Management of the Ascending Aorta in Routine Cardiac Surgery

Abstract

It is well known that subtle neurologic and neuropsychologic adverse effects are associated with cardiac surgery. Microgaseous emboli may arise from the cardiac pulmonary bypass apparatus; however, most particulate emboli arise from the ascending aorta. Atherosclerosis of the ascending aorta may effect up to 38% of cardiac surgical patients greater than 50 years of age. In addition to avoiding cardiopulmonary bypass with off-pump procedures, avoiding manipulation of the ascending aorta in any way is also associated with a reduction in embolic complications. Epiaortic scanning is the most accurate way to assess the location and severity of atheromata in the ascending aorta. Management of the atheromatous ascending aorta may include changes to cannulation options for cardiopulmonary bypass, such as femoral or axillary cannulation. Complete avoidance of the cross-clamp may be entertained. Aorta cannulae incorporate a number of filtration and deflection devices that may offer some protection to the brachiocephalic vessels. In some cases, replacement of the ascending aorta under deep hypothermic circulatory arrest is appropriate. Avoidance of the ascending aorta by using arterial revascularization as sequential or Y grafts, or placing proximal anastomoses on the subclavian arteries, may allow for complete revascularization without touching the ascending aorta. A full appreciation of the information obtained with epiaortic scanning or transesophageal echocardiography allows for decisions to be made to tailor each procedure to the patient's unique needs and circumstances for optimal outcomes.