Thoracic surgery encompasses the operative, perioperative, and surgical critical care of patients who acquired and congenital pathologic conditions within the chest. Thoracic surgeons treat diseased or injured organs in the chest, including the esophagus (muscular tube that passes food to the stomach), trachea (windpipe), pleura (membranes that cover and protect the lung), mediastinum (area separating the left and right lungs that contains the heart), chest wall, diaphragm (separates the chest from the abdomen), pericardium (membrane covering the heart), heart (including the pericardium, coronary arteries, valves and myocardium), and lungs. The most common diseases requiring thoracic surgery include heart lesions, such as coronary artery disease and valve problems, lung cancer, chest trauma, esophageal cancer, emphysema, and heart and lung transplantation.