Morphology of lymphatics of the mammalian heart with special reference to the architecture and distribution of the subepicardial lymphatic system

The subepicardial lymphatic system in the rat and dog heart has been investigated by means of scanning electron microscopy. Following application of hydrogen peroxide, the epicardium was removed with a forceps under a dissecting microscope. The subepicardial region contained a well-developed lymphatic system which consisted of the main lymphatic trunks and lymphatic capillaries. The lymphatic trunks of large diameters ran from the apex of the heart to its base. The subepicardial lymphatic capillaries were ramified and anastomosed with each other to form a relatively dense network which extended over the entire surface of both ventricles. These networks joined the main lymphatic trunks. Further, some similar networks were connected with the underlying myocardial lymphatic capillaries.