Researchers at Wake Forest University Baptist Medical Center reported that one part of the carotid artery that supplies the brain with blood actually expands due to the formation of atherosclerotic plaque where as two other sections don't which may lead to fatal stroke.
The researchers studied MRIs of 191 men and women who had no symptoms of carotid artery disease and found that when complex plaque made up of cholesterol, calcium and fibrous tissue forms in the common segment shared by the right and left carotid arteries, it expands by 11 percent, on average, to keep blood flowing. Whereas, the internal carotid artery which leads to the brain, decreases by as much as 16 percent when people have atherosclerotic plaque in their blood. The artery wall also increases to an average of 14 percent thicker.
This may help explain why so many significant blockages occur in the internal carotid and the (nearby) bulb area and so few occur in the common segment, which seems to be protected, said J. Greg Terry, a research associate in the endocrinology section of internal medicine at Wake Forest. The findings were presentedin June at the International Symposium on Atherosclerosis in Boston.
It is still unclear that why segments respond in such different manners, though the researchers theorize that the reasons for differences in arterial anatomy or local blood flow patterns were due to individual genetics or other risk factors.