March 18 (Reuters) - The U.S. Food and Drug

Administration on Tuesday classified the recall of Medtronic's ( MDT )

embolization device as "most serious", following reports

of the deaths of four patients.

The use of the affected product could lead to severe adverse

health consequences, including thrombosis, stroke, or death, the

agency said.

There have been thirteen reported injuries associated with

the use of devices known as Pipeline Vantage Embolization

devices.

The recall impacts the Pipeline Vantage devices compatible

only with 0.027" inner diameter microcatheters, Medtronic ( MDT ) said.

The company added that it has taken the necessary steps to

retrieve the recalled products and has notified regulatory

agencies globally as appropriate.

The devices in question are used to treat bulges in the

artery walls, or aneurysms, of the brain.

They are inserted into the blood vessels via a small

catheter and delivered to the aneurysm site, where a small,

braided tube is placed to obstruct blood flow to the bulging

area.

The recall involves the withdrawal of the device models from

all locations where they are currently in use or for sale.

Medtronic ( MDT ) is recalling the devices following reports of a

higher incidence of the flexible, braided tube part of the

device failing to properly attach or stay attached to the blood

vessel wall during and after procedures involving these devices.

Incomplete wall apposition and braid deformation, also

sometimes called fish-mouthing, braid narrowing, or braid

collapse, are known risks of these devices, the regulator said,

adding that the risks were higher in females, especially those

younger than 45 years of age.