Abbott's dissolving stent will require training: FDA

US regulators raised questions about the safety of Abbott Laboratories; Absorb, a medical device for propping open clogged heart arteries that dissolves back into the body over time, ahead of a decision on whether to clear the first-of-its-kind device for sale.

The stent, already approved in 100 countries, is one of the key items in the Abbott Park, Illinois-based company's pipeline for the US market. It was developed to reap the benefits of stents, which hold vulnerable arteries open to ensure sufficient blood flow to the heart, while also reducing their risks, such as the formation of clots around the metal scaffolding that can unintentionally block blood flow.

The US Food and Drug Administration is scheduled to convene a meeting of outside experts on March 15. Their input will help the agency decide whether Absorb demonstrates a reasonable assurance of safety and effectiveness, FDA staff said in the memo.

Absorb worked about as well as Abbott's market-leading stent Xience in the study conducted to win approval, though there were signs of additional risks when it was implanted into small vessels. The rate of stent thrombosis, when a blood clot forms inside or around the device, was more than twice as high with Absorb compared to the current of metal stents, FDA staff said.