Cerebral Dysfunction After Coronary Artery Bypass Surgery

Cerebral dysfunction after cardiac surgery remains a devastating complication and is growing in importance with our aging populations. Neurological complications following cardiac surgery can be classified broadly as stroke, encephalopathy (including delirium), or postoperative cognitive dysfunction (POCD). These etiologies are caused primary by cerebral emboli, hypoperfusion, or inflammation that has largely been attributed to the use of cardiopulmonary bypass. Preventative operative strategies, such as off-pump coronary artery bypass grafting (CABG), can potentially reduce the incidence of postoperative neurological complications by avoiding manipulation of the ascending aorta. Although off-pump CABG is associated with reduced risk of stroke, there are no convincing differences in POCD between off-pump and on-pump CABG. Recently, the focus of postoperative neurological research has shifted from managing cardiopulmonary bypass to patient-related factors. Identifying changes in brains of aged individuals undergoing cardiac surgery may improve strategies for preventing cerebral dysfunction. Advanced age is associated with more undiagnosed cerebrovascular disease and is a major risk factor for stroke and POCD following cardiac surgery. Preoperative cerebrovascular evaluation and adaptation of surgical strategies will provide preventative approaches for cerebral dysfunction after CABG. This review focuses on recent findings of the relationship between perioperative stress and underlying fragility of the brain in cardiac surgical patients.