The cerebral complications of coronary artery bypass surgery.

A prospective study of 79 coronary artery bypass surgery patients has been undertaken to determine the cerebral consequences of this form of surgery. Thirty comparative major vascular and thoracic non-cardiopulmonary bypass patients have also been studied. Detailed neurological, neuropsychological and cerebral blood flow investigations were undertaken preoperatively and at 8 days and 8 weeks postoperatively. Whilst stroke was rare following coronary artery bypass surgery, only one case in 76 being found (less than 1%), moderate or severe neuropsychological deficit was common, occurring in 49 of 67 patients (73%) 8 days after surgery and in 25 of 67 patients (37%) 8 weeks after surgery. However, the non-cardiopulmonary bypass patients also showed comparative levels of neuropsychological deficit. Cerebral blood flow was significantly reduced 8 days following coronary artery bypass surgery but not at 8 weeks and not in the comparative group. Significant cerebral blood flow reduction 8 days after coronary artery bypass graft surgery was not related to neuropsychological deficit found at a similar time. A greater neuropsychological deficit was found with longer cardiopulmonary bypass times but increased length of cardiopulmonary bypass appeared not to be related to an increased cerebral blood flow reduction.