Efficacy and safety of transanal opening of intersphincteric space in the treatment of high complex anal fistula: A meta‑analysis.

The best treatment of high complex anal fistula (HCAF) is to avoid anal incontinence while improving the cure rate. On this basis, several surgical procedures for preserving the anal sphincter have been proposed. The purpose of the present study was to evaluate the efficacy and safety of transanal opening of intersphincteric space for treating HCAF. PubMed, Cochrane Library, China National Knowledge Infrastructure and the Wanfang databases were searched to collate all the articles on transanal opening of intersphincteric space for treating HCAF. A total of two researchers independently completed the whole process, from screening and inclusion to data extraction and the data was included in the RevMan 5.3 software for analysis. The main outcomes included the patients' essential characteristics, primary healing rate, management after recurrence, final healing rate, anal incontinence score before and after surgery, postoperative complication rate and types of complications. A total of six articles were included in this meta-analysis. The results showed that the weighted final healing rate of patients following transanal opening of intersphincteric space was 89% [risk differences (RD)=0.89; 95% confidence interval (CI)=0.86-0.92; I=0%; P<0.00001]. The results of the anal incontinence score showed that there was no significant difference between the results before and after transanal opening of intersphincteric space surgery mean differences [(MD)=-0.04, Cl=-0.10-0.02, I=0%; P=0.21]. Only 11 patients were reported to have complications, including urinary retention and bleeding following transanal opening of intersphincteric space with a complication rate of 8% (11/138) and the weighted average complication rate was 6% (RD=0.06,95% CI=0.02-0.10; I=9%; P=0.003). Transanal opening of intersphincteric space has a high cure rate, a favorable anal incontinence score, fewer types of postoperative complications and a low complication rate; it can be used as a minimally invasive and sphincter-preserving surgical method for treating HCAF and is worthy of further promotion and research in clinical practice.