Lateral internal sphincterotomy with skin grafting for chronic anal fissure: protocol of a multi-center randomized controlled trial

Abstract Background: Anal fissure, a prevalent anorectal disorder, is defined as a longitudinal tear in the anoderm distal to the dentate line.Chronicity develops in a substantial fraction of anal fissures despite initial conservative success, resulting in significant quality-of-life deficits. Therapeutic efforts for these CAFes entail anal pressure reduction as a cornerstone, implemented through either nonsurgical agents or surgical procedures.Surgical intervention has historically constituted the primary approach chronic anal fissure-associated sphincter spasm, despite the absence of placebo-controlled trials to validate its efficacy.However surgical approaches take a long time to heal the wound. A multi-center randomized controlled trial is proposed to evaluate the efficacy of lateral internal sphincterotomy combined with surgical wound skin grafting in promoting anal fissure healing. Methods: It is is a multi-center, hospital-based, random controlled trial.This parallel-group, randomized controlled trial will be conducted at three hospitals. Eligible adult patients (n=104) with refractory anal fissures will undergo block randomization (block size=6) to the experimental or control group, ensuring equal group sizes.Lateral internal sphincterotomy with concurrent skin grafting will be performed in the experimental group, whereas lateral internal sphincterotomy alone will be administered to the control group.All surgical procedures will be conducted by attending colorectal surgeons or senior consultants. Efficacy and safety endpoints will be systematically monitored, documented, and statistically analyzed. Discussion: Lateral internal sphincterotomy demonstrates efficacy in resolving chronic anal fissures with low recurrence rates and an acceptable safety profile.Concurrently, autologous skin grafting accelerates wound epithelialization, potentially reducing healing duration in refractory chronic anal fissures. Trial registration: Chinese Clinical Trial Register, ID: ChiCTR2400079420. Registered on 3 January 2024.