Within-Session Repeatability of EUS-Guided Portal Pressure Gradient Measurement

This prospective multicentre observational reliability study will determine how much a repeated endoscopic ultrasound-guided portal pressure gradient (EUS-PPG) measurement differs from the first measurement in the same patient during the same procedural session. Each participant will undergo two complete EUS-PPG measurement sets using an identical 22-gauge measurement setup. The study will quantify within-session repeatability when the same expert performs both sets and inter-operator reproducibility when different operators perform the sets.

Inclusion Criteria: * Age 18 years or older * Clinical indication for EUS-guided portal pressure gradient measurement established independently of the study * Written informed consent, including consent for the additional measurement set Exclusion Criteria: * Contraindication to endoscopy, sedation, or endosonography-guided vascular puncture * Non-correctable coagulation disorder * Hemodynamic instability at the time of the procedure * Any intervention between the two measurement sets that may alter portal pressure, including fluid administration beyond maintenance requirements, vasoactive substances, paracentesis, or variceal band ligation * Technically non-evaluable first measurement set * Pregnancy or breastfeeding * Inability to provide informed consent