Overlapping compared with end-to-end repair of third and fourth degree obstetric anal sphincter tears

There is a significant risk of anal incontinence in women who sustain a third or fourth degree tear of the external anal sphincter (EAS) at the time of delivery. Optimizing the surgical correction of these injuries should result in the best functional outcome for women. The purpose of this review is to examine recent evidence.

The results of randomized trials are conflicting. Four trials have found no difference between the overlapping and end-to-end repairs. One trial found the overlapping procedure superior and one found the end-to-end procedure to be superior. Repair of the internal anal sphincter is an important part of the surgical repair. Surgeon experience with specific surgical procedures does not significantly affect outcomes. Methodological limitations have compromised the conclusions of the majority of the studies and longer-term follow-up is still needed.

At present, the bulk of the evidence (follow-up to 12 months) finds that there is no difference in symptomatic outcomes between the end-to-end or the overlapping repair of EAS defects. A surgeon should use the technique with which they are most familiar. Obstetricians should familiarize themselves with the most up-to-date evidence concerning the anatomy of the EAS and take care to identify and repair both the internal anal sphincter and EAS at the time of an obstetrical injury. Surgeon experience with specific repair procedures does not affect outcomes of EAS defect repair.