The incidence of wound complications following primary repair of obstetric anal sphincter injury: a systematic review and meta-analysis

Abstract

We aimed to systematically determine the incidences of wound infection and dehiscence after primary obstetric anal sphincter injury repair. MEDLINE, Embase, CINAHL, EmCare, the Cochrane Library, and Trip Pro databases were searched from inception to February2021. We included observational clinical studies reporting the incidences of wound infection and dehiscence after primary obstetric anal sphincter injury repair. Case series and reports were excluded. Conference articles and observational study abstracts were included if they contained enough information regarding study design and outcome data. Data were analyzed as incidence (percentage) with 95% confidence intervals. Moreover, the prediction intervals were calculated to provide a predicted range for the potential incidence of wound complications when applied to an individual study setting. Study quality and risk of bias were assessed using the relevant tool from the Joanna Briggs Institute. Of 956 studies found, 39 were selected for full-text review. Moreover, 10 studies (n=4767 women) were eligible and included in the meta-analysis. All 10 studies were conducted in high-income countries (Denmark [n=1], the United Kingdom [n=3], and the United States [n=6]). The incidences of wound infection (n=4593 women) and wound dehiscence (n=3866 women) after primary obstetric anal sphincter injury repair ranged between 0.1% to 19.8% and 1.9% to 24.6%, respectively. The overall incidences were 4.4% (95% confidence interval, 0.4-8.4) for wound infection and 6.9% (95% confidence interval, 1.6-12.2) for wound dehiscence. The prediction intervals were wide and suggested that the true incidences of wound infection and dehiscence in future studies could lie between 0.0% to 11.7% and 0.0% to 16.4%, respectively. Overall, 8studies had a high or unclear risk of bias across ≥1 assessed element. None of the studies used the same set of clinical parameters to define wound infection or dehiscence. Furthermore, microbiological confirmation with wound swabs was never used as a diagnostic measure. This was a systematic review and meta-analysis of wound infection and dehiscence incidences after primary obstetric anal sphincter injury repair. The incidence estimates from this review will be useful for clinicians when counseling women with obstetric anal sphincter injury and when consenting them for primary surgical repair.