Ultrastructural pathology of pediatric myocardium in acute ischemia: bioptic study before and after treatment with cardioplegic solution.

Protecting the myocardium from the risk of acute ischemia during heart surgery is still an unsolved problem; the problem is even more open and more pressing in pediatric heart surgery. To meet this greater risk it is advisable to use a cardioplegic solution with a composition that is better suited to the particular morphofunctional conditions of the myocardium in the child, i.e., a solution offering greater protection. To this purpose the authors experimented with Celsior cardioplegic solution during heart surgery in children to evaluate the efficacy compared to the standard St. Thomas solution. In this comparative study 15 children were treated with Celsior cardioplegic solution and 15 others with St. Thomas cardioplegic solution. Each patient underwent 2 biopsies of the myocardium, the first before cardioplegic treatment and the second immediately after reperfusion. In both groups, focal lesions involving both the cardiomyocytes and the vascular-stromal structures were randomly found. The former had undergone a necrotic-regressive process with changes in the myofibrils and the mitochondria. The vascular-stromal structures showed changes in the permeability of the capillary endothelia, with interstitial edema. The results show the lesions to be similar in the 2 groups both on a quality and quantitative level.