Mechanisms of cerebral injury from cardiac surgery

Abstract

Cerebral injury is a frequent complication of cardiac surgery, and it has been associated with high mortality, morbidity, hospital costs; an increased likelihood of admission to a secondary care facility after hospital discharge; and impaired quality of life. This article examines postulated mechanisms for cerebral injury from cardiac surgery. Most emphasis has been placed in the past on the intraoperative interval as being the period of highest cerebral vulnerability. Many clinical cerebral events, however, occur in the postoperative period.

Figure 1

Diffusion weighted brain magnetic resonance image of a patient with stroke after cardiac surgery. The bright images represent brain ischemic injury. The location of the injury in the end vascular territory of the anterior and middle cerebral arteries and the middle and posterior cerebral arteries is consistent with a watershed infarction due to cerebral hypoperfusion.

Figure 2

Transesophageal echocardiographic images demonstrating increasing severity of atherosclerosis of the aorta using incremental 5point grading system. From Fox JA, Formanek V, Friedrich A, et al. Intraoperative Echocardiography. In: Cohn LH and Edmunds, LH Jr., eds. Cardiac Surgery in the Adult, 2^nd Edition. New York: McGraw-Hill, 2003:283-314 with permission.