Overlapping compared with end-to-end repair of third- and fourth-degree obstetric anal sphincter tears: a randomized controlled trial.

Objective: To compare overlapping repair with end-to-end repair of obstetric tears and to investigate which procedure results in a higher rate of flatal incontinence.

Methods: One-hundred forty-nine primiparous women sustaining a complete third- or a fourth-degree tear of the perineum were assigned randomly to a primary sphincter repair using either an end-to-end (n=75) or an overlapping surgical technique (n=74) using 3-0 polyglyconate. Outcome measures at 6 months included rates of flatal and fecal incontinence, quality-of-life scores, integrity of the internal and external anal sphincters by anal ultrasonography, and anal sphincter function as reflected by anal manometry.

Results: Women who underwent overlapping repair compared with end-to-end repair had higher rates of flatal incontinence, 61% compared with 39% (odds ratio [OR] 2.44, confidence interval [CI] 1.2-5.0). The rate of fecal incontinence was also higher, 15% compared with 8% (OR 1.97, CI 0.62-6.3) but did not attain statistical significance. Rates of internal and external anal sphincter defects did not differ significantly between groups and did not correlate with anal incontinence symptoms. Fecal incontinence was higher when there was a defect in both sphincter muscles. Anal sphincter function as assessed by manometry did not differ significantly between groups.

Conclusion: End-to-end repair of third- or fourth-degree obstetric anal sphincter tears is associated with lower rates of anal incontinence when compared with overlapping repair.

Clinical Trial Registration: ISRCTN Register, isrctn.org, ISRCTN04149919.

Level Of Evidence: I.