Sphincter-preserving techniques for anal fistulas in Japan.

After the articles by Eisenhammer, Parks, Hanley, and Goligher and the classification system established by Sumikoshi, surgeons in Japan became very active in creating and modifying new sphincter-preserving surgical procedures for low intersphincteric and ischiorectal fistulas. This article reviews the literature, summarizes each procedure, identifies the transitions, and discusses recurrence rates, cures, and subsequent variations. Japanese surgeons favor sphincter-preserving techniques for low intersphincteric fistulas that involve partial or complete coring out of fistula tracts. Common sphincter-preserving procedures for ischiorectal fistulas involve coring-out techniques and muscle-filling procedures. The recurrence rates of sphincter-preserving procedures for low intersphincteric fistulas are between 5 and 6 percent, whereas the recurrence rates for the sphincter-preserving techniques used on ischiorectal fistulas are in the 7 to 10 percent range.