A thoracic surgeon provides the operative, perioperative care, and critical care of patients with pathologic conditions within the chest. Included is the surgical care of coronary artery disease, cancers of the lung, esophagus and chest wall, abnormalities of the trachea, abnormalities of the great vessels and heart valves, congenital anomalies, tumors of the mediastinum, and diseases of the diaphragm. The management of the airway and injuries of the chest is within the scope of the specialty. A general thoracic surgeon treats emphysema, swallowing problems, and gastroesophageal reflux. A congenital heart surgeon performs surgical corrections of heart defects and furnishes cardiovascular support to infants and children. Any of these subspecialists may perform heart, lung, and combined heart-lung transplantations. Thoracic surgeons have the knowledge, experience, and technical skills to accurately diagnose, operate upon safely, and effectively manage patients with thoracic diseases of the chest. This requires substantial knowledge of cardiorespiratory physiology and oncology, as well as capability in the use of heart assist devices, management of abnormal heart rhythms and drainage of the chest cavity, respiratory support systems, endoscopy, and invasive and noninvasive diagnostic techniques.