title: Factors associated with technical difficulties and adverse events of colorectal endoscopic submucosal dissection: retrospective exploratory factor analysis of a multicenter prospective cohort.
abstract: BACKGROUND
  Colorectal endoscopic submucosal dissection (C-ESD) is a promising but challenging procedure. We aimed to evaluate the factors associated with technical difficulties (failure of en bloc resection and procedure time, ≥2 h) and adverse events (perforation and bleeding) of C-ESD.
  
  
  METHODS
  We conducted a retrospective exploratory factor analysis of a prospectively collected cohort in 15 institutions. Eight-hundred sixteen colorectal neoplasms larger than 20 mm from patients who underwent C-ESD were included. We assessed the outcomes of C-ESD and risk factors for technical difficulties and adverse events.
  
  
  RESULTS
  Of the 816 lesions, 767 (94 %) were resected en bloc, with a median procedure time of 78 min. Perforation occurred in 2.1 % and bleeding in 2.2 %. Independent factors associated with failure of en bloc resection were low-volume center (<30 neoplasms), snare use, and poor lifting after submucosal injection. Factors significantly associated with long procedure time (≥2 h) were large tumor size (≥4 cm), low-volume center, less-experienced endoscopist, CO2 insufflation, and use of two or more endoknives. Poor lifting was the only factor significantly associated with perforation, whereas rectal lesion and lack of a thin-type endoscope were factors significantly associated with bleeding. Poor lifting after submucosal injection occurred more frequently for nongranular-type laterally spreading tumors (LST) and for protruding and recurrent lesions than for granular-type LST (LST-G).
  
  
  CONCLUSIONS
  Poor lifting after submucosal injection was the risk factor most frequently associated with technical difficulties and adverse events on C-ESD. Less experienced endoscopists should start by performing C-ESDs on LST-G lesions.
authors.affiliation: Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3 Nakamichi, Higashinari-ku, Osaka, 537-8511, Japan, takeuti-yo@mc.pref.osaka.jp.
authors.forename: Yoji
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iishi
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikematsu
authors.forename: Shin-Ei
authors.initials: SE
authors.lastname: Kudo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sano
authors.forename: Takashi
authors.initials: T
authors.lastname: Hisabe
authors.forename: Naohisa
authors.initials: N
authors.lastname: Yahagi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Saitoh
authors.forename: Masahiro
authors.initials: M
authors.lastname: Igarashi
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Hiroo
authors.initials: H
authors.lastname: Yamano
authors.forename: Seiji
authors.initials: S
authors.lastname: Shimizu
authors.forename: Osamu
authors.initials: O
authors.lastname: Tsuruta
authors.forename: Yuji
authors.initials: Y
authors.lastname: Inoue
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Watanabe
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujii
authors.forename: Noriya
authors.initials: N
authors.lastname: Uedo
authors.forename: Toshio
authors.initials: T
authors.lastname: Shimokawa
authors.forename: Hideki
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Kenichi
authors.initials: K
authors.lastname: Sugihara
mesh_terms: D000368:Aged; D002245:Carbon Dioxide; D002983:Clinical Competence; D020685:Colonoscopes; D003113:Colonoscopy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D004210:Dissection / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D005163:Factor Analysis, Statistical; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology; D006801:Humans; D007327:Insufflation; D007413:Intestinal Mucosa / Q000601:surgery*; D007416:Intestinal Perforation / Q000209:etiology; D008297:Male; D061646:Operative Time; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide