04:21 PM Abstract No. 82 Wedged Hepatic Venous Pressure As a Surrogate for Direct Portal Pressure: How Accurate is It?

Free and wedged hepatic venous pressure (WHVP) measurements are the preferred technique to evaluate for portal hypertension. We postulate that in the presence of intrahepatic hepatic venous collaterals (IHVC), there may be discordant measurements between WHVP and the direct portal pressure (DPP). In this study, we investigate the accuracy of WHVP as a surrogate for DPP. This is a retrospective study of patients who underwent transjugular intrahepatic portosystemic shunts (TIPS) with the aid of balloon occlusion CO2 venography between November 2017 and September 2018. Hepatic venous pressures, including free and wedged, and DPP were recorded. The cases were evaluated for IHVC and opacification of the peripheral and/or central portion portal veins on CO2 venography. The WHVP and DPP were compared and assessed for discrepancies of greater than 5 mm Hg. Statistical analyses were conducted with the Mann-Whitney-U test using IBM SPSS Statistics version 24.0. Our review included 22 cases with a mean WHVP of 23.8 ± 5.7 mm Hg, a mean DPP of 30.0 ± 5.6 mm Hg and a mean pressure discrepancy of 5.0 ± 8.0 mm Hg. IHVC were visible in 55% (12/22) with a mean pressure discrepancy of 9.2 ± 7.4 mm Hg. The presence of collaterals resulted in an accuracy of 33%, as a discrepancy of greater than 5mm Hg was present in 67% (8/12); this included cases with collaterals and portal venous system opacification (6), and without portal venous system opacification (6). In cases without visualization of IHVC (10/22), there was a mean discrepancy of -0.7 ± 3.8 mm Hg and the WHVP was 100% concordant with the DPP. The presence of IHVC resulted in a statistically significant difference (p<0.001) in mean pressure discrepancy. When balloon occlusion CO2 hepatic venography demonstrates the absence of IHVC, WHVPs may be concordant with DPPs. In the presence of IHVC, although portal hypertension was shown, there may be discrepant measurements. This study is limited to CO2 injection through a balloon occlusion catheter. More study is needed to investigate these findings with wedged end-hole catheters or iodinated contrast.