Retrograde Vs Antegrade Flush Administration

Standard antegrade pulmonary artery flush with intracellular type solutions is felt by many to cause pulmonary arterial microcirculatory vasoconstriction and fails to offer perfusion through the bronchial circulation. Borrowing from the concept of retrograde cardioplegia and coronary sinus retroperfusion experiments of Claude Beck, retrograde perfusion of preservation fluid given through the left atrium was reported in clinical use in 1993,22 with good lung transplant results in three patients. Pulmonoplegic solution was vented through the opened pulmonary artery, and left atrial pressures were kept < 20 mm Hg during infusion. Retrograde perfusion of the bronchial arteries was confirmed by observing flush solution flowing from the bronchial artery ostia through the opened descending aorta. Pulmonary artery vasoconstriction consequent to high K+ intracellular type solutions (EC) is unlikely to affect retrograde preservative distribution, and may even enhance it. It offers a simpler technique of dual lung circulation perfusion (than separate antegrade pulmonary artery and descending aorta) and may allow for better distribution of preservative solution while sparing the use of prostag-landins. Conspicuously absent from this clinical report, however, is the outcome of the hearts from the same three donors.

A porcine model comparing antegrade with retrograde perfusion of an intracellular type solution (EC) using dye-labeled microspheres demonstrated improved preservative flow to the airways, despite the absence of prostacyclin in the retrograde group.23 A canine study comparing ante- and retrograde EC flush demonstrated less lung edema, improved gas exchange, and lower peak airway pressures in the retrograde flush group; the antegrade flush group showed evidence of occluded capillaries, damaged epithelial basement membranes and thicker air-blood barrier on electron microscopy.24

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