Boston Scientific is jumping into the hot and potentially huge market for drug-coated balloons.

The balloons are increasingly being used instead of stents to treat the narrowing of major arteries in the legs, but only two models are available in the United States.

On Monday, Boston Scientific signed a temporary agreement with C.R. Bard to start selling one of them. Called the Lutonix, it is a drug-coated inflatable balloon originally designed by a firm of the same name in New Hope. It competes with Medtronic's In. Pact Admiral, which received regulatory approval last month.

The market for drug-coated balloons to treat peripheral artery disease could hit $100 million in 2015, the first full year when they'll be available for patients in the United States. That figure could double or triple within several years given recent trends in vascular surgery, analysts say.

Peripheral artery disease affects about 8 million people in the U.S., but the most common surgical treatments for major cases require painful and expensive repeat procedures.

Narrow arteries don't carry oxygen and nutrients as effectively as healthy ones do. Minneapolis vascular surgeon Dr. Peter Alden said the thigh's main artery is particularly prone to narrowing as fatty tissue and other material build up inside the vessel, leading to peripheral artery disease in the superficial femoral artery. But surgical treatment, even minimally invasive techniques, causes trauma whose healing makes the blood vessel narrow again.

In some cases, a flexible metal mesh tube called a stent is left inside the artery to prop it open — but arteries can narrow inside a stent as well. This has led to "frustrating" treatment options, like putting a new peripheral stent inside an older failed one, Alden said.

A drug-coated balloon like the Lutonix is intended to improve the rate of surgical success. A doctor feeds the artery-sized balloon into the clogged vessel and precisely inflates it, widening the vessel and coating the inside of it with a cancer drug called paclitaxel, which stops cells from dividing rapidly at an early stage and re-closing the artery.

Last October the Food and Drug Administration approved Lutonix, citing favorable results in clinical studies. After a year, one study found Lutonix patients avoided re-narrowing after 65 percent of surgeries, compared with 53 percent for patients with traditional untreated balloon treatments. However, longer-term research is ongoing in the U.S. and Europe.

Then in January, the FDA approved Medtronic's In. Pact Admiral drug-coated balloon, citing company data that found an even wider gap between the two groups. Medtronic expects its recent $49.9 billion acquisition of Covidien, which has a large vascular surgery sales force, will accelerate its sales of the Admiral balloon.

Boston Scientific, which employs about 5,000 people in the Twin Cities, declined to release financial details of its agreement to start selling C.R. Bard's Lutonix. But Boston peripheral-interventions division President Jeff Mirviss said in an interview that the agreement is intended to last until the company can market its own drug-coated balloon, called the Ranger. Boston also intends to market a drug-releasing peripheral-artery stent — a technology that has been available for cardiac stents for years.

"This agreement does not change our long-term plans with regard to any of our drug-eluting technologies, to include both drug-coated balloons and drug-eluting stents," Mirviss said. "The advent of drug eluting technologies in the leg has the similar value proposition that it does in the coronary arteries, in that it can reduce the need for repeat interventions for patients suffering with peripheral artery disease. That is obviously not only good for patients, but it also helps lower the overall cost for health care for patients."

Critics say peripheral stents are more difficult to use because arteries in the legs bear much more torsion and kinking. But Mirviss noted that patients with more serious peripheral artery disease may still benefit from having a permanent "scaffold" left in the vessel.

Joe Carlson • 612-673-4779

Twitter: @_JoeCarlson