Andrew A. Stec

PELVIC FLOOR ANATOMY IN CLASSIC BLADDER EXSTROPHY USING 3-DIMENSIONAL COMPUTERIZED TOMOGRAPHY: INITIAL INSIGHTS

PURPOSE We present the pelvic floor anatomy of the major pelvic floor musculature in classic bladder exstrophy, including the levator ani, obturator internus and obturator externus. By improving our knowledge of pelvic floor anatomy we hope to understand better the relationship of the pelvic floor to the bony anatomy as well as the role of osteotomy in changing pelvic floor anatomy to enhance urinary control after surgery. MATERIALS AND METHODS 3-Dimensional computerized tomography was done in 6 boys and 1 girl, including 5 patients 2 days to 5 months old (mean age 7 months) undergoing primary closure and 2 who were 4 and 8 years old undergoing repeat closure. The pelvic floor musculature, including the levator ani, obturator internus and obturator externus, in these cases was compared to that in 26 age and sex matched controls. RESULTS The levator ani musculature encompasses a significantly wider area of 9.5 cm.2 in patients with classic bladder exstrophy than in controls. The anterior segment of the levator ani was shorter (1.2 cm.) and the posterior segment of the levator ani was longer (2.5 cm.) than in controls. The degree of divergence of the levator ani in classic exstrophy was significantly more outwardly rotated (38.8 degrees) than controls. In addition, the transverse diameter of the levator hiatus was 2-fold that in our control group and in that of published controls, while the length of the hiatus was 1.3-fold that in normal controls. There was also significant flattening, involving a 31.7 degree decrease in steepness between the right and left halves of the levator ani, of the puborectal sling in classic bladder exstrophy versus controls. Because of these findings, there is more anterior superior rotation in the pelvic floor in exstrophy cases. The obturator internus was more outwardly rotated (15.1 degrees) in exstrophy and the obturator externus also showed more outward rotation (16.9 degrees) than in controls. CONCLUSIONS This study provides better understanding of the pelvic floor anatomy in classic bladder exstrophy. Significant differences have been documented in the pelvic floor in classic bladder exstrophy cases and controls. Hopefully these differences may have a pivotal role in providing new insight into long-term issues, such as urinary and fecal incontinence, and pelvic organ prolapse, in classic bladder exstrophy.

Evaluation of the bony pelvis in classic bladder exstrophy by using 3D-CT: further insights☆

OBJECTIVES To provide a complete look at the bony pelvis in children with classic bladder exstrophy: dimensions, orientation, and relationships. METHODS Three-dimensional computed tomography was used in 6 boys and 1 girl, 5 of whom underwent primary closure and 2 who underwent reclosure at 4 and 8 months. These exstrophy pelves (intrapelvic angles and osseous dimensions) were compared with 26 age and sex-matched controls. RESULTS The iliac wing angle was 11.4 degrees larger in the classic bladder exstrophy cases. The sacroiliac joint angle was 9.9 degrees more externally rotated in the exstrophy cases. The pelvis was rotated 14.7 degrees in the superoinferior plane in the exstrophy cases. The mean pubic diastasis was 4.2 cm (0.6 cm in controls). The inter-triradiate distance in the patients with classic bladder exstrophy averaged 6.0 cm (4.2 cm in controls). CONCLUSIONS These new findings provide a better understanding of the bony pelvis, especially its posterior portion, in patients with classic bladder exstrophy. The results of this study revealed the orientation of the sacroiliac joints to be more externally oriented than previously thought and the pelvis to be rotated inferiorly, a previously unknown observation. Both of these factors will be important in the planning of newer osteotomies and pelvic reconstruction.

Complete Primary Repair of Bladder Exstrophy: A Single Institution Referral Experience

PURPOSE The reasons for referral and treatment strategies in patients who underwent complete primary repair of bladder exstrophy elsewhere in the newborn period were evaluated. MATERIALS AND METHODS An institutionally approved database identified patients who underwent complete primary repair of exstrophy and were subsequently referred for continued care. RESULTS A total of 10 females and 55 males were referred for treatment between 1996 and 2010. Six females and 23 males were referred for complications following initial complete primary repair of exstrophy. Female complications included dehiscence (3 patients), prolapse (2) and stricture (1). Male complications included dehiscence (10 patients), prolapse (9), pubic separation (1) and stricture (3). Nine males had posterior urethral loss and 13 had major penile soft tissue injuries. Grade V vesicoureteral reflux and severe hydronephrosis were seen in the 4 patients with urethral strictures. Patients with dehiscence or prolapse underwent successful reclosure with osteotomy. Cases with posterior urethral loss or strictures were repaired with grafts. Four females and 32 males were referred for incontinence. Nine of these patients had poor bladder capacity, of whom 5 underwent bladder augmentation with continent stoma and 4 are awaiting further bladder growth. A total of 27 patients underwent bladder neck repair, with 15 (56%) subsequently continent, 5 (19%) daytime continent with nocturnal incontinence and 7 (26%) continuously incontinent. At initial closure osteotomy had been performed in all patients who were continent following bladder neck reconstruction and in 4 of 5 who were daytime continent. CONCLUSIONS Complications of complete primary repair of bladder exstrophy can result in undesired upper urinary tract changes and penile soft tissue loss. Surgical reconstruction of such complications and acceptable continence are attainable in select cases.

The role of osteotomy in surgical repair of bladder exstrophy

Classic bladder exstrophy (CBE) patients are born with a pubic diastasis that increases steadily with age from a mean value of 4 cm at birth to a mean of 8 cm at age 10, compared with a mean normal width of the pubic symphysis of 0.6 cm at all ages. The width of the sacrum and length of the posterior (iliac) segment of the pelvis in CBE patients are normal; however, the anterior (ischiopubic) segment of the pelvis is a mean 30% shorter and both the anterior and posterior segments are externally rotated compared to controls. The main role of osteotomy in treatment of CBE appears to be to relax tension on the bladder and repaired abdominal wall during wound-healing. Anterior innominate osteotomy with optional posterior vertical iliac osteotomy presents several advantages over the prior conventional technique of posterior iliac osteotomy. These include (a) less intraoperative blood loss, (b) better apposition and mobility of the pubic rami at the time of closure, (c) allowance for placement of an external fixator under direct vision, (d) allowance for secure external fixation in children over 6 months old, and (e) no requirement to turn the patient during the operation.

Fetal bony pelvis in the bladder exstrophy complex: normal potential for growth?

OBJECTIVES To provide the first look at the bony histologic features of fetuses with the exstrophy complex, specifically evaluating the endochondral ossification, stage of development, and microscopic potential for normal growth. METHODS Three fetuses between 28 and 30 weeks of gestation, one with classic bladder exstrophy, one with cloacal exstrophy, and one control, were obtained from France. The bony pelves were dissected and preserved in formalin, and multiple representative sections were sliced from all pelvic areas: pubis, ischium, ilium, and sacrum. These slices were sequentially processed as slides, stained with hematoxylin-eosin, and evaluated microscopically for histologic changes, developmental stage, and degree of endochondral ossification. RESULTS All slides from the three specimens showed cartilage analogue with endochondral ossification. Histologically the exstrophy specimens were identical to the control and appeared completely normal; bone development was occurring at an expected rate with the potential for continued normal growth. CONCLUSIONS These new findings illustrate that fetal bone in the exstrophy complex displays normal microscopic growth patterns and unhindered endochondral ossification at 28 weeks of gestation, well beyond the embryologic period. With no evident microscopic bony defect, the gross bony anomalies in exstrophy should be surgically correctable, leading us to conclude that early reapproximation of the physiologic shape of the pelvis could lead to more normal gross bone growth, decreased shortage of bone, and a more appropriate distribution of the mechanical and developmental forces on a closed, normally functioning pelvic ring.

Evaluation of Pelvic Floor Muscular Redistribution After Primary Closure of Classic Bladder Exstrophy by 3-Dimensional Magnetic Resonance Imaging

PURPOSE We used 3-dimensional magnetic resonance imaging reconstruction to generate models of the pelvic floor musculature in classic bladder exstrophy, allowing for statistical analysis of changes seen in the anatomy after primary closure. MATERIALS AND METHODS Patients with classic bladder exstrophy underwent pelvic magnetic resonance imaging before and after primary closure. Contours of the levator ani were mapped and measured in 3-dimensional space. In addition, 2-dimensional angles and measurements were used to make a quantitative and qualitative analysis of the pelvic floor before and after closure. RESULTS A total of 19 cases of classic bladder exstrophy were included in the study, with 12 closed as newborns without osteotomy and 7 closed later with osteotomy. In both groups the pre-closure exstrophy pelvic floor in the axial plane was box-like and after closure it had a more inward rotation. The steepness and angulation of the levator ani muscle remained relatively unchanged in both groups. The levator ani muscle group, with and without osteotomy, was redistributed into the anterior compartment of the pelvis after closure. Postoperatively a successfully closed exstrophy had the bladder positioned deeply within the pelvis. After closure the levator ani muscle regained the expected smooth contoured shape. CONCLUSIONS Primary closure of bladder exstrophy 1) reshapes the pelvis from a box-like configuration to a more inwardly rotated hammock, 2) redistributes a significant portion of the levator ani muscle into the anterior compartment and 3) facilitates a smooth uniform contouring to the pelvic floor. Closing the bony pelvic ring by pubic reapproximation in the newborn or by osteotomy in an infant produces similar changes in the pelvic floor.

Delayed Primary Repair of Bladder Exstrophy: Ultimate Effect on Growth

PURPOSE Late referrals or unsuitable bladder templates often require delayed primary repair of bladder exstrophy. We investigated longitudinal bladder growth rates and eventual outcomes following this approach. MATERIALS AND METHODS After institutional review board approval, we reviewed the medical records of patients with classic bladder exstrophy who underwent neonatal or delayed (more than 30 days) primary closure at our institution between 1970 and 2006. Clinical characteristics and annual cystographic bladder capacity before the continence procedure were compared. Failed primary exstrophy repairs were excluded. RESULTS A total of 33 patients with available bladder capacity measurements underwent delayed exstrophy closure due to small bladder template in 18 (88% male) and late referral in 15 (80% male) at respective median ages of 305 days (range 86 to 981) and 172 days (31 to 676). They were compared to 82 patients (71% male) undergoing neonatal closure at a median of 2 days of life (range 0 to 27). Pelvic osteotomy was performed in 32 of 33 delayed closures. Longitudinal analysis of the bladder capacities demonstrated that, compared to neonatally closed cases, bladder capacities were on average 36 ml smaller in those with delayed repair due to small templates (p = 0.01) and 29 ml smaller in those with late referrals (p = 0.13). However, the rate of bladder growth did not differ significantly among the 3 groups. CONCLUSIONS Delayed primary repair of exstrophy does not compromise the rate of bladder growth. However, children born with smaller templates will have overall smaller capacities and are less likely to undergo bladder neck reconstruction.

Embryology and bony and pelvic floor anatomy in the bladder exstrophy-epispadias complex.

The exstrophy-epispadias complex is a complex congenital anomaly that, although rare, remains the largest genitourinary birth defect that is surgically correctable. The primary defect in exstrophy is a derangement in midline developmental that presents with a spectrum of severity. In its mildest form, epispadias, the dorsal urethral unit is not fused and has failed to form into a tube. Next, patients with classic bladder exstrophy present with a bladder and urethra open and continuous with the abdominal wall; also associated is a failure of the abdominal muscles, pelvic ring, and pelvic floor musculature to fuse in the midline. Cloacal exstrophy, the most severe variant, includes exstrophied hindgut tube and a more severe degree of concomitant congenital derangements of musculoskeletal, genitourinary, gastrointestinal, and neurological systems. The embryology of the exstrophy-epispadias complex has been long studied, yet debate still exists over the specific origins of the anomaly. This article covers the embryologic theories of this congenital defect and the subsequent bony pelvic and pelvic floor muscular defects characteristic of exstrophy. Primarily, the anatomic focus will be on classic bladder exstrophy because it is the most common and well studied to date.

Is Pelvic Osteotomy Associated with Lower Risk of Pelvic Organ Prolapse in Postpubertal Females with Classic Bladder Exstrophy

PURPOSE Bladder exstrophy is a major congenital anomaly involving defects in the genitourinary tract and pelvic musculoskeletal system. It appears intuitive that closure of the pelvic ring using osteotomy would be associated with a decreased risk of pelvic organ prolapse. We investigated whether osteotomy is associated with a decreased risk of pelvic organ prolapse in females with classic bladder exstrophy. MATERIALS AND METHODS We searched our institutional review board approved exstrophy database of 1,078 patients and identified 335 females. We excluded patients who were younger than 13 years, had cloacal exstrophy or epispadias and did not have postpubertal imaging for measurement of pubic diastasis available. Our final study population consisted of 67 females. Univariate analysis was performed using t test or rank sum test for continuous variables and chi-square test for categorical variables. Logistic regression was used for multivariate analysis. RESULTS Median patient age was 23 years (range 13 to 60). A total of 20 patients (29.9%) had pelvic organ prolapse at a median age of 20 years (range 11 to 43). Of the 67 patients 25 (37.3%) had undergone osteotomy at a median age of 6 months (range birth to 10 years). Seven patients had at least 1 pregnancy (range 1 to 3), and 24 patients had undergone vaginoplasty. On univariate analysis only diastasis was associated with pelvic organ prolapse, with smaller diastasis associated with a decreased risk of prolapse. On multivariate analysis including diastasis and osteotomy only diastasis was statistically significant. CONCLUSIONS Osteotomy does not decrease the risk of pelvic organ prolapse in patients with classic bladder exstrophy. Rather, degree of diastasis is significantly associated with pelvic organ prolapse.

Delayed primary closure of bladder exstrophy: immediate postoperative management leading to successful outcomes.

OBJECTIVE To present the critical features of our postoperative plan for children undergoing delayed primary bladder closure because appropriate postoperative management is crucial to successful exstrophy repair. METHODS Using an institutionally approved database, patients with bladder exstrophy whose primary bladder closure was performed at least 1 month after birth were identified. All aspects of the postoperative management were reviewed. RESULTS A total of 20 patients (18 boys) were identified: 19 with classic bladder extrosphy and 1 with an exstrophy variant. The patients underwent closure at a mean age of 9.9 months. All patients underwent pelvic osteotomy and immobilization for an average of 34.8 days. Analgesia was administered by way of a tunneled epidural catheter in 90% of patients for an average of 18.8 days, and 12 patients (60%) required adjunct intravenous analgesia. Bilateral ureteral catheters and suprapubic tubes were used in all patients. Total parenteral nutrition was administered to 10 (83%) of 12 patients who underwent closure after 2000. All patients received preoperative antibiotics and 2 weeks of postoperative intravenous antibiotics that was followed by oral prophylaxis. The mean hospital stay was 6.3 weeks. With an average follow-up of 7.4 years, delayed closure was 100% successful. CONCLUSION Successful delayed primary closure of bladder exstrophy requires a multidisciplinary approach. The keys to success include osteotomy, pelvic immobilization, analgesia, nutritional support, maximal bladder drainage, and infection prophylaxis.