Restenosis following carotid endarterectomy. Evaluation by duplex ultrasonography.

This study evaluated the efficacy of duplex ultrasonographic scanning in assessing the status of carotid arteries after 155 endarterectomies in 131 patients. Duplex studies were done as early as one month and as late as 96 months postoperatively; 33 patients had serial studies. Only 59 (42%) of 142 arteries had no evidence of irregularity or reduction in diameter at the operative site. An additional 41 (29%) had a reduction in diameter between 10% and 29%; 19 (13%) had reductions of 30% to 49%; nine (6%) from 50% to 69%; six (4%) from 70% to 99%; and eight (6%) were occluded. In 51 vessels, angiographic studies confirmed the duplex findings. Symptoms suggestive of recurrent cerebrovascular disease occurred postoperatively in 25 instances; in only three were the anatomic findings suggestive of lesions appropriate to the symptoms. We conclude that duplex ultrasonographic scanning is a useful technique for assessing carotid arteries after endarterectomy and that postoperative narrowing of vessels occurs more commonly than suspected.