Blood vessels of the myocardial microcirculatory bed after radical correction of tetralogy of Fallot

: The intraoperative right ventricular myocardial biopsy specimens taken from 54 patients during radical correction of Fallot's tetrad were used to examine the microcirculatory vessels during combined pharmacological ice-chip cardioplegia (PICC) and reperfusion. The combined PICC was shown to fail to exclude myocardial microcirculatory vessel lesions, namely: ultrastructural evidence for edema and destructive changes in the membrane structures of endothelial cells, expanded interendothelial contacts, basal membrane stratification. The lesions were more marked in patients with cyanotic heart disease in cardioplegia lasting more than 65 min. Coronary blood flow recovery was accompanied by evolving endotheliocytic cytoplasmic edema, phenomena of microclasmatosis, microvascular obstruction with cell fragments and membrane structures. This impaired microcirculation, promoted interstitial edema and dystrophic cardiomyocytic changes and might be followed by acute heart failure in the postoperative period.