Chapter 75: Portal Vein Arterialization in Liver Transplantation

INTRODUCTION

A totally de-arterialized liver is an organ in which, in addition to hepatic artery (HA) ligation or resection, there is a complete interruption of all collateral sources of arterial inflow, including interlobar HAs, peribiliary plexus, collaterals in triangular ligaments, and lesser omentum.^1–4 This may occur in patients with hepatic artery thrombosis (HAT) after liver transplantation (LT), in which a totally dearterialized liver graft to which the HA is the only arterial inflow vessel is implanted. In these situations, if the HA is not reconstructed, biliary ischemia and necrosis are inevitable, and liver necrosis and fatal liver failure are possible due to lack of adequate oxygenation of the liver.

PORTAL VEIN ARTERIALIZATION

Portal vein arterialization (PVA) is a salvage technique used in a dearterialized liver to establish arterial inflow when all other possible strategies for the reconstruction of the artery have been ruled out.⁵ The procedure increases the oxygen saturation of portal vein (PV) blood significantly, prevents hepatic necrosis and insufficiency, and promotes liver regeneration.^6,7 It would also alleviate the ischemic state of bile ducts, as the terminal PV tributaries form anastomoses with the arterial peribiliary plexus.^6,8 Thus, hepatocytes as well as the biliary tree can “survive” with a PVA until such time that arterial collaterals develop.

EVOLUTION OF THE PVA CONCEPT IN THE SETTING OF LIVER TRANSPLANTATION

PVA was historically used in portal hypertension (PHT) surgery in conjunction with end-to-side portacaval shunting with the purpose of preserving liver perfusion and reducing the risk of hepatic failure and encephalopathy.^9,10 Human PVA in a dearterialized liver was first reported in 1992 by Iseki et al.,⁵ who performed PVA in a patient in whom HA ligation following arterial rupture and hemorrhage after a Whipple procedure was required. PVA continues to be used even today in situations such as accidental HA injury during major hepatectomy with no other option to gain hepatic artery inflow to the remnant¹¹ (Fig. 75-1). In the LT domain, temporary PVA during LT was first described by Sheil et al.,¹² who, after the suprahepatic inferior vena cava anastomosis, attached a cannula inserted in the recipient iliac artery to a donor PV cannula, resulting in early liver revascularization. PVA was later used in auxiliary heterotopic liver transplantation¹³ as a lifesaving measure. The aim was to provide temporary liver support, leaving the hilum of the native liver untouched and thus giving it the chance to regenerate. PVA has been used in the emergency setting to re-establish arterial inflow to the liver when thrombolysis by interventional radiology has failed and there is no other option for the reconstruction of the HA.¹⁴ It was first reported as a salvage or bridge technique (until a retransplantation could be performed) for post-LT HAT in the deceased donor setting by Cavallari.¹⁵ Shimizu et al.¹⁶ later reported PVA as ...