Noninvasive angiography for the diagnosis of vertebral artery disease using Doppler ultrasound (vertebral artery Doppler).

Abstract
A transoral noninvasive procedure in the oropharynx using local anesthesia was applied to detect flow in the vertebral arteries with a bidirectional continuous-wave Doppler ultrasound system. Common carotid artery compression was used to identify the vertebral artery. Flow direction, amplitude of flow signals, diastolic flow and reaction of flow on common carotid artery compression served as diagnostic parameters. The procedure was applied in 90 patients of whom 42 underwent angiography. The method was 82% accurate. It was most reliable in the diagnosis of occlusion or aplasia, subclavian steal and normalcy, and was less reliable in the detection of stenosis or hypoplasia of a vertebral artery. Eleven patients with subclavian steal, 5 patients with a missing vertebral artery, 3 patients with hypoplasia or stenosis and 15 patients with normal angiographical findings were correctly diagnosed by Doppler; normal Doppler findings were present in 3 patients with a missing or stenosed vertebral artery. Those patients (5) with Doppler indications of subclavian steal (1 patient), missing vertebral artery (2 patients) or stenosis (2 patients) had normal angiograms. Application of the Doppler procedure, after 11 subclavian endarterectomies, informed the surgeon immediately about the hemodynamic effect of surgical intervention. Rethrombosis was diagnosed in 2 patients by postoperative Doppler examination.