ABSTRACT
BACKGROUND: Topical glyceryl trinitrate (GTN) may produce healing of anal fissure by decreasing the high resting anal sphincter pressure in these patients. The present study assessed the efficacy of GTN in chronic anal fissure in a double-blind placebo-controlled trial. METHOD: Patients with chronic anal fissure (for more than 8 weeks) underwent measurement of maximum anal resting pressure (MARP) before and 12 minutes after application of either 0.2% GTN or placebo ointment in a randomized manner. They then received twice-daily local application of their respective ointment for 6 weeks. Symptoms and healing of fissure were assessed; patients were evaluated at 3 months for evidence of relapse. RESULTS: 19 adult patients (12 men) were studied; 10 received GTN and 9 placebo. Mean (SD) MARP decreased from 131.0 (32.3) cm H2O to 93.5 (28.4) cm H2O (p<0.05) with GTN and from 150.5 (36.9) cm H2O to 142.8 (35.0) cm H2O (p=ns) with placebo. Fissure healed in 7 of 10 patients treated with GTN and 2 of 9 patients treated with placebo (p<0.05). There was no relapse of fissure in either group. CONCLUSION: Local application of GTN was effective in healing chronic anal fissure.