title: Safety and efficacy of endoscopic submucosal dissection of rectal tumors extending to the dentate line.
abstract: OBJECTIVE
  Unique anatomical features render endoscopic resection for rectal tumors extending to the dentate line (RTDL) technically challenging. The aim of this study was to evaluate the feasibility of endoscopic submucosal dissection (ESD) for RTDLs.
  
  
  METHODS
  This retrospective study compared ESD for RTDLs with proximal rectal tumors between September 2002 and June 2012. En bloc resection rate, R0 resection rate, complications, and tumor recurrences were assessed.
  
  
  RESULTS
  A total of 45 RTDLs (median age 69 years; 15 males; median lesion size 38.4 mm) and 94 proximal rectal tumors were identified. En bloc resection and R0 resection rates were 95.6 % (43/45) and 53.3 % (24/45), respectively. The perforation rate was 4.4 %. Compared with proximal rectal ESD, ESD for RTDLs showed longer procedure time (104 vs. 60 minutes; P < 0.001), lower R0 resection rate (53.3 % vs. 70.2 %; P = 0.019), and more frequent high grade fever (22.2 % vs. 4.3 %; P = 0.002). No residual adenoma was observed at the first surveillance colonoscopy. Recurrence rate did not differ significantly between the two groups.
  
  
  CONCLUSIONS
  ESD for RTDLs demonstrated safety and effectiveness comparable to ESD in proximal rectal lesions.
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Imai
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Kinichi
authors.initials: K
authors.lastname: Hotta
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Department of Gastroenterology, Saku Central Hospital, Saku, Nagano, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Shinohara
authors.affiliation: Division of Gastroenterology, Toshiba Rinkan Hospital, Sagamihara, Kanagawa, Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Ooka
authors.affiliation: Division of Gastroenterology, Toshiba Rinkan Hospital, Sagamihara, Kanagawa, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Shinoki
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kakushima
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Takizawa
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsubayashi
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Oishi
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, Sunto-gun, Shizuoka, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
mesh_terms: D000236:Adenoma / Q000473:pathology / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004210:Dissection / Q000379:methods*; D016099:Endoscopy, Gastrointestinal / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome