Purpose: Nitric oxide is an important neurotransmitter mediating internal anal sphincter relaxation. Patients suffering from fissure-in-ano were treated with topical nitroglycerine. The clinical evidence for therapeutic adequacy was examined in a prospective, randomized study.
Methods: The study included 35 patients with acute and chronic anal fissures. In Group A, including 20 patients with the clinical diagnosis of acute (12 patients) and chronic (8 patients) anal fissures, treatment consisted of topical nitroglycerine. Group B, consisting of 15 patients (10 acute and 5 chronic fissures), received topical anesthetic gel during therapy. Manometry was performed before and on days 14 and 28 in the course of topical application of either 0.2 percent glyceryl trinitrate ointment or anesthetic gel (lignocaine). Anal pressures were documented by recording the maximum resting and squeeze pressures.
Results: In 60 percent of cases treated with topical nitroglycerine (Group A, 11 acute (91.6 percent) and 1 chronic (12.5 percent)), anal fissure healed within 14 days, in contrast to Group B in which no healing was observed. The healing rate after one month was 80 percent (11 acute (91.6 percent); 5 chronic (62.5 percent)) in Group A and was significantly superior to Group B (healing rate, 40 percent: 5 acute (50 percent); 1 chronic (20 percent)).
Discussion: Previously increased maximum resting pressures decreased from a mean value of 110 to 87 cm H2O. This represents a mean reduction of 20 percent (P = 0.0022). We also noted a significant decrease in squeeze pressures (from 177.8 to 157.9 cm H2O (11 percent)). However, anal pressures did not decrease significantly in the four chronic fissure patients from Group A, whose fissures only healed after 28 days. Similarly to these Group A chronic fissure patients, no significant anal pressure reduction was observed in any Group B patients. Except for mild headache (20 percent), no side effects of treatment were reported.
Conclusions: Topical application of nitroglycerine represents a new, easily handled, and effective alternative in the treatment of anal fissures. All of our patients reported a dramatic reduction in acute anal pain. However, it should be noted that a lack of sphincter tone reduction is a likely reason for the great tendency of chronic anal fissures to recur.