New Heart Bypass Procedure Sidesteps Heart-Lung Machine, Reduces Related Complications

With half a million Americans undergoing coronary bypass surgery each year, the four-decade-old procedure has become routine. But Sellers’ operation was not. In the first surgery of its kind at UC Davis Medical Center, Sellers’ heart kept beating throughout the procedure, sparing him the ordeal of a heart-lung machine.

Called “beating-heart” or “off-pump” bypass surgery, the technique reduces the trauma of conventional bypass surgery. Patients require fewer hours on a ventilator, spend fewer days in an ICU and face fewer complications, particularly stroke.

And beating-heart bypasses are proving as sturdy and durable as conventional bypasses. Sellers had his triple bypass procedure on a Friday morning, was out of the ICU by Sunday, and back home on Tuesday. When he compares his uneventful recovery to that of friends and relatives, Sellers counts himself fortunate.

“I was pretty lucky,” Seller says. “Mine went pretty well.” One of the members of the surgical team working on Sellers’ heart was J. Nilas Young. Young, who was among the first wave of cardiac surgeons in the United States to master the beating-heart bypass procedure five years ago, has now performed more than 300 of the operations, and has lectured on the technique across the country and in Russia. Today Young does 80 to 90 percent of his coronary bypass procedures without a heart-lung machine.

In conventional bypass surgery, the heart is flooded with cold fluids rich in potassium, an ion that arrests muscle contractions. The patient’s blood is then rerouted into a heart-lung machine. There, it is forced over cheesecloth-like membranes of porous plastic, through which oxygen percolates.

The blood is also cooled to about 82 degrees F, then pumped back into the body. Body temperature drops, slowing metabolism and lessening demand for oxygen. After surgery the body must be rewarmed.

Although coronary bypass surgery is over 95 percent successful, there remain serious side effects and occasional deaths — many resulting not from the surgery itself, but from the heart-lung machine.

Patients hooked up to the machine face a two- to four-percent chance of stroke and a 25-percent risk of transitory retinal damage. Post-operative infections may be more of a risk when the machine is used. And cognitive deficits are common.

Last June Duke University researchers reported in the New England Journal of Medicine that five years after bypass surgery, 42 percent of patients studied still suffered from a decline in intellectual function. The risk was greatest for the patients who were placed on heart-lung machines.

Heart-lung machines provoke the release of a riot of inflammatory molecules capable of harming organs throughout the body, including the brain.

Microscopic bubbles from the oxygenator or arterial plaque dislodged during placement of the tubes connecting patient and machine can block blood flow to the brain or other organs. Mechanical damage to fragile blood cells can result in clots.

Many elderly and very sick patients have been considered ineligible for coronary bypass surgery simply because they are too weak to withstand the rigors of the heart-lung machine.

The beating-heart bypass — likened by some to cutting a gemstone while on horseback — was pioneered in 1965 by a Russian cardiac surgeon, Vassily Ivanovich Kolessov. Although Kolessov achieved good results, the technique was procedure considered too radical and was never adopted by surgeons of the day.

But with the development of new instrumentation in the mid-1990s, the approach was revived. The new instruments stabilize a small area of the heart, allowing a cardiac surgeon to safely place a bypass graft, while the rest of the heart thrashes away normally.

One device looks like a sewing machine foot. Another uses tentacles fitted with a series of suckers that grip the heart muscle with a vacuum seal. More than 45,000 bypass surgeries have been performed worldwide using the latter system alone. Today about 20 percent of cardiac surgeons in the United States have been trained in beating-heart surgery, up from 1 percent just five years ago.

At the annual meeting of the International Society for Minimally Invasive Cardiac Surgery in Atlanta last June, Duke researchers reported on the first 32 patients to receive off-pump surgery at their institution. The off-pump patients spent much less time on a ventilator and in the ICU. The average cost for respiratory care services was $936 versus $1,634. Overall ICU costs were $2,716 versus $5,009.

Other studies have shown similar cost savings among off-pump patients, along with reduced need for blood transfusion, less respiratory dysfunction, and lower rates of stroke, kidney failure, retinal bleeding, cognitive problems and wound infection.