Doppler sonography of hepatic arterial blood flow velocity after percutaneous transhepatic portal vein embolization

OBJECTIVE. This study was conducted to elucidate the changes in hepatic art erial blood flow after portal vein embolization. SUBJECTS AND METHODS. We prospectively measured the flow velocity and resis tive index of the common, right, and left hepatic arteries, using Doppler s onography in 21 patients who underwent embolization of the right portal vei n, The measurements were performed before and 1, 3, 5, 7, and 14 days after embolization. We assessed the changes in liver volume with a volumetric st udy using CT. RESULTS. After embolization, flow velocity in the common hepatic artery inc reased significantly (p < 0.0001). Flow velocity in the right hepatic arter y also increased significantly (p < 0.0001), with a significant decrease in resistive index (p < 0.0001). The flow velocity and resistive index of the left hepatic artery were unchanged. The increase in flow velocity in the r ight hepatic artery significantly correlated with that in the common hepati c artery (r = 0.514, p < 0.05). The calculated volume of the embolized righ t hepatic lobe significantly (p < 0.0001) decreased, from 685 <plus/minus> 32 cm(3) before embolization to 568 +/- 28 cm(3) after embolization. The at rophy rare of the right hepatic lobe significantly correlated with the incr ease in Row velocity in the right hepatic artery (r = 0.700, p < 0.0005). CONCLUSION. Portal vein embolization induces an increase in hepatic arteria l blood flow velocity in the embolized hepatic segments, resulting from an increase in common hepatic arterial flow, but not from a steal phenomenon d ue ro decreased hepatic arterial blood flow in the nonembolized hepatic seg ments, This observation may be explained by the simple mechanical effect of interposing a slower flowing stream (portal flow) in the path of a faster flowing stream (arterial flow).