coronary bypass surgery

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A surgical procedure performed to improve blood supply to the heart by creating new routes for blood flow when one or more of the coronary arteries become obstructed. The surgery involves removing a healthy blood vessel from another part of the body, such as the leg, and grafting it onto the heart to circumvent the blocked artery.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun open-heart surgery in which the rib cage is opened and a section of a blood vessel is grafted from the aorta to the coronary artery to bypass the blocked section of the coronary artery and improve the blood supply to the heart