Results of endosonographic imaging of the anal sphincter 2-7 days after primary repair of third- or fourth-degree obstetric sphincter tears.

Objectives: To describe the endosonographic image of the anal sphincter 2-7 days after delivery in women who had undergone a primary repair of an obstetric sphincter tear.

Methods: Forty-eight women who had suffered a third- or fourth-degree sphincter tear at delivery and had undergone primary sphincter repair were examined with endoanal sonography 2-7 days after delivery. A score from 0 to 16 was used to describe the extent of the endosonographic defects, a score of 0 indicating no defect and a score of 16 a defect > 180 degrees involving the whole length and depth of the sphincter. Clinical information was retrieved from the delivery and operation records after the analysis of the ultrasound images and the classification of the sonographic defects had been completed.

Results: Clinically, 34 (71%) women had a partial third-degree tear, 11 (23%) had a total third-degree tear, and three (6%) had a fourth-degree tear. Forty-three (90%; 95% CI, 77-97%) women had sonographic defects, all hypoechoic. Twenty-three (54%) sonographic defects were confined to the proximal part of the anal canal and involved less than half of the length of the anal canal. Thirty (63%) defects were confined to the external sphincter. Five of nine women (56%) with an endosonographic sphincter defect score >/= 8 had undergone primary sphincter repair by a doctor in training vs. 9 of 39 women (23%) with an endosonographic sphincter score < 8 (P = 0.05), despite the fact that 86% (12/14) of the tears sutured by doctors in training were clinically partial third-degree tears vs. 65% (22/34) of those sutured by specialists (P = 0.15). Five (15%) of 34 women with a clinical partial third-degree tear had an endosonographic sphincter score >/= 8 vs. four (29%) of 14 with a clinical total third- or fourth-degree sphincter tear (P = 0.26).

Conclusions: Most women (90%) with a clinical third- or fourth-degree obstetric sphincter tear have endosonographic sphincter defects if they are examined 2-7 days after primary repair. The extent of the endosonographic defects seems to be determined mainly by the surgical experience of the doctor performing the repair, and not by the clinical degree of the tear.