See more of the story

Boston Scientific Corp. has issued a worldwide voluntary recall for an older version of one of its most commercially promising devices, the Lotus transcatheter aortic heart valve replacement system, following the deaths of three patients.

The Aug. 1 recall affects about 250 Lotus valve systems that were manufactured before March 2016 but have not yet been implanted in patients. About 15 of the devices are in the U.S.

The recall doesn’t raise safety concerns for valves that have already been implanted in patients’ hearts. Rather, the flaw involves a component that may break when the device is being implanted; the component is not left inside the body after the procedure.

The problem with the component — called the “release mandrel” — was fixed in March. The company said it has received no reports of broken release mandrels since then.

Although most of the malfunctions were resolved by just removing the device and its deployment system from the body, there were three cases that resulted in what the recall notice called “catastrophic vessel trauma associated with patient death.”

The recall isn’t expected to have a material financial effect on the company, a Boston Scientific spokesperson said via e-mail.

The Lotus valve is commercially available in Europe but only offered through clinical trials in the United States.

It’s part of a new wave of artificial heart valves that can be implanted without major surgery, because they’re designed to fit inside narrow tubes called catheters that can be inserted into a blood vessel and advanced to the heart using the body’s vascular system.

The release mandrel is a component of the system used to release the Lotus valve from the delivery system.

The valves are intended to shorten patients’ recovery time by eliminating the need for open-heart surgery, though they’re also more expensive than traditional versions. The U.S. market for the devices is expected to balloon to about $1.8 billion in five years, as transcatheter aortic valves gain wider acceptance and replace traditional mechanical and bioprosthetic valves.

The market for transcatheter aortic valves is one of the fastest-growing niches in the med-tech industry, though only two companies — Medtronic and Edwards Lifesciences — have permission from the Food and Drug Administration to sell them commercially in the U.S.

Stock analysts routinely mention the Lotus as one of Boston Scientific’s most commercially promising devices. The company, which employs some 7,300 people at its operations in the Twin Cities, acquired the Lotus technology in its 2011 acquisition of California-based Sadra Medical.

Company officials said they completed enrollment for its ongoing U.S. clinical trial of the Lotus last December and are anticipating a green light from the FDA for U.S. sales in late 2017 or early 2018.

Joe Carlson • 612-673-4779