DETECTION OF AORTIC EMBOLI BY TRANSESOPHAGEAL ECHOCARDIOGRAPHY DURINGCORONARY-ARTERY BYPASS-SURGERY

Objective: The purpose of this study was to determine whether emboli c an be detected within the aortic lumen in patients undergoing coronary artery bypass surgery (CABG) and to relate the appearance of emboli t o specific operative events. Design: Twenty patients were prospectivel y studied intraoperatively. Setting: Subjects were inpatients in an ac ademic medical center. Participants: Ail participants were scheduled f or elective, isolated CABG. Interventions: Patients were continuously monitored using transesophageal echocardiography (TEE) from aortic can nulation to bypass discontinuation. After completion of the aortic exa mination, the probe was focused at the level of the aortic arch, just before the takeoff of the left subclavian artery. Emboli were defined as echogenic intraluminal not present in the same position on consecut ive cross-sectional frames. Results: Intraluminal emboli were detected in all subjects, with a mean number of 535 and range of 8 to 1,885. E mbolization was unevenly distributed through the procedure. A mean of 224 (42%) of 535 were detected within 4 minutes of aortic cross-clamp release and another 140 (24%) appeared after partial occlusion clamp r elease. Together, damp placement and release represented 84% of all em boli. Emboli detected after clamp release ware large, echodense partic les easily distinguishable from the small, indistinct, poorly echogeni c signals observed at bypass initiation. Conclusions: Emboli can be vi sualized within the aortic lumen during CABG, Confirming previous repo rts, the majority of emboli detected are related to manipulation of ao rtic clamps. The composition and clinical significance of embolic mate rial are unclear. The value, of intraoperative TEE monitoring in predi cting neurologic outcome remains to be determined. Copyright (C) 1996 by W.B. Saunders Company.