Mediastinal tumor, the mediastinum is located between the two sides of the lungs, with the sternum and thoracic vertebrae as its anterior and posterior boundaries. There are many important organs inside, including large blood vessels, trachea, main bronchus, pericardium, esophagus, thymus and a large amount of fat, nerves and lymphatic vessels and other tissues, which become mediastinal tumors due to abnormal congenital development process or acquired cyst or tumor formation. There are many kinds of mediastinal tumors, both primary and metastatic, and benign tumors are common among primary tumors, but a considerable part of them are also malignant. In order to indicate where the lesion is located in the mediastinum, the mediastinum can be divided into several parts, with the level of the sternum and the lower edge of the 4th thoracic vertebra divided into upper and lower parts, the mediastinal space containing many important organs is called the visceral organ mediastinum (middle mediastinum), the space in front of the right trachea and pericardium is the anterior mediastinum; behind the trachea and pericardium (including the esophagus and paraspinal mediastinum) is called the posterior mediastinum. According to the domestic statistics, the incidence of mediastinal tumors is the first with neurogenic tumors, followed by teratomas, thymic tumors and thyroid progenitor tumors, and the least with various cystic tumors. The following diseases may cause damage above the tracheal ramus: 1. Bronchiectasis Bronchiectasis (bronchiectasis) is characterized by local irreversible anatomical abnormalities of the bronchi, which is due to chronic purulent inflammation and fibrosis of the bronchi and their surrounding lung tissues, causing destruction of the muscles and elastic tissues of the bronchial walls, resulting in bronchial deformation and persistent dilatation. Typical clinical symptoms include chronic cough, coughing up large amounts of purulent sputum and recurrent hemoptysis. The main causative factors are infection, obstruction and stretching of the bronchi, with some congenital genetic factors. Most patients have a history of childhood measles, pertussis or bronchopneumonia. With the improvement of people’s life, vaccination against measles and pertussis, and the application of antibiotics, this disease has been significantly reduced. 2, tracheobronchial foreign body Foreign body of trachea and bronchus is a common clinical emergency. Foreign body can be retained in the laryngopharyngeal cavity, laryngeal cavity, trachea and bronchus, causing hoarseness, dyspnea, etc. The right bronchus is thicker and shorter, so the foreign body is easy to fall into the right main bronchus. 75% of them occur in children under 2 years old. 3, inhalation injury inhalation injury is the inhalation of toxic fumes or chemical substances to the respiratory tract caused by chemical injury, serious cases can be directly damaged lung parenchyma. It occurs mostly in large areas, especially with head and facial burns patients.