Proposal of classification and terminology of interventional endoscopic ultrasonography/endosonography

Interventional endoscopic ultrasonography/endosongraphy (I-EUS) procedures have rapidly evolved since their introduction three decades ago; however, the classification and terminology for these procedures remain unstandardized. To address this, the Subcommittee for Terminology of I-EUS in the Japan Gastroenterological Endoscopy Society was established to define classifications and a glossary of I-EUS terms. They categorized I-EUS procedures into five types based on purpose and method: (i) EUS-guided sampling; (ii) EUS-guided through-the-needle examination; (iii) EUS-guided drainage/anastomosis (EUS-D/A); (iv) trans-endosonographically/EUS-guided created route (ESCR) procedures; and (v) EUS-guided delivery. EUS-guided sampling includes tissue acquisition and fluid sampling, classified by needle type into fine needle aspiration and fine needle biopsy. Through-the-needle examinations include imaging, measurements, and biopsies. EUS-D/A includes organ drainage/anastomosis, fluid collection drainage, and digestive tract anastomosis. In the EUS-D/A route, "anastomosis" is used for organ-to-organ procedures, whereas "tract" is for fluid drainage. ESCR is a newly proposed term for procedures via anastomosis or tract, such as endoscopic necrosectomy and EUS-guided antegrade stenting. The term "trans-luminal drainage/anastomosis stent" is used for stents that maintain the ESCR rather than treating strictures. EUS-guided delivery involves the delivery of substances, such as fluids, drugs, medical devices, and energy. This proposed categorization and terminology aimed to clarify I-EUS procedures and will require updates as new techniques and concepts emerge.