title: Retrospective study of technical aspects and complications of endoscopic submucosal dissection for laterally spreading tumors of the colorectum.
abstract: OBJECTIVE
  Laterally spreading tumors - non granular type (LST-NG) are more often considered candidates for endoscopic submucosal dissection (ESD) than laterally spreading tumors - granular type (LST-G), because of their higher potential for submucosal invasion. However, ESD for LST-NG can be technically difficult. The aim of our study was to compare our ESD results for LST-NG and for LST-G.
  
  
  METHODS
  Ninety-nine LST-NG and 169 LST-G measuring 20 mm in size or more were removed by ESD. We retrospectively evaluated the clinicopathological features of the tumors and treatment results (en bloc resection rate, procedure time and speed, rate of use of ancillary devices, and complication and recurrence rates).
  
  
  RESULTS
  Histopathology revealed that there were more submucosally invasive lesions in the LST-NG than in the LST-G group (28 % vs. 9 %; P < 0.0001). The en bloc resection rate, en bloc R0 resection rate, and en bloc curative resection rate of LST-NG were similar to those of LST-G (LST-NG: 99 %, 98 %, and 88 %; LST-G: 99 %, 98 %, and 91 %). In LST-NG, the median procedure time tended to be longer (LST-NG: 69 min; LST-G: 60 min) and the median procedure speed was slower (LST-NG: 0.15 cm (2)/min; LST-G: 0.25 cm (2)/min; P < 0.0001). Use of ancillary devices was higher for LST-NG (38 % vs. 15 % for LST-G; P < 0.0001), as was the perforation rate (5.1 % vs. 0.6 % for LST-G; P = 0.027). No recurrence was seen in either group.
  
  
  CONCLUSIONS
  ESD was an effective treatment method for both LST-NG and LST-G. However, the degree of technical difficulty appears higher for LST-NG than for LST-G lesions, as shown by the lower dissection speed and higher perforation rate. ESD for LST-NG should probably be performed by those with significant experience of colorectal ESD.
authors.affiliation: Department of Endoscopy, Kobe University Hospital, Kobe, Japan. toyonaga@med.kobe-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Toyonaga
authors.forename: M
authors.initials: M
authors.lastname: Man-i
authors.forename: T
authors.initials: T
authors.lastname: Fujita
authors.forename: J E
authors.initials: JE
authors.lastname: East
authors.forename: E
authors.initials: E
authors.lastname: Nishino
authors.forename: W
authors.initials: W
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Morita
authors.forename: T
authors.initials: T
authors.lastname: Sanuki
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: H
authors.initials: H
authors.lastname: Kutsumi
authors.forename: H
authors.initials: H
authors.lastname: Inokuchi
authors.forename: T
authors.initials: T
authors.lastname: Azuma
mesh_terms: D000368:Aged; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D004210:Dissection / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D007416:Intestinal Perforation / Q000209:etiology; D008297:Male; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies