STROKE DURING CORONARY-ARTERY BYPASS-GRAFTING USING HYPOTHERMIC VERSUS NORMOTHERMIC PERFUSION

Does the abandonment of hypothermic perfusion during cardiopulmonary b ypass compromise cerebral protection and thus lead to a higher inciden ce of stroke? From 1987 to June 1993, 2,585 consecutive patients under went myocardial revascularization using warm-body (perfusion at 37 deg rees C), cold-heart (cold cardioplegic arrest) surgical technique and were followed for new overt neurologic deficits. Perfusion pressure wa s maintained between 50 and 70 mm Hg, and hematocrit was kept around 2 0%. There were 25 operative deaths (1%) in this normothermic group, an d new neurologic deficits developed after operation in 25 patients (1% ). These results were compared retrospectively with those in 1,605 pat ients who underwent myocardial revascularization between 1980 and 1986 with moderate hypothermic (25 degrees to 30 degrees C) perfusion, the same surgical team, and similar operative techniques. The normothermi c group included more elderly patients, more patients with left ventri cular dysfunction and unstable angina, and more frequent use of an int ernal mammary artery conduit. Neurologic complication rates were 1% an d 1.3% for the normothermic and hypothermic perfusion groups, respecti vely. Risk factors for stroke that were identified included age greate r than 70 years, severity of aortic arch atherosclerosis, and severe h ypotension in the perioperative period. Thus, in a large clinical seri es, the incidence of overt neurologic injuries was found to be no high er with normothermic perfusion than with hypothermic perfusion.