Severe carotid arterial disease: a diagnostic enigma.

The development of the duplex scanner has made the diagnosis of carotid arterial disease easy to those trained in its interpretation. The difficulty lies in the ability to define the patient population most likely to benefit from early diagnosis and treatment. All patients referred to the vascular laboratories at two major hospitals for evaluation of neurologic symptoms were entered into the study. The indications for the study, comorbid conditions, and medications were tabulated and compared with the results of the carotid duplex scan. The purpose was to see whether there was a relationship between the severity of carotid arterial disease and symptoms. A total of 5,807 carotid duplex scans were performed on 5,001 patients. There were 525 patients (11%) with an internal carotid artery stenosis of >70 per cent and 252 patients (5%) with an occlusion of the internal carotid artery. In addition, there were a group of 139 patients with severe bilateral carotid disease. Bruit and a history of known carotid disease were the only indications that were statistically related to severe carotid arterial disease. Smoking, diabetes, peripheral vascular disease, cardiac conditions, and hyperlipidemia were also statistically related to patients with significant carotid disease. This study indicates that the classic indications for carotid duplex scans such as transient ischemic attack, amaurosis fugax, and dizziness have no correlation with the severity of the disease.