with the ischial and iliac bones (Fig. 120-7). Using computed to- mography (CT), Sponseller and colleagues further character- ized the pelvic anatomy of a large group of exstrophy patients, noting a significantly increased distance between the triradiate cartilages (31%), external rotation of the anterior pelvis (18%), and 30% shortening of the pubic rami.26 On theFIGURE 120-3 When the bladder has been exposed for at least 1 week basis of three-dimensional models generated by CT, Stec andafter birth and the mucosa is subjected to continued exposure and inflam- colleagues observed that among children with exstrophy, themation, polypoid excrescences typically appear, as in this female infant. levator ani muscles were more posteriorly positioned and out- wardly rotated. Furthermore, the puborectal sling had a moreMore recently, an MRI-based study by Silver and colleagues of flattened configuration and supported twice the body cavityadult men with exstrophy and age-matched controls found area in exstrophy patients.27 As mentioned previously, thesethat although the length of the posterior corporal bodies pelvic floor defects predispose to pelvic organ and rectalwas the same between groups, anterior corporal length in prolapse in this patient with exstrophy was nearly 50% shorter than that of con-trols.23 Therefore the penis appears shortened not only second- PRENATAL DIAGNOSISary to corporal divergence, dorsal chordee, and abnormalcrural attachments to the corpora cavernosa but also because The use of prenatal ultrasound (US) and MRI has improvedof an inherent deficiency of corporal tissue (Fig. 120-5). The the antenatal diagnosis of bladder exstrophy, allowing for ap-testes may appear to be undescended, but in most cases they propriate parental counseling and planning of postnatal man-are actually retractile and will eventually reside in the scrotum agement. The prenatal diagnosis of bladder exstrophy may bewithout the need for formal orchiopexy. Should it be required, suggested on US by failure to visualize the bladder in the pres-orchiopexy is performed in conjunction with inguinal hernia ence of normal kidneys and amniotic fluid.28–30 In a review ofrepair. prenatal US studies from 25 women who delivered infants 1 2 3 4 5 6 7FIGURE 120-4 Classic exstrophy in the male. The penis is pulled downward to expose the dorsal aspect, revealing the urethral plate leading to theexposed bladder. 1, umbilical cord; 2, bladder mucosa; 3, paraexstrophy tissues; 4, left ureteric orifice; 5, verumontanum; 6, urethral plate; 7, glans penis.
  4. 4. 1518 PART VIII GENITOURINARY DISORDERS 2 1 2 11 9 3FIGURE 120-5 Penile configura-tion in classic bladder exstrophy. 4Normal male perineum (A) and with 7bladder exstrophy (B). Note the lossof the normal triangular shape of 7 8 8the perineum and widening of the 6pubic symphysis. In the setting ofexstrophy, the corpora cavernosaare widely separated and are intrin- 6sically shorter. 1, corpus caverno- 9sum of the penis; 2, glans penis;3, corpus spongiosum; 4, bul-bospongiosus muscle; 5, ischium; 5 56, ischiopubic ramus; 7, pubis; 8,ischio-cavernosus muscle and crus 10 10of penis; 9, urogenital diaphragm;10, anus and external anal sphincter. A Bwith exstrophy, Gearhart and colleagues observed the follow- be accomplished in a multi- or single-stage (complete) features: absent bladder (71%), lower abdominal bulge Multiple contemporary approaches including the modern(47%) and anteriorly displaced scrotum with small phallus staged reconstruction of exstrophy (MSRE) and completein male fetuses (57%), low-set umbilical cord (29%), and primary reconstruction of exstrophy (CPRE) along with War-abnormal widening of the iliac crest (18%).31 saw,32 Erlangen,24 Mainz,33 and Kelly34 techniques have been published; however, for the purposes of this review, only the major principles of MRSE and CPRE are discussed.SURGICAL RECONSTRUCTIONSurgical management of classic bladder exstrophy consists offunctional closure of the native bladder, closure of the epispa-dic urethra and genitalia, and creation of a continence mech-anism to allow for proper urine storage. Reconstruction mayFIGURE 120-6 Typical appearance of classic bladder exstrophy in a fe- FIGURE 120-7 Plain radiograph of a neonate with bladder exstrophymale. Note the widely divergent labia and anterior displacement of the demonstrates the soft tissue mass effect of the exposed bladder, the widevaginal introitus and anus. diastasis of the symphysis pubis, and the posterior rotation of the acetabula.
  5. 5. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1519INITIAL MANAGEMENTAt birth, the umbilical cord should be ligated with a silk sutureto avoid irritation of the bladder surface from the traditionalplastic clip. The exposed bladder mucosa should be moistenedwith saline and protected with a nonadherent sheet of plasticwrap (e.g., Saran Wrap). A complete physical examination isperformed to rule out associated anomalies and to assess thesize of the bladder plate and extent of the genital defect.Renal US may be obtained to exclude hydronephrosis and/orother upper tract abnormalities. Prophylactic antibioticsshould be administered.MODERN STAGED RECONSTRUCTIONOF BLADDER EXSTROPHYA three-stage approach for the treatment of bladder exstrophywas first pioneered by Jeffs and Cendron in the 1970s,35,36and continued improvements in technique have contributedto increased success of the procedure.37–39 Stage 1 is per-formed at birth to protect the upper urinary tracts and assistlater continent reconstruction. It consists of early closure of FIGURE 120-8 Typical findings of classic bladder exstrophy in a femalethe bladder, posterior urethra, and abdominal wall with or and the incision template used for repair.without osteotomy. The primary objective of functional clo-sure is to convert the bladder exstrophy into a complete epis-padias.40 Stage 2 is performed in later infancy and involves distally to the verumontanum on both sides of the prostaticrepair of the epispadias, with the goal of optimizing genital urethra, leaving a wide strip of bladder neck and urethralfunction and appearance, as well as increasing outlet resis- plate.tance to promote bladder growth. Stage 3 is undertaken before A major objective of primary closure in the male patient isschool age and consists of bladder neck repair for continence to place the bladder and prostate deep within the pelvis toand ureteral reimplantation for vesicoureteral reflux. achieve a more normal anatomic position.44,45 In some boys, Primary functional closure is generally undertaken in the this maneuver results in inadequate length of the urethralneonatal period, which offers several potential advantages. plate for subsequent penile reconstruction. Duckett thereforeThe pliability of the pelvic ring, in infants younger than proposed transection of the urethral plate, distal to the veru-72 hours old, may obviate the need for osteotomy; early montanum, with the development of lateral paraexstrophicclosure prevents further exposure and scarring of the bladder skin flaps, which could be then rotated medially to bridgeplate; there is theoretically less opportunity for bacterial the gap between the transected edges of the urethra.46 Al-colonization of the plate with decreased risk of postoperative though this technique allows for better mobilization of theinfection. Alternatively, delayed closure in combination with bladder, Gearhart and colleagues41,47 reported a 40% compli-pelvic osteotomy may be performed, allowing for patient cation rate associated with the use of paraexstrophy flaps. Ure-growth and a period of time out of the hospital before thral stricture is the most common complication and may bereconstruction. secondary to local tissue ischemia. The routine use of such flaps appears to be decreasing, though their application re-Stage 1: Functional Closure mains a viable option when a short urethral plate prohibitsAt the time of surgery, the patient should be prepped widely adequate bladder mobilization.48including the entire body anteriorly and posteriorly below the If the urethral plate is left intact, it should be mobilized tonipple line so that intraoperative turning is easier. Cardiopul- the level of the prostate to create as much urethral length asmonary monitoring and adequate intravenous access are crit- possible. Following complete mobilization of the bladder,ical. Intraoperative and postoperative analgesia may be the corpora cavernosa are dissected off the inferior pubic ramiafforded by means of an epidural catheter. The most common bilaterally, taking care to preserve the neurovascular bundlestechnique of functional closure is based on descriptions by and avoid penile devascularization. This maneuver aids in pe-Jeffs and colleagues36,41,42 and Duckett and Caldamone.43 nile lengthening, primarily through release of dorsal chor-Figure 120-8 depicts the initial incisional template for bladder dee.23 After placement of a Malecot suprapubic tube andclosure in the female infant, and Figure 120-9 details the com- exteriorization of the ureteral catheters, the bladder is closedplete sequence of stage 1 closure in the male. Traction sutures anteriorly in the midline and the urethra tubularized over aare placed into the glans penis, and ureteral catheters are se- 10- to 12-Fr sound. The first-stage repair thus results in ancured in each ureteral orifice. An incision is made around the isolated penopubic epispadias, which is generally incontinent.periphery of the exstrophic bladder plate, and a plane of dis- Closure of the pelvic ring is required to assist in abdominalsection is established between the rectus fascia and bladder. wall closure. Pubic approximation without ancillary osteot-The umbilical cord is excised, and umbilicoplasty may be per- omy may be possible in the immediate newborn period, whenformed during or after the initial procedure. Dissection is con- the bones are still malleable; however, osteotomy is generallytinued toward the pubis, and the incision is then extended required after 3 days of age. Although multiple techniques are
  6. 6. 1520 PART VIII GENITOURINARY DISORDERS A B C D E F G H I J KFIGURE 120-9 Sequence of repair of bladder exstrophy in a male. A, Completion of the dissection around the periphery of the bladder and the urethralplate. B, Inversion of the bladder plate and approximation of the corpora as a first stage in epispadias repair. Also note the inferior paraexstrophy incisions.C, Further closure of the skin over the corpora and their partial freeing from the pubis. D, Placement of a suprapubic drainage tube. E, Further closure of theskin inferiorly, with approximation to the urethral plate. Creation of the paraexstrophy flaps is now evident. F, The urethral plate is prepared for tubular-ization over a catheter. G, The urethral plate is now tubularized, and ureteral catheters are placed bilaterally and brought out on each side of the bladder.The bladder is also in the process of being tubularized. H, Completion of tubularization of the bladder and urethra, and location of the various drainagetubes. I, After two-layer closure of the bladder and urethral plate, the bladder is reduced into the pelvis and fixed with sutures. J, Sutures are placed toencourage approximation of the pubic halves. K, Drainage tubes are brought out superiorly, and fascia, subcutaneous tissue, and skin are approximated.Approximation of the pubis helps protect the bladder closure and the abdominal wall closure.
  7. 7. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1521described, combined bilateral anterior innominate and verti- The technique for initial closure in a female patient is sim-cal iliac osteotomy is most frequently used to assist symphy- ilar to that described previously. The traction suture is initiallyseal approximation and medial rotation of the pelvic bones.49 placed anterior to the vagina, which is fully mobilized, as theFixator pins are then placed into the iliac wings and lower neourethra is tubularized. The vagina is then repositioned toosteotomized segments. Our group generally used bilateral create a more caudal angle of entry.anterior iliac osteotomies (Fig. 120-10). Closure of the pelvic Postoperatively, the patient is maintained on antibiotic pro-ring is performed using a large-sized, monofilament suture, phylaxis. Parenteral nutrition may be used initially in order totaking care to place the knot anteriorly to avoid erosion into avoid abdominal distension. Close attention must be given tothe soft tissue below. The newly closed bladder and urethra patient positioning and fixator pin sites to minimize the risk ofcan now be covered by reapproximation of the rectus fascia skin ulceration and nerve injury.and skin, with externalization of tubes and drains. External Stage 2: Epispadias Repairfixators are applied to the pins to hold the pelvis in the correctconfiguration. Lower extremity traction is applied to keep the The second stage of repair is generally undertaken betweenlegs still and prevent destabilization of the pelvis (Fig. 120-11). 6 and 12 months of age. It centers on reconstruction of theThe external fixator remains in place for 4 to 6 weeks after phallus, with repair of epispadias and urethroplasty. Thissurgery, allowing for callus formation at the osteotomy sites. may further optimize bladder capacity, through an increaseAs an alternative to external fixation, immobilization may also in outlet resistance.50 Although many techniques have beenbe accomplished through the application of a spica cast, which used, the method described by Cantwell and later modifiedenvelops the hips and lower extremities. The cast remains in by Ransley has been shown effective in accomplishing urethralplace for 4 to 6 weeks. relocation to the penile ventrum, correction of chordee, and a A FIGURE 120-10 A, If the pubis cannot be approximated in a new- born or if the procedure is under- taken later, when the pelvis is less flexible, pelvic osteotomy is re- quired. The location of an anterior il- iac osteotomy is shown. B, External fixator pins are used to hold the B pelvis, and the pubic halves are brought together in the midline.
  8. 8. 1522 PART VIII GENITOURINARY DISORDERS incised transversely at the point of maximum dorsal curvature, and the corporocavernostomy defects sutured together, thus covering neourethra. This maneuver places the urethra ven- trally between the corporal bodies, causes downward deflec- tion of the penis, and also provides extra length. If chordee is correctable by simple corporal rotation, bilateral corporo- tomies are not required. The glansplasty is completed in two layers, resulting in a ventrally placed neourethra.54 Fur- ther modifications to the technique of epispadias repair in- clude the use of full penile disassembly described by Mitchell and Bagli (Fig. 120-13).55 Stage 3: Bladder Neck Reconstruction and Ureteroneocystostomy The final stage of exstrophy repair involves the construction of a urinary continence mechanism and is generally undertaken around 4 years of age.56 During this interval, the patient is monitored periodically with renal US to evaluate the adequacy of upper tract drainage. Bladder capacity is also assessed be- fore bladder neck surgery. Jeffs and colleagues57 reported that a bladder capacity of greater than 60 mL typically allows for adequate functional storage capacity without the need for concomitant bladder augmentation, although others haveFIGURE 120-11 An infant in Bryant’s traction. The patient must remain reported median capacities of greater than 85 mL to be moreimmobilized for 4 to 6 weeks postoperatively. predictive of achieving continence.58 Regardless, it is generally agreed that continence is highly dependent on the size of thelow fistula rate (Fig. 120-12).51,52 This technique involves full original bladder plate, successful initial bladder closure, andmobilization of the corpora and dorsal urethral plate, which is an adequate preoperative bladder capacity.dissected free and tubularized. Correction of dorsal chordee is The Young-Dees-Leadbetter technique of bladder neck re-achieved by incising each corpora transversely, creating pair remains the most common approach to bladder neckdiamond-shaped defects and anastomosing their dorsal me- reconstruction (Fig. 120-14). After opening the bladder, thedial aspects over the tubularized urethra. A ventral meatotomy ureters are first mobilized and reimplanted into a more ceph-is then performed at the tip of the glans to produce a more alad position by either cross-trigonal or cephalotrigonal ure-anatomically normal meatal position.53 Other described teroneocystotomy.22,59 This procedure not only correctsmodifications of the Cantwell-Ransley technique include full vesicoureteral reflux, which occurs in virtually all cases ofdetachment of the urethral plate from the corporal bodies, closed bladder exstrophy, but also allows for creation of pos-leaving only the distal-most 1 cm of urethra attached to the terior bladder plate flaps for the bladder neck reconstruction.glans tip. The urethra is then tubularized, the corpora are A recent report by Braga and colleagues also describes A B CFIGURE 120-12 Steps in the Cantwell-Ransley epispadias repair. A, The urethral plate is dissected from the corpora and is tubularized, taking care topreserve the lateral blood supply of the urethra and the neurovascular bundles. B, Corporotomies are created at the midphallus, and the urethra is trans-posed to the ventral surface. C, The corpora cavernosa are rotated medially and reapproximated at the corporotomy sites, pulling the corporal bodiesinward and providing coverage of the neourethra. This procedure permits further urethral lengthening, approximation of the corpora with preservationof the blood supply, and full coverage of the urethra.
  9. 9. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1523 bladder, bladder neck, and urethra. As described by Grady and Mitchell,60 CPRE begins with intubation of each ureteral orifice with ureteral catheters. Traction sutures are placed into each hemiglans, the bladder plate is circumscribed, and dis- section is continued inferiorly along the ventral aspect of the penis. The urethral plate is mobilized off the penis, which is fully disassembled into separate right and left corporal bod- ies and the spongiosum-containing urethra. The intersymphy- seal band is incised (Fig 120-15), which allows the bladder unit to be positioned deep within the pelvis. A suprapubic tube is left in place, the ureteral catheters are externalized, and the bladder is closed. Similar to the staged approach, pel- vic osteotomy may be required for abdominal closure. The pu- B bic symphysis is approximated using PDS sutures, and the abdominal wall is closed. The urethral plate is tubularized and transposed to the penile ventrum, and the corporal bodies A are rotated medially and reapproximated (Fig. 120-16). Because of the new posterior positioning of the bladder unit, urethral length is often inadequate to reach the glans, and a hypospadiac meatus is left for future reconstruction (Fig. 120-17). Penile shaft coverage is achieved through the use of ventral rotational penile skin flaps. Postoperatively, the patient remains immobilized as previously described in the technique of staged closure. Additional procedures to cor- rect for residual hypospadias, vesicoureteral reflux, and incontinence may be required as the child grows. URINARY DIVERSION Urinary diversion, in the form of a bowel conduit or reservoir, may ultimately be required for patients with insufficient blad- C D der plate or after reconstructive efforts have been unsuccessful and is discussed in Chapter 118.FIGURE 120-13 Complete penile disassembly technique. A, The corpo-ral bodies and the hemiglans are separated. B, The urethra is tubularizedand moved ventrally. C, The corpora are reapproximated dorsally. D, Glans OUTCOMES AND COMPLICATIONSclosure is performed distally to complete the repair. (Modified fromMitchell ME, Bagli DK: Complete penile disassembly for epispadias repair: The most devastating complication of bladder closure is dehis-The Mitchell technique. J Urol 1996;155:300.) cence. Major contributing factors include wound infection, abdominal distension, bladder prolapse, and loss of ureteralsuccessful bilateral ureteral reimplantation at the time of pri- and/or suprapubic catheters within 6 days of closure.61 Uri-mary bladder closure.33 nary diversion, reclosure of the bladder as a urethral tube A strip of posterior bladder plate 2 cm  4 cm is marked for later augmentation, or delayed repair of the bladder mayoff, and the triangles of bladder laterally are demucosalized. be performed. If not performed in the initial setting, pelvicThe strip of bladder is tubularized, and the triangles of de- osteotomy is frequently necessary for successful reclosure.nuded muscle are mobilized laterally to provide coverage of Urinary incontinence remains a significant problem for upthe neourethra. If prior urodynamic evaluation has demon- to 30% of bladder exstrophy patients. In the case of bladderstrated inadequate bladder capacity, augmentation cystoplasty neck incompetence, injectable bulking agents, bladder neckwith a bowel segment may be performed at this setting. sling or artificial urinary sphincter have all been applied. Blad- der neck reconstruction or formal closure of the bladder neck, with the creation of a catheterizable channel, can also be per-SINGLE-STAGE RECONSTRUCTION: formed. In cases where incontinence is secondary to insuffi-COMPLETE PRIMARY REPAIR OF EXSTROPHY cient bladder capacity, augmentation cystoplasty remains the most viable treatment option.Recently, Mitchell and Grady minimized the number of re- Following epispadias repair, the most common complica-quired operations by combining bladder closure with epispa- tion is urethrocutaneous fistula, which ranges from 2% todias repair at birth in a technique known as complete primary 26% in modern series.51,54,62repair.60 Major potential benefits of this approach include the The incidence of adenocarcinoma of the bladder in adultsearlier creation of bladder outlet resistance, theoretically lead- with bladder exstrophy has been estimated to be 250 times thating to normal cycling and improved bladder capacity and of the normal population and is likely due to chronic inflam-functionality as the patient grows. Major principles of CPRE mation, infection, and metaplasia of an exposed bladderinclude total penile disassembly and division of the intersym- plate.63 A series by Woodhouse and colleagues, however, re-physeal band, which enables posterior positioning of the cently documented an 800-fold risk in the incidence of bladder
  10. 10. 1524 PART VIII GENITOURINARY DISORDERS A Bladder Suspensory sutures Urethra Lateral viewFIGURE 120-14 Young-Dees-Leadbetter procedure for bladderexstrophy repair. A, The ureters areappropriately reimplanted to avoidreflux. Triangular areas at the blad-der base are then denuded, andthe remaining muscle is tubularizedover a catheter. This serves tolengthen the urethra and providessufficient pressure to encouragethe development of improved blad-der capacity without causing ure-thral obstruction. B, The bladder isreclosed, and the bladder neck isfurther supported by sutures, which Bsecure it to the pubis anteriorly.malignancy among those with a history of bladder exstrophy by Bladder augmentation is preferred in patients without ade-age 40.64 The development of adenocarcinoma and transitional quate bladder capacity, and bladder neck closure with creationcell carcinoma of the bladder is also a potential risk in those of a continent catheterizable stoma may be performed whenpatients who have undergone augmentation cystoplasty.65,66 other continence procedures have failed. Fertility in patients with bladder exstrophy and epispadiaswas studied by Shapiro and colleagues,14 who surveyed 2500patients. Among these, 38 men had successfully fathered chil- Cloacal Exstrophydren and 131 women had given birth. Diminished fertility ------------------------------------------------------------------------------------------------------------------------------------------------rates among males may be secondary to retrograde ejaculation, Cloacal exstrophy is a rare condition occurring in 1 of 200,000though libido and erectile function appear to be normal to 400,000 live births68 and comprises the most severe defor-according to a report by Woodhouse and colleagues.67 Female mation along the EEC spectrum, which includes both epispa-patients face a significant risk of uterine prolapse. dias and classic bladder exstrophy. Cloacal exstrophy is also referred to as the OEIS complex (omphalocele, exstrophy, im-CONCLUSION perforate anus, and spinal defect) when other malformations of the urogenital, gastrointestinal, skeletal, and neurospinalContemporary reconstructive techniques for the repair of axis are present.bladder exstrophy have resulted in acceptable function and Although first described by Littre in 1709, historic survivalcosmesis for the majority of patients with classic bladder rates were dismal secondary to sepsis or fluid, electrolyte, andexstrophy. Overall continence rates range from 70% to 80%. nutritional derangements from short gut syndrome or
  11. 11. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1525 Cross section Correction of Exstrophy Plane of Cross section Incision through perineal membrane Bladder Symphysis Prostate Urethra Corpus spongiosum Perineal membrane Sup. Transverse perineal muscle AnusFIGURE 120-15 Pelvic view of male exstrophy repair as described by Grady and Mitchell. Aggressive dissection along each side of the urethra and divisionof the intersymphyseal band allow posterior positioning of the bladder in the pelvis. (Modified from Grady RW, Mitchell ME: Complete primary repair ofexstrophy. J Urol 1999;162:1416.)intestinal obstruction.69 The first successful repair was given no embryologic stage similar to cloacal exstrophy existsreported in 1960 by Rickham, who recommended staged sur- in normal development.76 Disruption of the cloacal membrane,geries for reconstruction.70 Advances in neonatal care and sur- as the principle underlying abnormality, has been supported bygical technique have resulted in present-day survival rates that surgically induced exstrophy in animal models.19,77 The pre-exceed 90%, and principle goals of treatment are now directed vailing developmental theories are further clouded by severaltoward improving quality of life in these patients.68,71–75 recent reports documenting rupture as late as 26 weeks.78,79 Rupture at 5 weeks gestation, as traditionally postulated, would cause anterior herniation of the bladder and small bowel, whichEMBRYOLOGY AND GENETICS would prevent normal midline fusion of the hindgut, bladderThe underlying defect in cloacal exstrophy is thought to be re- ¨ plate, genital tubercles, and mullerian ducts, thus resulting inlated to abnormal development and premature rupture of the the typical anatomic presentation of two open bladder halvescloacal membrane, as described earlier in the bladder exstro- separated by a strip of exstrophied cecum, hemiphallic halvesphy section. In the setting of cloacal exstrophy, it has been pos- with a widely separated pubic diastasis, an underdevelopedtulated that membrane rupture occurs within the first 8 weeks and blind-ending distal hindgut with imperforate anus, andof gestation. Confirmation of this theory is difficult, however, an omphalocele of varying size (Fig. 120-18). A BFIGURE 120-16 A, Closure of the urethral plate and bladder as a continuous unit. B, Placement of the urethra ventral to the corporal bodies by posi-tioning the bladder, bladder neck, and urethra posteriorly in the pelvis. (Modified from Grady RW, Mitchell ME: Complete primary repair of exstrophy. J Urol1999;162:1417.)
  12. 12. 1526 PART VIII GENITOURINARY DISORDERS ASSOCIATED ANOMALIES Unlike classic bladder exstrophy, cloacal exstrophy is typically associated with a variety of other anatomic defects (Table 120-1). GASTROINTESTINAL Ileocecal exstrophy with an associated omphalocele, hindgut remnant, and imperforate anus is the most common clinical presentation.54 Omphaloceles are present in 88% to 100% of infants and generally contain portions of small bowel and/or liver.54,89 Other findings include intestinal duplication anomalies, gastroschisis, ectopic anus, colonic exstrophy, and malrotation.90,91 Short gut syndrome may be a significant source of morbidity among patients with cloacal exstrophy and is observed in 25% of cases.71 The risk of short gut syndrome is markedly increased in patients subjected to ileostomy placement as the initial intestinal diversion proce-FIGURE 120-17 At completion of complete primary closure, placement dure.92,93 Furthermore, the phenomenon may occur evenof the bladder and urethral units deeper within the pelvis along with ven-tral transposition of the urethra may result in a hypospadiac meatus, which in the presence of normal bowel length, implicating an inher-can later be reconstructed with formal urethroplasty. ent absorptive abnormality of the intestine.71,72,90 No single environmental exposure or consistent genetic de- GENITOURINARYfect in the etiology of cloacal exstrophy has yet been identified.Thauvin-Robinet and colleagues recently identified an unbal- Abnormalities of the upper urinary tract have been reported inanced translocation between chromosomes 9q and Yq, and other 41% to 66% of cases.72,89 Unilateral renal agenesis, pelvic kid-studies have implicated mutations in homeobox genes such ney, and/or hydronephrosis were observed in up to 33% inas HLXB9 and HOX, which are involved in the development Diamond’s 1990 series.89 Less commonly reported findingsof embryonic mesoderm.80–82 Although there have been multi- include horseshoe kidney, fusion anomalies, and ureteral ab-ple reports of cloacal exstrophy among members of the same normalities.72,89,90 Complete separation or even absence offamily, these are generally anecdotal and have involved multigen- the phallic/clitoral halves may be observed, and the scro-erational relatives or nontwin siblings.83–85 Multiple instances of tum/labia are widely separated. Male infants frequently haveaffected monozygotic twins have been reported, however, undescended testes with associated bilateral inguinal hernias,which lends support to an underlying genetic cause.76,86–88 ¨ whereas failure of mullerian duct fusion in females results in varying degrees of uterine and vaginal duplication anomalies in the majority of patients.72,89 TABLE 120-1 Anomalies Associated with Cloacal Exstrophy Gastrointestinal Omphalocele Imperforate anus, anal atresia/stenosis Short gut syndrome Intestinal malrotation Intestinal duplication Genitourinary Unilateral renal agenesis Pelvic kidney Ureteral duplication Hydronephrosis Bilateral cryptorchidism, inguinal hernias Uterine duplication Vaginal duplication Central Nervous System Spinal dysraphism Skeletal Vertebral (absent, extra, hemi) Club footFIGURE 120-18 Typical presentation of cloacal exstrophy in a male in- Other lower limb (absence, shortening)fant. O, omphalocele; hB, hemibladder; Ce, exstrophied cecum; hP, hemi- Hip subluxationphallus; hS, hemiscrotum; I, prolapsed ileal segment.
  13. 13. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1527CENTRAL NERVOUS SYSTEM SURGICAL REPAIRSome form of spinal dysraphism including tethered cord, Immediate Postnatal Managementmyelomeningocele, or lipomyelomeningocele is present innearly all patients, with recent reports ranging from 64% to After delivery and stabilization of the newborn, exposed or-100%.74,84,91,94 Neurologic impairment is variable and may gans and mucosal surfaces including the omphalocele, blad-affect bladder function, urinary continence, lower extremity der, intestine, and myelomeningocele should be protectedmovement, and erectile function. Detailed postmortem micro- by enclosing the infant’s lower torso in a bowel bag or by firstdissection studies have demonstrated both aberrant origin and moistening surfaces with saline and covering with sterile plas-vascular supply of the pelvic autonomic nerves,95 and these tic wrapping.90 Urologic examination should attempt to notenerves are at additional risk of iatrogenic injury during oper- genetic sex and size of hemibladder plates. Baseline renalative repair. Other reported abnormalities include periventri- function, electrolyte, and hematologic status should be deter-cular leukomalacia, hydrocephalus, hypoplastic cerebellum, mined. Karyotyping can be performed if gender has not beenand Chiari malformation.84 previously determined or is not obvious on examination. Ini- tial imaging should include plain films of the chest and spine along with head, abdominal, renal, and spinal US. In the ab- sence of obvious spinal dysraphism, magnetic resonance im- aging (MRI) may be advisable for detection of occult lesions.SKELETAL Consultation should also be made to general surgery, neuro-Abnormalities of the spine, pelvis, and limbs have all been ob- surgery, and orthopedics for operative planning. Once the ini-served in the setting of cloacal exstrophy. Spinal anomalies, ex- tial evaluation has been completed, discussion may be hadcluding myelodysplasia, have been reported in 22% to 60% with the parents regarding gender assignment, surgical recon-and consist mainly of absent or extra vertebrae, scoliosis, struction, potential functional deficits, and overall expectedand kyphosis.90,96,97 The pelvic deformity is similar to that quality of life.of classic bladder exstrophy but typically more severe with sig-nificant widening of the pubic diastasis, external angling of theposterior and anterior segments, and external rotation and ab- Principles of Repairduction of the iliac wings.70 A review by Jain and Weaver The surgical management of cloacal exstrophy is typically un-found a 17% to 26% incidence of associated lower limb abnor- dertaken in the newborn period (48 to 72 hours) as a com-malities.98 Certain limb malformations like club foot and equi- bined effort between pediatric surgery and urology. In thenovarus deformities can be seen in association with setting of associated spinal dysraphism, neurosurgical consul-myelomeningocele, which often accompanies cloacal exstro- tation and closure should be undertaken as soon as the infantphy; however, a variety of true limb malformations including is medically stable. Early operation minimizes bacterial colo-hypoplasia, absence, split foot, and ectopic or additional digits nization of exposed viscera and may decrease the need for pel-have also been observed.98 vic osteotomy.68,104 The traditional approach of staged repair has been thoroughly described by Gearhart and Jeffs.40,94 Complete primary repair has also been reported by Howell and colleagues,68 Zderic and colleagues,105 Hendren,106PRENATAL DIAGNOSIS and most recently by Mitchell and Plaire.75 It is generally agreed that an individualized approach toward reconstruc-Early prenatal diagnosis allows time for thorough parental tion, whether in a single-staged or multistaged procedure, re-counseling and allows for consideration of pregnancy termi- sults in the best long-term outcomes.107 The main goals ofnation. Prenatal diagnosis was first reported by Meizner and reconstruction include secure abdominal wall and bladderBar-Ziv in 1985,99 and since then, several authors have pro- closure, preservation of renal function, prevention of shortposed criteria for the prenatal diagnosis of cloacal exstrophy. gut syndrome, creation of functionally and cosmetically ac-Principle findings include failure to visualize the urinary ceptable genitalia, and attainment of urinary and fecalbladder along with a large midline anterior abdominal wall continence.73,94defect and/or lumbosacral myelomeningocele.87,100–102 The Although various operative algorithms have been published,prolapsed ileal segment, which may appear as an “elephant all approaches begin with initial separation of the interveningtrunk–like” mass on US, has also been reported as a path- cecal plate from the two bladder halves, closure of the ompha-ognomic finding.103 From a review of 22 cases, Austin and locele, and hindgut preservation (Fig. 120-19).68,71,72,75,107colleagues102 developed a list of major and minor criteria In the past, the bowel was initially diverted through the creationfor prenatal US diagnosis on the basis of the frequency with of loop or end-ileostomies, and the hindgut segment was uni-which abnormalities were observed. Major criteria were those formly discarded. This practice has since fallen out of favor inseen in greater than 50% of cases and included nonvisualiza- order to maximize the absorptive capabilities of the intestinaltion of the bladder (91%); a large, midline, infraumbilical tract.72,74 Currently, after tubularization of the exstrophied ce-anterior abdominal wall defect or cystic anterior abdominal cum, it is recommended that the hindgut segment be broughtwall structure (82%); omphalocele (77%); and myelomenin- out as an end-colostomy.92 In the rare instance when the hind-gocele (68%). Minor criteria were observed in less than 50% gut remnant is not used, it may be left as a mucous fistula forand consisted of lower extremity defects (23%), renal anom- use in future urologic or vaginal reconstruction.90alies (23%), ascites (41%), widened pubic arches (18%), nar- The omphalocele is reduced to assist abdominal wall clo-row thorax (9%), hydrocephalus (9%), and single umbilical sure; however, in cases of large omphaloceles, complete initialartery (9%).102 reduction may not be possible. In this setting, a silo device
  14. 14. 1528 PART VIII GENITOURINARY DISORDERS Ileum Colon A B CFIGURE 120-19 Repair of cloacal exstrophy. A and B, The bowel and bladder mucosa are separated, and the ileocecal junction is tubularized and broughtout as an end-colostomy. The bladder halves are turned in, as in a complete exstrophy repair, with approximation of the pubic rami. C, Alternatively, thebladder halves are approximated in the midline and left open for staged repair if tubularization is not possible. The omphalocele is also closed.may be used or the omphalocele may be allowed to re- inherent preference toward male behaviors and sexual identi-epithelialize, converting it to a ventral hernia, which may be ties in these patients.75,105,109 It remains a topic of continuedrepaired at a later time (Fig. 120-20).94 study and debate. Gender reassignment has since been largely The hemibladders are dissected and then reapproximated abandoned in the current management of cloacal exstrophy,in the midline. In infants with few other associated malforma- though functional and aesthetic phallic reconstruction re-tions and who are medically stable, complete closure of the ab- mains challenging. Vaginal reconstruction is necessary in fe-dominal wall, bladder, and phallic halves may be undertaken at males and in gender-reassigned males and is accomplishedthis point in a single-stage procedure with or without pelvic through the use of bowel or skin grafts.osteotomy. If this is not possible at the initial setting, the two Gastrointestinal reconstruction, in the form of a pull-bladder halves can first be joined in the midline, recapitulating through procedure, may be performed in select patients, somethe appearance of classic bladder exstrophy, which can then be time after initial diversion and abdominal closure. The deci-repaired in a staged fashion as described in the previous section. sion is based on the potential for fecal continence and may Genital reconstruction consists of bringing the phallic be influenced by colonic length, ability to form solid stool,halves together to create an appearance congruent with the and the presence of anal stenosis versus imperforate anus.assigned gender. In the male infant with cloacal exstrophy, Like those with classic bladder exstrophy, these patientsthe phallic halves are characteristically diminutive, widely will also require the creation of antireflux and urinary conti-separated, and asymmetric. Historically, genetically male in- nence mechanisms. The presence of myelodysplasia in thesefants were routinely assigned to female gender at the time of patients usually necessitates augmentation cystoplasty withinitial closure, undergoing orchiectomy and feminizing geni- a bowel segment and intermittent catheterization in order totoplasty.108 Recent data regarding gender identity outcomes in achieve continence. Continence procedures include creationgender-reassigned cloacal exstrophy patients has suggested an of a neourethra, construction of a catheterizable abdominal stoma with concomitant bladder augmentation, and/or blad- der neck closure, the selection of which is influenced by the presence of short gut syndrome, manual dexterity, degree of mobility, and patient motivation.94 POSTOPERATIVE CONSIDERATIONS Given the high incidence of short gut syndrome, fluid and nu- tritional status must be carefully monitored and the initial use of total parenteral nutrition (TPN) is advocated.110 The keys to postoperative success are similar to those for repair of classic bladder exstrophy. Patients are immobilized in some type of traction device. In the setting of pelvic osteotomy, an external fixator is left for 4 to 6 weeks postoperatively. Broad-spectrum antibiotics are administered to minimize risk of wound in- fection and urosepsis. In contrast to patients with classic bladder exstrophy, the presence of associated myelodysplasia in cloacal exstrophy generally precludes use of an epidural catheter. Pain control in cloacal exstrophy patients can beFIGURE 120-20 If initial closure of the omphalocele is not possible, it challenging, and the involvement of the pediatric pain servicemay be allowed to epithelialize, converting the omphalocele to a ventral is recommended. Finally, the importance of limiting abdomi-hernia, which can be repaired at a later time. nal distension to ensure successful abdominal closure and
  15. 15. CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY 1529adequate drainage of both ureteral and bladder catheters medical and surgical management continue to improve func-cannot be understated.61,111,112 Following repair, close mon- tional and quality of life outcomes in these patients, but it isitoring of the upper tracts by US is mandatory to observe for important that these individuals remain under the care of aadequate renal growth and to detect evidence of obstruction multidisciplinary team of providers who can offer medicalor VUR, which has been reported in 50% to 60% of cloacal care, psychologic support, and lifelong follow-up.exstrophy patients after staged or complete primaryrepair.60,107 The complete reference list is available online at www. the past 20 years, survival among patients with cloacal SUGGESTED READINGSexstrophy has exceeded 90%.68,72,74,105 Death is typically re-lated to complications related to extreme prematurity, renal ¨ Ebert AK, Reutter H, Ludwig M, Rosch WH. The exstrophy-epispadias com-agenesis, or other complex malformations that are incompat- plex. Orphanet J Rare Dis 2009;4:23. Gearhart JP, Mathews R. The Exstrophy-Epispadias Complex: Research Con-ible with life. It is interesting to note that cardiovascular anom- cepts and Clinical Applications. New York: Kluwer Academic Publishers;alies are rarely observed in the setting of cloacal exstrophy. The 1999.various complications related to the management of patients Hernandez DJ, Purves T, Gearhart JP. Complications of surgical reconstructionwith cloacal exstrophy are similar to those of patients with of the exstrophy-epispadias complex. J Pediatr Urol 2008;4:460–466. Husmann DA. Surgery insight: Advantages and pitfalls of surgical techniquesclassic bladder exstrophy, as described in the previous section. for the correction of bladder exstrophy. Nat Clin Pract Urol 2006;3:Compared with those with classic exstrophy, however, cloacal 95–100.exstrophy patients face additional challenges of achieving Ludwig M, Ching B, Reutter H, Boyadjiev SA. Bladder exstrophy-epispadiasbowel and bladder continence secondary to the need for anal complex. Birth Defects Res A Clin Mol Teratol 2009;85:509–522.reconstruction and the associated defect of spinal dysraphism. Woodhouse CR, North AC, Gearhart JP. Standing the test of time: Long-term outcome of reconstruction of the exstrophy bladder. World J Urol 2006;24:It must be stressed that multiple operations are the rule, and 244–249.these patients will likely face significant medical, psychologic, Woo LL, Thomas JC, Brock JW. Cloacal exstrophy: A comprehensive review ofand social challenges throughout their lives. Advancements in an uncommon problem. J Pediatr Urol 2009 Oct; (Epub ahead of print).