A randomized clinical trial comparing primary overlap with approximation repair of third-degree obstetric tears

We compared, in a prospective, randomized clinical trial, the subjective and objective outcomes after primary anal sphincter overlap or approximation repair of third-degree obstetric tears.

In a prospective, randomized clinical trial at our university teaching hospital, we studied 112 primiparous women who sustained a third-degree tear during a 1-year period (July 1998-June 1999); they were randomly selected, at diagnosis, to receive either an overlap or an approximation repair. Obstetric personnel, trained in both methods, carried out the repairs immediately after delivery. Fifty-five women underwent an overlap procedure, and 57 women underwent an approximation repair. Outcome measures assessed were symptoms of fecal incontinence, abnormal findings on anal manometry, and abnormal findings on endoanal ultrasonography at 3 months post partum.

Obstetric factors, including mode of delivery, birth weight, duration of labor, and episiotomy incidence, did not differ significantly between the 2 groups. Experience of the operator, analgesia used, and place of repair were similar in both groups. The median incontinence scores were 0/20 after overlap repair and 2/20 after approximation repair (difference not significant). Eleven women (20%) complained of fecal urgency after overlap repair, in comparison with 17 (30%) after approximation repair (difference not significant). There were no significant differences in either anal manometry or endoanal ultrasonographic results between the 2 groups. Six women (11%) had a significant (>1 quadrant) anal sphincter defect after primary overlap repair, compared with 3 (5%) after approximation repair (difference not significant). Overall, 66% of women had ultrasonographic evidence of a residual full-thickness defect in the external anal sphincter after primary repair.

The outcome after primary repair of third-degree obstetric tear was similar whether an approximation or an overlap technique was used. Overall symptomatic outcome was good, although two thirds of women had ultrasonographic evidence of residual anal sphincter damage irrespective of the method of repair.