Morphological damage to the central nervous system (CNS) following open heart surgery

We investigated 40 patients who had died following open heart surgery between January 1990 and May 1992. Between this time, 703 open heart procedures were carried out at the University Medical School of Debrecen, 2nd Department of Surgery's Cardiac Surgery Unit with a mortality rate of 8.3%. We studied each individual's clinical records, autopsy findings, and histology of defined portions of brain tissue. Clinical information used were: sex, age, clinical stage (according to New York Heart Association (NYHA) classification) at time of surgery, type of procedure performed, and duration of time of extracorporeal circulation. Autopsy records collected and studied focused on the macroscopic and microscopic alterations in the CNS. The most common morphological findings in the CNS for the 40 studies cases were, cerebral edema in all cases, reactive microgliosis and nuclear pyknosis in most cases, and in a minority of the cases focal microscopic hemorrhage or focal microscopic white emolition. Also found were, destructive brain hemorrhage and global cerebral necrosis. Of the 40 cases studied there was only one case in which brain death was diagnosed perioperatively, and which was clinically diagnosed to be caused by global cerebral hypoxia.