Coronary artery bypass grafting (CABG, pronounced "cabbage") is an open-heart operation that creates new routes for blood to flow around severely blocked coronary arteries — restoring blood supply to the heart muscle.
During CABG, a cardiac surgeon harvests blood vessels — called grafts — from the chest wall (internal mammary artery), leg (saphenous vein), or arm (radial artery) and attaches them to the coronary arteries beyond the points of blockage. This "bypasses" the diseased segments and allows oxygen-rich blood to reach the heart muscle through new pathways.
The number of grafts depends on how many arteries are blocked — patients may hear their surgery described as "double," "triple," or "quadruple bypass" based on the number of grafts placed.
CABG is typically recommended for patients with complex multi-vessel coronary artery disease (blockages in two or three major arteries), left main coronary artery disease (a critical blockage in the main trunk supplying the left side of the heart), or diabetes with multi-vessel disease, where clinical trials have shown a long-term survival advantage for bypass surgery over stenting.
CABG may also be chosen when the anatomy of blockages makes stenting technically difficult or less durable — for example, long diffuse disease, heavy calcification, or chronic total occlusions.
The left internal mammary artery (LIMA) graft to the left anterior descending artery (LAD) is considered the most important component of bypass surgery. LIMA grafts have exceptional long-term patency — over 90% remain open at 10 years — and are associated with improved survival.
CABG is performed under general anesthesia, typically through a median sternotomy (incision down the center of the breastbone). Most operations use a heart-lung bypass machine to temporarily support the circulation while the surgeon works on the heart, though "off-pump" (beating heart) techniques are sometimes used.
The operation takes approximately 3–5 hours. Patients spend 1–2 days in the ICU and are typically in the hospital for 5–7 days. Full recovery takes 6–12 weeks, during which sternal precautions (avoiding heavy lifting and strain on the breastbone) are important. Cardiac rehabilitation is strongly recommended and has been shown to significantly improve recovery and long-term outcomes.
Risks include bleeding, infection (including sternal wound infection), stroke, atrial fibrillation, kidney injury, and cognitive changes. Mortality rates at experienced centers are typically 1–3% for elective CABG, though risk varies with patient-specific factors. Saphenous vein grafts may develop disease over time, while arterial grafts tend to remain open longer.