Pelvic floor magnetic resonance imaging after neonatal single stage reconstruction in male patients with classic bladder exstrophy

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 am 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 (I 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.