Pelvic Floor Magnetic Resonance Imaging after Neonatal Single Stage Reconstruction in Male Patients With Classic Bladder Exstrophy
Abstract
Purpose:
We evaluate a magnetic resonance imaging (MRI) protocol used to study the pelvic floor anatomy in male patients following neonatal single stage complete bladder exstrophy and epispadias repair with osteotomies.
Materials and Methods:
From 1996 to 2002, 9 males underwent surgical correction of bladder exstrophy and epispadias with osteotomies within 1 to 12 days of birth. Pelvic floor MRI was conducted comparing this group to 5 aged matched male patients with no pelvic anatomical abnormality who underwent MRI for other illness. We compared various measurement of pelvic musculature by unpaired Wilcoxon test.
Results:
Median followup was 3 years (range 0.5 to 5.3). All surgical procedures succeeded in closure of abdominal wall and genitalia defects. MRI data showed that in the exstrophy group symphyseal distance was significantly wider than that in controls (median 3.8 vs 1.1 cm). In addition, the levator ani fibers diverted more laterally (42 vs 22 degrees), the pelvic floor in coronal view was more flat (103 vs 80 degrees) and the anus was more anteriorly displaced (2.8 vs 4.4 cm). We also documented shorter anterior corporeal bodies in the exstrophy group (1 vs 2 cm). No statistical difference between the 2 groups was found in the dimensions of the levator and obturator muscles, sagittal angle of the pelvic floor, and the dimensions and angle of the posterior corporal bodies. Two patients achieved some degree of continence around the age of 4 years. They had the shortest symphyseal distance and sharpest angle of levator ani fiber divergence, and the bladder neck was more deeply located in the pelvic.
Conclusions:
We applied novel MRI parameters to the pelvic floor anatomy providing a new quantifiable approach. Our protocol is feasible and reproducible, allowing for future comparison of the impact of different surgical modalities, and correlation between anatomical findings and continence.
References
- 1 :
Bladder anomalies, exstrophy, and epispadias . In: Clinical Pediatric Urology. Edited by . London: Martin Dontz2002: 859. chapt. 27. Google Scholar - 2 : Penile length in adulthood after exstrophy reconstruction. J Urol1997; 157: 999. Link, Google Scholar
- 3 : Evaluation of the bony pelvis in classic bladder exstrophy by using 3D-CT: further insights. Urology2001; 58: 1030. Google Scholar
- 4 : Pelvic floor anatomy in classic bladder exstrophy using 3-dimensional computerized tomography: initial insights. J Urol2001; 166: 1444. Link, Google Scholar
- 5 : The pelvis of fetuses in the exstrophy complex. J Pediatr Orthop1997; 17: 402. Google Scholar
- 6 : Osteotomy and distraction of the anterior segment of the pelvic ring in epispadias repair: case report. J Pediatr Orthop1999; 19: 536. Google Scholar
- 7 : The role of magnetic resonance imaging in the preoperative assessment of anorectal anomalies. Pediatr Surg Int1998; 14: 71. Google Scholar
- 8 : MRI evaluation of the levator ani muscle: anatomic correlations and practical applications. Surg Radiol Anat1991; 13: 129. Google Scholar
- 9 : Use of MRI in evaluation of anorectal anomalies. J Pediatr Surg1990; 25: 817. Google Scholar
- 10 : The anorectal sphincter after rectal pull-through surgery for anorectal anomalies: MRI evaluation. Pediatr Radiol1989; 19: 179. Google Scholar
- 11 : Bladder exstrophy: staged reconstruction. Curr Opin Urol1999; 9: 499. Google Scholar
- 12 : Complete primary repair of exstrophy. Surgical technique. Urol Clin North Am2000; 27: 569. Google Scholar
- 13 : Urinary diversion in bladder exstrophy and incontinent epispadias: 25 years of experience. J Urol1995; 154: 1177. Link, Google Scholar
- 14 : Current status of tumor of the bowel following ureterosigmoidostomy: a review. J Urol1990; 144: 607. Link, Google Scholar
- 15 : Carcinoma of the colon after ureterosigmoidostomy and trigonosigmoidostomy for exstrophy of the bladder. Int Urol Nephrol1993; 25: 339. Google Scholar
- 16 : A population based analysis of continence outcomes and bladder exstrophy. J Urol2001; 165: 2418. Link, Google Scholar
- 17 : Combined bladder neck reconstruction and epispadias repair for exstrophy-epispadias complex. J Urol2001; 165: 2425. Link, Google Scholar
- 18 : Newborn exstrophy closure and epispadias repair. World J Urol1998; 16: 200. Google Scholar
- 19 : Complete primary repair of exstrophy. J Urol1999; 162: 1415. Link, Google Scholar
- 20 : Complete repair of bladder exstrophy in the newborn: complications and management. J Urol2001; 165: 2431. Link, Google Scholar
- 21 : The AP diameter of the pelvis: a new criterion for continence in the exstrophy complex?. Pediatr Radiol2001; 31: 640. Google Scholar
- 22 : Penile deformity in bladder exstrophy: correlation with closure of pelvic defect. J Pediatr Surg1991; 26: 201. Google Scholar
From the Division of Urology (SH, WF, JH, DJB, GAM, AEK) and Diagnostic Imaging (OK, AK), The Hospital for Sick Children, Toronto, Ontario, Canada
