Risk factors for small bowel obstruction after open rectal cancer resection

Small bowel obstruction (SBO) is observed in around 10% of patients with prior open abdominal surgery. Rectal resection causes the highest readmission rates. The aim of this study was to investigate risk factors for readmission for SBO and causes for SBO in patients who needed surgery following rectal cancer surgery.

A population-based registry with prospectively gathered data on 752 consecutive patients with rectal cancer who underwent open pelvic surgery between January 1996 and January 2017 was used. Univariable and multivariable regression analysis was performed, and the risk of SBO was assessed.

In total, 84 patients (11%) developed SBO after a median follow-up time of 48 months. Of these patients, 57% developed SBO during the 1st year after rectal cancer surgery. Surgery for SBO was performed in 32 patients (4.3%), and the cause of SBO was stoma-related in one-fourth of these patients. In the univariable analysis previous RT and re-laparotomy were found as risk factors for readmission for SBO. Re-laparotomy was an independent risk factor for readmission for SBO (OR 2.824, CI 1.129-7.065, P = 0.026) in the multivariable analysis, but not for surgery for SBO. Rectal resection without anastomoses, splenic flexors mobilization, intraoperative bleeding, operative time were not found as risk factors for SBO.

One-tenth of rectal cancer patients who had open surgery developed SBO, most commonly within the 1st postoperative year. The risk of SBO is greatest in patients with complications after rectal cancer resection that result in a re-laparotomy.