1. What are coronary arteries and how do they relate to the heart?
   
2. How many coronary arteries are there and what part of the heart do they supply?
   
3. What is coronary artery disease?
   
4. How do the plaques cause problems?
   
5. What are the options for a patient with coronary artery disease?
   
6. How does surgery work?
   
7. How do you get to the heart for the operation?
   
8. What about the leg?
   
9. What are the risks of CABG?
   
10. How successful does CABG tend to be?
    
11. How long does CABG surgery take and what happens afterward?
    
12. What happens after discharge from the hospital?
    
13. What medicines will still be necessary after the operation?
    
14. How do I get in touch with my surgeon if I have a question, or need to schedule an appointment?
    

This document is intended to introduce the important facts and concepts of surgery for blocked coronary arteries – coronary artery bypass grafting, or CABG. Though not comprehensive, we hope it will help as a start for understanding CABG surgery and for discussing the details of your situation and operation with your physician and surgeon. The information is structured in a question and answer format based on many discussions we have had with patients.

1. What are coronary arteries and how do they relate to the heart?
Your heart is really two muscular pumps that work side by side to collect blood from your body and send it to the lungs (right pump or ventricle) and then collect the renewed blood from the lungs and send it out to the body (left ventricle). The heart works continuously to do this and requires a constant supply of blood to do this work. The coronary arteries are the vessels that directly return fresh blood to the heart to allow it to do its work. Because they encircle the heart like a crown, they are named coronary. The heart is different from many other organs because it always removes all the oxygen and nutrients from the blood arriving through the coronary arteries to supply the muscle. If the heart is asked to do more work (for example during exercise or during times of stress), the coronary arteries are designed to open up and simply let more blood through. This unique mechanism makes the heart vulnerable to restrictions in its blood flow.

2. How many coronary arteries are there and what part of the heart do they supply?
Usually there are three main coronary arteries: right, left anterior descending, and circumflex. The right coronary supplies the right ventricle and often the undersurface of the left ventricle. The left ventricle is supplied by the anterior descending and circumflex arteries which have a common origin, separate from the right coronary, which is called the left main coronary artery. The left ventricle has to generate the arterial blood pressure which involves much more physical work than the right ventricle. Therefore it has much more muscle and requires more energy, and thus more blood flow.

3. What is coronary artery disease?
“Coronary artery disease” means the presence of abnormal blockages in the coronary arteries. Such blockages result from abnormal deposits of lipids (fats) in the walls of the coronary arteries themselves. These lipids appear to come from the bloodstream, and accumulate over many years. Over time these blockages, called plaques, tend to progressively increase in size. Currently we have no pills capable of shrinking or removing the plaques, though there are medicines which can reduce or eliminate symptoms caused by the blockages. To physically open up the arteries requires either angioplasty/stenting or surgery.

4. How do the plaques cause problems?
Plaques cause problems in two ways. One way involves the slow growth of the plaque, gradually choking off the ability of blood to travel through the artery. The blockage acts as a “governor” on the flow of blood through the artery. When the heart does more work and tries to increase its energy supply by increasing blood flow through the coronary artery, a problem develops. The blood flow cannot increase, and the heart muscle is no longer properly “paid” for the work it is trying to do. When this happens, the patient may have symptoms such as chest pain (angina), discomfort in the arms, neck, or shortness of breath (sometimes patients have no symptoms, though the situation may be detectable on a stress test). Abnormal rhythms may arise in the heart which are potentially dangerous. If the imbalance in supply and demand persists, the heart muscle may be irreversibly damaged.

The other mechanism for trouble occurs when the plaque (which is ordinarily covered by a thin layer of lining cells) develops a crack in its surface. Why this occurs is not clear, but it can occur in relatively minor as well as severe blockages. When the circulating blood is exposed to the abnormal inner portion of the plaque, it presumes an injury has taken place, and tries to wall off the area by covering it with a layer of clot. The clot can spread and suddenly block the flow of blood through the entire artery, causing sudden catastrophic injury and death to the muscle downstream. Pain, shortness of breath, and dangerous cardiac rhythms may result. This is usually the mechanism behind a “heart attack” or myocardial infarction. Irreversible damage to the muscle occurs, which in some instances can severely reduce the heart’s ability to pump, a situation known as heart failure.

5. What are the options for a patient with coronary artery disease?
Options fall into three basic categories: medical therapy, angioplasty/stenting, and surgery. Medicines can be very effective at reducing the heart’s demand for blood and can in many instances eliminate symptoms, but cannot open a blocked artery. Angioplasty is a technique performed in the catheterization laboratory by cardiologists in which the degree of blockage is reduced or eliminated by inflating a tiny tube-like balloon inside the artery at the location of the plaque. The plaque is pushed back mechanically by the balloon. A stent is a tiny tube of wire mesh that is left in the artery, designed to prevent the recoil or collapse of the plaque and artery wall after removal of the balloon. Angioplasty/stenting can effectively open many coronary blockages with low risk, although there is a small chance of damaging the artery, or a higher (15%-20%) chance of having the blockage return in the form of a scar at the site. Surgery, in the form of CABG, is performed in the operating room by a cardiac surgeon. Surgery is able to provide the most durable protection from recurrence of blood flow problems to the heart. The safest form of treatment for a particular patient depends on many factors, including the type of symptoms, location of blockages, and prior damage to the heart. Depending on the situation, surgery may be the safest treatment for a given patient.

6. How does surgery work?
CABG surgery works by creating a new pathway for blood to travel through, which allows the blocked section of the coronary artery to be completely avoided. It is important to note that the blockages in the arteries are not removed. Instead, segments of a non-essential vein from the leg (the saphenous vein) are connected to the aorta on one end, and the other end is connected to the opened coronary artery downstream of the blockage. Blood can then travel from the aorta into the saphenous vein and then into the coronary artery downstream of the blockage. Once returned to the coronary artery, the blood can go anywhere it needs to get to the muscle. An artery from the chest wall is also frequently used for bypass, the left internal mammary artery (LIMA). It is freed from its position on the inside of the front of the chest to the left of the sternum, and left connected at its origin off a branch of the aorta. Other vessels used for bypass may include the radial artery and right internal mammary artery (RIMA).

7. How do you get to the heart for the operation?
A midline incision is used which divides the breastbone vertically. While this sounds painful, our patients tell us routinely that it is not as bad as you think. The bone is not sensitive, and it is closed very securely with strong stainless steel wire so there is very little movement. This incision is much less painful than abdominal (belly) or thoracic (on the side, between the ribs) incisions. Where the LIMA is taken off the chest wall on the left side, there is usually some numbness and/or tingling due to associated nerves. This should resolve, but may take months as the nerves regenerate slowly.

8. What about the leg?
In the past, leg incision has bothered many patients more than the chest. Unlike most centers, we now remove the vein through two small incisions above and below the knee, in a process called endoscopic vein harvesting, which has greatly reduced discomfort. In some cases the procedure is not possible for anatomical reasons, but this is unusual. Because a small nerve travels close to the saphenous vein, there are usually some areas of numbness or tingling in the inner thigh or calf after the operation. Because peripheral nerves grow back slowly, this can take months to resolve completely, but tends to get better over time.

9. What are the risks of CABG?
Any procedure that requires a general anesthetic has an associated mortality risk. The risk of mortality with CABG depends on the characteristics of the individual in question. For a low risk patient, CABG mortality begins at or a little below 1%; in other words, 99% chance of surviving the operation. Your surgeon will be able to address these issues in more detail. When surgical risks are compared to risks of myocardial infarction, where mortality risks begin at 20% to 30% for a first heart attack, surgical risk can be seen in better perspective.
Other potential risks include stroke, infection, myocardial infarction, and bleeding requiring a return to the operating room. While not common, for some individuals the risks will be higher, and again your surgeon will be able to address these questions in more detail.

10. How successful does CABG tend to be?
Very successful. CABG surgery has a very high likelihood of preventing chest pain and heart attacks for years to come, and has a better track record in this regard than any other form of treatment. However, the operation does not change the underlying tendency to form plaques, which may develop in the arteries downstream of the grafts or in the grafts themselves. Still, after 10 years, only about 5% of patients will have had repeat CABG.

11. How long does CABG surgery take and what happens afterward?
Surgery takes 4 to 6 hours and the patients recover in the Surgical Heart Unit on the second floor at Sherman. Family members can spend time with the patient on the day of surgery by arriving 60 to 90 minutes before the scheduled start time (early morning entrance to the hospital is via the Emergency Room). During surgery families receive an update hourly via a voicemail system that can be dialed from any phone in the hospital. Families are oriented to this process by the OR nurse when the patient leaves the holding area for the OR. After surgery is completed, the surgeon will discuss the procedure with the family in the waiting area for the Surgical Heart Unit.

The patient is usually still asleep in the early recovery period, and the breathing tube that made the procedure possible will still be in place when the patient wakes up. As a consequence, the patient is initially unable to speak. Our goal is to remove the breathing tube as soon as possible after the operation, so as soon as the patient is awake and following commands, the nurses will allow the patient to breathe without much ventilator support. If this is successful, the tube is then removed. Two or three drains will be in place in the upper abdomen, and a catheter tube will be present to collect urine. Several monitoring lines are also present, and patients frequently are receiving medicines to control heart rate, blood pressure, and other parameters. When these medicines are no longer needed and the breathing tube is out, the patient will be considered for transfer to a telemetry bed out of the Surgical Heart Unit, usually one or two days after the operation.

The driving force in postoperative care is getting the patient up and moving – walking, deep breathing, and coughing, as soon as possible. Families can be very helpful in meeting these goals, so encourage the patient! When the patient’s drains are out, and the patient is off oxygen, walking well, able to eat, with good pain control, then discharge is considered. This can be as early as 3 days after surgery, but is always individualized to the patient’s needs. Again, the family can be very helpful in reassuring the patient that it is okay to go home; that recovery will go more smoothly in familiar surroundings.

12. What happens after discharge from the hospital?
For almost all patients, a visiting cardiac nurse will see the patient at home, to check incisions, go over medications ordered at discharge, and check general status. Initially, the transition to home may be a bit difficult. Many patients report a number of issues including mood swings, hoarseness, incisional pain, lack of appetite, difficulty sleeping, minor shortness of breath, and feelings of lack of energy or exhaustion. All these are expected events in a patient recovering from any major surgery. Remember that it may take four months or more to recover completely from the surgery, and it can be very difficult initially to judge your progress from day to day. Any problems felt to be significant (especially fever, redness or drainage around incisions, worsening shortness of breath, chest pain that is different from the usual incisional pain) should be communicated to the cardiac surgeon involved. Patients are scheduled to return to the office of Northern Illinois Cardiothoracic and Vascular Surgery (located in the new Sherman Hospital Medical Office building) to see their surgeon within 7 to 10 days after discharge. Further office visits will be scheduled at that time if necessary. For long term management of medications, patients continue to see their cardiologist and/or internist or personal physician. Many patients have correctly realized that diet and exercise (in addition to smoking cessation) will play a significant role in reducing the risk of future problems.

13. What medicines will still be necessary after the operation?
Aside from pain pills, which will usually be needed for two to three weeks, several types of medications have been shown to improve outcomes in people with coronary artery disease. These include aspirin, beta blockers, ACE inhibitors, and cholesterol-lowering agents. These medications will be individualized and managed in the long run by your cardiologist and/or internist. Any medications taken before surgery for other conditions (high blood pressure, diabetes, etc.) will usually need to be continued.

14. How do I get in touch with my surgeon if I have a question, or need to schedule an appointment?
During daytime hours (9 am to 5 pm), we can be reached through our office at 847/695-1620. For urgent problems at night, call the same number and simply follow the prompts. The cardiac surgeon on call will be paged. One of us is always available 24 hours a day.

We hope this discussion of issues related to CABG surgery is helpful to you both in understanding the process and in helping you and your family to communicate your questions and concerns to all members of the team that will be involved in your care.

Northern Illinois Cardiothoracic and Vascular Surgery
Dr. Choh
Dr. Thatcher
Dr. Steimle
Dr. James