EFFECTS OF CARDIOPLEGIC SOLUTIONS ON THE VASOREACTIVITY OF THE INTERNAL MAMMARY ARTERY

Background. During free internal mammary artery grafting, cardioplegia administration can be performed through the internal mammary artery. The present study examined whether cardioplegic solutions produce arte rial graft constriction and functional endothelial damage. Methods. Fo rty internal mammary artery segments from 10 patients were incubated i n Krebs solution (n = 10), University of Wisconsin solution (n = 10), Broussais Hospital solution (n = 10), or blood cardioplegia (n = 10). Results. There was a significant difference in sensitivity to norepine phrine between segments in Krebs solution and those in University of W isconsin solution or Broussais Hospital solution but not segments in b lood cardioplegia. There was a significant difference in relaxation to acetylcholine between segments in Krebs solution and those in the thr ee other cardioplegic solutions and between those in blood cardioplegi a and segments in University of Wisconsin solution or Broussais Hospit al solution. There was no significant difference in relaxation to sodi um nitroprusside between segments in any of the solutions. Conclusions . These experiments suggest that storage in the different cardioplegic solutions studied does not preserve the initial vasoreactivity of the internal mammary artery. However, blood cardioplegia appears to be le ss deleterious in regard to endothelial and myogenic vascular function . (C) 1998 by The Society of Thoracic Surgeons.