Muscle-derived cell injection to treat anal incontinence due to obstetric trauma: pilot study with 1 year follow-up

Objective: To treat anal incontinence due to obstetric external anal sphincter disruption via injection of autologous myoblast cells. Design: Observational pilot study. Setting: University hospital and district hospital Patients: 10 women suffering from anal incontinence due to obstetric anal sphincter injury, refractory to conventional non-surgical therapy. Interventions: Autologous myoblasts were cultured from a pectoralis muscle biopsy, harvested, and injected into the external anal sphincter defect using direct ultrasound guidance. Main outcome measures: Wexner incontinence score, anal squeeze pressures, and quality of life 12 months after injection. Safety and technical feasibility. Results: The procedure was well tolerated and no adverse events were observed. At 12 months the Wexner incontince score had decreased by a mean of 13.7 units (95% CI, -16.3 to -11.2), anal squeeze pressures were unchanged, and overall quality of life scores improved by a median of 30 points (95% CI, 25 to 42). Anal squeeze pressures did rise significantly at 1 month and 6 months post-injection (p=0.03). Conclusions: Injection of autologous myoblasts is safe, well tolerated, and significantly improves symptoms of anal incontinence due to obstetric anal sphincter trauma.