Ex vivo and in vivo models for endoscopic submucosal dissection training.

Endoscopic submucosal dissection is a technically challenging but highly effective technique for the treatment of well selected early neoplasms in the digestive tract. Although it is frequently performed in East Asian countries, the Western world has not adopted this technique yet, probably due in part to the difficulty to learn it. Ex vivo and in vivo animal models are invaluable tools to overcome at least the beginning of the learning curve, although the initial step is the acquisition of basic knowledge about early diagnosis of neoplasias, and observing real procedures in expert centers. The practical issues, advantages, and disadvantages of the ex vivo and in vivo models are discussed.