Tianjin Medical Journal ›› 2023, Vol. 51 ›› Issue (1): 86-90.doi: 10.11958/20220756

• Clinical Research • Previous Articles     Next Articles

Analysis of long-term effect and risk factors of modified TROPIS on postoperative anal function in patients with high anal fistula

HOU Yi1(), ZHENG Xueping1,(), TAN Yanyan1, ZHOU Feng1, HUANGFU Shaohua1, XU Dachao1, WANG Yan2   

  1. 1 National Center for Colorectal Disease Treatment, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing 210012, China
    2 Nanjing University of Chinese Medicine
  • Received:2022-05-14 Revised:2022-07-15 Published:2023-01-15 Online:2023-01-17
  • Contact: ZHENG Xueping E-mail:xunziyang2015@163.com;zhengxp025@163.com

Abstract:

Objective To evaluate the long-term effect of modified TROPIS on postoperative anal function in patients with high anal fistula, and analyze the risk factors influencing postoperative anal function. Methods A retrospective case-control study was used in this study. A total of 181 patients with high anal fistula who underwent surgical treatment were included. Patients were divided into the experimental group (n = 84) and the control group (n = 97) according to the surgical method. The experimental group was treated with modified TROPIS, and the control group was treated with incision-thread-drawing procedure. Follow-up period was 12-36 months (median, 21 months). The general condition, cure rate and anal function were compared between the two groups. Logistic regression analysis was used to analyze risk factors influencing postoperative anal function, and the area under the ROC curve (AUC) and the Hosmer-Lemeshow test were used to evaluate the predictive efficacy. Results The relapse rate was 8.33% in the experimental group, which was significantly lower than 20.62% in the control group. The total score of postoperative anal gas control, lifestyle and Wexner incontinence were significantly higher after surgery compared with those before surgery (P<0.01), but each score was significantly lower than that in the control group (P<0.01). Postoperative anal function declined in 79 patients. Logistic regression analysis showed that body mass index (OR=4.579), horseshoe anal fistula (OR=158.011), number of fistulas (OR=8.789), lesion involving external sphincter (OR=6.883) and surgical method (OR=7.082) were independent risk factors for postoperative anal function decline in patients with high anal fistula. Combined with each independent risk factor, the AUC of overall predictive probability was 0.903 (95%CI: 0.859-0.947, P<0.01). Hosmer-Lemeshow test demonstrated that χ2 =5.603, P=0.587, indicating that the combined prediction of each independent risk factor had high discrimination and accuracy. Conclusion Compared with the incision-thread-drawing procedure, modified TROPIS procedure is safer and more effective in the treatment of high anal fistula. However, this surgery still leads to long-term postoperative anal function decline. For patients with obesity and complicated fistula, anal sphincter should be protected as much as possible during surgery.

Key words: rectal fistula, colorectal surgery, anal canal, high anal fistula, modified TROPIS, anal function

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