title: Usefulness of training using animal models for colorectal endoscopic submucosal dissection: is experience performing gastric ESD really needed?
abstract: OBJECTIVE
  Despite the clinical advantages of colorectal endoscopic submucosal dissection (ESD), an effective training system, especially for Western endoscopists, has been challenging to establish. Herein, we propose a novel training program using ex vivo animal models and evaluate the learning curve of colorectal ESD trainees without gastric ESD experience.
  
  
  METHODS
  A total of 80 colorectal lesions were prospectively collected and removed by two novice operators. Before human ESD procedures, they received ESD training using an ex vivo porcine "proximal colon" model, which simulates a lumen with many folds and flexions. To assess the validity of our training system, the self-completion and en bloc R0 resection rates, the operation time, and prevalence of complications were compared between the first and latter period. Moreover the factors associated with prolonged operation time were evaluated.
  
  
  RESULTS
  The overall rates of self-completion and en bloc R0 resection were 98 % (78/80) and 100 % (80/80), respectively. The operation time during the first period was significantly longer than that during the latter period (86 ± 50 minutes vs. 60 ± 36 minutes, P = 0.01). Regarding complications, only two cases of perforations and delayed hemorrhage were observed during the first period; however, all of the complications were successfully managed endoscopically. The presence of fibrosis was identified as a significant independent predictor of a prolonged operation time during the first period (coefficient, 5.90; 95 %CI, 2.36 - 9.44, P = 0.002).
  
  
  CONCLUSIONS
  Our trainees achieved high rates of self-completion and R0 resection without severe complications even during the first 20 cases, suggesting that our training programs using ex vivo animal models are useful for trainees without gastric ESD experience.
  
  
  BACKGROUND
  UMIN000013566.
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Ohata
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Nonaka
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Yoshitsugu
authors.initials: Y
authors.lastname: Misumi
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Tsunashima
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Takita
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Minato
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tashima
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Sakai
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Muramoto
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Graduate School of Healthcare, Tokyo Healthcare University, Tokyo, Japan.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Hiejima
authors.affiliation: Division of Gastroenterology, NTT Medical Center Tokyo, Tokyo, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matsuhashi