FUNCTIONAL PERINEAL COLOSTOMY WITH PUDENDAL NERVE ANASTOMOSIS FOLLOWING ANORECTAL RESECTION - A CADAVER OPERATION STUDY ON A NEW PROCEDURE

Background. We have previously studied functional perineal colostomy t hat used skeletal muscle with pudendal nerve anastomosis (PNA) followi ng anorectal resection in an animal model. In that study the neosphinc ter reconstructed with PNA achieved the proper functions of the extern al anal sphincter resulting in a satisfactory defecatory condition. Th is study was a preliminary step before applying this procedure to huma n beings. Methods, We reconstructed a new anal sphincter by using the lower part of the gluteus maximus muscle (lower GMM) with PNA in a tot al of six sides of four human cadavers and investigated the anatomic p roblems associated with this procedure. Results, We classified the bra nching patterns of the inferior gluteal nerve into three types. The le ngth of the branches of the inferior gluteal nerve to the lower GMM va ried from 32 to 76 mm (median, 57 mm). The length of the pudendal nerv e (PN) passing out below the sacrotuberous ligament varied from 21 to 44 mm (median, 29.5 mm). The PN was anastomosed to the nerve innervati ng the lower GMM with the redundancy of 17 to 36 mm (median, 24.5 mm). In all cases the anal sphincter reconstruction with a PNA maneuver wa s anatomically feasible by using the lower GMM. The length of the new anal canal was 65 to 80 mm (median, 67.5 mm). Conclusions. The PNA man euver was an anatomically applicable method to make a neoanus in human beings. Preparation for the application of this method to human being s was accomplished.