Conventional techniques of endoscopic mucosal resection (EMR) by snare resection do usually not achieve resection of gastrointestinal mucosal neoplastic lesions larger than 1 cm in diameter in a single piece. Complete R0 resection cannot be histologically confirmed. In contrast to EMR the technique of endoscopic submucosal dissection (ESD) allows en-bloc resection even of large neoplastic lesions. The waterjet-assisted ESD technology (WESD) allows pressure controlled injection of fluids through the tip of a recently developed HybridKnife®. Submucosal injection, circumferential cutting and dissection of lesions as well as coagulation of bleeding sources can be performed with the same device without need for changing the instrument. Our group reported on effective en-bloc resection of esophageal areas in all of 14 cases of an Erlangen porcine model. We subsequently compared WESD with EMR of predefined esophageal mucosal lesions in anesthetizised pigs in a randomized controlled trial. The results demonstrated that WESD more frequently achieved a complete resection with a significantly lower number of specimen. WESD caused no perforations and bleedings could be endoscopically managed during the procedure. In addition we recently reported on this technology in a first clinical trial on WESD for early Barrett`s neoplasia . The results indicated that WESD can be safely and effectively performed in the esophagus.