Interposing Rectus and Gracilis Muscle Flaps For Pelvic Reconstruction in Bladder Exstrophy After Bladder Neck Closure

BACKGROUND: The exstrophy-epispadias complex is a spectrum of ventral wall malformations including classic bladder exstrophy (CBE) and cloacal exstrophy (CE). Patients undergo multiple soft-tissues procedures to achieve urinary continence. If unsuccessful bladder neck closure (BNC) is performed, muscle flaps may be used to reinforce BNC or afterwards for fistula reconstruction. In this study, patients reconstructed using a rectus abdominis or gracilis muscle flap were reviewed. METHODS: A retrospective cohort study of exstrophy-epispadias complex patients who underwent BNC and had a muscle fap was performed. Indication for flap use, surgical technique, risks for BNC failure including mucosal violations (MVs) were reviewed. MVs were prior bladder mucosa manipulation for exstrophy closure, repeat closure(s) and bladder neck reconstruction. Success was defined as BNC without fistula development. RESULTS: Thirty-four patients underwent reconstruction. Indications included during BNC (n=13), fistula closure after BNC (n=17), following BNC during open cystolithotomy (n=1) or fistula closure after open cystolithotomy (n=3). A vesicourethral fistula developed most frequently in CBE (88.9%) and vesicoperineal fistula in CE (87.5%). Thirty-three rectus flaps and 3 gracilis flap were used with success achieved in 97.1% and 66.7%, respectively. All 34 patients achieved success and 2 CE patients required a second flap. CONCLUSION: The rectus flap is preferred as it covers the antero-inferior bladder and pelvic floor to prevent urethral, cutaneous, and perineal fistula formation. The gracilis flap only reaches the pelvic floor to prevent urethral and perineal fistula development. Increased MVs, increase the risk of fistula formation and may influence the need for prophylactic flaps.