New deployment techniques of the lumen-apposing metal stent in walled-off necrosis filled with necrotic tissue: Chick opening its mouth (with video).

The lumen-apposing metal stent (LAMS) on an electrocautery-enhanced delivery system for endoscopic ultrasound-guided transluminal drainage has been widely used for the treatment of walled-off necrosis (WON). However, deployment of the LAMS can be technically difficult in WON, which contains a large amount of necrotic tissue and a low liquid component, owing to insufficient space for expansion of the distal stent flange. It has been recommended that the LAMS is placed in WON containing necrotic tissue, because additional endoscopic necrosectomy can be readily performed via the lumen of the LAMS. Here we introduce two new deployment techniques of the LAMS for WON filled with necrotic tissue, namely, the two-step puncture technique and the back-and-forth technique, which enable the distal stent flange to be expanded like a chick opening its mouth. These techniques are expected to further improve the clinical outcomes of refractory WON.