Medical Device Daily Washington Editor

GAITHERSBURG, Maryland – Though the majority of panel members praised the PAS-PORT technology – and more than one called it “impressive” and even “ingenious” – a lack of data offered by Cardica (Redwood City, California) may keep the FDA from clearing a 510(k) for the company’s proximal anastomosis device.

Cardica’s PAS-Port is designed to create an anastomosis between a large target vessel, such as the aorta, and a conduit, such as a venous conduit. Anastomosis refers to a surgical connection between two structures – most commonly between tubular structures such as blood vessels – and the PAS-Port is intended as a less-invasive alternative to suturing during coronary bypass surgery.

The Circulatory System Devices Panel of the FDA made no formal vote on the device at its Friday meeting, but panelists’ comments clearly will serve to recommend against approval.

Cardica won CE-marking for the PAS-Port almost two years ago, and it is distributed in Europe by Guidant (Indianapolis), which has invested roughly $14 million in Cardica over the past two years.

At the meeting, the company presented combined data from two separate trials, both conducted outside the U.S. The first study was a 55-patient, prospective, single-arm trial. The second study included data from a 54-patient cohort from a trial originally intended to evaluate Cardica’s C-Port distal anastomotic connector.

The panel expressed concern that the data supporting the PAS-Port application was compiled retrospectively from a subset of patients in the second trial, originally designed to evaluate another product. Some patients during the C-Port trial also received PAS-Port devices at surgeons’ discretion.

Panelists argued that pooling data was not enough to address the limitations of the first trial. They also raised questions regarding safety data and changes to product labeling.

“I don’t think the data submitted is sufficient to clear the device for marketing because I think there are too many gaps in the data,” said John Hirshfeld, MD, of the University of Pennsylvania Medical Center (Philadelphia). “That being said, I think the sponsor should be commended for designing an extremely ingenious device that looks as though it has a great deal of potential. I hope whatever the result of this process is, that it does not stymie the development and evaluation of this device.”

Clyde Yancy, MD, a surgeon with the University of Texas Southwestern Medical Center (Dallas), called the lack of data “disheartening,” but said it was important for the panel to insist upon “irrefutable” data before recommending that the device be cleared for marketing.

“In the best of circumstances, how much 50 or 90 patients tell us about what could be 300,000 human applications is limited,” said Mitchell Krucoff, MD, of Duke University Medical Center (Durham, North Carolina)

Krucoff added that he thought the device had “the right stuff” but that he would like to see more data on the rate of myocardial infarction.

Panel member John Somberg, MD, of the American Institute of Therapeutics (Lake Forest, Illinois), was the only panel member to come out and definitively support FDA clearance of the device.

“I think that with the material we had – plus the guidance that had been given initially, plus the knowledge we have from a previous device – that this could be approved with an adequate mandatory registry and follow up,” Somberg said.

Perhaps the FDA was becoming too conservative or cautious in its product evaluation, he said. “One of the things I learned when I got here in the first couple of meetings was that there is a transition in this area and that constant change in devices is to be expected as opposed to a drug. I am hearing dissidence in that area, which I think will make it very hard for manufacturers to work. I think that needs to be clarified.”

Norman Kato, MD, of the Cardiac Care Medical Group (Encino, California), agreed. “Unfortunately, times change, and there is more of a conservative wind blowing through the U.S. at this point,” he said.

Kato called the device “interesting,” but he also said that if the panel had taken a vote, he would have voted no, based on the lack of data offered.

In December of last year, St. Jude Medical (St. Paul, Minnesota) discontinued its Symmetry product line (Medical Device Daily, Sept. 27, 2004), which served as the predicate device for the PAS-Port 510(k) application.

At the time, George Fazio, president of the Cardiac Surgery Division of St. Jude, said that the company had been happy with the clinical performance and technical advances offered by the Symmetry Anastomotic device, and that it continued to believe in the value of the technology, but that market conditions in the sector had “proven to be increasingly challenging.”

According to Cardica, more than 650,000 bypass surgeries are performed annually worldwide.