Chapter 74: Liver Transplantation in Patients with Diffuse (Grade IV) Portal Vein Thrombus

INTRODUCTION

The incidence of portal vein thrombosis (PVT) at the time of liver transplantation (LT) in patients with end-stage liver disease varies between 2% and 26%.^1–3 This may be an underestimation of the actual incidence of PVT in cirrhotic patients (0.6% to 64%)^4,5 because the presence of PVT was until recently considered by many transplant centers to be at least a relative contraindication for LT, in view of the technical difficulties that it can present during transplantation (excessive bleeding and inability to establish adequate portal inflow) and its association with a higher rate of patient morbidity and mortality.

In 2000, Yerdel et al.⁶ proposed a grading system for PVT that is widely used today:

• Grade I: involving less than 50% of the portal vein (PV) lumen with or without minimal extension into the superior mesenteric vein (SMV)

• Grade II: more than 50% occlusion of the PV, including total occlusion, with or without minimal extension into the SMV

• Grade III: complete thrombosis of both the PV and the SMV trunk (distal SMV patent)

• Grade IV: complete thrombosis of both the PV and SMV (Fig. 74-1).

Until the last decade, patients with grade IV PVT without any significant collateral vessel (left gastric, middle colic, or choledochal veins) were not considered for LT. Recently, some of the options proposed to overcome this absolute contraindication have included caval inflow to the graft (CIG) in the form of a cavoportal anastomosis (CPA) or cavoportal hemitransposition (CPHT)^7–10 or renoportal anastomosis (RPA),^11–13 arterialization of the PV (PVA),¹⁴ and multivisceral transplantation (MVT).¹⁵

Anastomosis to a patent splanchnic tributary (APST): When feasible, this may be the preferred approach in the case of grade IV PVT. Virtually any large collateral (diameter of 2 cm or more) can suffice to supply the graft; these are mostly a bile duct varix (paracholedochal vein) or the middle colic vein or a coronary (left gastric) collateral vein^16,17 (Fig. 74-2).

When no such patent splanchnic collateral is available for inflow or the flow in them is inadequate, CPA either using an end-to-end (termino-terminal) CPA or end-to-side (latero-terminal) CPA with “calibration” of the retrohepatic vena cava has been proposed.

In CPA, the inflow from the IVC is used to perfuse the PV of the allograft. This seems to be the logical reconstruction for portal inflow in patients with grade IV ...