Preoperative radiotherapy for patients with rectal cancer: a risk factor for non-reversal of ileostomy caused by stenosis or stiffness proximal to colorectal anastomosis.

The influence of radiotherapy on permanent stoma and the bowel proximal to anastomosis was not well investigated. The current study aimed to analyze the effect of preoperative radiotherapy on colorectal anastomosis and incidence of non-reversal ileostomy. A total of 184 eligible patients with rectal cancer undergoing loop ileostomy were included. Patients were well selected by excluding some confounding factors and divided into two groups according to whether they received preoperative radiotherapy. Patients with preoperative radiotherapy had higher incidence of non-reversal stoma (12.8%, 0.004) and stenosis or stiffness around anastomosis (21.1%, < 0.01) including 13 patients with stenosis or stiffness proximal to anastomosis. Stenosis proximal to anastomosis was different from anastomotic stricture caused by surgery and could be described by imaging findings. Preoperative radiotherapy prolonged the interval to closure ( 0.008) and was defined as a significant risk factor for permanent stoma (HR, 0.627; 95% CI, 0.405-0.973; 0.04) by multivariate Cox regression analysis. In conclusion, Preoperative radiotherapy increased incidence of non-reversal ileostomy and stenosis or stiffness proximal to anastomosis in rectal cancer patients with radical resection and diverting ileostomy.