Risk factors for anastomotic fistula after total mesorectal excision: A monocentric retrospective study of 78 patients

Introduction

Anastomotic fistulas remain one of the most feared complications following rectal surgery, particularly after Total Mesorectal Excision (TME). They compromise prognosis, prolong hospitalization, and increase costs due to the additional interventions they necessitate.

Aims

To identify predictive factors for the occurrence of anastomotic fistulas, with the goal of personalizing and optimizing surgical management—particularly to guide decisions regarding the use of defunctioning stomas.

Materials and methods

We conducted a retrospective observational study on 78 patients who underwent TME with low rectal anastomosis for rectal adenocarcinoma at Hassan II University Hospital in Oujda, between December 2017 and May 2024.

Results

Of the 78 patients, 21 developed anastomotic fistulas, yielding an incidence rate of 26.9 ​%. Late-onset cases were predominant (16 cases, 76.19 ​%) compared to early-onset cases (five cases, 23.81 ​%). In univariate analysis, diabetes (p ​= ​0.002), intraoperative incidents (p ​= ​0.014) - particularly blood loss exceeding 150 ​cc (p ​= ​0.001) - and smoking (p ​= ​0.005) were significant risk factors for fistula development. In multivariate analysis, diabetes (OR ​= ​10.87; p ​= ​0.003) and intraoperative blood loss >150 ​ml (OR ​= ​7.38; p ​= ​0.030) emerged as independent predictors of fistula development. Active smoking showed a borderline association (OR ​= ​6.46; p ​= ​0.056), suggesting a potential but not statistically confirmed impact on anastomotic fistula. These findings are consistent with the existing literature. In contrast, other factors commonly reported in the literature, such as male sex (p ​= ​0.530), ASA score (p ​= ​0.612), anemia (p ​= ​0.324), and preoperative (p ​= ​0.781) and postoperative albumin levels (p ​= ​0.119), did not show a significant association in our study.

Discussion and conclusion

While the identified risk factors are relevant, they alone are insufficient to warrant major modifications in our surgical strategy, particularly regarding the decision to perform a defunctioning stoma. Further studies are necessary to validate these findings.