Intima-Media-Thickness (IMT) bei Patienten mit vertebrobasilären und karotidalen Stenosen/Verschlüssen
Introduction: The Intima-Media-Thickness (IMT) of the commom carotid artery (CCA) is often used as a parameter for generalized atherosclerotic lesions of the vessel wall. It is possible to visualize the increase of the IMT in an early degree of athrosclerosis as a double line pattern in the sonographical picture (B-mode). The demographic difference of the IMT (e.g. between men an women) and the effect of the classical cerebrovascular risk factors on the IMT are sufficiently known. The difference of the side (right and left carotid artery) and the localisation in the carortid arteries of the IMT are already illuminated. It is not known actually, if different types of atherosclerosis are accompanied by a different IMT. The purpose of the study was to invesigate the IMT in patients with stenoses or occlusions in the vertebrobasilar system (VBS) and the carotid system (CS). Patients and methods: The Intima-Media-Thickness (IMT) and the diameter (QD) of the common carotid artery (CCA) (as a parameter of proliferative and dilatative form of atherosclerosis) were measured on both sides on areas of vessel wall without stenoses and plaques. We examined of the neck 121 people, including 32 normal healthy counds, 57 patients with stenoses or occlusions in the CS and 16 patients with macroangiopathy exclusively in the VBS. Patients of the fourth group (n=16) suffered from both VBS- and CS-macroangiopathy (CS/VBS) (following doppler- and duplex sonographical criteria). The classical cerebrovascular risk factors (age, arterial blood pressure, hypercholesterolemia, diabetes mellitus, family history, smoking status) were entered in a questionnaire. Results: In control persons, a IMT of 0,67±0,2 mm and a CCA-diameter of 5,8±1,2 mm was found. Patients with CS-macroangiopathy exhibited a significant higher IMT with 0,97±0,2 mm (p<0,0001) and a larger CCA-diameter (6,6±1,2 mm, p<0,01). In comparison to the controls we also found a significant higher IMT (0,86±0,2 mm, p<0,001) and a larger CCA-diameter (6,8±0,9 mm, p<0,01) in patients with VBS-macroangiopathy. There was no significant difference between both groups, despite a tendency of less severe changes in patients suffering from VBS-macroangiopathy. Persons without macroangiopthy exhibited a significant thinner IMT (0,67±0,08 mm) than patients with stenoses and occlusions (1,03±0,26 mm, p<0,001). The diameter correlated only weakly (r=0,46) with the IMT. In men was found a significant thicker IMT (0,92±0,2 mm, p<0,05) than in women (0,81 p<0,050,2 mm). Also the diameter was in men with 6,9±1,3 mm significantly (p<0,001) larger than in women with 5,8±1,0 mm. Considering both sides of the IMT seperately (right/ left) there was no significant difference. Macroangiopathies of the cerebral arteries were found more frequently on the left side. Patients with arterial hypertension (0,95±0,3 mm, p<0,05) and patients with diabetes (1,03±0,2 mm, p<0,01) showed a significant thicker IMT than patients without arterial hypertension (0,84±0,2 mm, p<0,01) and diabetes (0,86±0,4 mm, p<0,01). In smokers we found a thinner IMT (0,81±0,2 mm, p<0,05) than in non-smokers (0,92±0,2 mm). Smoker (57 jears) were however on average ten years younger than non-smokers and the age correlated significantly (p<0,01) with the IMT. Discussion: The IMT between patients with stenosis or occlusions in the vertebrobasilar system (VBS) and the carotid system (CS) does not differ signifcantly in the examined collective of patients. Patients with macroangiopathy exhibit a thicker IMT than normal healthy counds. Both patients with CS- and VBS-macroangiopathy show a larger diameter of the CCA in comparison to the controls. Our results support earlier observations: The diameter of the CCA in men is larger than in women and men show a higher IMT than women. Considering both sides of the IMT seperately (right/ left) there is no difference. Macroangiopathy of the cerebral arteries is found more frequently on the left side. Patients with arterial hypertension or diabetes show a thicker IMT than patients without arterial hypertension or diabetes. The age correlates well with the IMT. Not only the classical cerebrovascular risk factors but also factors like genetic disposition, ethnic differences, socioecomomical aspects and environment may attribute to an increase in IMT.
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