Glyceryl trinitrate ointment for the treatment of chronic anal fissure - Results of a placebo-controlled trial and long-term follow-up

PURPOSE: A randomized, double-blind, placebo-controlled trial was performed to test the effect of intra-anal glyceryl trinitrate ointment in patients with chronic anal fissures that would normally have been treated by sphinct erotomy. Long-term follow-up was then performed to assess fissure healing. METHODS: Patients with chronic anal fissures were randomly assigned to 0.2 percent topical glyceryl trinitrate ointment or placebo. Anal manometry was performed before treatment, one week later, and 48 hours after treatment c eased at four weeks. Fissure healing was assessed by an observer blinded to the treatment arm. Pain was recorded on a linear analog scale. At the comp letion of the trial, treatment was continued with glyceryl trinitrate until fis sure healing was obtained or lateral sphincterotomy was performed if r equired for ongoing pain. A long-term follow-up assessment was made at a me an of 29 (range, 25-33) months. RESULTS: There was a significant reduction in anal resting pressure at Week 1 with glyceryl trinitrate (P = 0.001) but not placebo, and at Week 4 there was a significant reduction in pain score with glyceryl trinitrate (P = 0.001) and placebo (P = 0.01) and a signific ant reduction in fissure grade with glyceryl trinitrate (P = 0.0001) and pl acebo (P = 0.02). Forty-six percent of fissures healed with glyceryl trinit rate and 16 percent healed with placebo (P = 0.001). At long-term follow-up in 40 of 43 patients, 14 patients (35 percent) had undergone lateral sphin cterotomy, and in the remainder who were treated with glyceryl trinitrate t here was a significant reduction in pain score (P = 0.0002). Seventeen pati ents attended for repeat manometry and fissures were healed with glyceryl t rinitrate in ten (59 percent) cases. nigh internal sphincter pressures pers isted at long-term follow-up in patients successfully treated with glyceryl trinitrate, indicating that the sphincter is the cause rather than effect of anal fissure. CONCLUSION: Topical glyceryl trinitrate produces a success ful internal sphincterotomy, which resulted in long-term healing of 59 perc ent of chronic anal fissures and significant improvement: in pain. Internal sphincter spasm is the cause of chronic anal fissure.