Comparison of glycerine trinitrate and botulinum toxin-a for the treatment of chronic anal fissure: long-term results.

Purpose: This study was designed to compare the efficacy of two different "chemical sphincterotomies" for chronic anal fissure.
Methods: From January to December 2001, 30 consecutive patients (17 males; mean age, 41.8 years) with chronic posterior anal fissure were enrolled. The patients were randomly assigned to receive 0.2 percent glycerine trinitrate ointment applied three times daily at the anal margin for eight weeks (Group A) or 20 units Botulinum toxin A injection into the internal anal sphincter on each side of the anterior midline (Group B). The patients were reviewed at 15 days, 1, 3, 6, 12, and every other 12 months. Follow-up ranged between 36 and 46 months. Patients in either group who failed to improve were referred for surgical treatment.
Results: Twelve patients in Group A and 11 in Group B had improvement or relief from symptoms at the first visit. The fissure was healed in ten patients in Group A and in eight in Group B within three months (66.7 and 57.1 percent). Recurrence of the fissure occurred in five patients in each group during the follow-up. The healing rate at three years was 40 and 33.3 percent for Group A and B, respectively. No patients in either group reported serious adverse effects; however, three patients in Group A (20 percent) had transient headache. None had fecal incontinence.
Conclusion: Both treatments may be considered as first-line treatment even if less effective than surgery.