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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 …

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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  • 1. ------------------------------------------------------------------------------------------------------------------------------------------------ CHAPTER 120 Bladder and Cloacal Exstrophy Lynn L. Woo, John C. Thomas, and John W. Brock III The authors would like to acknowledge Romano T. DeMarco and James A. O’Neill, Jr. for their previous contributions to this chapter. Bladder Exstrophy Bladder exstrophy is a rare midline defect and exists as part of a larger spectrum of abdominal-pelvic fusion abnormalities, known collectively as the exstrophy-epispadias complex (EEC). Presentation of EEC can range from isolated glanular epispadias to cloacal exstrophy, in which several other organ systems may be affected. In the case of bladder exstrophy, the open bladder can be seen everting through a lower abdominal wall defect. This is accompanied by epispadias, a widened pu- bic diastasis, and an anus that is anteriorly displaced. Over the past 2 decades, continued improvements in the methods of functional bladder closure have dramatically increased recon- structive success rates; however, achieving the ultimate goals of adequate bladder capacity, urinary continence, and a good cosmetic outcome remain challenging. 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- 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 exstrophy 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- 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 outcomes were reported by others, spurring efforts to improve methods of surgical repair.11,12 EPIDEMIOLOGY The incidence of bladder exstrophy is estimated at between 1 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 be 1 in 275.14 Multiple reports of bladder exstrophy among identical twins have demonstrated variability in involvement of one or both twins. Subsequent siblings and the offspring of individuals with bladder exstrophy may be at increased risk of being affected.14,15 However, no clear pattern of inheritance has been characterized and no specific genetic or environmen- tal factor that predisposes to bladder exstrophy has yet been identified. EMBRYOLOGY The underlying embryologic defect shared by bladder exstro- phy and other variants of the EEC is due to abnormal devel- opment of the cloacal membrane, a bilaminar structure composed of endoderm and ectoderm that overlies the cloacal cavity at the caudal end of the germinal disk.16 In normal 1515
  • 2. development, lateral ingrowth of mesoderm occurs between the two layers of the cloacal membrane during the fourth and fifth weeks of gestation. This results in formation of the lower abdominal wall and pelvis. Subsequent caudal growth of the urorectal septum results in its fusion with the cloacal membrane, thus fully separating the cloaca into the bladder anteriorly and the rectum posteriorly (Fig. 120-1). The paired genital tubercles, which will give rise to the phallus, migrate medially to fuse in the midline. Normal perforation of the clo- acal membrane occurs after fusion with the urorectal septum, at approximately the sixth week, resulting in formation of separate urogenital and anal openings.17 Migratory failure of the lateral mesodermal folds and ab- normal overdevelopment of the cloacal membrane have both been proposed as potential causes of the prevention of normal mesodermal ingrowth to the cloacal membrane.16,18 The lack of adequate mesodermal reinforcement is thought to result in premature rupture of the cloacal membrane, the timing of which determines the extent of the abdominal wall defect and degree/severity of urogenital tract involvement.19 Rupture of 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 cloacal exstrophy (see later discussion). CLINICAL PRESENTATION In general infants with bladder exstrophy are born full term, without coexisting anatomic anomalies. At birth, an everted posterior bladder plate of varying size is seen in the midline of the lower abdomen. The mucosa of the exposed bladder in the newborn is typically smooth and pink. The umbilical cord exits from the superior-most border of the bladder plate, and a small umbilical hernia may be present (Fig. 120-2). In addition, there is significant widening of the pubic symphysis and the anus is anteriorly displaced. The levator ani complex is also divergent, leading to an inherent weakness in the pelvic floor and a tendency toward rectal prolapse and varying de- grees of fecal incontinence. Associated inguinal hernias are common and have been reported in 82% of boys and 10% of girls.20 The upper urinary tract is usually normal, though renal anomalies including ectopic, horseshoe, hypoplastic, dysplastic kidneys, and megaureters may be observed.21 Vesi- coureteral reflux occurs in the vast majority of children after bladder closure, secondary to an exaggerated lateral course of the ureters within the pelvis and lack of adequate submucosal tunnel in the bladder wall.22 With continued ex- posure and chronic inflammation, the exstrophied bladder becomes thickened and polypoid (Fig. 120-3). Long-term exposure may eventually result in a fibrotic, rigid bladder plate that is ultimately unsuitable for closure. GENITAL DEFECTS—MALE In the male infant, the open and everted urethral plate can be seen joining the exposed bladder. The penis is characteristi- cally short with a flattened, everted glans. The prepuce is lo- cated on the penile ventrum (Fig. 120-4). The ejaculatory ducts are typically normal and exit at the exposed verumon- tanum in the posterior urethra. The base of the penis and scro- tum are widely separated, with lateral displacement of the corporal bodies and neurovascular bundles. Historically it was believed that the individual corpora were of normal cal- iber and appeared shortened because of their attachment to the widened pubic diastasis and associated dorsal chordee. A B C Mesonephric duct Mesonephric duct Allantois Ureteric bud Urorectal septumUrorectal septum Hindgut Cloacal membrane Primitive urogenital sinus Anorectal canal Bladder Ureter Perineal body Phallus FIGURE 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 Sadler TW: Langman’s Medical Embryology, 8th ed. Philadelphia, Lippincott Williams and Wilkins, 2000, p 316.) 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 its superior border. The penis is foreshortened, with widely splayed corporal bodies and glanular separation. The urethral plate is short and located on the anterior surface of the split phallus. 1516 PART VIII GENITOURINARY DISORDERS
  • 3. More recently, an MRI-based study by Silver and colleagues of adult men with exstrophy and age-matched controls found that although the length of the posterior corporal bodies was the same between groups, anterior corporal length in men with exstrophy was nearly 50% shorter than that of con- trols.23 Thereforethepenisappearsshortenednotonlysecond- ary to corporal divergence, dorsal chordee, and abnormal crural attachments to the corpora cavernosa but also because of an inherent deficiency of corporal tissue (Fig. 120-5). The testes may appear to be undescended, but in most cases they are actually retractile and will eventually reside in the scrotum without the need for formal orchiopexy. Should it be required, orchiopexy is performed in conjunction with inguinal hernia repair. 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 the basis of three-dimensional models generated by CT, Stec and colleagues observed that among children with exstrophy, the levator ani muscles were more posteriorly positioned and out- wardly rotated. Furthermore, the puborectal sling had a more flattened configuration and supported twice the body cavity area in exstrophy patients.27 As mentioned previously, these pelvic floor defects predispose to pelvic organ and rectal prolapse in this patient population. PRENATAL DIAGNOSIS The use of prenatal ultrasound (US) and MRI has improved the antenatal diagnosis of bladder exstrophy, allowing for ap- propriate parental counseling and planning of postnatal man- agement. The prenatal diagnosis of bladder exstrophy may be suggested on US by failure to visualize the bladder in the pres- ence of normal kidneys and amniotic fluid.28–30 In a review of prenatal US studies from 25 women who delivered infants FIGURE 120-3 When the bladder has been exposed for at least 1 week after birth and the mucosa is subjected to continued exposure and inflam- mation, polypoid excrescences typically appear, as in this female infant. 6 1 3 4 5 7 2 FIGURE 120-4 Classic exstrophy in the male. The penis is pulled downward to expose the dorsal aspect, revealing the urethral plate leading to the exposed bladder. 1, umbilical cord; 2, bladder mucosa; 3, paraexstrophy tissues; 4, left ureteric orifice; 5, verumontanum; 6, urethral plate; 7, glans penis. 1517CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 4. with exstrophy, Gearhart and colleagues observed the follow- ing features: absent bladder (71%), lower abdominal bulge (47%) and anteriorly displaced scrotum with small phallus in male fetuses (57%), low-set umbilical cord (29%), and abnormal widening of the iliac crest (18%).31 SURGICAL RECONSTRUCTION Surgical management of classic bladder exstrophy consists of functional 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 may be accomplished in a multi- or single-stage (complete) repair. Multiple contemporary approaches including the modern staged reconstruction of exstrophy (MSRE) and complete primary reconstruction of exstrophy (CPRE) along with War- 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. 1 2 3 4 7 7 8 8 6 6 9 5 5 10 10 11 2 9 A B FIGURE 120-5 Penile configura- tion in classic bladder exstrophy. Normal male perineum (A) and with bladder exstrophy (B). Note the loss of the normal triangular shape of the perineum and widening of the pubic symphysis. In the setting of exstrophy, the corpora cavernosa are widely separated and are intrin- sically shorter. 1, corpus caverno- sum of the penis; 2, glans penis; 3, corpus spongiosum; 4, bul- bospongiosus muscle; 5, ischium; 6, ischiopubic ramus; 7, pubis; 8, ischio-cavernosus muscle and crus of penis; 9, urogenital diaphragm; 10, anus and external anal sphincter. FIGURE 120-6 Typical appearance of classic bladder exstrophy in a fe- male. Note the widely divergent labia and anterior displacement of the vaginal introitus and anus. FIGURE 120-7 Plain radiograph of a neonate with bladder exstrophy demonstrates the soft tissue mass effect of the exposed bladder, the wide diastasis of the symphysis pubis, and the posterior rotation of the acetabula. 1518 PART VIII GENITOURINARY DISORDERS
  • 5. INITIAL MANAGEMENT At birth, the umbilical cord should be ligated with a silk suture to avoid irritation of the bladder surface from the traditional plastic clip. The exposed bladder mucosa should be moistened with saline and protected with a nonadherent sheet of plastic wrap (e.g., Saran Wrap). A complete physical examination is performed to rule out associated anomalies and to assess the size of the bladder plate and extent of the genital defect. Renal US may be obtained to exclude hydronephrosis and/or other upper tract abnormalities. Prophylactic antibiotics should be administered. MODERN STAGED RECONSTRUCTION OF BLADDER EXSTROPHY A three-stage approach for the treatment of bladder exstrophy was first pioneered by Jeffs and Cendron in the 1970s,35,36 and continued improvements in technique have contributed to increased success of the procedure.37–39 Stage 1 is per- formed at birth to protect the upper urinary tracts and assist later continent reconstruction. It consists of early closure of the bladder, posterior urethra, and abdominal wall with or 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 repair of the epispadias, with the goal of optimizing genital function and appearance, as well as increasing outlet resis- tance to promote bladder growth. Stage 3 is undertaken before school age and consists of bladder neck repair for continence and ureteral reimplantation for vesicoureteral reflux. Primary functional closure is generally undertaken in the neonatal period, which offers several potential advantages. The pliability of the pelvic ring, in infants younger than 72 hours old, may obviate the need for osteotomy; early closure prevents further exposure and scarring of the bladder plate; there is theoretically less opportunity for bacterial colonization of the plate with decreased risk of postoperative infection. Alternatively, delayed closure in combination with pelvic osteotomy may be performed, allowing for patient growth and a period of time out of the hospital before reconstruction. Stage 1: Functional Closure At the time of surgery, the patient should be prepped widely including the entire body anteriorly and posteriorly below the nipple line so that intraoperative turning is easier. Cardiopul- monary monitoring and adequate intravenous access are crit- ical. Intraoperative and postoperative analgesia may be afforded by means of an epidural catheter. The most common technique of functional closure is based on descriptions by Jeffs and colleagues36,41,42 and Duckett and Caldamone.43 Figure 120-8 depicts the initial incisional template for bladder closure in the female infant, and Figure 120-9 details the com- plete sequence of stage 1 closure in the male. Traction sutures are placed into the glans penis, and ureteral catheters are se- cured in each ureteral orifice. An incision is made around the periphery of the exstrophic bladder plate, and a plane of dis- section is established between the rectus fascia and bladder. The umbilical cord is excised, and umbilicoplasty may be per- formed during or after the initial procedure. Dissection is con- tinued toward the pubis, and the incision is then extended distally to the verumontanum on both sides of the prostatic urethra, leaving a wide strip of bladder neck and urethral plate. A major objective of primary closure in the male patient is to place the bladder and prostate deep within the pelvis to achieve a more normal anatomic position.44,45 In some boys, this maneuver results in inadequate length of the urethral plate for subsequent penile reconstruction. Duckett therefore proposed transection of the urethral plate, distal to the veru- montanum, with the development of lateral paraexstrophic skin flaps, which could be then rotated medially to bridge the gap between the transected edges of the urethra.46 Al- though this technique allows for better mobilization of the bladder, Gearhart and colleagues41,47 reported a 40% compli- cation rate associated with the use of paraexstrophy flaps. Ure- thral stricture is the most common complication and may be secondary to local tissue ischemia. The routine use of such flaps appears to be decreasing, though their application re- mains a viable option when a short urethral plate prohibits adequate bladder mobilization.48 If the urethral plate is left intact, it should be mobilized to the level of the prostate to create as much urethral length as possible. Following complete mobilization of the bladder, the corpora cavernosa are dissected off the inferior pubic rami bilaterally, taking care to preserve the neurovascular bundles and avoid penile devascularization. This maneuver aids in pe- nile lengthening, primarily through release of dorsal chor- dee.23 After placement of a Malecot suprapubic tube and exteriorization of the ureteral catheters, the bladder is closed anteriorly in the midline and the urethra tubularized over a 10- to 12-Fr sound. The first-stage repair thus results in an isolated penopubic epispadias, which is generally incontinent. Closure of the pelvic ring is required to assist in abdominal wall closure. Pubic approximation without ancillary osteot- omy may be possible in the immediate newborn period, when the bones are still malleable; however, osteotomy is generally required after 3 days of age. Although multiple techniques are FIGURE 120-8 Typical findings of classic bladder exstrophy in a female and the incision template used for repair. 1519CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 6. A B C D E F G H I J K FIGURE 120-9 Sequence of repair of bladder exstrophy in a male. A, Completion of the dissection around the periphery of the bladder and the urethral plate. 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 the skin 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 drainage tubes. 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 to encourage 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. 1520 PART VIII GENITOURINARY DISORDERS
  • 7. described, combined bilateral anterior innominate and verti- cal iliac osteotomy is most frequently used to assist symphy- seal approximation and medial rotation of the pelvic bones.49 Fixator pins are then placed into the iliac wings and lower osteotomized segments. Our group generally used bilateral anterior iliac osteotomies (Fig. 120-10). Closure of the pelvic ring is performed using a large-sized, monofilament suture, taking care to place the knot anteriorly to avoid erosion into the soft tissue below. The newly closed bladder and urethra can now be covered by reapproximation of the rectus fascia and skin, with externalization of tubes and drains. External fixators are applied to the pins to hold the pelvis in the correct configuration. Lower extremity traction is applied to keep the legs still and prevent destabilization of the pelvis (Fig. 120-11). The external fixator remains in place for 4 to 6 weeks after surgery, allowing for callus formation at the osteotomy sites. As an alternative to external fixation, immobilization may also be accomplished through the application of a spica cast, which envelops the hips and lower extremities. The cast remains in place for 4 to 6 weeks. The technique for initial closure in a female patient is sim- ilar to that described previously. The traction suture is initially placed anterior to the vagina, which is fully mobilized, as the neourethra is tubularized. The vagina is then repositioned to create a more caudal angle of entry. Postoperatively, the patient is maintained on antibiotic pro- phylaxis. Parenteral nutrition may be used initially in order to avoid abdominal distension. Close attention must be given to patient positioning and fixator pin sites to minimize the risk of skin ulceration and nerve injury. Stage 2: Epispadias Repair The second stage of repair is generally undertaken between 6 and 12 months of age. It centers on reconstruction of the phallus, with repair of epispadias and urethroplasty. This may further optimize bladder capacity, through an increase in outlet resistance.50 Although many techniques have been used, the method described by Cantwell and later modified by Ransley has been shown effective in accomplishing urethral relocation to the penile ventrum, correction of chordee, and a B 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 pelvis, and the pubic halves are brought together in the midline. 1521CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 8. low fistula rate (Fig. 120-12).51,52 This technique involves full mobilization of the corpora and dorsal urethral plate, which is dissected free and tubularized. Correction of dorsal chordee is achieved by incising each corpora transversely, creating diamond-shaped defects and anastomosing their dorsal me- dial aspects over the tubularized urethra. Aventral meatotomy is then performed at the tip of the glans to produce a more anatomically normal meatal position.53 Other described modifications of the Cantwell-Ransley technique include full detachment of the urethral plate from the corporal bodies, leaving only the distal-most 1 cm of urethra attached to the glans tip. The urethra is then tubularized, the corpora are 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 have reported median capacities of greater than 85 mL to be more predictive of achieving continence.58 Regardless, it is generally agreed that continence is highly dependent on the size of the original bladder plate, successful initial bladder closure, and an adequate preoperative bladder capacity. The Young-Dees-Leadbetter technique of bladder neck re- pair remains the most common approach to bladder neck reconstruction (Fig. 120-14). After opening the bladder, the ureters are first mobilized and reimplanted into a more ceph- alad position by either cross-trigonal or cephalotrigonal ure- teroneocystotomy.22,59 This procedure not only corrects vesicoureteral reflux, which occurs in virtually all cases of closed bladder exstrophy, but also allows for creation of pos- terior bladder plate flaps for the bladder neck reconstruction. A recent report by Braga and colleagues also describes FIGURE 120-11 An infant in Bryant’s traction. The patient must remain immobilized for 4 to 6 weeks postoperatively. A B C FIGURE 120-12 Steps in the Cantwell-Ransley epispadias repair. A, The urethral plate is dissected from the corpora and is tubularized, taking care to preserve 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 bodies inward and providing coverage of the neourethra. This procedure permits further urethral lengthening, approximation of the corpora with preservation of the blood supply, and full coverage of the urethra. 1522 PART VIII GENITOURINARY DISORDERS
  • 9. successful bilateral ureteral reimplantation at the time of pri- mary bladder closure.33 A strip of posterior bladder plate 2 cm  4 cm is marked off, and the triangles of bladder laterally are demucosalized. The strip of bladder is tubularized, and the triangles of de- nuded muscle are mobilized laterally to provide coverage of the neourethra. If prior urodynamic evaluation has demon- strated inadequate bladder capacity, augmentation cystoplasty with a bowel segment may be performed at this setting. SINGLE-STAGE RECONSTRUCTION: COMPLETE PRIMARY REPAIR OF EXSTROPHY Recently, Mitchell and Grady minimized the number of re- quired operations by combining bladder closure with epispa- dias repair at birth in a technique known as complete primary repair.60 Major potential benefits of this approach include the earlier creation of bladder outlet resistance, theoretically lead- ing to normal cycling and improved bladder capacity and functionality as the patient grows. Major principles of CPRE include total penile disassembly and division of the intersym- physeal band, which enables posterior positioning of the 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- 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 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- der plate or after reconstructive efforts have been unsuccessful and is discussed in Chapter 118. OUTCOMES AND COMPLICATIONS The most devastating complication of bladder closure is dehis- cence. Major contributing factors include wound infection, abdominal distension, bladder prolapse, and loss of ureteral and/or suprapubic catheters within 6 days of closure.61 Uri- nary diversion, reclosure of the bladder as a urethral tube for later augmentation, or delayed repair of the bladder may be performed. If not performed in the initial setting, pelvic osteotomy is frequently necessary for successful reclosure. Urinary incontinence remains a significant problem for up to 30% of bladder exstrophy patients. In the case of bladder neck incompetence, injectable bulking agents, bladder neck 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- formed. In cases where incontinence is secondary to insuffi- cient bladder capacity, augmentation cystoplasty remains the most viable treatment option. Following epispadias repair, the most common complica- tion is urethrocutaneous fistula, which ranges from 2% to 26% in modern series.51,54,62 The incidence of adenocarcinoma of the bladder in adults with bladder exstrophy has been estimated to be 250 times that of the normal population and is likely due to chronic inflam- mation, infection, and metaplasia of an exposed bladder plate.63 A series by Woodhouse and colleagues, however, re- cently documented an 800-fold risk in the incidence of bladder A B C D FIGURE 120-13 Complete penile disassembly technique. A, The corpo- ral bodies and the hemiglans are separated. B, The urethra is tubularized and moved ventrally. C, The corpora are reapproximated dorsally. D, Glans closure is performed distally to complete the repair. (Modified from Mitchell ME, Bagli DK: Complete penile disassembly for epispadias repair: The Mitchell technique. J Urol 1996;155:300.) 1523CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 10. ------------------------------------------------------------------------------------------------------------------------------------------------ malignancyamong thosewith ahistoryofbladderexstrophyby age 40.64 Thedevelopmentofadenocarcinomaandtransitional cell carcinoma of the bladder is also a potential risk in those patients who have undergone augmentation cystoplasty.65,66 Fertility in patients with bladder exstrophy and epispadias was studied by Shapiro and colleagues,14 who surveyed 2500 patients. Among these, 38 men had successfully fathered chil- dren and 131 women had given birth. Diminished fertility rates among males may be secondary to retrograde ejaculation, though libido and erectile function appear to be normal according to a report by Woodhouse and colleagues.67 Female patients face a significant risk of uterine prolapse. CONCLUSION Contemporary reconstructive techniques for the repair of bladder exstrophy have resulted in acceptable function and cosmesis for the majority of patients with classic bladder exstrophy. Overall continence rates range from 70% to 80%. Bladder augmentation is preferred in patients without ade- quate bladder capacity, and bladder neck closure with creation of a continent catheterizable stoma may be performed when other continence procedures have failed. Cloacal Exstrophy Cloacal exstrophy is a rare condition occurring in 1 of 200,000 to 400,000 live births68 and comprises the most severe defor- mation along the EEC spectrum, which includes both epispa- dias and classic bladder exstrophy. Cloacal exstrophy is also referred to as the OEIS complex (omphalocele, exstrophy, im- perforate anus, and spinal defect) when other malformations of the urogenital, gastrointestinal, skeletal, and neurospinal axis are present. Although first described by Littre in 1709, historic survival rates were dismal secondary to sepsis or fluid, electrolyte, and nutritional derangements from short gut syndrome or Bladder Suspensory sutures Urethra Lateral view A B FIGURE 120-14 Young-Dees- Leadbetter procedure for bladder exstrophy repair. A, The ureters are appropriately reimplanted to avoid reflux. Triangular areas at the blad- der base are then denuded, and the remaining muscle is tubularized over a catheter. This serves to lengthen the urethra and provides sufficient pressure to encourage the development of improved blad- der capacity without causing ure- thral obstruction. B, The bladder is reclosed, and the bladder neck is further supported by sutures, which secure it to the pubis anteriorly. 1524 PART VIII GENITOURINARY DISORDERS
  • 11. intestinal obstruction.69 The first successful repair was reported in 1960 by Rickham, who recommended staged sur- geries for reconstruction.70 Advances in neonatal care and sur- gical technique have resulted in present-day survival rates that exceed 90%, and principle goals of treatment are now directed toward improving quality of life in these patients.68,71–75 EMBRYOLOGY AND GENETICS The underlying defect in cloacal exstrophy is thought to be re- lated to abnormal development and premature rupture of the cloacal membrane, as described earlier in the bladder exstro- phy section. In the setting of cloacal exstrophy, it has been pos- tulated that membrane rupture occurs within the first 8 weeks of gestation. Confirmation of this theory is difficult, however, given no embryologic stage similar to cloacal exstrophy exists in normal development.76 Disruption of the cloacal membrane, as the principle underlying abnormality, has been supported by surgically induced exstrophy in animal models.19,77 The pre- vailing developmental theories are further clouded by several 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, which would prevent normal midline fusion of the hindgut, bladder plate, genital tubercles, and mu¨llerian ducts, thus resulting in the typical anatomic presentation of two open bladder halves separated by a strip of exstrophied cecum, hemiphallic halves with a widely separated pubic diastasis, an underdeveloped and blind-ending distal hindgut with imperforate anus, and an omphalocele of varying size (Fig. 120-18). Bladder Corpus spongiosum Perineal membrane Incision through perineal membrane Plane of Cross section Correction of Exstrophy Cross section Anus Sup. Transverse perineal muscle Prostate Urethra Symphysis FIGURE 120-15 Pelvic view of male exstrophy repair as described by Grady and Mitchell. Aggressive dissection along each side of the urethra and division of the intersymphyseal band allow posterior positioning of the bladder in the pelvis. (Modified from Grady RW, Mitchell ME: Complete primary repair of exstrophy. J Urol 1999;162:1416.) BA FIGURE 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 Urol 1999;162:1417.) 1525CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 12. No single environmental exposure or consistent genetic de- fect in the etiology of cloacal exstrophy has yet been identified. Thauvin-Robinet and colleagues recently identified an unbal- anced translocation betweenchromosomes9q and Yq,andother studies have implicated mutations in homeobox genes such as HLXB9 and HOX, which are involved in the development of embryonic mesoderm.80–82 Although there have been multi- ple reports of cloacal exstrophy among members of the same family,thesearegenerallyanecdotalandhaveinvolvedmultigen- erational relatives or nontwin siblings.83–85 Multipleinstances of affected monozygotic twins have been reported, however, which lends support to an underlying genetic cause.76,86–88 ASSOCIATED ANOMALIES Unlike classic bladder exstrophy, cloacal exstrophy is typically associatedwithavarietyofotheranatomicdefects(Table120-1). 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- dure.92,93 Furthermore, the phenomenon may occur even in the presence of normal bowel length, implicating an inher- ent absorptive abnormality of the intestine.71,72,90 GENITOURINARY Abnormalities of the upper urinary tract have been reported in 41% to 66% of cases.72,89 Unilateral renal agenesis, pelvic kid- ney, and/or hydronephrosis were observed in up to 33% in Diamond’s 1990 series.89 Less commonly reported findings include horseshoe kidney, fusion anomalies, and ureteral ab- normalities.72,89,90 Complete separation or even absence of the phallic/clitoral halves may be observed, and the scro- tum/labia are widely separated. Male infants frequently have undescended testes with associated bilateral inguinal hernias, whereas failure of mu¨llerian duct fusion in females results in varying degrees of uterine and vaginal duplication anomalies in the majority of patients.72,89 FIGURE 120-17 At completion of complete primary closure, placement of the bladder and urethral units deeper within the pelvis along with ven- tral transposition of the urethra may result in a hypospadiac meatus, which can later be reconstructed with formal urethroplasty. FIGURE 120-18 Typical presentation of cloacal exstrophy in a male in- fant. O, omphalocele; hB, hemibladder; Ce, exstrophied cecum; hP, hemi- phallus; hS, hemiscrotum; I, prolapsed ileal segment. 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 foot Other lower limb (absence, shortening) Hip subluxation 1526 PART VIII GENITOURINARY DISORDERS
  • 13. CENTRAL NERVOUS SYSTEM Some form of spinal dysraphism including tethered cord, myelomeningocele, or lipomyelomeningocele is present in nearly all patients, with recent reports ranging from 64% to 100%.74,84,91,94 Neurologic impairment is variable and may affect bladder function, urinary continence, lower extremity movement, and erectile function. Detailed postmortem micro- dissection studies have demonstrated both aberrant origin and vascular supply of the pelvic autonomic nerves,95 and these nerves are at additional risk of iatrogenic injury during oper- ative repair. Other reported abnormalities include periventri- cular leukomalacia, hydrocephalus, hypoplastic cerebellum, and Chiari malformation.84 SKELETAL Abnormalities of the spine, pelvis, and limbs have all been ob- served in the setting of cloacal exstrophy. Spinal anomalies, ex- cluding myelodysplasia, have been reported in 22% to 60% and consist mainly of absent or extra vertebrae, scoliosis, and kyphosis.90,96,97 The pelvic deformity is similar to that of classic bladder exstrophy but typically more severe with sig- nificant widening of the pubic diastasis, external angling of the posterior and anterior segments, and external rotation and ab- duction of the iliac wings.70 A review by Jain and Weaver found a 17% to 26% incidence of associated lower limb abnor- malities.98 Certain limb malformations like club foot and equi- novarus deformities can be seen in association with myelomeningocele, which often accompanies cloacal exstro- phy; however, a variety of true limb malformations including hypoplasia, absence, split foot, and ectopic or additional digits have also been observed.98 PRENATAL DIAGNOSIS Early prenatal diagnosis allows time for thorough parental counseling and allows for consideration of pregnancy termi- nation. Prenatal diagnosis was first reported by Meizner and Bar-Ziv in 1985,99 and since then, several authors have pro- posed criteria for the prenatal diagnosis of cloacal exstrophy. Principle findings include failure to visualize the urinary bladder along with a large midline anterior abdominal wall defect and/or lumbosacral myelomeningocele.87,100–102 The prolapsed ileal segment, which may appear as an “elephant trunk–like” mass on US, has also been reported as a path- ognomic finding.103 From a review of 22 cases, Austin and colleagues102 developed a list of major and minor criteria for prenatal US diagnosis on the basis of the frequency with which abnormalities were observed. Major criteria were those seen in greater than 50% of cases and included nonvisualiza- tion of the bladder (91%); a large, midline, infraumbilical anterior abdominal wall defect or cystic anterior abdominal wall structure (82%); omphalocele (77%); and myelomenin- gocele (68%). Minor criteria were observed in less than 50% and consisted of lower extremity defects (23%), renal anom- alies (23%), ascites (41%), widened pubic arches (18%), nar- row thorax (9%), hydrocephalus (9%), and single umbilical artery (9%).102 SURGICAL REPAIR Immediate Postnatal Management After delivery and stabilization of the newborn, exposed or- gans and mucosal surfaces including the omphalocele, blad- der, intestine, and myelomeningocele should be protected by enclosing the infant’s lower torso in a bowel bag or by first moistening surfaces with saline and covering with sterile plas- tic wrapping.90 Urologic examination should attempt to note genetic sex and size of hemibladder plates. Baseline renal function, electrolyte, and hematologic status should be deter- mined. Karyotyping can be performed if gender has not been 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. Consultation should also be made to general surgery, neuro- surgery, and orthopedics for operative planning. Once the ini- tial evaluation has been completed, discussion may be had with the parents regarding gender assignment, surgical recon- struction, potential functional deficits, and overall expected quality of life. Principles of Repair The surgical management of cloacal exstrophy is typically un- dertaken in the newborn period (48 to 72 hours) as a com- bined effort between pediatric surgery and urology. In the setting of associated spinal dysraphism, neurosurgical consul- tation and closure should be undertaken as soon as the infant is medically stable. Early operation minimizes bacterial colo- nization of exposed viscera and may decrease the need for pel- 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,106 and most recently by Mitchell and Plaire.75 It is generally agreed that an individualized approach toward reconstruc- tion, whether in a single-staged or multistaged procedure, re- sults in the best long-term outcomes.107 The main goals of reconstruction include secure abdominal wall and bladder closure, preservation of renal function, prevention of short gut syndrome, creation of functionally and cosmetically ac- ceptable genitalia, and attainment of urinary and fecal continence.73,94 Although various operative algorithms have been published, all approaches begin with initial separation of the intervening cecal plate from the two bladder halves, closure of the ompha- locele, and hindgut preservation (Fig. 120-19).68,71,72,75,107 In the past, the bowel was initially diverted through the creation of loop or end-ileostomies, and the hindgut segment was uni- formly discarded. This practice has since fallen out of favor in order to maximize the absorptive capabilities of the intestinal tract.72,74 Currently, after tubularization of the exstrophied ce- cum, it is recommended that the hindgut segment be brought out as an end-colostomy.92 In the rare instance when the hind- gut remnant is not used, it may be left as a mucous fistula for use in future urologic or vaginal reconstruction.90 The omphalocele is reduced to assist abdominal wall clo- sure; however, in cases of large omphaloceles, complete initial reduction may not be possible. In this setting, a silo device 1527CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY
  • 14. may be used or the omphalocele may be allowed to re- epithelialize, converting it to a ventral hernia, which may be repaired at a later time (Fig. 120-20).94 The hemibladders are dissected and then reapproximated in the midline. In infants with few other associated malforma- tions and who are medically stable, complete closure of the ab- dominal wall, bladder, and phallic halves may be undertaken at this point in a single-stage procedure with or without pelvic osteotomy. If this is not possible at the initial setting, the two bladder halves can first be joined in the midline, recapitulating the appearance of classic bladder exstrophy, which can then be repaired in a staged fashion as described in the previous section. Genital reconstruction consists of bringing the phallic halves together to create an appearance congruent with the assigned gender. In the male infant with cloacal exstrophy, the phallic halves are characteristically diminutive, widely separated, and asymmetric. Historically, genetically male in- fants were routinely assigned to female gender at the time of initial closure, undergoing orchiectomy and feminizing geni- toplasty.108 Recent data regarding gender identity outcomes in gender-reassigned cloacal exstrophy patients has suggested an inherent preference toward male behaviors and sexual identi- ties in these patients.75,105,109 It remains a topic of continued study and debate. Gender reassignment has since been largely abandoned in the current management of cloacal exstrophy, though functional and aesthetic phallic reconstruction re- mains challenging. Vaginal reconstruction is necessary in fe- males and in gender-reassigned males and is accomplished through the use of bowel or skin grafts. Gastrointestinal reconstruction, in the form of a pull- through procedure, may be performed in select patients, some time after initial diversion and abdominal closure. The deci- sion is based on the potential for fecal continence and may be influenced by colonic length, ability to form solid stool, and the presence of anal stenosis versus imperforate anus. Like those with classic bladder exstrophy, these patients will also require the creation of antireflux and urinary conti- nence mechanisms. The presence of myelodysplasia in these patients usually necessitates augmentation cystoplasty with a bowel segment and intermittent catheterization in order to achieve continence. Continence procedures include creation 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 be challenging, and the involvement of the pediatric pain service is recommended. Finally, the importance of limiting abdomi- nal distension to ensure successful abdominal closure and CA B Ileum Colon FIGURE 120-19 Repair of cloacal exstrophy. A and B, The bowel and bladder mucosa are separated, and the ileocecal junction is tubularized and brought out as an end-colostomy. The bladder halves are turned in, as in a complete exstrophy repair, with approximation of the pubic rami. C, Alternatively, the bladder halves are approximated in the midline and left open for staged repair if tubularization is not possible. The omphalocele is also closed. FIGURE 120-20 If initial closure of the omphalocele is not possible, it may be allowed to epithelialize, converting the omphalocele to a ventral hernia, which can be repaired at a later time. 1528 PART VIII GENITOURINARY DISORDERS
  • 15. adequate drainage of both ureteral and bladder catheters cannot be understated.61,111,112 Following repair, close mon- itoring of the upper tracts by US is mandatory to observe for adequate renal growth and to detect evidence of obstruction or VUR, which has been reported in 50% to 60% of cloacal exstrophy patients after staged or complete primary repair.60,107 CONCLUSION For the past 20 years, survival among patients with cloacal exstrophy has exceeded 90%.68,72,74,105 Death is typically re- lated to complications related to extreme prematurity, renal agenesis, or other complex malformations that are incompat- ible with life. It is interesting to note that cardiovascular anom- alies are rarely observed in the setting of cloacal exstrophy. The various complications related to the management of patients with cloacal exstrophy are similar to those of patients with classic bladder exstrophy, as described in the previous section. Compared with those with classic exstrophy, however, cloacal exstrophy patients face additional challenges of achieving bowel and bladder continence secondary to the need for anal reconstruction and the associated defect of spinal dysraphism. It must be stressed that multiple operations are the rule, and these patients will likely face significant medical, psychologic, and social challenges throughout their lives. Advancements in medical and surgical management continue to improve func- tional and quality of life outcomes in these patients, but it is important that these individuals remain under the care of a multidisciplinary team of providers who can offer medical care, psychologic support, and lifelong follow-up. The complete reference list is available online at www. expertconsult.com. SUGGESTED READINGS Ebert AK, Reutter H, Ludwig M, Ro¨sch WH. The exstrophy-epispadias com- plex. Orphanet J Rare Dis 2009;4:23. Gearhart JP, Mathews R. The Exstrophy-Epispadias Complex: Research Con- cepts and Clinical Applications. New York: Kluwer Academic Publishers; 1999. Hernandez DJ, Purves T, Gearhart JP. Complications of surgical reconstruction of the exstrophy-epispadias complex. J Pediatr Urol 2008;4:460–466. Husmann DA. Surgery insight: Advantages and pitfalls of surgical techniques for the correction of bladder exstrophy. Nat Clin Pract Urol 2006;3: 95–100. Ludwig M, Ching B, Reutter H, Boyadjiev SA. Bladder exstrophy-epispadias complex. Birth Defects Res A Clin Mol Teratol 2009;85:509–522. 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: 244–249. Woo LL, Thomas JC, Brock JW. Cloacal exstrophy: A comprehensive review of an uncommon problem. J Pediatr Urol 2009 Oct; (Epub ahead of print). 1529CHAPTER 120 BLADDER AND CLOACAL EXSTROPHY

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