Abstract No. 593 Using a Non-focal Percutaneous Biopsy to Measure Portal Hypertension in a Swine Model

Portal venous pressures are an indicator for portal hypertension and an important prognostic indicator. Non-focal liver biopsies are commonly done to evaluate for liver dysfunction whereas portal venous pressure requires a transjugular hepatic vein wedge pressure vs. a direct portal venous approach. We hypothesized that the parenchymal pressure measured via percutaneous access during a non-focal liver biopsy may represent portal venous pressure. Using an IACUC approved protocol, a porcine (40 Kg) non-cirrhotic liver was percutaneously accessed under ultrasound guidance using a 17-gauge Bard introducer. The hepatic vein, portal vein, and hepatic parenchyma were directly accessed and pressures measured using a standard arterial line pressure transducer with a wet to wet connection. Hepatic parenchyma pressure measurements were taken before and after core needle biopsy. Hepatic vein pressure measured 6/2 (mean, 3 mm Hg), direct portal pressure measured 9/1 (mean, 4 mm Hg), and hepatic parenchymal pressure measured 9/2 (mean, 4 mm Hg)) before biopsy, and 7/2 (mean, 3.7 mm Hg) after an 18-gauge core needle biopsy (2 cm throw). Injection of 200 cc of fluid into the portal venous system resulted in a ∼ 1:1 increase in portal pressure and parenchymal up to a mean 13 mm Hg. Ultrasound images before and after core biopsy were not significantly affected by addition of pressure measurements. Hepatic parenchymal pressures may represent portal venous pressures as seen in a porcine model. Future studies are needed to evaluate to what extent a hepatic parenchymal measurement corresponds to portal venous pressure in a cirrhotic model, and to what degree of prognostic capability hepatic parenchymal pressures provide from non-focal liver biopsies in humans.