To explore the anatomical features of lymph node reflux status for pulmonary lobe and pulmonary segment.

Nine adult cadavers were treated with anatomical latex filler for thoracic lymph node perfusion. Then anterior mediastinum, middle mediastinum, posterior mediastinum lymph nodes were dissected and removed, as well as the upper, middle, lower of the right pulmonary lobe and pulmonary segments, and the upper, lower left pulmonary lobe and pulmonary segments, in addition with hilar lymph nodes. lymph node distribution, number and lymphatic reflux status were observed carefully.

A total of 212 mediastinal lymph nodes were observed in the specimens, with an average of 23.5. The number of lymph nodes was the highest in the tracheal traction (7) and the lower right trachea (4R), followed by the right tracheal (10R), the left bronchus (10L) and the main pulmonary artery window area (5) lymph nodes. The mediastinal area had the largest lymph nodes in the subduction area (7), followed by the right tracheal bronchial (10R) lymph nodes. Lymph nodes increased gradually, and the right side was greater than the left, which means that the lower was greater than the upper and the right was greater than the left. Left lung and right lung pulmonary lymph nodes were generally in accordance with the sub-lymph node→segment lymph nodes→leaf lymph nodes→leaf lymph nodes/hilar lymph nodes and tracheal traction; right upper lobe, middle lobe and hilar lymph nodes usually flowed back to the mediastinal lymph nodes. The lower lobe flowed back to the mediastinal lymph nodes. While the left upper lobe general drained to the main-pulmonary artery window lymph nodes and tracheal traction, the lower lobe was also draining to the mediastinal lymph nodes.

The lobar and mediastinal lymphatic reflux has a certain regularity, which provides anatomical basis for the choice of lobular specific/systemic lymph node dissection.