A COMPARISON OF BOTULINUM TOXIN AND SALINE FOR THE TREATMENT OF CHRONIC ANAL-FISSURE

Background Chronic anal fissure is a tear in the lower half of the ana l canal that is maintained by contraction of the internal anal sphinct er. Sphincterotomy, the most widely used treatment, is a surgical proc edure that permanently weakens the internal sphincter and may lead to anal deformity and incontinence.Methods We conducted a double-blind, p lacebo-controlled study of botulinum toxin for the treatment of chroni c anal fissure in 30 consecutive symptomatic adults. All the patients received two injections (total volume, 0.4 ml) into the internal anal sphincter; the treated group (15 patients) received 20 U of botulinum toxin A, and the control group (15 patients) received saline. Success was defined as healing of the fissure (formation of a scar), and sympt omatic improvement was defined as the presence of a persistent fissure without symptoms.Results After two months, 11 patients in the treated group and 2 in the control group had healed fissures (P=0.003); 13 in the treated group and 4 in the control group had symptomatic relief ( P = 0.003). The maximal voluntary pressures were similar to those at b ase line in both groups, and the resting anal pressure was reduced by 25 percent in the treated group but not in the control group. Three pa tients in the control group later underwent sphincterotomy, and 10 rec eived botulinum-toxin injections (20 U). Of the latter, seven had heal ed fissures after two months; the other three left the study and under went surgery. Four patients in the treated group were later re-treated (with 25 U of botulinum toxin); all had healed fissures after two mon ths. One patient in the control group had temporary flatus incontinenc e after treatment with botulinum toxin. No relapses occurred during an average of 16 months of follow-up. Conclusions Local infiltration of botulinum toxin into the internal anal sphincter is an effective treat ment for chronic anal fissure. (C) 1998, Massachusetts Medical Society .