OC178: Endosonographic anal sphincter defect classification after primary repair of obstetric sphincter tears: relation to sphincter pressure and anal incontinence

Abstract

Objective: To classify endosonographic obstetric sphincter defects and relate the endosonographic results to anal sphincter pressure and symptoms of anal incontinence. Methods: Forty-one women who had undergone primary repair of third or fourth degree perineal tear at delivery underwent anal endosonography and anal manometry at 1 week, 3 months and 1 year after the tear. The extension of the endosonographic defects were classified using scores (1–16; the higher the score the larger the defect). The women answered a questionnaire with regard to bowel function at 1 and 4 years after delivery. Wexner incontinence score (1–20) was used for classification of anal incontinence. Results: 90% of the women had endosonographic defects at 1 week, 3 months and 1 year. The endosonographic defect scores increased significantly between the first and the second examination, then remained unchanged. At 1 and 4 years 54% and 61% of the women, respectively, reported anal incontinence. At 1 year there was a negative correlation between endosonographic sphincter defect score and sphincter pressure (resting pressure: r2 = 0.39, p < 0.0001; squeeze pressure: r2 = 0.16, p = 0.01; resting pressure area: r2 = 0.29, p = 0.0003). There was a positive correlation between endosonographic sphincter defect score at 1 year and incontinence score at 1 year (r2 = 0.13, p = 0.02) and 4 years (r2 = 0.22, p = 0.002). Multiple linear regression analysis showed resting pressure to be the only variable to independently predict Wexner score at 1 year and endosonographic defect score to be the only variable to independently predict Wexner score at 4 years. Conclusion: Endosonographic sphincter defects are common after primary suture of obstetric sphincter tears. The more damaged the sphincter appears to be at endosonography, i.e. the higher the endosonographic defect score, the lower is the sphincter pressure and the higher is the incontinence score.