Abstract: Objective To investigate the clinical value of ligation of the intersphincteric fistula tract(LIFT) combined with endorectal advancement flap(ERAF) in the treatment of high complex anal fistula.Method From August 2016 to December 2021, a total of 40 patients with high complex anal fistula in the anorectal Department were included.They were randomly divided into the experimental group and the control group according to the method of drawing lots,with 20 cases in each group.The experimental group was treated with LIFT+ERAF,and the control group was treated with LIFT.The patients were followed up for 6-12 months to compare the clinical efficacy.Results There was no significant difference in pain degree on the first day after operation,wound healing time and cure rate between the two groups(P＞0.05).There was no significant difference in Wexner anal incontinence score,anal resting pressure and anal maximum systolic pressure before operation,after wound healing and 6 months after operation in both groups(P＞0.05).The anal resting pressure and the maximum anal systolic pressure after wound healing and 6 months after operation were significantly different from those before operation in both groups(P＜0.05).Followed up for 6-12 months,there was no recurrence in the experimental group and there were 3 recurrences in the control group.There was significant difference in the recurrence rate between the two groups(P＜0.05).Conclusion LITF combined with ERAF is a new surgical method with good curative effect,less pain,short course of disease,low postoperative recurrence rate and little impact on anal control function.

Key words: ligation of the intersphincteric fistula tract, endorectal advancement flap, high complex anal fistula, anal function, recurrence