Open heart surgery is any operation where the chest is opened through the breastbone to access the heart directly. It’s one of the most common major surgeries performed worldwide, used to repair damaged valves, bypass blocked arteries, fix structural defects, and treat problems with the aorta. Despite its intensity, modern open heart surgery has remarkably low mortality rates, with some valve procedures reporting 0% operative deaths in recent years at high-volume centers.
Why Open Heart Surgery Is Performed
The most common reason is coronary artery bypass grafting, often called CABG or “cabbage.” When the arteries supplying blood to the heart muscle become severely narrowed or blocked, surgeons take a healthy blood vessel from another part of your body and use it to reroute blood flow around the blockage. This restores oxygen delivery to the heart muscle and relieves chest pain.
Valve repair or replacement is the second major category. Your heart has four valves that keep blood flowing in the right direction. When one becomes too narrow to open properly or too loose to close completely, the heart works harder than it should. Surgeons can either reshape the existing valve or replace it with a mechanical or biological substitute. Other conditions treated through open heart surgery include aortic aneurysms (dangerous bulges in the main artery leaving the heart), congenital heart defects present from birth, and heart transplantation.
How the Chest Is Opened
The procedure begins with a sternotomy. A surgeon uses a scalpel to cut through the skin in a line between the collarbones, running down to the bottom of the breastbone. Then a specialized saw cuts through the middle of the breastbone from top to bottom. A retractor is placed inside the split bone and spread apart, creating a window to the heart. The full incision is typically eight to ten inches long.
At the end of surgery, the breastbone is closed with eight to twelve stainless steel wires that hold the two halves together while the bone heals. These wires usually stay in your body permanently and are safe for most imaging scans.
The Bypass Machine
For most open heart procedures, surgeons need the heart to be completely still. A cardiopulmonary bypass machine, sometimes called the heart-lung machine, takes over the work of both organs during surgery. Blood drains from the two large veins entering your heart into tubes connected to the machine’s reservoir. Inside the machine, the blood passes through an oxygenator that adds oxygen and removes carbon dioxide, mimicking what your lungs normally do. The machine then pumps this refreshed blood back into your body through a tube connected to the aorta.
Once the machine is running and circulating your blood, the surgeon delivers a special solution that stops your heart from beating. Operating on a still heart is far more precise than working on a moving target. When the repair is complete, the heart is restarted (sometimes with a small electrical shock) and the bypass machine is gradually weaned off as the heart resumes its normal workload.
Success Rates and Risks
Outcomes have improved dramatically over the past few decades. At Cleveland Clinic, one of the highest-volume cardiac surgery centers, isolated aortic valve replacement had a 0% operative mortality rate in 2022 across 405 cases. Isolated mitral valve repair reported 0% operative mortality across nearly 4,000 cases over an eight-year period. Even more complex procedures like combined valve replacement with bypass surgery had mortality rates well under 1%. Aorta surgery, which tends to carry higher risk, had a 2.1% operative mortality overall, dropping to 0.9% for planned (non-emergency) cases.
These numbers reflect top surgical centers, and individual risk depends on your age, overall health, and the complexity of the procedure. Still, the broader trend is clear: open heart surgery is far safer than most people assume.
That said, complications do occur. The most significant risks include irregular heart rhythms, which are common in the days after surgery and usually temporary. Blood clots can form and potentially cause a stroke. Infection at the incision site or deeper in the chest is possible, which is why your skin is washed with antibiotic soap before the procedure. Many patients also experience memory problems, difficulty concentrating, or a general mental fogginess after surgery. These cognitive changes, sometimes informally called “pump head” because they’re linked to time on the bypass machine, typically improve within a year.
What Recovery Looks Like
Recovery from open heart surgery is measured in weeks and months, not days. Most people spend about a week in the hospital, with the first day or two in intensive care. During this time, you’ll have drainage tubes in your chest, a catheter, and multiple monitoring lines. The breathing tube placed during surgery is usually removed within hours of waking up, though your throat may feel sore afterward.
The breastbone takes roughly six to eight weeks to heal. During that period, you’ll be told not to lift anything heavy, push or pull with your arms, or drive. Simple activities like walking are encouraged almost immediately, starting with short distances in the hospital hallway and gradually increasing. Many people feel surprisingly tired for weeks after surgery, even from small efforts. This is normal. Your body is diverting energy toward healing bone and tissue.
By six weeks, most people can return to light daily activities. Full recovery, meaning a return to your previous energy levels and physical capacity, generally takes about three months. Cardiac rehabilitation, a supervised exercise and education program, significantly improves outcomes during this period and is recommended for nearly everyone after open heart surgery.
Preparing for Surgery
In the days before your procedure, your surgical team will give specific instructions about when to stop eating and drinking, and which medications to pause or continue. Blood thinners are commonly stopped several days in advance. The area where the incision will be made is shaved, and you may be asked to shower with a special antibacterial soap the night before and morning of surgery.
You’ll also want to prepare your home for recovery. This means setting up a sleeping area where you don’t need to climb stairs, stocking easy meals, and arranging for someone to help you for at least the first two weeks. You won’t be able to drive for several weeks, so plan transportation for follow-up appointments in advance.
Minimally Invasive Alternatives
Not everyone needs the full sternotomy. Minimally invasive approaches can accomplish many of the same repairs through much smaller openings. A mini-sternotomy uses a three-inch incision in just the upper part of the breastbone. A mini-thoracotomy goes between the ribs with a two- to three-inch cut. Robotic-assisted surgery requires only a 1.5- to 2-inch incision plus a few small port sites for camera and instrument access.
These approaches generally mean a shorter hospital stay of two to five days, less pain, smaller scars, and a faster return to normal life. But they aren’t suitable for everyone. Your surgical team will evaluate your heart’s condition, whether multiple areas need repair at the same time, your BMI, smoking history, and other health factors. People who need work on several parts of the heart at once often benefit more from the traditional open approach, which gives the surgeon full visibility and access.
The best procedure is the one that gives your surgeon the clearest path to a complete, durable repair. In many cases that’s still the traditional sternotomy, and given the low complication rates at experienced centers, the size of the incision matters far less than the quality of the result.