BOTULINUM TOXIN INJECTIONS IN THE INTERNAL ANAL-SPHINCTER FOR THE TREATMENT OF CHRONIC ANAL-FISSURE - LONG-TERM RESULTS AFTER 2 DIFFERENT DOSAGE REGIMENS

Objective To investigate the effects of two different dosage regimens of botulinum toxin to induce healing in patients with idiopathic anal fissure. Summary Background Data Chronic anal fissure is maintained by contraction of the internal anal sphincter. Sphincterotomy, which is successful in 85% to 95% of patients, permanently weakens the sphincte r and therefore might be associated with anal deformity and incontinen ce. Methods Fifty-seven consecutive outpatients were evaluated. Type A botulinum toxin was injected into the internal anal sphincter. Result s Patients were divided into two treatment groups based on the number of botulinum toxin units injected. Patients in the first group were tr eated with 15 units and retreated with 20 units. Patients in the secon d group were treated with 20 units and retreated with 25 units. Two mo nths after treatment, 10 patients in the first group and 23 patients i n the second group had a healing scar. Symptomatic improvement was obs erved in 13 patients in the first group and in 24 patients in the seco nd group. Statistical analysis showed that resting anal pressure varie d from baseline values as a function of treatment; in contrast, the tr eatment had no effect on maximum voluntary pressure. Long-term healing was achieved in 13 patients in the first group and in all patients in the second group who underwent a complete treatment. Conclusions Botu linum toxin is safe and effective in the treatment of anal fissure. It is less expensive and easier to perform than surgical treatment. No a dverse effects resulted from injections of the toxin. The higher dosag e is effective in producing long-term healing without complications.