Meta-analysis of operative techniques for fissure-in-ano

Operative techniques commonly used for fissure-in-ano include anal stretch, open lateral sphincterotomy, closed lateral sphincterotomy, posterior midline sphincterotomy, and to a lesser extent dermal flap coverage of the fissure. Reports of direct comparisons among these techniques are variable in their results and for the most part underpowered. A rigorous analysis of the combined reports was therefore undertaken to determine whether a preferred technique for fissure surgery can be elucidated.

MEDLINE was searched for all published reports using the key words "surgery" and "anal fissure." All reports in which there was a direct comparison between at least two operative techniques were reviewed, and when more than one report existed for any given pair, that report was included in the meta-analysis. If crude data were not presented in the report, the authors were contacted, and crude data were obtained. The two most commonly used end points in these reports were persistence of the fissure and postoperative incontinence of flatus. These are the only two end points included in the meta-analysis. The meta-analysis was performed using Epi-Info software obtained from the Centers for Disease Control and Prevention (www.cdc.gov).

Seventeen publications fulfilled the criteria of the study, encompassing 2,727 patients. Significant differences were found for both persistence and incontinence to flatus when comparing anal stretch to all forms of sphincterotomy. No significant difference was found comparing open to closed lateral internal sphincterotomy for persistence or incontinence. Posterior midline sphincterotomy was not significantly different from lateral sphincterotomy related to persistence or incontinence.

Internal anal sphincterotomy is superior to anal stretch and should probably be performed in the lateral location, although both the open and closed techniques seem equally efficacious.