Efficacy and safety of an innovatively modified cutting seton technique for the treatment of high anal fistula: A protocol for a randomized controlled trial.

Background Anal fistula is a common anorectal disease. So far, operation is still the optimal method to cure anal fistula. High anal fistula (HAF) is an even more clinically difficult disease to treat. Evidence suggested that seton placement can be a definitive treatment for HAF. However, tightening the seton brings great pain to patients, which affects the clinical application of the therapy. Also, this may lead to difficulty in controlling anal fluids and gas because of the larger scar left and the local defect in the anal after the operation. We propose an innovative seton technique for the treatment of HAF, after long term attempts, the operation of the modified seton cutting technique. The aim of our present study is to compare the difference of anal function, healing time, pain severity, recurrence, and complications between the procedure of the modified seton cutting technique and the conventional cutting seton operation against HAF with a randomized, controlled, prospective study. Methods 204 participants in this trial will be randomly divided into treatment group (procedure of the modified seton cutting technique) and control group (cutting seton technique) in a 1:1 ratio. The outcomes of continence state, pain severity after tightening, complete healing of fistula, duration to healing, operation time, recurrence rates, and postoperative complications will be recorded at 1, 2, 3, 4 weeks, then every month in the outpatient clinic. Data will be analyzed by SPSS version 22. Conclusions The findings of the study will help to explore the efficacy and safety of the procedure of the modified seton cutting technique against AF. Trial registration number DOI 10.17605/OSF.IO/V6G2S.