Non-malignant portal vein thrombi in patients with cirrhosis consist of intimal fibrosis with or without a fibrin-rich thrombus.

2021 
Background and aim Portal vein thrombosis (PVT) is a common complication of cirrhosis. The exact pathophysiology remains largely unknown and treatment with anticoagulants does not lead to recanalization of the portal vein in all patients. A better insight in the structure and composition of portal vein thrombi may assist in developing new strategies for the prevention and treatment of PVT. Methods Sixteen prospectively and 63 retrospectively collected non-malignant portal vein thrombi from cirrhotic patients who underwent liver transplantation were included. Histology, immunohistochemistry and scanning electron microscopy were used to assess structure and composition of the thrombi. Most recent computed tomography (CT) scans were reanalysed for thrombus characteristics. Clinical characteristics were related to histological and radiological findings. Results All samples showed a thickened, fibrotic tunica intima. Fibrin-rich thrombi were present on top of the fibrotic intima in 9/16 prospective cases and in 21/63 retrospective cases. A minority of the fibrotic areas stained focally positive for fibrin/fibrinogen (fg, 16% of the cases), Von Willebrand Factor (VWF, 10%) and CD61 (platelets, 21%), while most of the fibrin-rich areas stained positive for those markers (fg, 100%; VWF, 77%; CD61, 100%). No associations were found between clinical characteristics including estimated thrombus age and use of anticoagulants and presence of fibrin-rich thrombi. Conclusion Here we demonstrated that PVT in cirrhotic patients consists of intimal fibrosis with an additional fibrin-rich thrombus in only one-third of the cases. We hypothesize that our observations may explain why not all portal vein thrombi in cirrhotic patients recanalise by anticoagulant therapy.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    0
    References
    1
    Citations
    NaN
    KQI
    []