The role of venous digital subtraction angiography of the carotid bifurcation in the evaluation of patients with reversible ischemic attacks or stroke.

The diagnostic value of venous digital subtraction angiography (VDSA) was evaluated in 168 consecutive patients with suspected or known atherosclerotic lesions of the internal carotid artery. The VDSA findings were correlated with that of arterial angiography (AA) in 50 patients, yielding a sensitivity of 84%, a specificity of 93% and an accuracy of 89%. Correlation of the results of Doppler with that of AA and VDSA provided support for the reliability of VDSA. Clinical data relevant to the selection of angiographic technique was collected, comparing patients who underwent only VDSA, only AA and VDSA followed by AA. The conclusions of our study are: If the image quality is good a normal VDSA practically excludes the presence of surgical lesions in the internal carotid artery and obviates the need for AA. The presence of therapeutically relevant obstructive disease is reliably detected by VDSA, but the degree of obstruction cannot be determined accurately enough to proceed with cerebrovascular surgery without AA. Patients with ischemic events in the carotid territory who are potential candidates for surgery should undergo VDSA when the non-invasive tests are normal and AA when these tests indicate the presence of a stenosis or occlusion.