The Clinical Outcomes of Patients with Portal Vein Tumor Thrombi After Living Donor Liver Transplantation

The purpose of this study was to evaluate the feasibility of living donor liver transplantation for treatment of patients with hepatocellular carcinoma and segmental portal vein tumor thrombus (PVTT) below the second-order branch. Between January 2005 and December 2015, we retrospectively analyzed 242 patients in a control group (n=184), a microvascular invasion (MVI) group (n=24), and a PVTT group (n=34). To assess the risks associated with PVTT, we evaluated recurrence, the disease-free survival (DFS) rate, the overall survival (OS) rate, and various other factors based on the characteristics of patients and tumors. Of the 242 patients, 5-year DFS and OS rates were 79.5% and 70.7%. A total of 34 (14.0%) patients had PVTT, of whom 7 had lobar PVTT in first-order branches. The control, MVI, and PVTT groups significantly differed in terms of tumor morphology (maximal and total diameters) and biology (alpha-fetoprotein [AFP] and protein induced by vitamin K absence or antagonist II). The control, MVI, and PVTT groups significantly differed in terms of the recurrence, DFS, and OS rates. Especially, lobar PVTT reduced the 5-year DFS and OS rates to dismal and 14.3%, respectively, but segmental PVTT was associated with favorable 5-year DFS and OS rates (63.9% and 50.3%, respectively). We found no statistically significant difference in the DFS and OS rates of patients with MVI alone and segmental PVTT alone. In patients in the segmental PVTT group with AFP levels of <100 ng/mL, the 5-year DFS and OS rates were 90.9% and 71.3%, respectively. In conclusion, a tumor thrombus in a lobar portal vein remains a contraindication to liver transplantation. However, a segmental PVTT is acceptable, especially when the AFP level is <100 ng/mL.