Association between portal vein thrombosis and survival of liver transplant recipients: A systematic review and meta-analysis of observational studies

Abstract

Background & Aims: Portal vein thrombosis (PVT) increases the technical complexity of liver transplantation (LT). This systematic review and meta-analysis aim to analyze the association of pre-LT PVT with the overall survival after LT. Methods. PubMed, EMBASE, and Cochrane library databases were used to search for papers related to the association between pre-LT PVT and survival of LT recipients. The differences in the survival rates between the LT recipients with and without pre-LT PVT were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Results. Twenty-seven papers were included. Overall meta-analysis showed that the total LT recipients with pre-LT PVT had a significantly lower 1-year survival rate than those without pre-LT PVT (OR=0.733, 95%CI=0.621-0.865; P=0.0002). But no statistically significant difference was observed in the in-hospital (OR=0.713, 95%CI=0.343-1.482; P=0.365), 1-month (OR=0.679, 95%CI=0.345-1.333; P=0.261), or 5-year survival rate (OR=0.788, 95%CI=0.587-1.058; P=0.113). Additionally, the 1-year survival rate was significantly lower in the LT recipients with complete PVT than in those without PVT (OR=0.503, 95%CI=0.295-0.858; P=0.012). However, no statistically significant difference in the 1-year survival rate between them was observed in the meta-analysis of high-quality studies (OR=0.899, 95%CI=0.657-1.230; P=0.505) or that of studies in which LT was performed after 2000 (OR=0.783, 95%CI=0.566-1.083; P=0.140). Conclusion. Pre-LT PVT, especially complete PVT, decreased the 1-year survival rate after LT. However, the detrimental effect of pre-LT PVT on the survival of LT recipients became inconclusive in high-quality studies. Additionally, further well-designed cohort studies should validate the association in patients undergoing LT during the latter years.