Screening of the internal carotid arteries in patients with peripheral vascular disease by colour-flow duplex scanning.

The prevalence of internal carotid arterial disease was assessed in 416 consecutive patients with peripheral arterial disease (PAD). Colour-flow duplex scanning was performed to determine the extent of the disease. Major internal carotid artery disease (MICAD), meaning 75% stenosis and/or occlusion, was found in 14.9% (62) of the patients; 12.5% (52) had unilateral disease and 2.4% (10) had bilateral disease. In 7.7% (32) there was a stenosis of 75-99%. An occlusion was seen in 7.2% (30). No correlation was found between the severity of the internal carotid artery disease and the severity of the peripheral arterial disease. The 16.0% (60) prevalence in MICAD in patients with obstructive disease was significantly higher than the 4.7% (2) in aneurysm patients (p less than 0.05). The results show that there was no correlation between MICAD and the risk factors: hypertension, gender, age, diabetes mellitus, hypercholestolaemia, smoking and ischaemic heart disease. The high prevalence of MICAD in patients with PAD suggests that it would be useful to start a screening programme to determine if high grade stenosis should be operated upon.