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Wednesday, May 14, 2003Each year, 300,000 Americans have bypass surgery to improve blood flow to their hearts. Most of the operations succeed. But a minority of patients leave the hospital confused or forgetful, unable to think clearly or unable to concentrate. "Pumpheads," some doctors privately call those patients, and the information shows that a third or more may be affected. As the term implies, doctors attributed the problems to the pump, the heart-lung machine that takes over during surgery when doctors literally stop a heart from beating so that they can repair its blocked vessels. Doctors theorize that something about the pump — little fat fragments or tiny clots that may be thrown into the blood or maybe blood pressure levels in the brain that are too high or too low — may be causing damage. Doctors also thought they had a solution to the problem, avoiding the pump altogether with surgical tours de force in which they actually operate on a slippery blood-coated beating heart. The older, more established method of doing coronary bypass surgery involves stopping the beating heart and rerouting the blood through a heart-lung machine. The pump serves not only as a pump, but as a lung, filtering out the carbon dioxide from the blood and adding oxygen before returning it to the body. The newer method keeps the heart beating throughout the operation, but it does require some machinery of its own. (A detailed comparison can be found here.) In theory, the newer method should be less traumatic to the heart. The heart doesn’t have to be jump-started at the end of the surgery since it’s never been stopped. And, the blood is kept in the safer environment of the body rather than being filtered through a man-made machine. But, theory doesn’t always translate well into real life, and some surgeons have found the new method less beneficial than they expected: Dr. Felix Hernandez Jr. of the Eastern Maine Medical Center in Bangor said he had the ability to learn off-pump surgery and took the time to do so. Soon, he said, he was using it for 90 percent of his bypasses. Then he began to have second thoughts. Small studies were inconclusive on the whole, he said. But a study from Johns Hopkins raised questions about whether the problem should be called pumphead or atherosclerosis-head. That study, by Dr. William A. Baumgartner, chief of cardiac surgery at Hopkins, and his colleagues compared 140 patients who had standard bypasses with heart-lung machines to 92 closely matched patients who had severe heart disease but no operations. All had detailed neuropsychiatric assessments at the start of the study, before any patients had their operations, and three months after the surgery and again a year later. Patients in each group declined in their mental abilities, Dr. Baumgartner found. But there was no difference in the rate or extent of decline in those who had the surgery as compared to those who did not. Most likely, he said, the declines stemmed from aging and chronic diseases like diabetes and high blood pressure and the effects of blocked blood vessels that supply the heart and brain. The article implies that the off-pump method is being used as a marketing tool. That might be true at some centers. Few CEO’s can resist the urge to brag that their hospitals are providing state-of-the-art, cutting edge medical care. But, overall, the method used probably depends on which method the surgeon is most comfortable with. The few studies that have been done suggest the two methods are equivocal. Open heart surgery is an inherently risky surgery. It requires prolonged anesthesia, and it involves opening the chest cavity, a cavity that is designed to work as a vacuum. It isn’t all that surprising that people with known atherosclerotic arteries will have some small neurological changes afterwards. Atherosclerosis doesn’t limit itself to the heart. If the arteries in the heart are bad, you can bet the ones in the brain and elsewhere are, too. And it only takes a small insult in the brain to cause noticeable problems. If faced with the need for coronary bypass surgery, the method is probably the least important consideration. Far more important is the skill of the surgeon and the experience of his support staff. posted by Sydney on 5/14/2003 08:12:00 AM 0 comments 0 Comments: |
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