Open heart surgery is an intervention reserved for serious cardiac and aortic conditions that cannot be managed effectively with medication or less invasive procedures. It is defined as any surgery where the chest is opened, typically by dividing the breastbone, to allow direct access to the heart, arteries, or major veins. For complex repairs, the heart must be temporarily stopped, requiring the patient to be connected to a heart-lung machine, or cardiopulmonary bypass (CPB) system. This machine takes over the work of the lungs and heart, circulating and oxygenating the blood while the surgeon operates on a still, bloodless field.
Addressing Blocked Coronary Arteries
Coronary Artery Disease (CAD) is a common reason for open heart surgery in adults, occurring when the arteries supplying blood to the heart muscle become narrowed or blocked. This narrowing, known as atherosclerosis, results from the buildup of fatty plaque on the inner walls of the coronary arteries. When blockages restrict blood flow, the heart muscle is starved of oxygen, leading to chest pain (angina) or a heart attack.
The surgical solution for severe blockages is Coronary Artery Bypass Grafting (CABG), often referred to as bypass surgery, which is the most common form of open heart surgery performed. Surgeons create new pathways for blood to flow around the blocked segments of the coronary arteries. This is accomplished by harvesting healthy blood vessels, such as the internal thoracic artery or the saphenous vein from the leg.
The surgeon connects one end of the harvested vessel to the aorta and the other end to the coronary artery just past the blockage, forming a bypass or “graft.” This rerouting restores the supply of oxygenated blood to the heart muscle, relieving symptoms and improving heart function. Open surgery is required instead of less invasive catheter procedures, such as stenting, when the disease is widespread, affecting multiple vessels, or when blockages are complex or located in the left main coronary artery. The ability to place multiple grafts makes the open surgical approach the preferred method for revascularization in high-risk scenarios.
Repairing or Replacing Faulty Heart Valves
The heart relies on four valves—the mitral, aortic, tricuspid, and pulmonary—to maintain unidirectional blood flow through its four chambers. These valves operate like synchronized gates, opening to allow blood to move forward and closing tightly to prevent backflow. When a valve becomes damaged or diseased, its function is compromised, forcing the heart to work harder to move blood.
One form of valve failure is stenosis, where the valve leaflets become stiff, thickened, or fused, causing the valve opening to narrow. This restriction generates resistance, requiring the heart muscle to exert greater force to push blood through the smaller opening, which can eventually lead to heart muscle weakening and heart failure. Aortic stenosis, frequently caused by age-related calcification, is a common indication for open heart intervention.
The opposite problem is regurgitation, or insufficiency, which occurs when a valve does not close completely, allowing blood to leak backward into the preceding chamber. This backward flow causes a volume overload on the heart chambers, decreasing the efficiency of the heart as a pump. Both stenosis and regurgitation cause strain on the heart, making open surgery necessary when the damage is severe and causing symptoms like shortness of breath or fatigue.
Open heart surgery offers surgeons the ability to either repair the damaged valve or replace it entirely. Valve repair techniques may involve reconstructing the valve leaflets or supporting the valve ring (annuloplasty). If the damage is too extensive, the valve is replaced with a prosthesis, which can be a durable mechanical valve requiring lifelong blood thinning medication, or a biological valve derived from animal tissue.
Correcting Major Structural Damage
Beyond blocked arteries and faulty valves, open heart surgery is necessary to correct major structural damage to the heart and the great vessels exiting it. This often involves the repair of issues affecting the aorta, the body’s largest artery. An aortic aneurysm is a localized ballooning or bulge in the wall of the aorta, while an aortic dissection is a tearing of the inner layer of the aortic wall.
Type A aortic dissections, which involve the ascending aorta closest to the heart, require emergency open heart surgery because they pose a high risk of catastrophic rupture or obstruction of blood flow. During the open procedure, the compromised section of the aorta is repaired by replacing it with a synthetic tube graft, often made of Dacron. This repair stabilizes the vessel wall and prevents the risk of fatal bleeding.
Open heart surgery is also required to correct many congenital heart defects—structural abnormalities present from birth. These conditions include septal defects, which are holes in the walls separating the heart chambers, such as Atrial Septal Defects (ASD) or Ventricular Septal Defects (VSD). These internal repairs often require the heart to be stopped and accessed directly using the heart-lung machine to allow for precise stitching or patching of the defect.
Other structural indications for open heart surgery include the removal of cardiac tumors or the repair of damage sustained from severe physical trauma. These procedures are complex and require the direct visualization and access to the interior of the heart and surrounding structures that only an open surgical approach can provide.