Coronary artery BYPASS surgery, commonly referred to as a BYPASS, is a surgical procedure used to treat coronary artery disease. It involves taking a healthy blood vessel from another part of the body and using it to create a detour around a blocked or narrowed artery in the heart. This allows for improved blood flow to the heart muscle, reducing the risk of a heart attack. BYPASS surgery is one of the most common types of heart surgery and can be performed on an open-heart basis or with minimally invasive techniques.