[The treatment of anal fissure with botulinum toxin]

The use of botulinic toxin has led to new perspectives in the treatment of anal fissures. However, the most effective dose, length of treatment and long term results require further studies to determine the most appropriate place for this therapy.

A prospective study was carried out in 40 consecutive patients diagnosed with anal fissure of more than 3 months in duration. Fifteen U of botulinic toxin were injected in the external anal sphincter and the evolution was studied over 6 months. The patients completed a pain scale designed for the study after 1 week, and 1, 3 and 6 months after the injection. The degree of pain, healing and need for surgery were evaluated during the follow up.

Healing occurred in 17 patients after 3 months (42.5%) and after 6 months in 3 more patients (50%). Eight patients required surgery during follow up (20%). In the remaining patients, the pain significantly decreased allowing conservative management. Only 2 patients demonstrated incontinence for slight, transitory gases (5%).

Injection of botulinic toxin is well tolerated and is relatively effective as an alternative in the treatment of anal fissure. Most patients respond in the first days after treatment and the effect persists for at least 6 months. The use of doses higher than those used in this study merits further studies.