Transurethral autologous myoblast injection for treatment of urinary incontinence in children with classic bladder exstrophy

Purpose: The application of autologous myoblasts is an area of active research that may represent an improved alternative for the treatment of urinary incontinence. In this study we investigated the effectiveness of autologous myoblast injection for the treatment of urinary incontinence in children with classic bladder exstrophy. Materials and Methods: Seven boys and 1 girl with persistent urinary incontinence were entered in the study. All children had undergone staged bladder repair and bladder neck reconstruction, and 5 patients had received 1 to 3 transurethral injections of bulking agent. Autologous myoblasts were isolated from abdominal muscle biopsy and cultured before endourethral injection. After the procedure patients underwent pelvic floor electrical stimulation and continued pelvic floor exercises that had been started at least 1 year before injection. The clinical outcomes (based on a 24-hour voiding diary), and cystometric and urodynamic studies were evaluated. Followup ranged from 12 to 18 months (average 15.3). Results: There was a significant, time dependent improvement in urinary continence. At final followup all 7 boys (88% of patients) were socially dry (daytime dryness more than 3 hours), including 3 (38%) who were completely dry. Urodynamic studies revealed an increase in mean bladder capacity (p < 0.001), detrusor leak point pressure (p < 0.001) and average maximum urinary flow (p < 0.01). All 7 boys (vs only 2 patients preoperatively) achieved normal voiding with demonstrable voiding detrusor contraction in the presence of a compliant stable bladder (p < 0.05). Conclusions: Our results suggest that transurethral autologous myoblast injection is a valid option for the treatment of structural urinary incontinence in children with classic bladder exstrophy. However, favorable preoperative urodynamic profiles and postoperative pelvic floor electrical stimulation may have contributed to the outcome in this series.