The extent of endosonographic anal sphincter defects after primary repair of obstetric sphincter tears increases over time and is related to anal incontinence.
OBJECTIVE: To describe and classify endosonographic obstetric sphincter defects at 1 week, 3 months and 1 year after primary repair, and to relate the endosonographic results to anal sphincter pressure and to symptoms of anal incontinence over time. METHODS: Forty-one women who had suffered a third- or fourth-degree perineal tear at delivery underwent anal endosonography and anal manometry 1 week, 3 months and 1 year after primary suture of the tear. The extent of the endosonographic defects was described using defect scores ranging from 0 (no defect) to 16 (maximal defect), the score taking into account the location and the longitudinal and circumferential extent of the defect. The women answered a questionnaire with regard to bowel function 1 and 4 years after delivery, the degree of incontinence being expressed as a Wexner score. RESULTS: Some 90% (37/41) of the women had endosonographic defects at 1 week, 3 months and 1 year. The endosonographic defect scores increased significantly between the first and second examinations and then remained unchanged. At 1 year there was a negative correlation between endosonographic sphincter defect score and sphincter pressure. At 1 and 4 years, 54% (22/41) and 61% (25/41) of the women, respectively, had a Wexner score >/= 1. There was a positive correlation between the endosonographic sphincter defect score at 1 week, 3 months and 1 year and the Wexner incontinence score at 1 and 4 years. The endosonographic sphincter defect score at 1 week was the variable that was most predictive of the Wexner score at 4 years (r = 0.48, P = 0.002). CONCLUSION: The higher the endosonographic sphincter defect score after primary repair of an obstetric sphincter tear the lower the sphincter pressure and the higher the risk of anal incontinence.