Formalin instillation for hemorrhagic radiation proctitis

Although formalin instillation has been proven to be an effective treatment of hemorrhagic radiation proctitis, different techniques with varying success rates have been reported. The aim of this study was to assess our experience with formalin instillation for the treatment of radiation proctitis. After Institutional Review Board approval, all patients who presented with radiation proctitis and were treated with 4% formalin instillation were identified from a prospective database. Techniques of instillation were as follows: a formalin-soaked sponge stick was applied via a proctoscope (SS) and placed at each quadrant with a mean contact of 2.5 minutes (range, 0.5-3 minutes), or the formalin solution was introduced through a proctoscope in aliquots for a total of 350 to 400 mL irrigation (IR), with a mean contact time of 30 seconds in each aliquot. The patients were divided into two groups according to the method of formalin instillation and their outcomes were compared. Between March 1995 and September 2003, 21 patients who underwent formalin treatment were identified: 17 patients were in the SS and 4 patients were in the IR group. The mean age was 74.8+/-6.4 years and 70.5+/-6.8 years and the male/female ratio was 16:1 and 3:1 in the SS and IR groups, respectively. Indications for radiation therapy were prostate cancer in 19 patients: 16 (95.1%) SS patients and 3 (75%) IR patients. Four (23.5%) patients in the SS group were receiving anticoagulants or antiplatelet medications before the procedure. The mean duration of bleeding before formalin instillation was 11.7 months (range, 2-48 months) in the SS and 10.5 months (range, 7-12 months) in the IR group. Sixteen (94.1%) patients in the SS and 4 (100%) in the IR group had previous treatments for radiation proctitis, including hydrocortisone enema, 5-aminosalicylate mesalamine, and endoscopic coagulation. Eight (47.1%) patients in the SS and 2 (50%) in the IR group received a preprocedural blood transfusion, and 1 patient in the SS group required a blood transfusion after the formalin instillation. This patient subsequently underwent restorative proctosigmoidectomy because of persistent bleeding. The mean length of the procedure was 27.1+/-10.8 minutes in the SS group and 22.5+/-6.5 minutes in the IR group. The bleeding was successfully stopped on the first attempt in 14 patients (82.4%) in the SS group and 3 (75%) in the IR group. The instillation was repeated in 1 patient (5.9%) in the SS group and in 1 (25%) in the IR group. Four patients (23.5%) in the SS group experienced rectal pain after the procedure. One patient (5.9%) developed a new onset of fecal incontinence, while another (5.9%) had anococcygeal pain accompanied by worsening of fecal incontinence. One patient (25%) in the IR group developed acute colitis consistent with formalin instillation, which was managed by intravenous antibiotics. The patients were followed for a mean of 10 months (range, 1 to 38 months). Formalin instillation is effective in controlling refractory hemorrhage secondary to radiation proctitis.