The Journal of Thoracic and Cardiovascular Surgery, Vol 70, 995-1009, Copyright © 1975 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The superiority of aortic cross-clamping with profound local hypothermia for myocardial protection during aorta-coronary bypass grafting
RB Griepp, EB Stinson, PE Oyer, JG Copeland and NE Shumway
Two different operative techniques for aorta-coronary bypass grafting were
utilized in two comparable groups of patients. In one group (155 patients)
distal anastomoses were carried out with the aorta cross- clamped and
myocardial protection provided by profound local hypothermia (clamped
group). In a second group (149 patients) distal anastomoses were carried
out with the aorta unclamped and the left ventricle fibrillating and vented
(unclamped group). Mortality rates were similar in the two groups (0.6 per
cent in clamped group versus 1.3 per cent in unclamped group). The
incidence of perioperative infarction was 15 per cent in the unclamped
group and 8 per cent in the clamped group (p less than 0.05). Postoperative
serum glutamic oxaloacetic transaminase (SGOT) and lactic dehydrogenase
(LDH) levels were significantly higher for the first 4 postoperative days
in the unclamped group than in the clamped group. Hemodynamic studies in a
subset of each group revealed no important differences in left ventricular
function in the immediate postoperative period. The data demonstrate that
in patients undergoing aorta coronary bypass grafting, performance of
distal anastomoses with aortic cross-clamping and profound local
hypothermia results in less intraoperative myocardial injury than
performance of distal anastomoses in the perfused, fibrillating, and vented
left ventricle.
