Novel delivery of botulinum toxin for the treatment of anal fissures

OBJECTIVE: Botulinum toxin A (Botox) has been used as a local treatment for anal fissure since 1994. It effects a reversible chemical sphincterotomy without the need for patient compliance. This study examines the feasibility of injecting the treatment using a needle-less system. PATIENTS AND METHODS: The optimal angle for injection was determined in a preclinical study using fresh porcine specimens. Ten patients with chronic anal fissures were then injected with 20 units Botox at the site of the fissure. They underwent assessment with a visual analogue pain scale, incontinence score and anal manometry pre-injection, at 48 h postinjection and at six and 12 weeks postinjection. They were also examined at the initial and final visits. RESULTS: The optimal angle for injection was 60 degrees . All 10 patients (5 male; median age 40.5 years (range 26-68 years)) attended the 48 h follow up visit but only seven attended the six and 12 week visits. Six of seven patients healed their fissures. The remaining three were contacted by telephone at six months post injection and two of three remained asymptomatic without further treatment. In seven patients who underwent full follow up the median pain score pre-injection was 5.5 out of 10 (range 1-10) and this dropped to a median of 1 (range 0-6) at 12 weeks. The median drop in resting pressure was 47 cm H2O or 37% at six weeks. CONCLUSION: No needle injection of Botox is feasible with similar healing rates and reduction of resting pressure to conventional injection techniques.