Delayed Disruption of Anastomosis Caused by Severe Radiation Proctitis: A Case Report

Abstract

The role of radiotherapy in the treatment of rectal cancer has been well established. However, radiotherapy-associated complications are sometimes unavoidable. Chronic radiation proctitis is a representative complication, with the incidence ranging from 5% to 20%, which in turn, can cause other severe complications such as necrosis, perforation, fistula, and stricture. Although radiation influences anastomosis wound healing, delayed anastomotic disruption caused by severe radiation proctitis is extremely rare. Here, we present a case of delayed anastomotic disruption after postoperative radiotherapy. A 66-year-old woman presented with bloody diarrhea. She had undergone low anterior resection for rectal cancer 11 months ago, and had received 28 times radiotherapy for 6 weeks with a total radiation dose of 5040 cGy, postoperatively. Sigmoidoscopy showed circumferential necrosis and gangrenous change above the previous anastomosis site on the rectum, and pelvic magnetic resonance imaging revealed disruption of the previous anastomosis site. During the operation, the affected colonic segment, including the anastomosis site, was resected and coloanal pull-through anastomosis and ileostomy were performed. This case presents an unusually severe form of late radiation injury. Although radiotherapy is necessary for the treatment of advanced rectal cancer, predicting factors for radiation injury should be clarified for personalized treatment.