Obstetric anal sphincter injuries (OASIS) and secondary repair (overlapping sphincteroplasty) in a colorectal unit: case series.

Background: Obstetric anal sphincter injuries (OASIS) represent a significant complication of childbirth, with global variation in incidence. Although overlapping sphincteroplasty is widely regarded as the gold-standard surgical treatment, managing delayed or inadequately repaired cases remains challenging. Prevention through improved obstetric practices and early recognition of injuries is considered the optimal approach to minimizing the burden of OASIS. Objectives: This case series aimed to evaluate the clinical outcomes of overlapping sphincteroplasty in patients presenting with delayed or missed OASIS. Methods: The study included 12 female patients treated at a single institution over 4 years. All participants had a history of instrumental delivery and episiotomy, with symptoms of incontinence. Preoperative and postoperative assessments were performed using the Wexner scoring system. Overlapping sphincteroplasty was performed in all cases. Follow-up was conducted at 3 months, 6 months, 1 year, and 2 years to evaluate symptomatic improvement and patient satisfaction. Results: The mean age of the participants was 38 years (range: 26-53 years). All patients experienced symptomatic improvement following surgery, with significant reductions in the Wexner scores and high patient satisfaction rates. The mean duration of symptoms before surgery was 14 months (3-36 months). Complications included a 25% rate of superficial wound breakdown and one case of deep wound breakdown requiring secondary repair. Despite this, no incontinence symptoms were reported at the 2-year follow-up. Conclusions: Delayed overlapping sphincteroplasty is an effective surgical approach for treating missed or inadequately repaired OASIS, offering satisfactory outcomes. However, prevention through improved obstetric practices remains an optimal strategy.