Do particulate emboli from the ascending aorta in coronary bypass grafting correlate with aortic wall thickness?

This study investigated the previously uncertain relationship of embolic load captured during coronary artery bypass grafting and the extent of ascending aortic atherosclerosis as measured by wall thickness. Patients (n=113) underwent isolated arrested heart coronary artery bypass grafting. Ascending aortic wall thickness measures were obtained by epiaortic ultrasound. Aortic segmental values (distal, mid, proximal) were determined by the summation of measures (anterior lateral, posterior, medial) at each segment. An intraaortic filter (EMBOL-X) System, Edwards Lifesciences, Irvine, CA) was placed into the arterial cannula, distal to the aortic measurements, just before releasing the aortic cross-clamp. Particulate debris was found in 96% (109/113) of filters. Mean number of particles was 6.8+/-4.8 (range 0-23) and mean particle surface area was 5.5+/-7.0 mm(2) (range 0-51 mm(2)). Total aortic wall thickness, distal third, mid third, and proximal third thicknesses were 27.4+/-4.4 mm, 9.5+/-2.0 mm, 9.0+/-1.9 mm, and 8.8+/-1.4 mm, respectively. There was no significant correlation between the number of particles or surface area and any of the aortic wall thickness measures. These results suggest that during on-pump, arrested heart coronary artery bypass grafting, embolic load from the ascending aorta is independent of the extent of ascending aortic atherosclerosis in patients with low or moderate risk aortic pathology.