Echocardiographic and pathological evaluation of atherosclerosis in the ascending aorta during coronary artery bypass grafting

We performed intraoperative echocardiography with an epiaortic probe to ass ess the correlation between echocardiographic appearance and pathological f indings of the aorta and to examine the effect of crossclamping on the aort ic wall in 276 patients who underwent coronary artery bypass grafting. The ascending aorta was divided into three segments as follows: lower (L), uppe r (U), and innominate. The anterior (ant) and posterior (post) intimal thic knesses of each of the three segments were measured. The echogenicity at ea ch of the six locations was examined and was classified as isoechoic or non isoechoic (hyperechoic, hypoechoic, or mixed type). Tissue punched from the ant L wall of the ascending aorta for vein anastomosis was examined for th e presence of atheroma. At the ant L, the prevalence of atheroma tvas signi ficantly higher in nonisoechoic walls than in isoechoic wails (P = 0.049). We divided patients into two groups according to echogenicity at the U segm ents. Group A (n = 213) consisted of patients whose echogenicities at both ant U and post U were isoechoic. Group B (n = 63) consisted of patients wit h nonisoechoic echogenicity at ant U and/or post U. The intimal thicknesses at all six locations in Group B patients were greater than those of Group A (P < 0.01). Deformities at the clamp site after cardiopulmonary bypass we re observed significantly more often in Group B than in Group A (P < 0.01). Our data suggest that a nonisoechoic aortic wall indicates more advanced a theroma and a higher risk of deformities at the clamp site. Examination of the echogenicity of the ascending aorta may be one method to reduce periope rative neurological complications.