The spread of the tumor on the left main bronchus or the presence of metastases in the “aortic window” can be the cause of tumor lesions of the extrapulmonary anatomical structures of this mediastinal segment. The intracranial part of the left main bronchus and the numerous tracheobronchial and paroaortic lymph nodes located here are in complex and very close relationships with a number of important anatomical structures. This is, first of all, the aortic arch and the initial section of its descending part, the left pulmonary artery, the vagus nerve and the returning laryngeal nerve, the esophagus and the thoracic lymphatic duct. The aortic arch restricts access to the left tracheobronchal angle and in the initial section of its descending part is intimately connected with the back wall of the left main bronchus by fibrous cords,the so-called “aorto-bronchial Gillette ligaments ” .
In the area of the aortic arch, in direct contact with the upper-posterior wall of the left main bronchus, bronchial arteries are located , the damage of which may be complicated by bleeding that is difficult to stop.
In the presence of a tumor or a conglomerate of lymph node metastases, germinating mediastinal pleura in the projection of the lung root, a wide mediastinotomy is performed and the possibility of extrapericardial treatment of the elements of the lung root is assessed by careful preparation. During the germination of the pericardium, the inability to isolate sufficient areas of the pulmonary vessels to ensure safe conditions for their processing, it is necessary to proceed to the implementation of intrapericardial revision. The peculiarity of the structure of the left pulmonary artery — the relatively small extent, the presence of the arterial ligament, and the proximity to the upper lobe bronchus — determines its frequent involvement in the tumor process and the features of surgical treatment. The left pulmonary artery is located mainly extrapericardially, only its front-lower surface is covered with the posterior leaflet of the pericardium.
By palpation through the transverse sine of the pericardium, it is possible to assess the condition of the lower wall of the initial segment of the left pulmonary artery and the left side wall of the pulmonary trunk. Isolation of the pulmonary artery during intrapericardial treatment is carried out mainly by combining transpericardial and extrapericardial access to the vessel. Squeezing the upper pulmonary vein down, expose the front surface of the pulmonary artery.
Under the control of view, pulling off a free sheet of pericardium, cut it to the lower edge of the artery wall in the transverse direction. The anatomical reference point corresponding to the border of the pulmonary artery and its left branch from the bottom surface is the lateral end of the residual fold of pericardial torsion of the upper pulmonary vein. Exfoliating the pericardium along the anterior and lower surfaces, the periarterial fascial case is opened, in the plane of which the pulmonary artery is released. In the presence of dense adhesions of the pericardium or enlarged lymph nodes in the area of the upper wall of the vessel and the lower surface of the aortic arch, it is imperative that you first dissect the pericardium and, under visual control, prepare them.