Reliability of imaging techniques in assessing portal venous thrombosis in patients with hepatocellular carcinoma candidates for liver transplantation

Aims: Portal venous thrombosis (PVT) is considered an absolute contraindication to liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) when neoplastic PVT cannot be excluded. Aim of the study is to assess whether imaging techniques allow evaluation of nature of PVT in HCC-patients allowing safe selection of candidates to LT. Methods: We analyzed 34 HCC-patients with PVT detected at the time of assessment for LT or developed while on the waiting list. The benign nature of the thrombus was established using the following criteria: lack of vascularization of the thrombus at contrast enhanced ultrasound with SonoVue and ceCT or ceMRI, steadiness/regression of thrombosis during follow-up, absence of mass-forming aspects of PVT on ultrasound examination, absence of features of disruption of the vessel walls, and negative biopsy of the thrombus in case of uncertainty. Patients who did not fulfill the criteria for benignity of PVT were excluded from the waiting list. Results: The outcome of 34 patients analyzed is as follows: 13 were listed and transplanted, with no sign of malignant PVT at explant pathological examination; 9 were admitted in the list and are actively waiting. Two patients died for HCC unrelated causes while actively listed. Of the remaining 10 patients, 7 were not included or excluded from the list for the suspicion or confirmation of malignant PVT, whereas 3 were included and subsequently excluded for progression of HCC without evidence of malignant PVT. Conclusions: Imaging techniques allow safe not-invasive assessment of the nature of PVT in HCC-candidates to LT.