Vasa nervorum of epicardial nerves and valves of small veins investigated in porcine heart by two types of vascular injections

Abstract

The morphology of the vascular supply of peripheral branches of cardiac nerves has not been systematically described until now. The aim of this study was to describe the architectonics of the vasa nervorum of epicardial nerves in porcine hearts by using two injection techniques. Twenty‐three hearts from young healthy pigs were used. In 10 hearts India ink solution was injected into the origin of the anterior interventricular branch. In another 10 hearts India ink solution was injected retrogradely through the coronary sinus. The hearts were then analyzed using a magnifying glass and light microscopy. The arterial injection showed the entirety of the rich venous components of the vasa nervorum, which often consisted of paired veins accompanying the epicardial nerves. The thickness of the nerves ranged from 50 to 815 μm. The vasa nervorum drained into larger subepicardial veins. In seven of the hearts prepared with venous injections the vasa nervorum of epicardial nerves were visualized in the same detail as in the arterial preparations and India ink solution filled the right ventricle via the smallest cardiac veins. The histological analysis of these seven hearts showed complete dehiscence and functional insufficiency of small and larger veins valves. In the other three hearts prepared with venous injections the valves were competent, which prevented retrograde filling of larger and smaller veins. The results obtained expand the current knowledge on epicardial nerves vasa nervorum and provide anatomical evidence behind the mechanism of retrograde application of cardioplegic solutions in cardiac surgery.