What Is a Heart Bypass Surgery?

Bypass heart surgery is an open heart surgery that is done when the blood vessels that feed the heart are too clogged to function properly. This type of heart surgery is usually performed as an open heart procedure, meaning the surgeon opens the chest in order to see the heart and perform surgery. 

The surgery can be performed as a minimally invasive procedure where the chest is not opened. That procedure is less common than the more standard open heart surgery, as far fewer patients are physically appropriate for that technique.

To understand a bypass procedure, it is essential to understand a few things about the anatomy of the heart and heart disease. The blood vessels that supply the heart with its own blood supply are called the coronary arteries. In some people, the coronary arteries become blocked, a condition known as coronary artery disease.

If a blockage is severe, it can completely stop blood flow to the area of the heart that is fed by that particular blood vessel. Stopping the blood flow to the heart is extremely serious—even in the smallest of blood vessels—because it can cause chest pain, a heart attack, or even death.

The number of vessels that are diseased typically dictates the number of grafts—vessels that need bypasses—that will be performed. If three vessels are blocked and need to be bypassed, the surgery is referred to as a triple bypass because three grafts are performed. If two vessels are bypassed the surgery is called a double bypass, and so on. Quintuple bypass procedures, where five vessels are bypassed, are fairly rare, but the four vessel quadruple bypass is fairly common.

In addition to the risks of general anesthesia, the risks associated with an open heart procedure increase with the number of bypasses required, as the surgery takes longer and the coronary artery disease being treated is more severe.

In many cases, coronary artery disease can be treated with medication, lifestyle changes, and less invasive procedures such as the placement of stents. However, for some patients the blockage(s) are so severe that surgery is necessary to make sure the heart continues to receive adequate blood flow. This procedure is known as coronary artery bypass graft surgery (CABG).

Performed under general anesthesia, the procedure starts with blood vessels being taken from another area of the body, typically the leg and the left side of the chest. The vein harvesting is often done by one healthcare provider such as a physician assistant (PA), while the chest portion of the procedure is done by a cardio thoracic surgeon at the same time.

These vessels are then sewn onto the existing heart vessel before and after the blockage.

This entire open heart portion of the procedure is usually done using a heart lung bypass machine, which is a complex machine that does the work of the heart and lungs during surgery. The surgeon works quickly to limit the amount of time the patient spends "on pump," to minimize potential complications.

The use of this machine typically requires ample fluid and often donated blood to compensate for the amount of blood and fluid leaving the body, being oxygenated, then returned to the body. For that reason, many individuals find that they have temporarily gained a few pounds and may find that they are slightly "puffy" in the days following surgery. Once the patient is up and moving, this excess fluid leaves the body in the form of urine.

Once the surgeon has finished the procedure, chest tubes are placed to drain fluid that might otherwise build up around the heart and prevent the heart from functioning well or from healing taking place. These tubes are typically removed within a few days of surgery. The sternum (breastbone) is sewn together using a special surgical wire and the skin is closed with sutures or staples.

Unlike most surgeries, the patient is allowed to wake slowly and naturally from anesthesia, rather than a medication being given to wake the patient up. For this reason, it is often four to six hours after surgery before the patient begins to be awake and alert, and the breathing tube remains in place until that time. The first day after surgery is typically spent in a cardiac care unit or ICU, where the nurses can keep a watchful eye over the patient as they begin their recovery.

The recovery from this type of procedure will take several days in the hospital and several months after returning home. For some, recovery will include cardiac rehabilitation—physical exercise performed under the watchful eye of a therapist—to help strengthen the heart. For most, recovery will take six to 12 weeks, and will end with a return to the activities that were enjoyed prior to surgery. For some, they will be able to do more activities, as their exercise will not be limited by chest pain.

Hearing that you or a loved one needs a complicated surgery is, undoubtedly, worrisome. Knowing what to expect will help you prepare for the surgery and for the recovery afterwards. Keep an open line of communication with your doctor and surgeon—don't hesitate to ask and discuss any thoughts or questions that come to mind. If you can, bring along a loved one to help you take notes and understand the procedure.

In most cases, the surgery goes smoothly and you'll be able to look forward to returning to your daily life and the activities you love soon enough—just be sure to follow the directions your surgeon provides prior to and after the surgery. For example, it's likely that eating and drinking is not allowed in the hours prior to surgery and a healthy diet will be necessary after surgery to prevent the problem from returning. Part of recovery is implementing healthier lifestyle changes—perhaps it's improving your diet or exercise routine in order to decrease the chances that you'll need a second surgery. Work closely with your healthcare team to craft a plan that's most helpful for you.