How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial.

Objective: To compare two surgical techniques and two types of suture material for anal sphincter repair after childbirth-related injury.

Design: Factorial randomised controlled trial.

Setting: Tertiary referral maternity unit.

Population: Women with an anal sphincter injury sustained during childbirth.

Method: Women were randomised into four groups: overlap repair with polyglactin (Vicryl); end-to-end repair with polyglactin (Vicryl); overlap repair with polydioxanone (PDS); and end-to-end repair with PDS. All repairs were completed as a primary procedure by staff trained in both methods.

Main Outcome Measures: Suture-related morbidity at six weeks. Bowel symptoms at 3, 6 and 12 months. Anorectal physiology at three months. Quality of life scores at 3 and 12 months.

Results: One hundred and fifty women (1.5% of deliveries) were eligible and 112 (75%) were randomised. One hundred and three (92%) attended follow up visit at 6 weeks, 89 (80%) at 3 months, 79 (71%) at 6 months and 60 (54%) at 12 months. At six weeks, there was no difference in suture-related morbidity between groups (P=0.11) and 70% patients were completely asymptomatic. Incidence of bowel symptoms and quality of life disturbances were low, with no differences between the four groups.

Conclusion: Obstetric anal sphincter repair carried out by appropriately trained staff is associated with low morbidity, irrespective of the suture material and repair method used.