Intraoperative colonoscopy for the assessment and prevention of anastomotic leakage in low anterior resection for rectal cancer

Purpose: Anastomotic leakage (AL) after stapled anastomosis in rectal cancer surgery is a major concern. Various types of intraoperative anastomotic air leakage tests (ALTs) have been proposed to reduce AL. This study aimed to evaluate the impact of intraoperative colonoscopy (IOC) as an intraoperative ALT in low anterior resection for rectal cancer. Methods: A total of 1266 patients were retrospectively reviewed. Among them, 215 patients who underwent IOC as an ALT in rectal cancer surgery were identified. IOC was performed after anastomosis to visualize the anastomosis line and to perform an ALT by insufflating the neorectum. Propensity score matching was used to match this group at a 1:1 ratio with 215 patients who underwent ALT with a 250-mL bulb irrigation syringe. Anastomotic defects that were found intraoperatively were resolved either by means of primary repair of the anastomotic defect, if possible, or by performing a preventive diverting ileostomy. Results: The patient characteristics, pathologic outcomes, and operation details showed no significant difference between the two groups. Comparison of the AL rate showed a significant difference between the groups (IOC group without intraoperative leaks vs. non-IOC group without intraoperative leaks 4.3 vs. 11.7%, P = 0.007). The incidence of preventive diverting ileostomy because of a positive ALT was significantly higher in the IOC group than in the non-IOC group (10 vs. 2 cases, P = 0.036). Conclusion: IOC can be a valuable method for the assessment of stapled anastomosis and has the additional benefit of directly visualizing the anastomosis line.