For nearly 45 years, U.S. physicians have been using balloon angioplasty to clear clogged arteries around the heart. Stands to reason that such devices would start being adapted to improve cardiovascular health in other parts of the body.

On Friday, Fridley-based Medtronic announced the U.S. and international launch of a balloon catheter to clear blockages from arteries below the knees. The devices, balloon catheters that expand when inflated to improve blood flow, have regulatory approval in Europe and from the U.S. Food and Drug Administration.

Medtronic said that doctors already have started using the device, called the Amphirion Plus Percutaneous Transluminal Angioplasty (PTA) catheter.

Angioplasty was first used in 1977. Medtronic's device applies angioplasty to the treatment of peripheral artery disease in the legs below the knees. Peripheral artery disease can contribute to poor circulation in the calf, ankle, foot and toes, which can lead to sores, amputations and even death.

The new catheter joins Medtronic's Amphirion Deep PTA balloon catheter, which targets lesions in arteries below the ankle.

Risk factors such as a history of smoking, poor diet and lack of exercise can contribute to peripheral artery disease, which affects more than 100 million people worldwide. In the United States, the illness afflicts about 10 million people.

According to Medtronic, research indicates that 50 percent of patients who undergo amputation because of peripheral artery disease die within five years.

James Walsh • 612-673-7428