Abstract
Neurological dysfunction after cardiac surgery is a devastating complication and is associated with increased mortality and prolonged hospital stay. The population is aging and elderly patients undergo a disproportionaly high rate of cardiac surgery. Advanced age is often associated with increased systemic atherosclerosis and a major risk factor for stroke after cardiac surgery. Postoperative neurological dysfunction is primary caused by cerebral emboli, hypoperfusion, systemic atherosclerosis or inflammation. Embolization is the most common cause of intraoperative strokes and is associated with advanced atherosclerosis in the ascending aorta. The operative strategies of preventing emboli and maintaining higher perfusion pressure during CPB confer protection against neurologic complications and attenuate the ischemic cascade in the brain following embolic load. Recently, off-pump CABG appears to promise elimination of microemboli from the ascending aorta and of inflammatory response, and may lead to a lower incidence of postoperative neuropsychological dysfunction. Diffusion-weighted imaging MRI (DWI-MRI) has found ischemic lesions in the brain after cardiac surgery and left cardiac catheterization. Patients with pre-existing cerebral injury may be more vulnerable to the adverse effects of cardiac surgery. Preoperative DWI-MRI allows convenient non-invasive assessment of preoperative cerebral ischemia and may be useful to decide optimal treatment strategies in cardiac surgery.
