Role of observation of live cases done by Japanese experts in the acquisition of ESD skills by a western endoscopist

Abstract

AIM: To evaluate the role of observation of experts performing endoscopic submucosal dissection (ESD) in the acquisition of ESD skills.

METHODS: This prospective study is documenting the learning curve of one Western endoscopist. The study consisted of three periods. In the first period (pre-observation), the trainee performed ESDs in animal models in his home institution in the United States. The second period (observation) consisted of visit to Japan and observation of live ESD cases done by experts. The observation of cases occurred over a 5-wk period. During the third period (post-observation), the trainee performed ESD in animal models in a similar fashion as in the first period. Three animal models were used: live 40-50 kg Yorkshire pig, explanted pig stomach model, and explanted pig rectum model. The outcomes from the ESDs done in the animal models before and after observation of live human cases (main study intervention) were compared. Statistical analysis of the data included: Fisher’s exact test to compare distributions of a categorical variable, Wilcoxon rank sum test to compare distributions of a continuous variable between the two groups (pre-observation and post-observation), and Kruskal-Wallis test to evaluate the impact of lesion location and type of model (ex-vivo vs live pig) on lesion removal time.

RESULTS: The trainee performed 38 ESDs in animal model (29 pre-observation/9 post-observation). The removal times post-observation were significantly shorter than those pre-observation (32.7 ± 15.0 min vs 63.5 ± 9.8 min, P < 0.001). To minimize the impact of improving physician skill, the 9 lesions post-observation were compared to the last 9 lesions pre-observation and the removal times remained significantly shorter (32.7 ± 15.0 min vs 61.0 ± 7.4 min, P = 0.0011). Regression analysis showed that ESD observation significantly reduced removal time when controlling for the sequence of lesion removal (P = 0.025). Furthermore, it was also noted a trend towards decrease in failure to remove lesions and decrease in complications after the period of observation. This study did not find a significant difference in the time needed to remove lesions in different animal models. This finding could have important implications in designing training programs due to the substantial difference in cost between live animal and explanted organ models. The main limitation of this study is that it reflects the experience of a single endoscopist.

CONCLUSION: Observation of experts performing ESD over short period of time can significantly contribute to the acquisition of ESD skills.

Keywords: Endoscopic submucosal dissection, Training, Animal models, Early gastric cancer, Learning curve

Core tip: Endoscopic submucosal dissection is complex procedure which and requires intense and lengthy training. There is a consensus that an essential component of the training is observation of experts performing endoscopic submucosal dissection (ESD). In this study, we prospectively evaluated the impact of observation of experts performing ESD on the acquisition of ESD skills. Our data show a decrease in time needed to remove the lesion and a decrease in complication rate after the period of observation, which confirm that observing experts while performing ESD has significant impact in acquiring ESD expertise. Interestingly, there was no significant difference in the time needed to remove lesions in different animal models, which has implications in designing training courses or programs due to the substantial difference in cost between live animals and explanted organs.