March 21 (Reuters) - The U.S. health regulator on

Thursday classified corrections made to the instructions for the

use of blood pumps manufactured by Johnson & Johnson's ( JNJ )

Abiomed unit as most serious due to the risk of serious injuries

and death with their current use.

The labeling updates, which FDA classified as its most

serious Class I recall, gave revised instructions for using the

device, such as carefully positioning the pump catheter during

operative procedures and using imaging when advancing it.

Abiomed's so-called recall of some models of its Impella

Left Sided Blood Pumps, used in some high-risk heart procedures

to provide short-term support, was because of the possibility

they could cut through the left ventricle wall of the heart

during operations, the FDA said.

The use of the affected pumps may also cause serious adverse

health consequences, including hypertension, lack of blood flow

and death, according to the health regulator.

The recall is a correction, not a product removal, the FDA

said.

"This notification is not a device removal and Impella heart

pumps remain on the market and available for patients," a J&J

spokesperson said.

The company said it had updated instructions for the use of

the Impella system to further address the potential risk of a

rare complication, left ventricular perforation.

The agency said there have been 129 reported serious

injuries, including 49 reports of death as a result of their

use.

The medical device maker started the recall process on Dec.

27 last year and has recalled 66,390 devices in the United

States. The recalled devices were distributed for two years

until Oct. 10, 2023.

Abiomed sells other pumps under the Impella brand, which are

used for different therapeutic reasons.

Johnson & Johnson ( JNJ ) struck a massive $16.6 billion

all-cash deal in 2022 to buy Abiomed to boost growth in its

medical devices unit. Abiomed operates as a standalone business

under J&J's MedTech unit.

(Reporting by Bhanvi Satija and Mariam Sunny in Bengaluru;

Editing by Anil D'Silva and Krishna Chandra Eluri)