title: Per anum intersphincteric rectal dissection with direct coloanal anastomosis for lower rectal cancer: the ultimate sphincter-preserving operation.
abstract: OBJECTIVE
  The most important goal of sphincter-preserving operations for rectal cancer is to secure a distal surgical margin of safety and the anal sphincter. However, it is not always easy to transect the rectum and to secure a distal surgical margin of safety through the abdominal approach for tumors situated extremely low in the rectum. The aim of this study was to describe and to evaluate a new technique of per anum intersphincteric rectal dissection and coloanal anastomosis.
  
  
  METHODS
  The rectum, including the entire width of the internal anal sphincter, is transected circumferentially via the anal route to secure the surgical margin of safety under direct vision and is mobilized proximally as far as possible through the intersphincteric plane. Per anum coloanal anastomosis is performed following transabdominal resection of the rectum.
  
  
  RESULTS
  This technique has been used in 12 patients. There have been no instances of short-term or long-term anastomotic complications.
  
  
  CONCLUSIONS
  This technique is safe when anastomosis must be performed at the dentate line. It is the best sphincter-preserving operation for lower rectal cancer and does not result in serious postoperative anal dysfunction.
authors.affiliation: Department of Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Teramoto
authors.forename: M
authors.initials: M
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Kitajima
mesh_terms: D001003:Anal Canal / Q000601:surgery*; D000714:Anastomosis, Surgical / Q000379:methods; D003106:Colon / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016737:Proctocolectomy, Restorative / Q000379:methods*; D012004:Rectal Neoplasms / Q000601:surgery*; D012007:Rectum / Q000601:surgery*