Objective To investigate the efficacy of transanal opening of intersphincteric space (TROPIS) modified thread-drawing method and incision thread-drawing surgery in treatment of high anal fistula and its effects on pain index, wound area, anal function and postoperative complications.

Methods A total of 88 patients with high anal fistula were selected as the research subjects. They were randomly divided into control group (44 cases, using incision thread-drawing surgery) and observation group (44 cases, using TROPIS modified thread-drawing method). The postoperative efficacy, perioperative indexes, wound recovery, pain index, anal function and postoperative complications were compared between the two groups.

Results After treatment, the total clinical effective rate of the observation group was significantly higher than that of the control group (P < 0.05). Wound healing, hematochezia, pus shedding, operation and hospitalization time in the observation group were significantly smaller than those in the control group, and wound scar area was significantly smaller than that in the control group (P < 0.05). After 1 day and 7 days of treatment, the pain score of the observation group was significantly lower than that of the control group (P < 0.05). The scores of gas, liquid and solid incontinence, hygiene pad use and lifestyle change in the observation group were significantly lower than those in the control group (P < 0.05). The total complication rate of the observation group was significantly lower than that of the control group (P < 0.05).

Conclusion Compared with incision thread-drawing surgery, TROPIS modified thread-drawing method is effective in treatment of high anal fistula, which can relieve postoperative pain and improve the anal function of patients, and the risk of complications is low.