Incontinence after primary repair of obstetric anal sphincter tears is related to relative length of reconstructed external sphincter: a case-control study.

OBJECTIVE: To determine if anatomic primary repair with end-to-end reconstruction of the external anal sphincter (EAS) in its full length combined with separate repair of coexisting internal anal sphincter (IAS) tear, when present, results in less incontinence and better anal sphincter integrity compared with conventional primary end-to-end repair in which the IAS is not actively reconstructed. METHODS: Women who sustained third- or fourth-degree obstetric tears were included prospectively in the study following anatomic primary repair. Women treated with conventional primary repair prior to the study period comprised the control group. Three-dimensional endoanal ultrasonography (3D-EAUS) images were classified according to the EAUS defect score, and incontinence according to St Mark's score. RESULTS: Sixty-three women were included in the study group and 61 in the control group, with mean follow-up times of 11 and 21 months, respectively. Among women who had not delivered vaginally prior to the tear, St Mark's score ≥ 3 was reported by 9.6% (5/52) in the study group and 37.5% (15/40) in the control group at follow-up (P = 0.002). The corresponding numbers among women who had previously delivered vaginally were 36.4% (4/11) and 42.9% (9/21), respectively (non-significant). St Mark's score correlated with the EAUS defect score (P = 0.017). An EAS defect exceeding 50% of the sphincter length was significantly less common in the study group, and in a multivariable logistic regression model, mode of repair (anatomic vs conventional) was the only factor explaining the difference in EAS sphincter length between the two groups (P = 0.007). CONCLUSION: Improved continence status after anatomic primary repair was associated with a better longitudinal reconstruction of the EAS, while the integrity of the IAS did not differ between the groups. Women with a history of vaginal delivery prior to the sphincter tear had an inferior outcome regardless of mode of repair.

Correlation between anal sphincter defects and anal incontinence following obstetric sphincter tears: assessment using scoring systems for sonographic classification of defects.

OBJECTIVE: To determine if there is a correlation between the sonographic extent of anal sphincter defects revealed by three-dimensional endoanal sonography (EAUS) and the degree of anal incontinence following primary repair of obstetric sphincter tears. METHODS: This was a follow-up study of women who had suffered anal sphincter tearing during vaginal delivery at Aalesund Hospital between January 2002 and July 2004. Incontinence was assessed by St Mark's score. The anal canal was assessed with three-dimensional endoanal sonography (EAUS). Sphincter defects were classified according to the Starck score and our new EAUS defect score. The EAUS images were interpreted by an observer blinded to other patient data. RESULTS: Sixty-one women were included in this study. Incontinence was reported by 32 (52%) women at a median of 21 (range, 9-35) months after delivery. Three-dimensional EAUS datasets were obtained in 55 women. There was a significant correlation between St Mark's score and our EAUS defect score (P = 0.034), and correlation approached but did not reach significance between St Mark's score and the Starck score (P = 0.053). There was a strong correlation between our EAUS defect score and the Starck score (P < 0.001). CONCLUSIONS: There is a positive correlation between the extent of sphincter defects and the degree of anal incontinence following primary repair of obstetric sphincter tears. Our findings highlight the importance of adequate reconstruction of the anal sphincters during primary repair.