WASHINGTON - Government lawyers backing Minnesota medical technology giant Medtronic Inc. argued before the U.S. Supreme Court on Tuesday that federally approved medical devices should be largely immune from lawsuits seeking damages for injuries.

Without that immunity, "there would be a serious undermining of the [government's] approval authority and its balancing of risks and benefits," said Deputy U.S. Solicitor General Edwin Kneedler, who joined Theodore Olson, a former Bush administration solicitor general now representing Medtronic.

The high court heard arguments in a case brought by the family of Charles Riegel, a New York man who was injured when a Medtronic catheter burst during an angioplasty operation for a badly blocked right coronary artery in 1996.

Riegel survived the operation but sued the Fridley-based medical device manufacturer, alleging design flaws and inadequate labeling instructions.

The case is being followed by medical technology companies around the nation, particularly those, like Medtronic, that make sophisticated medical devices that go through so-called premarket approval by the Food and Drug Administration (FDA).

Legal analysts note that millions of dollars in potential liability are at stake for Medtronic, as well as millions more in potential research and development capital nationwide for innovative but risky medical devices.

The Riegels' lawyer, Public Citizen attorney Allison Zieve, told the justices that shielding federally approved devices from product-liability lawsuits would give patients little recourse when things go wrong.

"Once on the market, a [federally approved] device may prove to be unsafe," she said. "Most problems don't occur until the product is on the market."

Medtronic and its industry allies argue that the FDA provides a rigorous approval process and that without broad legal protections medical device manufacturers would be subject to overlapping and contradictory state and federal standards.

"As was made clear in today's arguments, the safety and efficacy of medical technologies are best determined by Food and Drug Administration scientists, not by lawsuits filed in courtrooms across the country," said Christopher White, general counsel for AdvaMed, a medical technology industry organization.

The justices wrestled with arguments presented by both sides. But Justice Antonin Scalia, an influential conservative on the court, indicated that he thinks federal law gives the FDA ultimate authority to regulate medical devices.

"It is clear Congress didn't want any additional requirements," Scalia said.

In light of evidence that Riegel's doctors might have used the Medtronic device improperly, Zieve struggled to answer a question from Justice Stephen Breyer asking her to identify a specific design flaw in Medtronic's catheter.

"Every time there is an accident or something bad happens, the lawyers assert a design claim," said Breyer, a member of the court's liberal wing.

Others on the court probed for the limits of FDA authority and the duties of manufacturers who discover design or labeling flaws in their devices once they're on the market.

"How are newly discovered flaws dealt with?" asked Chief Justice John Roberts, summarizing a line of questioning that preoccupied much of the court.

Olson argued that companies must report new problems to the FDA, and that failure to adhere to federal reporting requirements can result in criminal sanctions as well as civil liability -- if people are injured.

Olson called for a balance between risk and benefits in new medical devices. "We don't want to discourage marketing of devices that can save lives," Olson said. "They may not all be perfect."

Zieve argued that the threat of litigation, supplementing the federal regulatory scheme, is the best way to ensure that manufacturers market the safest devices possible.

Riegel, who filed suit in New York, faced several court setbacks before his death in 2004. The 11-year-old case is now being pursued by his widow, Donna.

Kevin Diaz • 202-408-2753