Treatment of Chronic Anal Fissure, Lateral Internal Sphincterotomy Versus Local Injection of High Dose Botulinum Toxin: A Randomized Clinical Trial

This randomized comparative clinical trial was carried out over 2 year in the period between January 2018 and December 2019 on total number of 96 patients suffering chronic anal fissure the participants were randomly allocated into two groups each 48 patients ; group (1) the botulinum ( Botox) group, they were subjected to 80 IU Botox injection as an intervention for treatment of chronic anal sphincter, and group 2 the sphincterotomy group, underwent internal sphincterotomy as a surgical intervention for treatment of chronic anal fissure.

The study was approved by the institutional review board and the local ethical committee of our university hospital The condition of the current study is chronic anal fissure defined as the presence of anterior or posterior chronic anal wound with skin tag at its lower end and hypertrophied anal papilla at its upper end with induration around its edges in patients complaining of anal pain, constipation, and/or fresh anal bleeding for at least two months.

Randomization was achieved using computer generated cards. Inclusion criteria; patients suffering chronic anal fissure aged above 16 years old Exclusion criteria; those with previous anal surgery, complicated anal fissure, unfit for surgery, specific disease as Crohn's disease and ulcerative colitis, malignancy, anal fistula or abscess those with systemic disease requiring treatment with calcium channel blockers and /or nitrates Patients of both groups were subjected to thorough history taking, clinical examination, digital rectal examination and anorectal manometry for diagnosis of chronic anal fissure and exclusion of any other anal condition and incontinence, patient signed an informed written consent, routine preoperative investigations performed as usual.

Interventions;

1. Botulinum toxin (Botox) injection; was performed under general anesthesia in the lithotomy position, where 80 IU of Botox was injected in four positions each 20 IU namely in 5, 7, 11, and 1 O'clock positions in the intersphincteric space not deeper than the midpoint of the anal canal.
2. Lateral internal sphincterotomy; was performed under general anesthesia where the lower part of the internal sphincter was cut by electrocautery on the left lateral position to an extent not beyond the proximal end of the fissure, the sentinel pile was also removed.