surgery in great vessels (aortic coarctation repair, blalock-taussig shunt creation, closure of patent ductus arteriosus) became common after the turn of the century and falls in the domain of cardiac surgery, but technically cannot be considered heart surgery. one of the more commonly known cardiac surgery procedures is the coronary artery bypass graft (cabg), also known as "bypass surgery." in this procedure, vessels from elsewhere in the patient's body are harvested, and grafted to the coronary arteries to bypass blockages and improve the blood supply to the heart muscle.