Portal vein thrombosis and liver transplant survival benefit.

Portal vein thrombosis (PVT) complicates the liver transplant operation and potentially affects waiting list survival. The implications on calculations of survival benefit, which balance both waiting list and posttransplant survival effects of PVT, have not been determined. The objective of this study is to describe the effect of PVT on the survival benefit of liver transplantation. Using Scientific Registry of Transplant Recipients data on adult liver transplant candidates wait-listed between September 2001 and December 2007, Cox proportional hazard models were fitted to estimate the covariate-adjusted effect of PVT on transplant rate, waiting list survival, and posttransplant survival. We then used sequential stratification to estimate liver transplant survival benefit by cross-classifications defined by Model for End-Stage Liver Disease (MELD) score and PVT status. The prevalence of reported PVT among 22,291 liver transplant recipients was 4.02% (N = 897). PVT was not a predictor of waiting list mortality (hazard ratio = 0.90, P = 0.23) but was a predictor of posttransplant mortality (hazard ratio = 1.32, P = 0.02). Overall, transplant benefit was not significantly different for patients with PVT versus without PVT (P = 0.21), but there was a shift in the benefit curve. Specifically, the threshold for transplant benefit among patients without PVT was MELD score >11 compared to MELD score >13 for patients with PVT. PVT is associated with significantly higher posttransplant mortality but does not affect waiting list mortality. Among patients with low MELD score, PVT is associated with less transplant survival benefit. Clinicians should carefully consider the risks of liver transplantation in clinically stable patients who have PVT.