'Beating Heart' Bypass Surgery May Be Riskier

Nov. 5, 2009— -- It's been about six weeks since Frank Aylor had open heart surgery, and he's already up and jogging again.

"I'm not the type that likes to sit at home, I like to be at work," Aylor said.

Fortunately for Aylor, only one month after his heart bypass surgery at Vanderbilt University Medical Center in Nashville, Tenn., he was able to return to work.

"I'm amazed, people at work are amazed, they can't believe that I had open heart surgery a month ago," he said.

Vanderbilt's approach to this type of surgery is not the typical one. While about 80 percent of bypass surgeries done nationwide are performed with the patient on a heart and lung machine -- an approach called an "on-pump" bypass -- 95 percent of the bypass surgeries done at Vanderbilt use a newer, and often controversial, technology that allows the surgery to be done "off-pump."

During off-pump, or "beating heart" surgery, a surgeon uses a device to stabilize the heart so it does not move as much as it beats. The heart continues beating on its own throughout the procedure -- a situation that makes the surgery more technically difficult. However, some reports in the past have suggested that the off-pump technique could lead to a lower risk of certain negative effects on cognitive function after on-pump surgery.

But on Wednesday, a new study of more than 2,200 bypass surgery patients suggested that off-pump surgery may not be the best choice in many cases. The study, published in the Nov. 5 issue of the New England Journal of Medicine, found that bypass surgery patients have a lower risk of heart attack or stroke if the surgeons opt for on-pump instead of off-pump bypass procedures.

And perhaps the biggest surprise: the study found that the on-pump group was no more likely to have thinking or memory problems than those who had beating heart surgery, said Dr. Eric David Peterson of Duke University Medical Center in Durham, N.C., in an accompanying editorial.

Still, the study is unlikely to end the debate over use of the heart-lung machine in bypass surgery, because many doctors, even those who are skeptical of the off-pump procedure, still feel it has its place in the realm of bypass surgeries.

Dr. Patrick McCarthy, chief of Cardiothoracic Surgery at Northwestern Memorial Hospital in Chicago -- where over 90 percent of bypass surgeries are done on-pump -- commented that, "off-pump has not achieved the promises of a decade ago [but] I would ... hasten to add that it is still a useful technique in a subset of patients."

"I think that the findings of the study are applicable to the vast majority of patients requiring [this] surgery," said Dr. Aubrey Galloway, chairman of the Department of Cardiothoracic Surgery at New York University, "[but] certain caveats do exist, however. The study excluded certain high risk groups, and off-pump remains a valuable technique that may lower the risk of stroke in select elderly patients with advanced [heart] disease."

On the other hand, Dr.Clyde Yancy, president of the American Heart Association, concluded that "based on these results, any patient who is a reasonable candidate for on-pump bypass -- even if the option for off-pump exists -- should undergo on-pump surgery."

To Pump or Not to Pump? Bypass Technique Questioned

For decades, all patients undergoing bypass surgery had so-called "on-pump procedures" because it much easier to sew a new artery into an empty heart in a bloodless field, explained lead study author Dr. Frederick L. Grover of the Denver VA Medical Center and the University of Colorado.

But over time, reports circulated that use of the pump might actually damage the heart and the kidneys. Of special concern were a number of reports of problems with thinking and memory function after on-pump surgery. While it is more technically difficult, the off-pump procedure gained popularity in the 1990s, as some studies suggested it caused lower blood loss and fewer neurological issues than on-pump.

Still, the majority of hospitals still prefer the traditional on-pump approach, and on-pump proponents, such as Massachusetts General Hospital in Boston, use it for more than 95 percent of their heart bypass surgeries.

But some doctors and medical centers, like Vanderbilt, have become strong proponents of the less invasive nature of the off-pump procedure, and use it almost exclusively. Nationwide, about 1 out of every 5 of the half a million heart bypass surgeries done each year is performed off-pump.

Dr. John Conte, associate director of Cardiac Surgery at Johns Hopkins in Baltimore, Md., occupies the middle ground in this debate. He does about 50/50 split between on-pump and off-pump surgeries and says that that the choice between procedures should be made on a "patient-by-patient call... based on the differing advantages and disadvantages of both."

Doctors Disagree Over 'Beating Heart' Bypass Technique

He agreed with Galloway that the new technology is useful for certain high risk groups, and adds that he prefers to use off-pump when patients have borderline kidney function that may be aggravated by the heart and lung machine, or when the patient still has good heart function and is in stable condition at the time of surgery and might benefit from a less-invasive procedure.

Aylor falls into the latter category.

"I [had] never been in the hospital a day of my life, never had surgery, but my wife convinced me to go to the doctor [because] I had been getting short of breath," he said. After doctors found a large blockage in his heart, Aylor was told he was going to be transferred to Vanderbilt for open heart surgery.

"My doctor told me they can go through the chest [for the procedure, but] I could be out [of work] for six months," Aylor said, so they decided on a minimally invasive, off pump procedure that accessed the heart through his ribs instead.

John Byrne of Vanderbilt University in Nashville, Tenn., where Aylor received his off-pump bypass, adds that "to become an expert off-pump surgeon, one must essentially dedicate oneself to perform just about all [of these procedures] using this technique."

Indeed, for Aylor, the doctors made all the difference.

"The procedure was great, [my doctor] said this would be perfect for me [but] I never thought it would be as good as it was," Aylor said. "I think they're the best doctors I've ever seen."

A full discussion of this issue by experts contacted by ABC/MedPage Today can be found at http://www.medpagetoday.com/Surgery/ThoracicSurgery/16811.