Off-pump coronary bypass operations significantly reduce S100 release: An indicator for less cerebral damage?

Background. Cardiac operations using extracorporeal circulation bear a risk of cerebral complications. The aim of our study was to investigate if off- pump operations without heart-lung machines can reduce cerebral injury. Methods. S100, a protein specific for cerebral tissue, was used as a marker for cerebral impairment in 108 randomized patients undergoing coronary byp ass operation: 67 patients (group A) were operated on with extracorporeal c irculation and cardioplegic cardiac arrest, and 41 patients (group B) under went off-pump beating heart revascularization. Both groups were similar reg arding age, sex, ejection fraction, and number of anastomoses. S100 levels were measured from induction of anesthesia until 24 hours after the operati on. Results. Data collection was 100% complete. There was no in-hospital death. Nonfatal myocardial infarctions occurred in 2 patients in group A, and 1 p atient in group B required resternotomy for bleeding. There was no neurolog ic deficit in either group. S100 levels increased only slightly in the off- pump patients (group B), whereas in group A there was a sharp rise in S100 concentration during extracorporeal circulation, only returning to baseline 6 hours after the end of the operation. Peak S100 levels were four times h igher in group A than in group B (2.1 mug/L versus 0.5 mug/L; p < 001). Conclusions. The results of our study suggest that perioperative cerebral i mpairment is reduced in cardiac operations without the use of extracorporea l circulation. Further large-scale studies are needed to show whether this result is reflected by fewer neurologic deficits. (Ann Thorac Surg 2000;70: 1577-9) (C) 2000 by The Society of Thoracic Surgeons.