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 has proved to be 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 subclavin steal, five patients with a missing vertebral artery three patients with hypoplasia or stenosis, and 15 patients with normal angiorgraphical findings were correctly diagnosed by Doppler; normal Doppler findings were present in three patients with a mission or stenosed vertebral artery. Those patients (five) with Doppler indications of subclavian steal (one patient), missing vertebral artery (two patients), or stenosis (two patients) had normal angiograms. Application of the Doppler procedure, after 11 subclavin endarterectomies, informed the surgeon immediately about the hemodynamic effect of surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Cerebral Angiography↗

PubMedDate not supplied

Noninvasive measurement of velocity profiles and blood flow in the common carotid artery by pulsed Doppler ultrasound.

A computer-controlled 14-channel pulsed Doppler ultrasound instrument was used as a noninvasive means to evaluate instantaneous velocity profiles and flow in the comlon carotid arteries of 22 healthy persons and in 22 patients. Of the later, 13 had severe obstructions of the extracranial portion of the carotid artery, four had obstruction of the intracranial portion, and five had severe aortic valve insufficiency (AI), with more than 60% regurgitation in all cases. Measurements could be performed within an accuracy of about +/- 20% under clinical conditions and revealed perfusion values of 5 to 8 ml per second (300 to 480 ml per minute) in healthy persons. Of the patients, values less than 3 ml per second (180 ml per minute) were detected in nine, between 3 and 5 mm per second (180 to 300 ml per minute) in four, and normal values in another four, while significant backflow was observed only in patients with severe AI. Consecutive blood flow profiles were recorded every 4 msec; these demonstratedthat, for a period lasting from 40 msec to 280 msec after the initial systolic peak, blood flow decelerated more rapidly in the central portion of the vessel lumen than near the wall. This situation was present in all healthy persons and in most patients with pathological flow. In patients with AI, flow reinversion from reverse to normal began near the vessel wall, while in the middle third of the vessel lumen, blood was still flowing backward. These phenomena seem to be in agreement with the theoretical and experimental findings of Wormersly, Müller, and others. The AI patients who underwent artificial valve implantation were studied ten days after operation and showed no or little backflow in the common carotid artery at that time.

Adult↗