When something like construction, flooding, or a fallen tree blocks off a road and makes it impossible to continue, transportation authorities set up a detour. A similar situation can occur on the route that blood typically takes through the body. The arteries that carry blood to the heart itself can become clogged with hard deposits called plaque. These blockages prevent blood from moving through the blood vessels as it normally does.
To allow the blood to reach the heart, doctors can perform a procedure called coronary bypass surgery. In coronary bypass surgery, doctors take a blood vessel from another area of the patient’s body and move it to the heart. This effectively establishes a detour, or an alternate course around the blocked artery for the blood to follow. There are different types of coronary bypass surgery, but regardless of the type, there are risks, and recovery takes several weeks. Coronary bypass surgery can be lifesaving, but patients often have to make lifestyle changes after the procedure to reduce the risk of other arteries becoming blocked.
Coronary Bypass Surgery: Treatment for Coronary Artery Disease
When plaque composed of cholesterol, fat, and other substances builds up in the arteries over time, the condition is called atherosclerosis. Atherosclerosis is a type of heart disease and decreases the diameter of the arteries, making it difficult for blood to flow through.
Blood carries several important substances like nutrients and oxygen to tissues all over the body. When arteries become obstructed by atherosclerosis, the tissues supplied by these arteries may not get all of the nutrients and oxygen they need. If the blood vessels that carry blood to the heart (known as the coronary arteries) become blocked, the condition is called coronary artery disease. Someone with coronary artery disease does not get enough oxygen to the heart, a life-threatening condition that can lead to a heart attack.
Doctors perform coronary bypass surgery to treat coronary artery disease, but it is a major surgical procedure, so it is not used as a first treatment option. A patient may be eligible for coronary bypass surgery if:
• He or she has severe chest pain (called angina) even during light exercise or when at rest caused by narrowed or blocked coronary arteries.
• He or she has multiple blocked coronary arteries that are interfering with the heart’s ability to pump blood.
• He or she has one or more blocked coronary arteries that are not appropriate to treat with medications or other procedures.
• He or she has one or more blocked coronary arteries that have been treated unsuccessfully with medications or other procedures. Coronary bypass surgery may be an option if an artery has re-narrowed after an angioplasty.
• He or she is having a heart attack and has not responded to other emergency treatments.
Types of Coronary Bypass Surgery
There are different types of coronary bypass surgery. The type of coronary bypass surgery performed depends on factors including the patient’s health, the location of the blockages within the heart, and the number of blockages that must be bypassed.
Doctors will conduct several tests including chest X-rays, blood tests, and a coronary angiogram prior to the surgery to determine which type of surgery is appropriate. In a coronary angiogram, a liquid dye is injected into the arteries of the heart. This makes the arteries visible to the doctor on X-rays and video monitors so that he or she can see any blockages.
Types of coronary bypass surgery include:
Traditional coronary bypass surgery: Most of the time, coronary bypass surgery is performed using the traditional method. This procedure can take anywhere from four to six hours, and usually between two and four artery blockages are bypassed.
First, the patient is given a medicine called general anesthesia that makes him or her fall asleep.
Then, the surgeon makes an incision (usually about 10 inches) down the middle of the patient’s chest, separates the breastbone (the bone in the middle of the ribcage), and spreads apart the ribcage, exposing the heart.
After separating the ribcage, the surgeon temporarily stops the patient’s heart and hooks the patient up to a heart-lung machine that takes over the heart’s job of pumping blood through the body.
Next, the surgeon takes a section of a healthy blood vessel from another part of the patient’s body and attaches the ends of it above and below the clogged part of the coronary artery. This allows the blood to flow around the blockage.
Usually, the section of healthy blood vessel comes from an artery inside the chest wall called the internal mammary artery. Using this artery leads to the best long-term results because the internal mammary artery already has oxygen-rich blood flowing into it. Thus, it only needs to be reattached at one end instead of two.
Sections of healthy blood vessels in the lower leg or the lower arm can also be used for the bypass because the lower leg and lower arm receive blood from several pathways. This means that those parts of the body can still receive enough blood to function normally after part of a blood vessel has been removed from them.
Once the blocked artery has been bypassed, the surgeon starts the patient’s heart again, closes the breastbone with a wire that remains inside the patient’s chest, and stitches up the incision along the middle of the chest.
Off-pump or beating heart coronary bypass surgery: Patients who have previously had strokes or who have certain health problems including breathing problems, kidney problems, and narrowed arteries leading to the brain have an increased risk of complications when the heart-lung machine is used in traditional coronary bypass surgery. For these patients, it may be best for doctors to perform the coronary bypass surgery “off-pump,” meaning without the heart-lung machine.
Off-pump coronary bypass surgery is done the same way as traditional coronary bypass surgery except for the use of the heart-lung machine. In off-pump coronary bypass surgery, the surgeon does not stop the heart after separating the ribcage. Instead, he or she uses advanced operating equipment to stabilize parts of the heart during the surgery while the heart still pumps blood through the body. The decision to use the off-pump method is typically made once the ribcage has been separated because then the surgeon can evaluate the condition of the heart more closely.
Minimally invasive coronary bypass surgery: If a patient is going to have a coronary artery on the left side of the heart bypassed using an internal mammary artery from the left side of his or her chest, that patient may be a candidate for minimally invasive coronary bypass surgery. This procedure is like the traditional method except that the surgeon makes a much smaller incision in the chest (around three inches long), does not separate the ribcage, and does not stop the heart. It is possible to perform the procedure with this smaller incision because the surgeon is operating on the left side of the heart with a blood vessel from the left side of the chest. Sometimes, it is possible to perform minimally invasive coronary bypass surgery with an even smaller incision if the surgeon can use robotics and video technology to conduct the operation.
Coronary bypass surgery is a major surgical procedure, so there are several risks. The most common risks associated with coronary bypass surgery include:
Bleeding: There is a risk of bleeding because coronary bypass surgery is invasive, and the incision that the surgeon makes causes the body trauma. There is a greater risk of bleeding with the traditional method than with the minimally invasive method because the traditional method involves a larger incision and more disruption of the body’s tissues.
Irregular heart rhythms: If the heart becomes irritated during coronary bypass surgery, it may beat too slowly or too quickly.
Other, less common risks include:
Infection of the incision site: The skin is one of the body’s defense mechanisms against germs. When it is damaged by a surgeon’s incision, for example, the wound can become infected. This is less of a risk in the minimally invasive method than the traditional method because the minimally invasive method involves a smaller incision and damages less skin.
Blood clots: Blood clots are a risk for any type of surgery. If a blood clot disrupts blood flow to the heart, a heart attack may occur. If a blood clot disrupts blood flow to the brain, a stroke may occur.
Memory loss or trouble thinking clearly: Doctors do not fully understand why some patients have memory loss or trouble thinking clearly after coronary bypass surgery. Whatever the cause, memory loss typically goes away several months after surgery.
Recovering after coronary bypass surgery takes time. Patients usually spend about a week in the hospital after the procedure. They spend the first day or two of that week in the intensive care unit where their heart, blood pressure, breathing, and other vital signs are closely monitored for signs of complications.
Patients typically cannot drive, return to work, or perform daily chores for four to six weeks following coronary bypass surgery. Even walking short distances may be difficult for the first few weeks after the operation.
Minimally invasive coronary bypass surgery is less traumatic for the body than the traditional form of the surgery, so it also has a shorter, less painful recovery time. Patients undergoing minimally invasive coronary bypass surgery may only need to spend two to three days in the hospital after the operation and may be able to return to their normal activities two or three weeks following the procedure.
Although coronary bypass surgery can treat coronary artery disease and relieves symptoms like chest pain for as long as 15 years, it cannot cure coronary artery disease. Thus, it is important to maintain a healthy lifestyle after the procedure to decrease the risk of having another blocked artery. Guidelines for living a healthy lifestyle include:
• Avoiding or quitting smoking. The chemicals in tobacco smoke damage blood vessels and make them more vulnerable to atherosclerosis. Also, nicotine and carbon monoxide, two chemicals found in cigarette smoke, make the heart work harder to pump blood. Nicotine narrows the blood vessels. Carbon monoxide replaces some of the oxygen in the blood so that the heart has to pump more blood to ensure that tissues receive adequate amounts of oxygen. This weakens the heart over time.
• Exercising regularly. Being physically active for 30 minutes on most (if not all) days makes the heart stronger, helps one achieve and maintain a healthy weight, decreases stress, and reduces one’s risk of developing conditions like high cholesterol, high blood pressure, and diabetes that strain and weaken the heart.
• Eating a healthy diet. Eating a healthy diet means eating fruits, vegetables, lean meats, whole grains, and high-fiber foods and avoiding foods that are high in cholesterol, saturated fat (which is found in animal products), and trans fats (which are found in fried foods, packaged snack foods, and baked goods). A healthy diet can help someone achieve and maintain a healthy weight, lower cholesterol levels, lower blood pressure, and ultimately lower the risk of developing coronary heart disease.
To help them make and adhere to these lifestyle changes, patients of coronary bypass surgery may be advised by their doctors to enter cardiac rehabilitation programs. These programs center around exercise and education and are designed to help people recover from heart attacks and surgery related to heart disease.