Histopathology of inferior vena cava obstruction in Budd–Chiari syndrome by clamp biopsy

OBJECTIVE: We aimed to analyze the pathological changes of the occlusive area of the inferior vena cava (IVC) in patients with Budd–Chiari syndrome (BCS) and to explore its possible etiology and pathogenesis. METHODS: Color Doppler ultrasound and IVC angiography were used to evaluate causes of occlusion. Clamp biopsies were performed in the occlusive area of the IVC in 31 patients with BCS, and the specimens were examined pathologically. Clinical data were collected retrospectively. RESULTS: The success rate of clamp biopsy was 100% (31/31) and the sensitivity of pathology was 96.8% (30/31). By microscopic analysis, we found 27 cases of fibrous connective tissue, including 8 cases of thrombosis and 19 cases of inflammatory cell infiltration, vitreous degeneration, or mucinous degeneration of fibrous connective tissue; 3 cases showed thrombus organized with fibrosis. CONCLUSION: The occluding lesion in the IVC of BCS may be caused by local thrombosis, followed gradually by organization and fibrosis.