Abstract: Objective To explore the clinical efficacy of modified incision and suture of anal fistula in patients with high complex anal fistula (CAF) and the influencing factors of anal fistula healing.Methods A total of 104 patients with CAF who visited our hospital from January 2021 to March 2024 were selected as the research objects.They were divided into the observation group and the control group by the random number table method,with 52 cases in each group.The observation group was treated with the modified anal fistula incision and suture technique,while the control group was treated with the traditional anal fistula incision and suture technique.The perioperative indicators and the wound bleeding score,wound exudate score,anal distension score and wound pain score at 1,3 and 7 days after the operation were compared between the two groups of patients.The Wexner anal incontinence score,anal canal resting pressure (ARP) and anal canal maximum systolic pressure (AMCP) levels of the two groups of patients before the operation and at 7 days,1 and 3 months after the operation were also compared.The clinical efficacy and postoperative complications of the two groups of patients were compared.The Cox regression analysis was used to analyze the effect of the modified incision and suture of anal fistula on the non-healing of anal fistula in patients.Results The hospitalization time [(8.05±1.12)d],wound healing time [(27.26±4.38)d] and intraoperative blood loss [(28.29±4.47)ml] of the observation group were significantly lower than those of the control group [(11.24±2.06)d,(32.07±5.21 )d and (34.18±5.61)ml,respectively)] (P<0.05).The wound bleeding score,wound exudate score,anal distension score and wound pain score of the observation group and the control group 7 days after the operation were (1.61±0.25) points and (1.75±0.33) points,(1.52±0.24) points and (1.66±0.29) points,(1.47±0.44) points and (1.65±0.46) points,(3.46±0.35) points and (4.27±0.43) points,respectively.There was a statistically significant difference between the two groups (P<0.05)
At 7-days,1 month and 3 months after the operation,the Wexner anal incontinence scores of both groups showed an increasing and decreasing trend.The scores of the observation group at each time point were lower than those of the control group (P<0.05).At 7 days,1 month and 3 months after the operation,AMCP and ARP of both groups of patients showed a decreasing trend (P<0.05).There was no statistically significant difference in the total effective rate between the two groups (P>0.05).The total incidence of adverse reactions in the observation group (7.69%) was significantly lower than that in the control group (25.00%) (P<0.05).The results of Coxregression analysis showed that the modified incision and suture of anal fistula could reduce the risk of unhealed anal fistula in patients ,and the results were consistent in different subgroups.Conclusion The modified incision and suture surgery for anal fistula has a good clinical effect on CAF,with a low incidence of postoperative complications.It has obvious advantages in rapid pain relief,accelerated wound healing and maintenance of anal function after surgery.

Key words: high-level complex anal fistula, improved incision and suture technique for anal fistula, therapeutic effect, healing of anal fistula