NEW YORK — It seemed like a great idea — doing bypass surgery while the heart is still beating, sparing patients the complications that can come from going on a heart-lung machine.
Now the first big test of this method has produced a surprise: Bypass has fewer problems and is more successful done the old way.
Most surprisingly, there were no signs of mental decline in those on the machines. Avoiding this problem was thought be one of the benefits of so-called "off-pump" surgery without a machine.
"For the vast majority, there's no advantage to doing it off-pump and there may be some disadvantages," said Frederick Grover of the University of Colorado Denver, one of the leaders of the study.
Never miss a local story.
Heart bypass is believed to be the most common surgery in the world — an estimated 253,000 Americans have the operation each year. Traditionally, the surgery is done while the patient is hooked up to a heart-lung machine which takes over the job of circulating blood while the beating heart is stopped. That "on-pump" method makes it easier for surgeons to attach new arteries or veins to create detours around clogged arteries.
But the heart-lung machine carries a small risk of complications. In the 1990s, surgeons began doing off-pump surgery — without the machine but with devices that stabilize the beating heart.
Today, about one in five bypasses are done off-pump, and it's been hotly debated which is better.
The research reported in today's New England Journal of Medicine is the largest to date to compare the two techniques in a rigorous manner. The study involved 2,203 patients at 18 Veterans Affairs medical centers.
About half were randomly assigned to bypass surgery with a heart-lung machine, half without.
A month after surgery, there was no difference in the number of deaths or other complications in the two groups.
But a year later, the off-pump group had worse outcomes. About 10 percent had either died, had a heart attack or needed another bypass or procedure to open a blocked artery, compared to about 7 percent of the on-pump group.
"We always have the idea that less is more — less invasive or less anything seems to be a better answer. That isn't always the case," said Eric Peterson, a heart doctor at Duke University Medical Center.