Early neurobehavioral disorders after cardiac surgery: A comparative analysis of coronary artery bypass graft surgery and valve replacement

Objective: To analyze neurobehavioral disorders in the early postoperative period after valve replacement and coronary artery bypass graft (CABG) surgery. Design: Prospective study. Setting: University hospital. Participants: Patients undergoing elective cardiac surgery with cardiopulmonary bypass; 42 patients in the valve replacement surgery group and 42 patients in the CABG surgery group, with both groups matched post hoc for age, sex, and preoperative cognitive status. Measurements and Main Results: All subjects were investigated preoperatively as well as 2 and 7 days postoperatively with a comprehensive neuropsychologic and neuropsychiatric assessment. The groups did not significantly differ with respect to the incidence of postoperative neuropsychiatric disorders. Valve replacement surgery patients exhibited more severe neuropsychologic deficits and showed a slower recovery than patients who underwent CABG surgery. In both groups, postoperative neuropsychologic alterations were most marked in fluency, arithmetic, and memory performance. Conclusion:These results indicate that patients after valve replacement surgery have a higher risk of postoperative neuropsychologic alterations mainly attributable to temporal lobe dysfunction. This finding corresponds to a specific vulnerability of hippocampal structures to transient hypoxia. Copyright (C) 2001 by W.B. Saunders Company.