Brain protection during cardiac surgery: circa 2012

Abstract

Brain injury during cardiac surgery can cause a potentially disabling syndrome consisting mainly of cognitive dysfunction but can manifest itself as symptoms and signs indistinguishable from frank stroke. The cause of the damage is mainly the result of emboli consisting of solid material such as clots or atherosclerotic plaque, fat, and/or gas. These emboli enter the cerebral circulation from the cardiopulmonary bypass machine, break off the aorta during manipulation, and enter the circulation from cardiac chambers. This damage can be prevented or at least minimized by avoiding aortic manipulation, filtering aortic inflow from the pump, preventing air from entering the pump plus careful deairing of the heart. Shed blood from the cardiotomy suction should be processed by a cell saver whenever possible. By doing these maneuvers, inflammation of the brain can be avoided. Long-term neurocognitive damage has been largely prevented in large series of patients having high-risk surgery, which makes these preventive measures worthwhile.

Figure 1.

(A–B) Small lipid microemboli (SCADs) in arterioles (dark arrows), vasospasm (white arrow). (C) SCAD stained black with osmium indicating fat. Arrows indicate tissue edema and vacuoles from injury. Osmium-stained, paraffin-embedded 5-mm thick section.