The Journal of Thoracic and Cardiovascular Surgery, Vol 95, 1008-1013, Copyright © 1988 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The effect of superoxide dismutase and catalase on the extended preservation of the ex vivo heart for transplantation
F Gharagozloo, FJ Melendez, RA Hein, RJ Shemin, VJ DiSesa and LH Cohn
Department of Surgery, Harvard Medical School, Boston, Mass.
The applicability of heart transplantation remains limited in part by the
inability to preserve the excised heart for long periods of time. Free
radical scavengers have been shown to protect the anoxic myocardium by
preventing damage to the cell membrane and may, therefore, be effective in
extending successful preservation of donor hearts. We perfused 10 sheep
hearts for 8 hours in an ex vivo perfusion system. The effect of superoxide
dismutase combined with catalase, 60,000 units/L, was studied in five
sheep, and five received placebo. Control determinations and determinations
after 8 hours of preservation were obtained with the heart perfused with
autologous blood at 37 degrees C at an aortic perfusion pressure of 60 mm
Hg and flow of 180 to 200 ml/min. After control readings, the hearts were
arrested and perfused with a cold (6 degrees to 8 degrees C) oxygenated
buffered crystalloid solution with or without superoxide dismutase and
catalase at a perfusion pressure of 30 cm H2O for 8 hours. Left and right
ventricular compliance was measured sequentially with separate
intraventricular balloons. After 8 hours of ex vivo preservation, hearts
receiving superoxide dismutase and catalase had significantly better left
and right ventricular performance, higher myocardial oxygen consumption,
and lower lactate production than the control group. The hearts preserved
with superoxide dismutase and catalase showed significantly better left and
right ventricular compliance, much less increase in heart weight, and no
change in the diastolic pressures. The results suggest that superoxide
dismutase combined with catalase may be effective in extending ex vivo
preservation of hearts for cardiac transplantation.