Popliteal vein compression due to popliteal artery aneurysm: effects of aneurysm size.

Unlike the venous compression associated with larger popliteal artery aneurysms, which frequently is associated with deep vein thrombosis, the venous compression caused by the moderate sized (greater than 2 cm and less than 3 cm) aneurysms in the reported cases is not associated with thrombosis. The extrinsic compressive effect of these moderate sized popliteal artery aneurysms on the adjacent vein is shown to vary with the patient's leg position. Three of the four patients with unilateral leg swelling discussed here had bilateral popliteal artery aneurysms.

Doppler diagnosis of partial vertebral/subclavian steals convertible to full steals with physiologic maneuvers.

Subclavian steal syndrome has been classically described as a unidirectional phenomenon in which retrograde flow occurs in the ipsilateral vertebral artery in cases of high-grade proximal subclavian stenosis. Pulsed Doppler examination in cases of subclavian stenosis shows that partial steals with to-and-fro flow do occur. A model based on fluctuating pressure gradients to explain the partial steal phenomenon is discussed.

Doppler sonographic demonstration of the progressive spontaneous thrombosis of pseudoaneurysms.

In three patients with diagnosed pseudoaneurysms, surgical intervention was delayed because of the patients' clinical condition. In successive follow-up examinations in one patient, development of a new lobe to the previously single-lobed pseudoaneurysm was noted with progressive centripetal thrombus formation in each lobe leading to the eventual complete thrombosis of the pseudoaneurysm without surgical intervention. The sequence of steps leading to the complete thrombosis of the pseudoaneurysm as seen by color Doppler and pulsed Doppler examination is described.