Background: Portal hypertension is necessary for the development of most clinical complications of cirrhosis. We recently reported a novel, endoscopic ultrasound (EUS)-guided technique for direct portal pressure measurements using a digital pressure wire.
Aims: The aims of this study were to (1) evaluate safety in an animal survival model and (2) compare direct portal vein (PV) versus transhepatic access of a first-order venule.
Materials and methods: Yorkshire pigs, weighing 40-55 kg. Procedures were performed under general anesthesia. PV was identified using a linear array echoendoscope and accessed with a 22-G fine needle aspiration needle preloaded with a digital pressure wire. Access was confirmed by portal venography. Mean digital pressure measurements were recorded over 30 seconds, and again after accessing a first-order portal venule in a transhepatic manner. Procedure times and video logs were maintained throughout. Animals were survived for 2 weeks. Repeat portal pressure measurements were performed before euthanasia and necropsy.
Results: EUS-guided portal pressure measurements ranged from 3 to 11 mm Hg (mean 6.1) and were performed in a mean time of 214 seconds. There was no difference in measurement between the PV and first-order venule, or between baseline and 2-week follow-up. Five of 5 animals survived without incident. On necropsy, there was no evidence of thrombus or hemorrhage.
Conclusions: This study represents the first survival study after EUS-guided direct portal pressure measurements using a digital pressure wire. This method appears safe, straightforward, and precise. Measurements of the PV and a first-order portal venule appear equivalent, and serial measurement seems feasible.
Keywords: chronic liver disease; endoscopic ultrasound; hepatic venous pressure gradient; portal hypertension; portal pressure.