The effects of retrograde perfusion of cardioplegic solution in cardiac operations.

The effects of continuous retrograde coronary perfusion of a cardioplegic solution were investigated in 42 patients. From each patient, a needle biopsy was taken on the anterior left ventricular free wall during cardiac operations and investigated by electron microscopy. With the use of our well-standardized ultrastructural criteria of ischemic injury, we found that the retrograde perfusion technique provides cardiac protection of a quality superior to that of antegrade perfusion. This finding applied to the state of the myocardial cells. The cardiac microvessels, on the other hand, were more severely injured by retrograde perfusion, and extracellular edema occurred more frequently. It is concluded, therefore, that the retrograde perfusion of a crystalline cardioplegic solution during cardiac operation has beneficial effects on the preservation of myocardial cells in comparison to the antegrade application. Unfortunately, we also conclude that the occurrence of extracellular edema and of microvascular damage represents a serious drawback in the clinical use of this method. This technique, therefore, needs to be improved before it may routinely be applied in patients undergoing cardiac operations.