Abstract :
Cardiac surgical patients face the threat of neurologic complications in all phases of their disease and its treatment. The incidence of preoperative transient ischemic attacks and stroke ranges from 5% to 14% and from 2% to 11%, respectively. The risk of preoperative cerebrovascular accidents is higher in patients with valvular disease than in those with coronary artery disease. The prevalence of postoperative neurologic disorders varies widely because of differences in defining the clinical criteria, heterogeneity of patient populations, timing of evaluation, follow-up times, study designs, and surgical and anesthesia-related procedures. Fatal cerebral damage is very rare (<0.1%). Focal cerebral deficits, or definite stroke, are encountered in 1% to 3% of patients and minor clinical abnormalities, in 5% to 10%. Recent studies have shown that contrary to previous concepts, valve replacement does not carry essentially higher neurologic risks than coronary bypass grafting. The most common causes of operation-related neurologic disorders are microembolization or macroembolization and hypoperfusion. Although most disorders resolve early postoperatively, some deficits persist. From the neurologic standpoint, a main objective of a cardiac surgical intervention is to prevent stroke. Today, the incidence of cardiogenic cerebrovascular accidents is very low after reparative cardiac procedures. Despite surgical and anesthesia-related improvements, neurologic complications do occur. Multidimensional investigatory procedures have shown that cardiopulmonary bypass often causes cerebral dysfunction. Whether the harmful consequences are detected depends on the evaluation criteria and the investigatory methods and timing used. Further methods are needed to prevent or treat preoperative cerebrovascular accidents and particularly to improve cerebral protection during operative procedures.
