Heart bypass surgery, also known as coronary artery bypass grafting (CABG), is a surgical procedure used to treat coronary artery disease (CAD). CAD occurs when the blood vessels (coronary arteries) that supply blood to the heart muscle become narrowed or blocked due to the buildup of cholesterol and other substances on the inner walls of the arteries. This can lead to reduced blood flow to the heart, causing chest pain (angina) or, in severe cases, a heart attack.

During heart bypass surgery, the surgeon creates a detour (bypass) around the blocked or narrowed coronary artery, allowing blood to flow more freely to the heart muscle. Here is an overview of the procedure:

1. Preparation: The patient is placed under general anesthesia, and the surgical team prepares the patient for the procedure.
2. Harvesting Grafts: The surgeon harvests blood vessels, known as grafts, from other parts of the body, typically the saphenous vein from the leg or the internal mammary artery from the chest. These grafts will be used to create the bypasses.
3. Opening the Chest: A vertical or horizontal incision is made in the chest to access the heart. In some cases, minimally invasive techniques may be used, involving smaller incisions.
4. Cardiopulmonary Bypass: The patient is connected to a heart-lung machine, which takes over the function of the heart and lungs during the surgery. This allows the surgeon to stop the heart temporarily, making it possible to work on the blood vessels.
5. Grafting: The surgeon attaches one end of the graft to the aorta (the main artery leaving the heart) and the other end to the coronary artery beyond the blockage. This creates a bypass, restoring blood flow to the heart muscle.
6. Completing the Procedure: After the grafts are in place, the heart is restarted, and the patient is gradually weaned off the heart-lung machine. The chest incision is closed, and the patient is taken to the recovery area.

Heart bypass surgery is often performed when medications and less invasive procedures like angioplasty are not sufficient to treat severe coronary artery disease. The number of bypasses performed during the surgery can vary, with some patients requiring multiple bypass grafts.

Recovery from heart bypass surgery typically involves a hospital stay, and patients may need several weeks or months to fully recover. Lifestyle changes, including a healthy diet, regular exercise, and medications, are often recommended to manage coronary artery disease and prevent future complications. As with any surgical procedure, there are risks associated with heart bypass surgery, and the decision to undergo the surgery should be made in consultation with a healthcare professional.