How to Repair an Anal Sphincter Injury After Vaginal Delivery: Results of a Randomized Controlled Trial

Abstract

Anal sphincter injuries have been reported to complicate up to 20% of vaginal deliveries. Fecal urgency and incontinence as well as dyspareunia and perineal pain are among the sequelae of these injuries. Traditionally, they have been repaired at the time of injury by trainee obstetricians who perform end-to-end approximation of the torn sphincter. There is some evidence that the overlap technique may yield better outcomes. In addition, monofilament sutures may be preferable to braided sutures because of a longer life but may themselves cause discomfort or stitch abscess. Among 10,266 women who delivered vaginally were 150 (1.5%) who sustained a third- or fourth-degree anal sphincter tear. Three fourths of them were randomized to have overlap pair with braided polyglactin (Vicryl) sutures, end-to-end repair with the same sutures, or either type of repair using polydioxanone (PDS) sutures. All repairs were carried out as primary procedures under full aseptic conditions by staff trained in both methods. Patients received either regional or general anesthesia. No significant differences in suture-related morbidity—the primary outcome—were evident after 6 weeks. A substantial majority of patients (70%) were totally asymptomatic at this time. Bowel symptoms were infrequent as was an adverse change in quality of life. The 4 treatment groups did not differ in these respects. All but 2% of women were sexually active 12 months postoperatively. The most common symptoms were vaginal dryness and loss of libido. Fewer than 10% of women reported fecal incontinence. No differences in outcome were found between women having a complete third- or fourth-degree tear and those with a partial third-degree tear. When properly trained individuals repair postvaginal delivery anal sphincter tears, long-term morbidity is infrequent and does not depend on the method of repair or the suture material used. All medical staff assigned to labor wards should be trained to accurately diagnose these injuries.