Methods of repair for obstetric anal sphincter injury

Primary repair of anal sphincter injury with both the approximation and overlap repair techniques seem to be associated with reduced risk of fecal urgency, incontinence score and deterioration of anal continence. Further trials of appropriate size are required to assess the efficacy and safety of the two techniques when used at different level of health care.

RHL Commentary by Quijano C


This Cochrane review (1) includes three trials with a total of 279 women. There were variations in the trials in terms of primary and secondary outcome measures and follow-up periods. One trial compared two suture materials in addition to the two tissue repair techniques (2). In all studies, ultrasonography and manometry were used after anal sphincter repair to evaluate sphincter function, but the interval between repair and evaluation was different in each study.

The authors conclude that primary repair with both the approximation and overlap repair techniques seem to be associated with reduced risk of fecal urgency, incontinence score and deterioration of anal continence. They stress that the results are based on a small number of women, and the available data are not enough to recommend one method of repair over the other. Also, it is highlighted that the experience of the surgeon is a very important factor in evaluating the effectiveness of the techniques.

The reviewers used sound methods to find and select the trials, collect and analyse the data, and present the findings in text and graphics.


2.1. Magnitude of the problem

Obstetric anal sphincter injury should be corrected appropriately in the immediate postpartum period since its consequences (faecal incontinence) become more severe with the passing of time. The true incidence of such injuries in under-resourced settings is not known. In the international literature the figures vary from 0.5% to 17% (3–5). Factors related to the physician, the patient and the health-care setting sometimes contribute to the problem. For example, physicians may not inform the patients about the injuries due to fear of litigation. On the other hand, women may consider the signs and symptoms of incontinence as normal (3, 6–11), or may not come from treatment due to embarrassment.

2.2. Applicability of the results

In under-resourced settings a physician with experience in anal sphincter repair may not be readily available. Also, proper sphincter repair requires good instruments, lighting and suture material, and these may not be easily available in under-resourced settings, limiting the applicability of the results.

2.3. Implementation of the intervention

The methods analysed are feasible and desirable for use in any setting that meets the conditions mentioned in the above section. While it is important to repair anal sphincter injury promptly, it is equally important to use antibiotics and laxatives to prevent infection and treat postpartum constipation, respectively, for a minimum of 30 days.


Trials of appropriate size are required to assess the efficacy and safety of the two methods when used at different level of health care. The trials should not only compare the two techniques, but also the suitability of suture materials (polydioxanone versus polyglactin) for the concerned tissues. There should preferably be standard intervals between repair and follow up. More research is also required to identify the most appropriate quality-of-life scoring systems related to incontinence.


  • Williams A, Adams EJ, Tincello DG, Alfirevic Z, Walkinshaw SA, Richmond DH. How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial. BJOG: an international journal of obstetrics and gynaecology 2006;113(2):201{7.
  • Sultan AH, Kamm MA, Hudson CN, Bartrum CI. Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair. BMJ 1994;308:887-91.
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  • Haadem K, Dahlstrom JA, Lingman G. Anal sphincter function after delivery: a prospective study in women with sphincter rupture and controls. European Journal of Obstetrics & Gynecology and Reproductive Biology 1990;35(1):7-13.
  • Sultan AH, Kamm MA, Hudson CN, Thomas JM, Bartram CI. Anal sphincter disruption during vaginal delivery. New England Journal of Medicine 1993;329:1905-11.

This document should be cited as: Quijano C. Methods of repair for obstetric anal sphincter injury: RHL commentary (last revised: 27 August 2007). The WHO Reproductive Health Library; Geneva: World Health Organization.