Formalin application for the treatment of radiation-induced hemorrhagic proctitis

Radiation-induced hemorrhagic proctitis (RIHP) is a serious complication of pelvic irradiation, and a 4% formalin solution has been used for 20 years in treating this sequelae. The first case involving formalin application for treatment of RIHP in Korea was reported in 1996, but there are no additional studies beyond this date. Our study reviews the use of formalin instillation and selective application. The purpose of this study was to retrospectively evaluate the outcome of such treatments, beginning with the first case at our hospital. From 1996 to 2005, five RIHP patients had received formalin treatment for RIHP symptoms intractable to other medical treatments. All treatments were performed by a single surgeon in the operating room, under spinal anesthesia or intravenous sedation. The mean duration of symptoms before treatment was 15.6 months (which was longer than in other studies), and the transfusion before treatment varied from once per month to twice per week. Using sigmoidoscopy, 100 ml of a 4% formalin solution was instilled directly (or by using a formalin-soaked gauze) and irrigated for five minutes. Formalin-soaked cotton was then applied selectively to focal remnant lesions. Four patients improved after the first treatment, but one patient received the treatment twice because of recurrent symptoms. Complications after treatment included perianal pain (one case), and aggravated incontinence (one case), which improved three months after conservative management. In conclusion, the formalin combination application method in our study is comparable to other formalin treatments for intractable RIHP.