Endoscopic step-up approach. Endoscopic step-up approach consisting of endoscopic transluminal drainage (ETD) and endoscopic transluminal necrosectomy (ETN). A large peripancreatic collection containing fluid and necrosis is shown. (A) ETD: the collection is punctured through the gastric wall, followed by balloon dilatation of the tract. Two double-pigtail stents and a nasocystic catheter for continuous postoperative irrigation are placed. (B) ETN: the cystostomy tract is dilated, the collection is entered with a endoscope, and necrosectomy is performed. (Reprinted from van Brunschot et al. ; copyright 2013, with permission from Elsevier).