The lymphatics of the canine parietal pericardium

A careful anatomical study of the lymphatic drainage from the parietal pericardium reveals a complicated network that is notably different from that defined by the instillation of markers into the pericardial sac. The pericardial cupola and the posterior (dorsal) area of the parietal pericardium drain directly to the cardiac lymph node in the right upper mediastinum by relatively short lymphatics. The lymphatics of the anterior and lateral areas of the parietal pericardium pass to collecting vessels that travel cranially or caudally along the phrenic nerves. The former traverse specific lymph nodes and then enter the right or left venous angles. The latter pass caudally and then drain to the major collecting systems from the area of the diaphragm.