Application of 10 percent formalin for the treatment of radiation-induced hemorrhagic proctitis

PURPOSE: Rectal instillation of 4 percent formalin solution has been described as a successful treatment for hemorrhagic radiation proctitis recalcitrant to medical treatment. We present our experience with a new method of treatment involving the topical application of 10 percent buffered formalin, which is well tolerated and suitable for office use. METHODS: Patients with marked or refractory rectal bleeding and clinical features consistent with radiation proctitis were reviewed. Treatment involved direct application of a 10 percent buffered formalin solution to the affected mucosa using a 16-inch cotton tip applicator applied through a proctoscope in the office setting. RESULTS: A total of 100 patients with a mean age of 75 (range, 49-91) years were followed for 18 (range, 1-79) months. The interval from radiation exposure to formalin treatment was 21 months. Overall, 93 percent of patients had cessation of bleeding after an average of 3.5 formalin applications at two-week to four-week intervals. Patients with severe (Grade 3) proctitis and those taking aspirin required an average of 1.5 additional treatments. A total of eight patients rebled at a mean of 24 months from treatment; however, all responded to further applications of formalin. Three patients complained of anal pain and one experienced dizziness postprocedure for a complication rate of 1.1 percent. CONCLUSIONS: We present a simple, cost-effective, and well-tolerated method of controlling hemorrhagic radiation proctitis. It is performed by using materials readily available in the office of a colon and rectal surgeon, eliminating the need for bowel preparation, anesthesia, or a surgical suite.