The Journal of Thoracic and Cardiovascular Surgery, Vol 106, 172-179, Copyright © 1993 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Mechanism of changes of the collagen matrix of reperfused myocardium in donor heart preservation
M Ohnuki, M Sunamori, J Amano and A Suzuki
Department of Thoracic-Cardiovascular Surgery, Tokyo Medical and Dental University, School of Medicine, Japan.
Isolated canine hearts were preserved for 6 hours at 5 degrees C followed
by normothermic reperfusion for 2 hours. Dogs were divided into two groups:
group I (group Ia [n = 7] and group Ib [n = 3] with the left ventricle
unloaded during reperfusion) received a preservation solution containing
potassium (20 mmol/L), and group II (n = 9) received University of
Wisconsin solution. Left ventricular diastolic function was better
preserved in group II. Degradation and loss of the collagen network during
reperfusion, as assessed by scanning electron microscopy, were more
extensive and significantly more frequent in group Ia than in group II (6/7
versus 2/9; p < 0.05). Furthermore, extensive disruption of the collagen
network was significantly more prevalent in hearts with a left ventricular
end-diastolic pressure of more than 20 mm Hg than in hearts with a left
ventricular end-diastolic pressure of less than 20 mm Hg (8/10 versus 0/6;
p < 0.05), and no disruption of the collagen network occurred in group
Ib, regardless of the type of preservation solution. These results suggest
that the greatest disruption is caused by barotrauma resulting from an
elevated left ventricular end-diastolic pressure after ventricular
dysfunction caused by ischemic reperfusion injury.
