Analysis of diverting ileostomy for colorectal cancer surgery: Stenosis and T4 invasion are risk factors of reoperation due to anastomotic leakage, even when ileostomy is performed

Purpose In colorectal cancer (CRC), diverting ileostomy prevents the occurrence and severity of anastomotic leakage (AL) during surgery. However, an ileostomy cannot prevent reoperation due to severe AL in some cases, and an approach other than ileostomy may be required. This study identified the risk factors of AL and reoperation due to AL in patients with diverting ileostomies. Methods Patients diagnosed with CRC who underwent resection surgery accompanied by diverting ileostomy between January 2015 and December 2023 were included. We analyzed the risk factors for AL and reoperation due to AL. Stoma-related complications and perioperative results of stoma reversal surgery were also analyzed. Results In total, 120 patients were enrolled. AL occurred in 21 (17.5%) patients. Multivariate analysis revealed that tumor location in the lower rectum was the only risk factor for AL (P = 0.0095). Of these 21 patients, four (19.0%) required reoperation, while 17 (81.0%) recovered without reoperation. The rates of T4 tumors (P = 0.022) and stenosis (P < 0.001) were significantly higher in the reoperation group. Among the 120 patients, a high-output stoma was observed in 36 patients (30.0%), and outlet obstruction occurred in 19 patients (15.8%). In stoma reversal surgery, two patients (1.7%) experienced severe complications (Clavien–Dindo grade ≥ III). Conclusion Lower rectal tumors are associated with a high risk of AL, and diverting ileostomy should be considered in such cases. However, in patients with stenosis and T4 invasion, the merits of ileostomy might be restricted, and an alternative strategy, such as colostomy, might be required.