Cardiothoracic surgeons operate on diseases that occur in the heart, lungs, esophagus, and other organs in the chest. Some of the common surgeries include coronary artery bypass grafting (CABG), lobectomy, ventricular septal defect surgery, mitral valve repair and replacement, surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR), esophagectomy, tetralogy of fallot surgery, and the arterial switch operation (for transposition of the great arteries).