Yes, traditional coronary artery bypass grafting (CABG) is open heart surgery. It involves cutting through the breastbone to access the heart directly, and in most cases, temporarily stopping the heart while a machine keeps blood flowing through your body. That said, newer variations of bypass surgery blur the line, with some techniques avoiding the breastbone cut entirely or keeping the heart beating throughout the procedure.
What Makes It “Open Heart”
The term “open heart surgery” refers to any procedure where the chest is opened through the breastbone and the surgeon works directly on the heart. In a traditional CABG, a surgeon makes a 6- to 8-inch incision down the center of your chest and saws through the breastbone (a procedure called a sternotomy) to reach the heart. Once the chest is open, a heart-lung bypass machine takes over. This machine drains blood from the heart, adds oxygen, removes carbon dioxide, manages blood temperature, and pumps the refreshed blood back into your body. Meanwhile, medication temporarily stops the heart so the surgeon can work on a still, bloodless surface.
This is the classic version of bypass surgery, and it’s what most people picture when they hear the term. The heart-lung machine essentially replaces both your heart and lungs for the duration of the operation, giving the surgeon a clear, motionless field to attach new blood vessels around the blocked arteries.
What the Surgery Actually Does
Bypass surgery reroutes blood around clogged coronary arteries. Your surgeon takes a healthy blood vessel from another part of your body, typically an artery from behind the chest wall or a vein from the leg, and grafts it onto the heart to create a new pathway for blood flow. If you have multiple blockages, you may receive several grafts in a single operation (this is where terms like “triple bypass” or “quadruple bypass” come from).
The choice of graft material matters for long-term results. Arteries taken from the chest wall tend to stay open longer than veins taken from the leg. In one large study, chest wall artery grafts had a blockage rate of about 5% after one year compared to nearly 13% for vein grafts. Surgeons typically use a chest wall artery for the most critical blockage and vein grafts for the rest.
When Bypass Is Chosen Over a Stent
The less invasive alternative to bypass surgery is a stent, a tiny mesh tube threaded through a blood vessel in your wrist or groin and placed inside the blocked artery to hold it open. No chest incision, no heart-lung machine, and a much shorter recovery. So why would anyone choose open heart surgery?
Bypass consistently outperforms stenting in certain situations. If you have three or more blocked coronary arteries, significant disease in the main artery feeding the left side of your heart, or reduced heart pumping function, bypass tends to produce better long-term outcomes. Diabetes is another major factor. Multiple large studies and meta-analyses have shown that people with diabetes and multi-vessel blockages do significantly better with surgery than with stents, making bypass the preferred approach in that population. A multidisciplinary heart team typically reviews each case to determine the best strategy based on the number and location of blockages, overall heart function, diabetes status, and other health conditions.
Variations That Aren’t Fully “Open Heart”
Not every bypass surgery follows the traditional open heart playbook. Two important alternatives exist.
Off-pump bypass (OPCAB) uses the same large chest incision through the breastbone, but the surgeon works on the heart while it’s still beating. There’s no heart-lung machine involved. Special stabilizing devices hold a small area of the heart steady while the surgeon sews the graft. The chest is still opened in the traditional way, so it’s technically still open heart surgery, just without the bypass machine. Some surgeons have also begun performing off-pump bypass through smaller incisions between the ribs, which moves it closer to minimally invasive territory.
Minimally invasive direct coronary artery bypass (MIDCAB) avoids the breastbone cut altogether. Instead, the surgeon works through a small 2- to 3-inch incision between the ribs on the side of the chest. Because the breastbone stays intact, this isn’t classified as traditional open heart surgery. Recovery is faster and less painful, but MIDCAB is only suitable for certain blockages, usually one or two arteries that are accessible from the small incision.
Risks During and After Surgery
Open heart bypass surgery is one of the most commonly performed heart operations, but it carries real risks. One of the more common complications is a new irregular heart rhythm called atrial fibrillation, which develops in roughly 26% of patients after surgery. In a study of nearly 8,000 bypass patients, about 2.5% experienced a stroke either during or after the procedure. Infection at the incision site, bleeding, and kidney problems are other recognized risks. Your overall risk depends heavily on your age, heart function going into surgery, and whether you have other conditions like diabetes or lung disease.
What Recovery Looks Like
The breastbone takes about eight weeks to heal after a traditional sternotomy. During that time, your upper body movements are significantly restricted. You shouldn’t lift anything heavier than 10 pounds, which is roughly a gallon of milk. When you do lift, you’ll need to use both arms and keep them close to your body. Most people can drive again about a month after surgery, though this varies.
Cardiac rehabilitation typically starts while you’re still recovering from the incision. Rehab involves supervised exercise, dietary guidance, and monitoring to help your heart regain strength. The first few weeks at home often feel harder than people expect. Fatigue, chest soreness, appetite changes, and mood swings are all common. The full recovery arc, from surgery to feeling like yourself again, usually takes two to three months, though some people need longer before they’re back to their usual activity level.
If your surgeon uses a minimally invasive approach instead, recovery is generally shorter because the breastbone remains intact. The smaller incision between the ribs still needs time to heal, but the restrictions on upper body movement are less severe and the hospital stay is typically shorter.