Mediastinal anatomy for the mediastinoscopist.

Mediastinal dissections were performed on 20 fresh cadavers to determine the anatomical relationships of special importance to the mediastinoscopist. In all specimens, the right and left upper lobe bronchi as well as the left atrium were found to be within reach of the 14.5-cm mediastinoscope. The average interpleural distance in the tracheal plane was greater in heavier cadavers and increased from the thoracic inlet to the carina. The ease of identification of major paratracheal and parabronchial structures by blunt dissection was estimated. An average of 31 nodes were grossly available for biopsy in the mediastinoscopic field.