[The diagnosis of obstructions of the vertebral and subclavian arteries by means of directional Doppler sonography (author's transl)].

The Doppler examination of the vertebral and subclavian arteries was compared with the angiographic findings in 40 cases. The vertebral flow was recorded at its atlas slope, the subclavian artery at the supraclavicular fossa. Twenty-seven normal Doppler results were confirmed by angiography in 26 cases. In one case there was a 70% stenosis at the origin of the vertebral artery. Occlusions, stenoses, and severe hypoplasia of the vertebral artery can be detected, but not distinguished from each other by the Doppler examination. Diagnostically relevant findings are either nondetectable flow above the vertebral artery or only minor pulsations with amplitudes less than 25% of the normal side. Eleven cases showed a flow reversal in a vertebral artery. Five of them were angiographically controlled and all showed a typical subclavian steal syndrome. Although the precision of the results of the examination of the vertebral artery is not as good as for the carotid arteries, it is a rough, suitable atraumatic screening method particularly for the subclavian steal syndrome.