The Annals of Thoracic Surgery, Vol 48, 397-403, Copyright © 1989 by The Society of Thoracic Surgeons
Asanguineous reperfusion in a canine model of cardiopulmonary bypass and controlled postischemic work
IM Rebeyka, GJ Wilson, RA Axford-Gatley, AD Romaschin and DA Mickle
Department of Surgery, Toronto General Hospital, Ontario, Canada.
This study was designed to test the hypothesis that asanguineous
reperfusion with a standard crystalloid cardioplegic solution results in
improved myocardial salvage after a period of global ischemia. Four groups
of 6 dogs each were placed on cardiopulmonary bypass. Control group A (work
only) performed two hours of controlled work by contracting against a
saline-filled left intraventricular balloon. Control group B (ischemia
only) underwent 45 minutes of global normothermic ischemia before simple
blood reperfusion while supported on bypass. Groups C and D were subjected
to ischemia and reperfusion as in group B, followed by controlled work
stress as in group A. Group D, however, received 500 mL of St. Thomas'
Hospital solution immediately before blood reperfusion. Morphological
analysis showed no significant injury in groups A and B, whereas group C
had 11.4% +/- 2.4% necrosis of heart mass versus 2.5% +/- 1.1% in group D
(p less than 0.001). Biochemical data from left ventricular biopsies showed
no significant differences between groups B, C, and D. Functional analyses
showed deterioration of diastolic compliance in group C (p less than 0.05),
although a significant difference in systolic functional indexes could not
be detected. Myocardial protection and salvage was improved by initial
reperfusion with an asanguineous cardioplegic solution versus reperfusion
with blood alone.
