Gastric endoscopic submucosal dissection: from animal model to patient.

AIM: To assess whether the use of porcine models is useful for learning endoscopic submucosal dissection (ESD), thus contributing to its subsequent application in human patients. METHODS: This study/learning process was carried out in 3 phases: Phase I: Ex vivo animal; Phase II: In vivo animal; Phase III: Humans. One endoscopist performed 30 gastric ESDs in porcine models, and later 5 gastric ESDs in 5 patients. The ESD was done following the method practiced at the National Cancer Center in Tokyo, Japan. Technical aspects, size, time and speed of ESD, as well as complications were registered. In patients, their clinical, endoscopic and histologic evolution was additionally added. RESULTS: Thirty en bloc ESDs were carried out in animal models. The mean ± SD size of the pieces was of 28.4 ± 1.2 mm, and the time of ESD was 41.7 ± 2.4 min. The time of ESD in the first 15 procedures was 43.0 ± 3.0 min whereas in the next 15 procedures, the time was 40.3 ± 3.9 min, P = 0.588. The speed in the first 15 ESDs was 1.25 ± 0.11 cm(2)/min vs 2.12 ± 0.36 cm(2)/min in the remaining 15, P = 0.028. There were no complications. In patients, 5 lesions were resected en bloc. The size of the pieces was 25.2 ± 5.1 mm and the time was 85.0 ± 25.6 min. Endoscopic and histological controls did not show evidence of residual neoplastic tissue. CONCLUSION: A sequential ESD training program of a unique endoscopist, based on the practice in porcine models, contributed to learning ESD for its subsequent application in humans, yielding good results in efficacy and safety.

[Endoscopic inanimate biological simulators for training in endoscopic mucosal dissection]. / Entrenamiento en la disección endoscópica de la submucosa "mediante el uso de simuladores biológicos inanimados.

BACKGROUND: Simulators have been used as a training method; they allow training, skill development, standardization of techniques and the performance of a greater number of risk-free procedures. Endoscopic submucosal dissection (ESD) is the standard treatment for early gastric cancer since it allows en bloc resection of larger lesions however requires longer procedure time and has more complications than endoscopic mucosal resection. OBJECTIVE: To evaluate the use of biological inanimate simulators in endoscopic training for the development of skills required for ESD. METHODS: Experimental design using a biological inanimate simulator to evaluate the development of endoscopic skills. Five trained endoscopists with knowledge of the ESD technique, but without previous experience were selected. Technical success, complication rate and procedure time were evaluated. Each participant performed a self-evaluation. RESULTS: 18 lesions of 10-20 mm in diameter were dissected, with a mean area of 2.64 ± 2 cm2 and a mean procedure time of 21.08 ± 14.01 minutes (5.48 - 48.61). Self-evaluation and instructor's evaluation showed a strong positive correlation. There was no correlation between lesion size and procedure time. There was one perforation (5.8%), which was successfully managed with one endoclip. Complications such as bleeding could not be assed. CONCLUSIONS: The use of inanimate biological simulators allows training in complex endoscopic procedures such as ESD with a wide safety margin. Lesion size did not correlate with procedure time. It is necessary to increase the number of procedures to improve the learning curve. This simulator does not allow evaluation of complications other than perforations.