Endoscopic Ultrasound-Guided Diagnosis and Treatment of Gastrointestinal Diseases

Diagnostic endoscopic ultrasound (EUS) is an indispensable tool for staging and histologic sampling of upper and lower GI lesions, aided by elastography, contrast-enhanced EUS and artificial intelligence in diagnostic EUS. In the early 1990s EUS became interventional and since then the scope and range of EUS-guided interventions has dramatically increased, extending from EUS-assisted rendez-vous ERCP, EUS-guided celiac plexus block/neurolysis and fiducial placement, and EUS-guided biliary and pancreatic drainage-both in regular and altered anatomy-to the treatment of cysts and solid lesions in the pancreas/liver with EUS-guided local therapies (such as the EUS-guided injection of antitumoral agents/immunotherapy or EUS-guided ablative techniques), EUS-guided coiling/glue injection for gastric varices, and EUS-guided drainage of abdominopelvic collections. The introduction of lumen-apposing metal stents (LAMSs) revolutionized the therapeutic capabilities of EUS by allowing the creation of new gastrointestinal anastomoses. This, in turn, made possible interventions that were previously part of the surgical or interventional radiology realm, such as EUS-guided cystogastrostomy (EUS-CG)/endoscopic necrosectomy, EUS-guided gastroenterostomy (EUS-GE), EUS-guided gallbladder drainage (EUS-GD), EUS-directed transgastric ERCP (EGDE), and EUS-directed transenteric ERCP (EDEE). These and many other tremendous advances, too many to enumerate in a short paragraph, make diagnostic and therapeutic EUS a very exciting field. In this Special Issue, we summarize the current state of the art regarding EUS and EUS-guided therapies.