Gel immersion endoscopic papillectomy using a double-balloon endoscope to resect an ampullary tumor.

The usefulness of underwater endoscopic papillectomy for treating ampullary tumors in patients with surgically altered anatomy has been reported [1], but difficulties in managing the water flow in the gastrointestinal tract, and the nature of water, which mixes with blood and bile, thus impairing the endoscopic view, remained to be overcome.