Comparison of transanal opening of intersphincteric space and cutting seton for high complex anal fistula: a meta-analysis

INTRODUCTION: The ideal treatment for highly complex anal fistula (HCAF) is to cure the disease through surgery while preventing the recurrence of anal fistula and avoiding the occurrence of anal incontinence caused by anal sphincter injury. Unfortunately, until now, there is no surgical method that can fully achieve the ideal state. This study aimed to compare the advantages of transanal opening of intersphincteric space (TROPIS) with cutting seton (CS) in the treatment of HCAF.EVIDENCE ACQUISITION: According to the preferred reporting items for systematic review and meta-analysis, we searched PubMed, Cochrane Library, China National Knowledge Infrastructure, and the Wanfang Database to collate all the articles compared TROPIS with CS for treating HCAF. 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, anal incontinence score, pain score, healing time, effective rate, postoperative anal resting pressure, complications rate, and types of complications.EVIDENCE SYNTHESIS: A total of 6 articles involving 372 patients were included in this meta-analysis. The results showed that, in contrast to CS, TROPIS has lower anal incontinence score (MD=-1.72, 95% CI: -2.81 to -0.64, I2=96%, P=0.002), lower pain score (MD=-1.41, 95% CI: -1.79 to -1.02, I2=72%, P<0.00001), and lower complication rate (OR=0.19,95% CI: 0.07 to 0.51, I2=0%, P=0.001). There are fewer types of complications occurring after the TROPIS. At the same time, TROPIS has higher postoperative anal resting pressure (MD=1.60, 95% CI: 0.57 to 2.64, I2=97%, P=0.002), shorter healing time (MD=-11.16, 95% CI: -13.65 to -8.67, I2=69%, P<0.00001), and higher effective rate (OR=2.93, 95% CI: 1.35 to 6.35, I2=0%, P=0.007).CONCLUSIONS: Compared with CS, the TROPIS has some advantages for HCAF. It can better preserve the anal sphincter, reduce the occurrence of anal incontinence, lighten the postoperative pain, shorten the postoperative healing time, depress the incidence of postoperative complications, reduce the type of complications, and improve the effective rate. As a surgical method to preserve the anal sphincter for the treatment of HCAF, the TROPIS deserves further clinical promotion and research.