DR. DUDLEY JOHNSON, WHO was one of a handful of doctors who popularized the modern coronary bypass operation, first knew he wanted to practice medicine while in seventh or eighth grade — but he didn't know he wanted to be a surgeon until he got into medical school.
"And then I didn't really have any illusions about being a heart surgeon," Johnson said in a 1999 interview. "But I figured if I had experience in the chest, I could get a little better job in a clinic somewhere, so I also trained to do lung surgery along with general surgery. As it turned out, the doctor in Milwaukee, Dr. Derward Lepley, Jr., who was in charge of the heart surgical realm, which was really in its infancy in the middle sixties, asked me to join him in practice, so I ended up staying in heart surgery."
It was a fortunate decision for the field of heart surgery. At the time, surgical teams across the country were experimenting with various treatments for arteriosclerosis in the coronary arteries. Endarterectomy, or stripping plaque from the coronary arteries, was an accepted treatment. Bypass grafts, which were being placed into the coronary arteries of animals, remained a controversial procedure that many surgeons thought wouldn't work. Various attempts were made, including one in 1962 by Dr. David Sabiston, who probably performed the first bypass in a human. Unfortunately, his patient died only days later of a stroke.
Meanwhile, a team of doctors in Houston under the leadership of Dr. Michael DeBakey was developing its own bypass program. "If you go back to that period, you will find there was a great deal of work being done in the experimental laboratory on coronary bypass and other types of coronary surgery," DeBakey said. "In 1961, we wrote our last article on our experimental work with animals. We came out with the conclusion that we had about a 50 percent rate at the end of six months with the bypass graft staying open. We said that was very encouraging and we felt that more experimental work ought to be done."
DeBakey's team did continue its animal research — until a historic moment in 1964. The surgical team, having already heard about Sabiston's unsuccessful bypass, was in the midst of an endarterectomy for a patient when an unforeseen opportunity arose. DeBakey recently told the story:
"This fellow had total blockage of the right coronary, and the only thing he was living on really was his left anterior descending (LAD) coronary artery and a little diagonal branch, and he had a blockage in the left main coronary, right where the LAD began. It was a complicated lesion. When we got in and tried to do the endarterectomy, we kept trying to find the cleavage plane, but we couldn't find it. We knew we couldn't get this fellow off the table unless we restored circula
Dudley Johnson tion in the one artery that was supplying all the blood to his heart. So we decided right then and there to do what we had been doing in animals. We got a little piece of vein out of his leg and put it in and it worked."
This was probably the first successful coronary artery bypass graft surgery. Drs. H. Edward Garrett, Edward W. Dennis, and DeBakey, however, didn't report this success in the medical literature until eight years after the procedure. "In the final analysis, I don't think we deserve all that great a credit for having done the first coronary bypass in a patient," he recently said.
"It was an accident! I think the most important thing to point out about this was the fact that we were doing experimental work, and if we had not been doing the experiments, we wouldn't have thought of doing it in a patient I
think that's about as good an example as you can provide for the usefulness of animal laboratory experimental work.."
While this first successful graft remained pretty much unknown throughout the mid-1960s, other surgeons at various heart centers continued their work. Johnson, by then a heart surgeon himself, remembered visiting the Cleveland Clinic to watch early coronary patch grafts, which only widened the narrow and diseased portion of the artery. After seeing the technique, he went home and "promptly did two such patches."
Johnson, however, did not like sewing a patch onto the most diseased portion of the artery when the disease had obviously spread beyond the patch. "It occurred to me that the diseased area could be avoided completely by opening the artery beyond the disease. A vein could be attached like a patch, and the other end of the vein simply attached to the aorta."
But there was much controversy surrounding a complete bypass procedure, beginning with the technique used to connect the vein graft to the coronary artery and the aorta. Surgeons also debated if more than one vein graft could be placed, or how many "bypasses" were practical.
In 1969, Johnson introduced the modern saphe-nous vein bypass with the end-to-side sewing technique. He helped settle many of these controversies with his string of successful operations and the multiple-bypass technique he developed, including the double, triple, and quadruple bypass. Since then, he has performed more than ten thousand coronary bypass operations.
"The long-term results of coronary artery bypass graft surgery have been evaluated in several centers. In many subgroups of patients, life expectancy has returned to normal or even better than normal," Johnson said. "Coronary artery bypass graft surgery has stimulated more than nine thousand published reports in the medical literature. It does more to change quality and length of life than what medicine can do for most other major chronic diseases. The coronary artery bypass graft operation does nothing for the basic cause of the disease, however, and prevention is, of course, the ultimate answer."
Michael DeBakey descending or even to the posterior margin branches.
"Double vein grafts are now used in over 40 percent of patients and can be used to graft any combination of arteries This direct approach to coronary flow immediately improves heart function and alleviates most clinical symptoms."
In discussing Johnson's presentation, a prominent New York surgeon named Dr. Frank Spencer commented: "I would like to congratulate Dr. Johnson very heartily. We may have heard of a milestone in cardiac surgery today If the exciting data by Dr. Johnson remains valid and the grafts remain patent [i.e., open] over a long period of time, a total revision of thinking will be required regarding the feasibility of direct arterial surgery for coronary artery disease."
Since its development, the coronary bypass operation has evolved into the leading surgery to treat clogged heart arteries. Patients who have bypasses are often relieved of angina immediately, and their bypass grafts usually stay open for years to come. Hundreds of thousands of bypass operations are performed every year.
Almost fourteen million Americans alive today have a history of heart attack, angina pectoris, or both. In 1999, it was estimated that more than one million Americans will have a new or recurrent heart attack. It will be fatal in about one-third of these cases. At least 250,000 people a year in the United States die of a heart attack within one hour of the onset of symptoms — even before they can reach the hospital. Based on the Framingham Study in Massachusetts, 5 percent of all heart attacks occur in people under age forty years, whereas 45 percent occur in people under age sixty-
five years (statistics released by the American Heart Association for 1998).
Although each person's coronary artery system is somewhat different, most people have two coronary arteries that come off the aorta: the right coronary and the left main coronary. The left main coronary artery is like a short tree trunk, and it usually divides after a half inch or so into two major branches — the left anterior descending coronary and the left circumflex coronary (See Chapter Two).
When physicians talk about coronary arteries, they are usually referring to these three: the right coronary, the left anterior descending, and the left circumflex. Many of my patients wonder how it's possible to have a quadruple or quintuple bypass if there are only three major coronary arteries. As it turns out, the coronary arteries are like branches on a tree. The main trunks split into major branches, which split into smaller branches and on and on until the arterial branches become so small they cannot be seen by the naked eye. Any one of these many, many arterial branches can be blocked, meaning that as many as eight or nine, and perhaps even more, bypasses may be necessary.
What Causes Coronary Artery Disease?
The most common cause of coronary artery disease is atherosclerosis, sometimes referred to as "hardening of the arteries." In this condition, fatty buildups develop on the arterial lining (Fig. 8.1). These buildups are soft and almost look like cottage cheese. In fact, the word atherosclerosis comes from the Greek "athero" meaning porridge, and "sclerosis" meaning hardening.
As these fatty buildups become larger, they damage the artery wall, and a scar forms. This scar is then infiltrated with calcium, which further hardens the atherosclerotic material. At some point, the arteries become very brittle and calcified, and the buildups gradually narrow the opening until blood has difficulty getting past the blockages.
When the heart does not get enough oxygen, portions of it may become ischemic, which results in a type of pain called angina pectoris. This pain is often described as pressure, and it usually occurs over the breastbone. It can feel like a band tightening around the chest. Some of my patients have described it as a pile of bricks or heavy weights that has been placed on their chest. This could be a pain that goes from the chest to the neck and lower jaw or a numbness down the arm, particularly the left arm. Sometimes it can manifest itself as a discomfort in the upper portion of the abdominal wall. It may be mistaken for heartburn, a gall bladder attack, or even an upset stomach.
Chest pain does not always accompany hardened arteries. Some patients have what is called an angina equivalent. This could be a form of shortness of breath or other symptoms that, after appropriate testing, turn out to be caused by a lack of oxygenated blood getting to the heart muscle.
Diabetic patients, especially those who have been taking insulin for a long time, often lack this angina warning system. These people may have what is called diabetic neuropathies, or diseases related to their nervous system, and may not have the same sensitivity and same warnings that other people would have. This is especially dangerous. People who have a defective warning system could be playing tennis or doing some other strenuous activity with no sign that the heart is not getting enough blood. They could then suffer a heart attack without any warning. Angina alerts people to imme diately stop whatever they are doing and rest.
As atherosclerotic material builds up, it may actually starve the heart muscle for blood. Heart attacks occur not only when the plaque on the arterial wall blocks blood flow but also when the artery breaks or ruptures. When this happens, platelets, which are designed to begin blood clotting, attach to the raw surface of the crack and form a growing clump. This further blocks the coronary artery and may result in a heart attack. Even a temporary clumping of platelets can result in a heart attack.
Coronary arteries themselves can also go into spasm and block off. This is believed to be genetically related as some people are more prone to have coronary arteries that will go into spasm. If this happens, the blood flow beyond the spasm is severely compromised, which can cause angina or even a heart attack.
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