[Interventional endoscopic ultrasound in the hepatopancreatobiliary system : What is possible, what is safe and what...

Interventional endoscopic ultrasound (EUS) has become established as an important diagnostic and therapeutic pillar in diseases of the hepatobiliary and pancreatic system. It complements or replaces conventional strategies and expands the spectrum of endoscopic procedures but requires a high level of expertise and interdisciplinary interpretation of indications. One focus is the treatment of necrotizing pancreatitis: The use of EUS-guided drainage is part of the step-up approach and is superior to surgical procedures. Lumen-apposing metal stents (LAMS) facilitate the access and enable direct necrosectomy but double pigtail stents also retain their role. Pancreatic pseudocysts and postoperative fluid accumulation can also be effectively drained endoscopically. In complex bile duct stenoses, EUS-guided drainage is a back-up method, for example as a rendezvous technique, hepaticogastrostomy or choledochoduodenostomy, especially when an endoscopic retrograde cholangiopancreatography (ERCP) is not technically possible. Similarly, the pancreatic duct can be reached endosonographically, although EUS-guided drainage is only advisable under strict clinical indications. Gallbladder drainage using LAMS is an alternative to percutaneous drainage in severe cholecystitis without surgical options. The EUS gastroenterostomy is increasingly replacing surgical procedures for the treatment of gastric outlet obstructions and also enables the endoscopic ultrasound-directed transgastric ERCP (EDGE) procedure for easier ERCP in an anatomically altered stomach. Other emerging fields include EUS-guided ablation of small insulinomas, endovascular interventions for portal hypertension and celiac plexus block, although the benefits of the latter are limited.