[Endoscopic submucosal dissection of a transpyloric early gastric cáncer. A case report and literature review].

The endoscopic sumucosal disection (ESD) is an advanced endoscopic technique that achieves the curative resection of superficial neoplasms of the gastrointestinal tract, getting block exeresis with margins free of neoplasia avoiding surgery. However, tumors located in the esophagogastric junction, or pylorus, are technically more complex to resect by ESD. When a neoplasm settles in the pylorus, the anatomical characteristics of this region can affect the adequate assessment of the margins and the performance of the procedure. We present the case of a 70-year-old male patient who, in a high digestive endoscopy, showed a flat multilobulated lesion of 18 mm x 10 mm, located mostly in the lower 2 quadrants of the pyloric canal and minimal compromise of the upper-posterior quadrant, it mainly covers the gastric side of the pyloric channel and extends into the duodenum. Therefore, it was decided to perform en bloc resection of the lesion with the endoscopic submucosal dissection technique. The ERBEJET system was used with a knife type Hybrid knife, saline injection with methylene blue diluted 0.04% on the distal margin, submucosal injection being complemented with 0.4% hyaluronic acid. A "capsule" or straight transparent distal plastic device was used to be able to pull the lesion and allow anterograde visualization of the margins of resection, including the intraduodenal portion, allowing adequate submucosal dissection. Histopathology showed a moderately differentiated tubular adenocarcinoma with surgical edges free of injury. Thanks to the DSE strategy used, our patient could benefit from the curative resection of his gastric cancer with preservation of the organ and with perfect functionality. This case, the first described in the country, shows the progress of national therapeutic endoscopy.