Duplex sonography of vascularization of venous thrombosis.

BACKGROUND

Changes in the echogenicity of an ageing intravenous thrombus have already been described in B-mode sonography. We tried to investigate the phenomena of vascularisation of the intravenous thrombotic material during the organisation using colour Doppler sonography.

METHODS

We carried out a prospective investigation of 8 jugular vein, 6 femoral vein and 1 inferior caval vein thrombosis. The thromboses were investigated with a colour Doppler sonographic device from Siemens, type Elegra, every second or third day for 4 weeks after making the diagnosis. We looked for intrathrombotic colour Doppler signals with an arterial pulsatile blood flow in the pulsed Doppler mode.

RESULTS

We found arterial signals in the intravenous thrombus in 8 of the 15 patients. Such arterial Doppler signals were supposed to be arterial vessels which develop during the organisation of the thrombotic material. The arterial vessels appeared only in a short range of time from the 11th to the 25th day and were present in circumscribed areas of the thrombus. Arterial blood vessels in the surrounding tissue of the veins which may supply blood to the intrathrombotic vessels could not be demonstrated.

CONCLUSIONS

Thus the intravenous documentation of arterial vessels in an organising intravenous thrombus is possible. This may give information about the mechanism of thrombogenesis and about the degree of organisation and may also help in determining the age of the thrombosis.