Portal vein thrombosis in liver transplantation: radiologic evaluation, risk factors, and occult diagnosis

Aim: Portal vein thrombosis (PVT) in the liver transplant recipient poses many challenges. Unfortunately, the risk factors and effects on outcomes of PVT are not well-defined. Methods: This study analyzed the experience with PVT in liver transplant program from 2007 to 2013. This included the effectiveness of PVT diagnostics and its risk factors using logistical regression. The primary endpoints were Kaplan-Meir patient and graft survival. The secondary endpoints were the length of stay (LOS), transfusion rate, and overall morbidity. Independent predictors of survival were identified using a Cox’s proportional hazards model. Results: Two hundred and sixteen consecutive liver transplant recipients were examined, and 30 (13.8%) had either a total or partial PVT. Two hundred and five patients had imaging within 1 year of liver transplantation with only 7 (23.3%) of the 30 PVTs identified pre-operatively. Calculated sensitivity (4.8-50%) and negative predictive values (10.5-22.2%) were poor. Only, age significantly predicted PVT [P = 0.037/hazard ratio (HR) =0.95]. Ninety-day-patient and graft survival for PVT was similar at 6 months, although 1-year survival was significantly lower. “Occult” PVT was not associated with inferior survival. Model for end-stage liver disease score u003e 25 (P = 0.001, HR = 0.49/P = 0.004, HR = 0.52) and age u003e 60 years (P = 0.017, HR = 0.64/P = 0.013, HR = 0.67) were significant predictors of patient and graft survival. Although the transfusion rate was significantly greater with PVT, LOS, and morbidity were not. Conclusion: Older recipients had a greater likelihood of PVT. Diagnostic studies were not effective at excluding PVT, and occult diagnosis did not affect the outcome. PVT was not an independent predictor of mortality or graft loss, but was associated with greater blood loss but not increased LOS or morbidity.