Background: 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 between operative techniques for anal fissure are variable in their results. These reports are either subject to selection bias (in non-randomized studies) or observer bias (in almost all studies) or have inadequate numbers of patients enrolled to answer the question of efficacy.
Objectives: To determine the best technique for fissure surgery.
Search strategy: MEDLINE and the Cochrane Library were searched using the key words: "surgery, anal fissure". Additional search terms such as "anal sphincterotomy" and "anal fissure therapy" disclosed no additional reports. The list of cited references in all included reports also was helpful in finding additional comparative studies.
Selection criteria: 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. If crude data were not presented in the report, the authors were contacted and crude data obtained.
Data collection and analysis: The two most commonly used end points in all reported studies were persistence of the fissure and post operative incontinence of flatus. These are the only two endpoints included in the meta-analysis.
Main results: Anal stretch has a higher risk of fissure persistence than internal sphincterotomy and also a significantly higher risk of minor incontinence than sphincterotomy. The combined results of open versus closed partial lateral internal sphincterotomy show little difference between the two procedures both in fissure persistence and risk of incontinence.
Reviewer's conclusions: Anal stretch and posterior midline internal sphincterotomy should probably be abandoned in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open and closed partial lateral internal sphincterotomy appear to be equally efficacious. More data are needed to assess the effectiveness of posterior internal sphincterotomy.