Delayed sphincter repair for obstetric ruptures: analysis of failure

The aim of this study was to examine the clinical results after anterior anal sphincter repair in patients with obstetric trauma and to evaluate possible risk factors for poor outcome.

In years 1990-99 anterior anal sphincter repair for anal incontinence due to obstetric trauma was performed in 39 patients at Helsinki University Central Hospital. Clinical examination with Parks' classification and patients' questionnaire with endoanal ultrasound (EAUS) were done before and after surgery. Pudendal nerve terminal motor latency (PNTML) was measured postoperatively. The median follow-up time after the operation was 22 months (range 2-99).

The follow-up results of the patients' questionnaire for 12 patients (31%) were good, for 15 patients (38%) acceptable and for 12 patients (31%) poor. Postoperative EAUS showed sphincter overlap in 28 (72%) patients but a defect was still found in 11 (28%) patients. A defect found on postoperative EAUS correlated with poor clinical result according to Parks' (R = 0.8, P < 0.01) and patients' questionnaire results (R = 0.7, P < 0.01). Patients with poor clinical results (Parks III/IV) were statistically significantly older (median 63 years, range 26-73) than those with favourable results (Parks I/II) (median 45 years, range 27-79) (P < 0.05). Further, the duration of incontinence symptoms correlated with poor functional results (R=0.4, P < 0.05).

After obstetric trauma anterior anal repair gives acceptable short-term clinical results. EAUS investigation is easy and harmless to perform and should be used pre- and post-operatively. Advanced age, pre-operative signs of perineal descent, long-lasting severe incontinence symptoms and a persistent defect on postoperative EAUS seem to be related to poor clinical result.