Brain damage and neurological outcome after open-heart surgery.

Cerebral damage remains a major hazard of open-heart surgery. A one-year follow-up investigation of 100 consecutive patients who underwent open-heart operation for valve replacement revealed an incidence of postoperative cerebral disorders of 37%. The occurrence of brain damage was clearly related to the presence of a history of previous neurological diseases, to operative hypoxia, and to unexpected events during operation, but long perfusion time proved to be the most significant risk factor. In contrast to previous findings, age and moderate operative hypotension proved unimportant. The abnormalities tended to resolve rapidly but, one year after operation seven patients still displayed residual signs. An interesting interhemispheric difference in susceptibility to damage was evident, the clinical signs indicating lesions of the right hemisphere in 71% of the damaged cases. The nature of both preoperative and postoperative signs and symptoms, the determinants of brain damage and the significance of the observed disparity between the hemispheres are discussed. The continuous occurrence of brain damage obliges us to develop preventive measures more efficient than those now available.