ObjectiveTo observe the effect of modified ligation of intersphincteric fistula tract (LIFT) combined with acellular anal fistula repair matrix packing in the treatment of high anal fistula, and to evaluate its clinical efficacy and safety.MethodsAll 86 patients who met the diagnostic criteria of high anal fistula in Beijing Anorectal Hospital from October 2018 to August 2019 were selected and randomly divided into observation group and control group. The observation group was treated with modified LIFT combined with acellular anal fistula repair matrix tamponade, while the control group was treated with traditional low incision and high thread drawing surgery. The curative effect, wound healing time, postoperative pain score, intraoperative blood loss, postoperative complications, hospitalization time, patient satisfaction and recurrence at 6 months after operation were compared between the two groups.ResultsThe effective rate of the observation group was 92.9% (39/42), and that of the control group was 86.4% (38/44), there was no significant difference between the two groups (Z=−1.251, P=0.211). The healing time of the observation group and the control group were (24.8±8.5) days and (32.1±10.9) days, respectively, the difference was statistically significant (t=3.472, P<0.001). Compared with the control group, the observation group had less intraoperative blood loss, less postoperative pain and shorter hospital stay (P<0.05). There was no anal incontinence after operation in the two groups, and the incidence of postoperative complications such as bloody stool, anal border edema and urinary retention were lower in the observation group (11.9%) compared with the control group (31.8%), with a statistically significant difference (P<0.05). The treatment satisfaction of the observation group was 90.5%, and that of the control group was 81.8%. There was no significant difference between the two groups (Z=−1.284, P>0.05).ConclusionModified LIFT combined with acellular anal fistula repair matrix in the treatment of high anal fistula has the advantages of small trauma, quick recovery and low incidence of complications.