Ascending aortic aneurysms: Asymmetrical differences in aortic cross-sectional wall motion detected by epiaortic echocardiography

Objective: To evaluate in vivo cross-sectional conformational changes of ascending aortic wall excursion in patients undergoing resection for aortic aneurysm with those undergoing elective coronary artery bypass grafting (CABG) using epi-aortic echocardiography. Design: A prospective observational investigation. Setting: A single tertiary care university hospital. Participants: Thirty-four patients undergoing elective ascending aorta resection and 23 elective CABG patients. Intervention: In an open-chest model and with use of an epi-aortic echocardiographic probe, measurements of aortic wall excursion were made on the ascending aortic aneurysms. Control measurements were made on the transitional neck portions of the aneurysmal aortas (internal control) and CABG aortas (external control). Measurements and Main Results: The aortic aneurysm measurements exhibited no difference (2.8%, p < 0.62) between the excursion of the anterior and posterior walls. In contrast, under similar hemodynamic conditions, the anterior wall of the aneurysm neck moved 48.2% (p < 0.0004) more than the posterior wall. Similarly, in the CABG control group, the anterior wall moved 24% (p < 0.027) more than the posterior wall. Conclusion: This in vivo study documented a lack of asymmetric aortic wall motion in ascending aortic aneurysms. In contrast, both the internal and external control groups (aneurysm neck and CABG) demonstrated asymmetric wall motion. The lack of asymmetric wall motion may be an important aspect of aneurysm pathophysiology and key to the development of management strategies for timing of surgical intervention.