and disability. Stroke is the third leading cause of death and is the major cause of disability in the United States. 1-3 Approximately one half of patients in long-term care facilities require treatment because of strokes.Over one half of strokes are caused bv arteriosclerotic lesions in the cervical carotid artery and are potentially preventable.4-6 Duplex scanning of the carotid artery has evolved as the prime means of discovering strokc-potential carotid artery lesions and provides a rapid, safe, and reliable means of ferreting out such lesions. 1 Prospective randomized clinical trials have shown that safely performed carotid endarterectomy (CEA) can prevent strokes. In the North American Symptomatic Carotid Endarterectomy Trial (NASCET), 24% of patients with carotid artery lesions with greater than 70% diameter reduction who were treated medically had an ipsilateral cerebrovascular accident within 18 months compared to 7% of those patients who underwent CEA .7 Over one half of the strokes occurring in patients in the medical arm of that study were severe or fatal. Two other similar trials, the European Carotid Surgery Trial&dquo; and the Veterans Affairs Cooperative Studies Program Trlal9 for symptomatic carotid endarterectomv showed nearly identical results.The Veterans Affairs Cooperative Study Group 10 for symptomatic carotid artery stenosis found that 9.4% of patients with no symptoms or nonlateralizing symptoms and greater than 50% carotid artery stenosis who were treated medically had ipsilateral strokes during the period of StLidB' compared to 4.5% who had CEA. Transient ischemic attacks occurred in 11.1°lo of those treated medically and the risk of combined neurologic events (stroke plus transient ischemic attack) was 26% for those treated medicaih and 8% for those treated surgically (statistically significant). Although the combined incidence of stroke and death was not significantly different in the medical and surgical patients, it can be surmised that a vascular surgeon with a low perioperative stroke and death rate could prevent strokes in these asymptomatic patients. This is important because approximately 50% of strokes are not preceded by lateralizing events.