Atrophic inferior vena cava is a marker of chronicity of intra-filter and inferior vena cava thrombosis: based on CT findings.

BACKGROUND

A permanently indwelling filter in the inferior vena cava (IVC) may induce caval thrombosis, which could develop and evolve from an acute to a chronic phase. The differential diagnosis of acute and chronic thromboses determines the treatment strategy. The role of computed tomography (CT) in diagnosing acute and chronic intra-filter and IVC thromboses has not been well established. This retrospective study summarizes the CT signs that indicate acute and chronic phases of intra-filter and IVC thromboses.

METHODS

This study included eight patients who developed a lower-extremity deep venous thrombosis (DVT) and were treated with intracaval filter placement as an alternative to anticoagulation and thrombolysis. During the follow-up, all patients developed an intra-filter thrombosis in the IVC confirmed by CT and/or CT venography (CTV). Demographic and CT data of all patients during the follow-up period were collected for analysis.

RESULTS

All patients had normal-appearing IVCs prior to filter placement, as shown on trans-femoral venography. Eight filters (five TrapEase, three OptEase) were placed in the eight IVCs, respectively. Subsequently, IVC-CT or CTV revealed acute intra-filter or IVC thrombosis in all eight patients, manifesting as an intracaval filling defect and thickened IVC wall. Filter protrusion and secondary caval atrophy seen on CT indicated a chronically occluded IVC.

CONCLUSIONS

IVC thrombosis may result from filter placement. The chronicity of caval thrombotic occlusion is likely to be associated with filter protrusion and secondary IVC atrophy revealed on CT scans.