Preoperative Portal Vein Embolization: An Approach to Improve the Safety of Major Hepatic Resection

Abstract

Surgery has therefore become a mainstay in the treatment of both primary and metastatic liver lesions. Unfortunately, despite these advances, extended resections yielding small volume liver remnants continue to pose risks resulting from decreased functional liver capacity, both in patients with underlying hepatic disease and in those with otherwise-healthy livers. 3,4 Preoperative portal vein embolization (PVE) has thereby emerged as a significant adjunct to major hepatic resection (more than 3 Couinaud segments), allowing for an increased volume of the future liver remnant (FLR) and resultant improved outcomes in patients with small anticipated residual liver volume. 5-10 Embolization of the portal branches in the liver to be resected results in diversion of portal bloodflow to the nonembolized segments. This rerouted portal blood, rich in hepatotropic substances, stimulates hypertrophy of the liver parenchyma. 11 PVE thus increases the mass of FLR before surgery, and in the proper patient setting, may permit safe, potentially curative resection in patients who would otherwise not be surgical candidates because of their risk of postoperative liver failure.12 The benefits of preoperative PVE are not limited to increased size of the liver remnant; however, the greater number of hepatocytes does allow improved synthetic function and avert cholestasis. Embolization of the portal vein before hepatic resection also diminishes the otherwise-abrupt increase in portal venous pressure after resection that can lead to hepatocellular injury. In addition, PVE dissociates any damage caused by increased portal pressures from the direct trauma inflicted upon the FLR during resection. 13