Endosonography in the evaluation of anal function after primary repair of a third-degree obstetric tear

Background: Disruption of the anal sphincter occurs in 0.6%-6% of women during delivery and almost half have persistent defecatory symptoms despite primary repair. Our aim was to prospectively analyse anal endosonography and rectoanal manometry after primary repair of a third-degree obstetric tear in order to compare the findings with the clinical outcome. Methods: Twenty-one women aged 27-41 (mean 31.5 years) who had undergone primary suture of a third-degree disruption of the anal sphincter were interviewed on their pelvic floor function and explored by manometry and endosonography 4 months after delivery. Results: Twelve women had anal incontinence. External sphincter defect was identified on endosonography in 22% continent and in 91% incontinent women (P < 0.01). The presence of an external sphincter defect was associated with anal incontinence in 91.7%. Surgical repair was identified on endosonography in 88% continent women and in 25% incontinent women (P < 0.03). The combination of a visible surgical repair and absence of defect was highly associated with normal continence (91.7%). Squeezing pressures were higher in continent women (87 +/- 23 cm H2O) than in incontinent women (48 +/- 36 cm H2O; P = 0.04), but no anal pressure threshold could achieve better results than endosonography in predicting the clinical outcome. Conclusion: After primary repair of a third-degree obstetric tear, endosonographic pattern of the anal sphincter correlates with the continence status.