LAUSR

Walled-off pancreatic necrosis (WON) is one of the most severe complications of acute pancreatitis, and endoscopic necrosectomy may be necessary to treat this complication [1, 2]. When treating a large WON, if only the shallow section is treated, the route to the deepest section may be closed, leaving a space wherein endoscopic necrosectomy cannot be performed [3]. It is important to identify the deepest section of the WON and secure the route by stent placement. Herein, we propose a novel “tunnel creation method” (TCM), which is an endoscopic bougie under fluoroscopy along the stent deployed at the deepest part of the WON that provides a wide working space and a route to the deepest part (▶Fig. 1). A 75-year-old man was transferred from another hospital for treatment of a large WON. Endoscopic ultrasound-guided transgastric drainage was performed using a lumen-apposing metal stent with a diameter of 15mm (Hot AXIOS; Boston Scientific, Marlborough, Massachusetts, USA). Contrast-enhanced computed tomography 12 days after the procedure revealed that a large amount of necrotic tissue remained (▶Fig. 2). The left side of the WON was filled with necrotic tissue, making it difficult to secure a clear visual field during endoscopic necrosectomy. TCM was performed (▶Fig. 3, ▶Fig. 4, ▶Fig. 5, ▶Video 1). Following this procedure, the route through which the scope passed was dilated, providing a wide working space and securing a clear visual field during necrosectomy. The patient was discharged without any adverse events after six sessions of endoscopic necrosectomy. E-Videos