Fig. 1From: Novel modified endoscopic mucosal resection of large GI lesions (> 20 mm) using an external additional working channel (AWC) may improve R0 resection rate: initial clinical experiencea AWC mounted on the tip of the endoscope with a freely adjustable distance to the regular working channel. b AWC-valve attached to the shaft of the endoscope. c External installation of the AWC on a single-channel gastroscopeBack to article page