We report a rare case of a large presacral fistula that developed after proton beam therapy for locally recurrent colorectal cancer and was successfully closed using a posterior thigh flap. A woman who had been treated with sigmoidectomy at age 45 years and subsequently underwent surgery for pelvic and peritoneal recurrence developed a pelvic abscess that left a fistula. At age 48 years, she developed a sacral recurrence and underwent proton beam therapy. The fistula progressed to a presacral cavity with exposure of the small intestine and bladder, causing severe pain that prevented sitting. The fistula was surgically debrided, with staged closure using a posterior thigh flap. Postoperatively, the fistula was closed without bladder or intestinal leakage, the pain resolved, and the patient regained her ability to sit comfortably. Coverage of the exposed viscera with a well-vascularized flap resulted in reliable wound closure and markedly improved quality of life.
Morioka et al. (Thu,) studied this question.