Novel quantitative assessment indicators for efficiency and precision of endoscopic submucosal dissection in animal training models by analyzing an electrical surgical unit

Objectives: Although endoscopic submucosal dissection (ESD) training is important, quantitative assessments have not been established. This study aimed to explore a novel quantitative assessment system by analyzing an electrical surgical unit (ESU). Methods: This was an ex vivo study. Step one: to identify the novel efficiency indicators, 20 endoscopists performed one ESD each, and we analyzed correlations between their resection speed and electrical status. Step two: to identify the novel precision indicators, three experts and three novices performed one ESD each, and we compared the stability of the electrical status. Step three: three novices in step two performed 19 additional ESDs, and we analyzed the learning curve using novel indicators. Results: Step one: the percentage of total activation time (AT) of ESU in the procedure time (β coefficient, 0.80; P < 0.01) and AT required for submucosal dissection (β coefficient, −0.57; P < 0.01) were significantly correlated with the resection speed. Step two: coefficient of variation of the AT per one pulse (0.16 [range, 0.13–0.17] vs. 0.26 [range, 0.20–0.41], P = 0.049) and coefficient of variation of the peak electric power per pulse during mucosal incision (0.14 [range, 0.080–0.15] vs. 0.25 [range, 0.24–0.28], P = 0.049) were significantly lower in the experts than in the novices. Regarding the learning curve, the percentage of total AT of ESU in the procedure time and AT required for submucosal dissection had a trend of improvement. Conclusion: Novel indicators identified by analyzing ESU enable quantitative assessment for endoscopist's skill.