A miniaturized heart-lung machine used for the first time in an elective procedure last week may greatly expand the number of heart patients who can receive angioplasty instead of coronary artery bypass surgery, surgeons at the University of Maryland Hospital have reported. The new machine, called a percutaneous bypass machine, may also be used to prevent heart muscle damage during a heart attack, they said.

"This machine provides the support and safety of a heart-lung machine, but it doesn't require surgery to use it," said Dr. Robert A. Vogel, chief of cardiology and a member of the team that treated Richard Paff, 68, in a two-hour angioplasty procedure last week in Baltimore. "And while we didn't really know what we were getting into, it turned out that the machine is remarkably simple to use. Getting it going was not much more complicated than the procedure itself."

Angioplasty is a technique for opening up a blocked coronary artery. A thin tube, called a catheter, is threaded into an artery in the groin or the arm and into the arteries of the heart. A second catheter, carrying a balloon on its tip, is then placed across the blockage in the coronary artery. Inflating the balloon opens the blockages. Last year 200,000 such procedures were performed.

Angioplasty is less costly than coronary artery bypass surgery -- about $5,000 compared to about $25,000 -- and recovery is a matter of days rather than the three months for bypass surgery.

But angioplasty isn't always appropriate for heart patients. Circulation through the blocked artery is always cut off for short periods during the procedure. Unless the patient has good heart muscle reserve, and enough healthy arteries to continue feeding the heart, this interruption of blood flow could be fatal. In the case of Richard Paff, a retired maintenance manager from Timonium, Md., the heart was so weak that, without the percutaneous bypass machine to raise the amount of oxygen in his blood, he would not have been able to withstand angioplasty, Vogel said. Patients in this situation usually are treated with open-heart surgery to perform a coronary artery bypass.

With the use of the new machine, "we think about 10 to 30 percent of patients now undergoing bypass could receive angioplasty instead," Vogel said. He estimated this could lead to an annual savings nationally of at least $200 million.

Paff's angioplasty was performed in a catheterization laboratory rather than an operating room. The patient was awake throughout the procedure. The percutaneous bypass machine, which weighs just 20 pounds and runs on batteries, was wheeled to his bedside on a cart. Two narrow catheters were connected to Paff's circulation through the blood vessels in his groin, one to draw out blood from the femoral vein, the other to return oxygenated blood through the femoral artery.

A full-sized heart-lung machine performs a similar function, but its tubes are so large that they must be inserted directly into the larger vessels leading into the heart -- a process that requires open-heart surgery.

Vogel said the machine, which costs about $25,000, also could be used to provide respite to individuals experiencing a heart attack. "We would give TPA {the newly approved clot-dissolving drug} first to all heart attack patients," he said, "but that only opens about 60 percent of the vessels. For the patients who have significant narrowing in other vessels, which isn't helped by dissolving a blood clot, this machine can help minimize the damage to the heart muscle."

Vogel said the emergency room team at University Hospital is ready to use percutaneous bypass during a heart attack "as soon as the right patient comes up."