Endoscopic ultrasound-guided portal pressure gradient measurement: a pilot animal study

Objective To evaluate the feasibility and safety of endoscopic ultrasound-guided portal pressure gradient (EUS-PPG) measurement in the normal porcine model. Methods Four pigs, 2 male and 2 female, aged 8-12 months, weighing 20-30 kg were selected in the experiment. Under general anesthesia and EUS guidance, a 22 G fine needle connected to electrocardiograph monitor with a central vein pressure manometer was used to puncture and measure pressures in the portal vein (PV) and hepatic vein (HV) or inferior vena cava (IVC). Pressures were measured three times for each vessel and the mean pressure was recorded. The PPG was recorded as the difference between the PV pressure and HV or IVC pressure. Vital signs during and after the procedure and operation-related complications were monitored. Results EUS-PPG measurement was successful in all targeted vessels. The PV pressure, HV or IVC pressure, and PPG was 11.0±1.0 mmHg(1 mmHg=0.133 kPa), 7.3±1.1 mmHg and 3.8±0.9 mmHg, respectively. No adverse event occurred. Conclusion EUS-PPG measurement has a high successful rate and reliable accuracy and safety reflecting the portal vein pressure. Key words: Endosonography; Hypertension, portal; Portal pressure gradient; Hepatic venous pressure gradient