THE LYMPHATIC DRAINAGE OF THE PARIETAL PERICARDIUM IN MAN

Parietal pericardial lymphatics were visualized by indirect and direct India ink injections in 35 human cadavers. Studies included examinati on of cleared specimens under the dissecting microscope and standard l ight microscopy. The lymphatic vessels of the ventral pericardial surf ace most often pass along the phrenic nerves cranially to terminate in the anterior right and left and transverse mediastinal nodes, or caud ally to the diaphragm or prepericardial lymph nodes. The lymphatics dr aining the lateral parts of pericardium pass to the anterior mediastin al, tracheobronchial, lateropericardial, prepericardial and posterior mediastinal (juxtaesophageal) lymph nodes. The posterior part of the p ericardium drains to the juxtaesophageal and tracheobronchial nodes. L ymphatics from the diaphragmatic part of the pericardium pass to the r ight lateropericardial and prepericardial, juxtaesophageal and tracheo bronchial nodes. The pericardial cupula is anteriorly drained to the a nterior mediastinal nodes, and posteriorly to the tracheobronchial nod es. In cleared specimens two networks of lymphatic vessels are seen to surround the pericardial space. On the ventral surface, the lymphatic s of the parietal pericardium connect to lymphatics in the pericardial fat and areolar tissue. On the lateral and posterior surfaces, the ly mphatics of the parietal pericardium anastomose with lymphatics of the reflected mediastinal pleura. These anatomical observations offer new insights into the mechanisms of turnover of pericardial fluid and int o the mechanisms of occurrence of chylopericardium.