Criteria for diagnosing benign portal vein thrombosis in the assessment of patients with cirrhosis and hepatocellular carcinoma for liver transplantation

Malignant portal vein thrombosis is a contraindication for liver transplantation. Patients with cirrhosis and early hepatocellular carcinoma (HCC) may have either malignant or benign (fibrin clot) portal vein thrombosis. The aim of this study was to assess prospectively whether well-defined diagnostic criteria would enable the nature of portal vein thrombosis to be established in patients with HCC under consideration for liver transplantation. Benign portal vein thrombosis was diagnosed by the application of the following criteria: lack of vascularization of the thrombus on contrast-enhanced ultrasound and on computed tomography or magnetic resonance imaging, absence of mass-forming features of the thrombus, absence of disruption of the walls of veins, and, if uncertainty persisted, biopsy of the thrombus for histological examination. Patients who did not fulfill the criteria for benign thrombosis were not placed on the transplantation list. In this study, all patients evaluated at our center during 2001-2007 with a diagnosis of HCC in whom portal vein thrombosis was concurrently or subsequently diagnosed were discussed by a multidisciplinary group to determine their suitability for liver transplantation. The outcomes for 33 patients who met the entry criteria of the study were as follows: in 14 patients who were placed on the transplantation list and underwent liver transplantation, no malignant thrombosis was detected when liver explants were examined histologically; 5 patients who were placed on the transplantation list either remained on the list or died from causes unrelated to HCC; in 9 patients, liver transplantation was contraindicated on account of a strong suspicion, or confirmation, of the presence of malignant portal vein thrombosis; and 5 patients who were initially placed on the transplantation list were subsequently removed from it on account of progression of HCC in the absence of evidence of neoplastic involvement of thrombosis. In conclusion, for a patient with HCC and portal vein thrombosis, appropriate investigations can establish whether the thrombosis is benign; patients with HCC and benign portal vein thrombosis are candidates for liver transplantation.