Beating heart surgery: why expect less central nervous system morbidity?

Background. The incidence and etiology of brain dysfunction after conventional coronary artery bypass surgery using cardiopulmonary bypass (CPB) are reviewed. Methods. Stroke rates and incidences of cognitive dysfunction from various studies are considered. Mechanisms of injury including cerebral embolization as detected by transcranial Doppler and retinal angiography, and imaging-based evidence for postoperative cerebral edema, are discussed. Preliminary results from a prospective clinical trial assessing cognitive dysfunction after beating heart versus conventional coronary artery bypass with CPB are discussed. Results. Initial evidence for lower overall postoperative morbidity, and for a lower incidence of cognitive dysfunction specifically, after nonpump coronary revascularization is presented. Conclusions. Beating heart surgery results in less potential for generation of cerebral emboli and appears to produce a lower incidence of cognitive dysfunction in both short- and intermediate-term postoperative follow-up periods as compared with conventional coronary artery bypass surgery using CPB.