Doppler spectral analysis of the internal carotid before and after endarterectomy.

In 37 randomly selected patients, stenosis of the internal carotid artery was evaluated with Doppler spectral analysis before and 6-10 weeks after endarterectomy. Postoperatively 20 of the vessels were entirely within the normal variation range and four, though not normal, showed significantly lower blood flow velocity, indicating wider vascular lumen. In ten cases there were no significant postoperative change, and in three significant worsening of the Doppler shift was seen without clinical implications. The method is useful for evaluating the endarterectomized carotid noninvasively without use of contrast medium, and when bilateral operation is contemplated the analysis is most valuable for ruling out occlusion in the artery first operated on.