LASER-DOPPLER FLUX IN THE NORMAL AND ATHEROSCLEROTIC CAROTID-ARTERY WALL IN NORMOTENSIVE AND HYPERTENSIVE SUBJECTS

The aim of this study was to evaluate in vivo the perfusion of the art erial wail in normal sections of the carotid artery, in sections with fibrotic plaques and in sections with plaques and heavy calcifications using laser-Doppler flowmetry. Patients with carotid plaques undergoi ng carotid endarterectomy were studied, Using intraoperative ultrasoun d three different levels of atherosclerosis involvement of the arteria l wall were defined: normal arterial wail where all components (intima , media and adventitia) were clearly separated and intact; wall with i ntima-media thickening and fibrotic plaques (no calcification); sectio ns with diffusely calcified plaques, In 20 patients 20 normal sections , 20 sections with fibrotic plaques and 20 sections with large plaques and heavy calcifications were studied, Diabetic patients were exclude d, Also the carotid wall of 10 patients with essential hypertension we re evaluated, Wall flux was measured on the external surface of the co mmon carotid artery before endarterectomy, Measurements were recorded when at least 3/4 of the adventitia was intact for a lenght of at leas t 4 cm, Results, The average flux in normal sections was higher (p<0.0 5) than in sections with fibrotic plaques and in sections with calcifi ed plaques, A significant difference in flux (p<0.05) between fibrotic (decreased flux) and calcified areas (very low flux), In hypertensive subjects flux measurements were significantly lower than in non-hyper tensive patients (p<0.05), In conclusions a higher wall perfusion was observed in normal arterial sections in comparison with sections with plaques, Sections with calcifications and large plaques had a markedly low flux, In hypertensive subjects ail sections had a significantly l ower flux.