Bypass: a detour around the blockage
A stent reopens a blocked artery from the inside. Coronary artery bypass grafting (CABG, said “cabbage”) takes the opposite approach: it leaves the blockage alone and builds a detour around it. The surgeon takes a spare blood vessel — often an artery from inside the chest wall or a vein from the leg — and sews one end above the blockage and the other below it. Blood now flows through the new bridge, skipping the diseased segment entirely. One operation can build several such grafts to several arteries at once.
Bypass shines when disease is widespread — many vessels narrowed, or a critical blockage in the left main or proximal left anterior descending artery — and especially in people with diabetes, where studies show surgery often outlasts stenting. The arterial graft from the chest wall is prized because it tends to stay open for decades. The trade-off is honest: CABG is bigger surgery with a longer recovery, but for the hardest coronary artery disease it can offer the most durable result.
How surgeons operate on a beating organ
Sewing a graft onto a vessel a few millimetres wide is impossible while the heart heaves with every beat. The solution is cardiopulmonary bypass — the heart-lung machine. Tubes divert the patient's blood to a machine that adds oxygen and pumps it back to the body, taking over the jobs of both heart and lungs. With circulation handled externally, the surgeon can stop the heart, empty it of blood, and work on a still, quiet target. At the end, the heart is restarted and weaned off the machine.
The same still-heart setup makes open valve surgery possible. A surgeon can repair a leaky valve or remove a severely diseased one and sew in a prosthetic heart valve — mechanical (durable but requiring lifelong blood thinner) or tissue (no long-term blood thinner but wears out sooner). Open surgery is still chosen for younger patients, for valves a catheter cannot yet reach well, and when several problems are fixed in one operation. If a weak heart struggles to come off bypass, an intra-aortic balloon pump can temporarily support it.
Catheter or scalpel? The heart team decides
Across this whole track a single question keeps returning: when do you reach for the catheter, and when for the chest? There is rarely one right answer. PCI is faster, less invasive, and recovery is quick, but for very complex disease its results may not last as long. Surgery is a larger undertaking but can be more durable and complete. Age, other illnesses, the exact anatomy, and the patient's own wishes all tip the balance.