Botolinum toxin-A in chronic anal fissure

We evaluated the results of injecting different doses of botolinum toxin-A (BT) for the treatment of chronic anal fissures (CAF). All patients (pts) with posterior midline CAF were included in a randomized, prospective trial. Five (group A) or 7.5 (group B) units of diluted BT in 0.9% NaCl was injected on each side of the anal orifice into the internal sphincter, and under the anal fissure (total dose, 15 and 22.5-units, respectively) after subcutaneous infiltration with 1% lignocaine. 78 pts (41 males) were included in the study; 40 and 38 pts in group A and B, respectively. Median age was 32 years (range, 18-62 years). One month after BT injection, 32 (80%) and 33 pts (87%) were cured in group A and B, respectively (p>.05). 13 pts with persistent symptoms were reinjected with BT, but none of them was cured and lateral internal sphincterotomy was performed. One patient (1.3%) had a perianal abscess which was drained. During a median follow up time of 18 months (range, 10 to 36 months), 3 pts in each group had recurrent fissures (32 pts in group A, 9.4% and 33 pts in group B, 9%, p > .05) 8 to 22 months after BT injection. Conclusion: Injection of botolinum toxin -A into the internal sphincter is a reliable and safe option for non-surgical treatment of CAF.