A Prospective, Randomized Study Comparing the Outcome of Overlap and End-to-end Repair in Anal Sphincter Rupture During Delivery

Rupture of the external anal sphincter occurs in about 4% percent of deliveries in our department. It is not clear from other studies whether the results concerning anal function are better with the overlap repair or end-to-end repair of the injured muscle. Our routine has been to perform an end-to-end repair, though anal surgeons, in the setting of a secondary repair, prefer the overlap method. Former studies, when the repair was performed by highly skilled operators, have indicated that the overlap method is better.

We wanted to compare the two methods through a RCT with the end-points examination results after one year addressing endoanal sonography findings, anal manometric results and continence score evaluated by a Weksner score questionnaire. Our study is performed in the routine clinical setting. The patients are recruited to the study during delivery when the injury is recognized. When she has given her informed consent she is randomized to one of the two operation methods. The operation is performed by the consultant obstetrician on call or the resident supervised by the consultant. The proctologist who performs the anal manometry and sonography after one year is blinded to the surgical method.

We plan to include approximately 160 patients at one center. In our center we have about 4500 deliveries per year.