Boston Scientific collects stents, offers assurances

Boston Scientific Corp. disclosed more complaints about its new drug-coated cardiac stent yesterday, even as it tried to limit the damage from the recall of its flagship medical product.

The Natick company rushed to replace the potentially malfunctioning devices yesterday after a manufacturing flaw forced it to undertake a voluntary recall on Friday of its Taxus drug-coated stent and an earlier version of the stent.

On Friday, the company said the stents had been linked to three deaths and 43 injuries.

Yesterday, in a note to doctors, the company said it had received a total of 43 complaints about Taxus stents with balloons that did not deflate properly. The balloons are used to implant the stents.

In addition, there were 52 simx ilar complaints about the early version of the stent, Express2.

The numbers of deaths and injuries remained the same, according to the note.

Patients who have received the stents are not affected by the recall, doctors said, since the risk of malfunction occurs as the stents are being implanted, not after they are in the body. Still, several prominent hospitals have stopped implanting the Boston Scientific products.

Yesterday, Boston Scientific sent nearly 300 sales representatives to visit doctors nationwide with the dual mission of collecting the recalled stents and reassuring them that the rest of its inventory is safe.

‘‘We appreciate your understanding as we take action to ensure patient safety and customer satisfaction,’’ wrote Nancy Lelicoff, a Boston Scientific vice president, in a letter to customers.

A Food and Drug Administration official said the agency learned of problems with the stents in April, but did not require a total recall because the benefits of the new drug-coated stent outweighed the risks of cutting supplies for some patients.

Stents are small wire-mesh tubes implanted to prop open clogged arteries during a common procedure known as angioplasty. Taxus, one of only two drug-coated stents on the market, was considered a major advance when it was launched in March because it reduces the buildup of scar tissue after the procedure.

Surgeons thread the stents into patients with catheters and expand them into place with tiny balloons. Then the balloons are deflated and withdrawn from the body.

The recall, the second this month, followed reports of balloons that failed to deflate and blocked blood flow, which in some cases required emergency surgery to remove the balloons.

The recall comes at a critical moment for Boston Scientific, which is locked in a fierce battle with Johnson & Johnson to dominate the lucrative market for drug-coated stents, estimated at $3 billion annually. Over the past year, anticipation for Taxus has driven up Boston Scientific’s share price to make it the most valuable life-sciences company in Massachusetts.

Taxus stents have been implanted in about 500,000 patients, the company says. The recall affects 85,000 Taxus stents, and 11,000 Express2 bare-metal stents, which lack Taxus’s drug coating.

Many stock analysts maintained positive ratings on Boston Scientific, believing it can fix its production problem. Yesterday, the shares lost 3 percent, falling $1.25 to close at $36.15 — the lowest this year.

Boston Scientific has not disclosed the number of injuries associated with another problem dogging Taxus: scattered reports from doctors who said they had trouble withdrawing balloons because they seemed to stick to the stent’s drug coating.

Still, several prominent hospitals, including Lahey Clinic in Burlington and Boston’s Beth Israel Deaconess Medical Center and Brigham and Women’s Hospital, have stopped using Taxus until the company provides more data.

Richard Nesto, chairman of Lahey Clinic’s department of cardiovascular medicine, said doctors have stopped implanting Taxus stents in part because patients who received the stents might sue. ‘‘You would have to explain to a patient why you’re putting in the stent,’’ he said.

One prominent cardiologist criticized Boston Scientific, saying it was trying to downplay the incidence of problems by comparing the numbers of deaths and injuries to the number of Taxus stents implanted so far.

‘‘The relevant number is one death and 18 serious injuries out of 43 no-deflation complaints,’’ said Dr. Jesse Currier, co-director of the Adult Cardiac Catheterization Laboratory at UCLA Medical Center in Los Angeles. ‘‘When this happens, it’s a bad thing.’’

Rival Johnson & Johnson’s Cordis unit, which makes the Cypher drug-coated stent, sent a salesperson yesterday to the Lahey Clinic to see what the company could do to win back the hospital’s stent business.

‘‘They felt they had the market, they felt they lost the market, and now they see the chance to get it back,’’ Nesto said. ‘‘It’s almost like a three-act play.’’ A Cordis spokesman declined to discuss the company’s efforts in detail.

Tufts-New England Medical Center continues to use Taxus, since the number of complaints was low, said Carey Kimmelstiel, director of interventional cardiology. He also said Johnson & Johnson probably couldn’t meet the demand for drug-coated stents alone.

Boston Scientific makes Taxus stent systems in Galway, Ireland, and Maple Grove, Minn. On Friday, the company said the majority of those being recalled were made at the Irish plant, where the company did not keep records in enough detail to identify batches likely to have the defect. A manufacturing glitch in some batches left the hole between the catheter and balloon too small, apparently interfering with the deflation of the balloons.

Boston Scientific first discussed manufacturing problems in April and asked the FDA for permission to alter its production and inspection processes. The FDA approved the changes May 5. Boston Scientific officials said they initiated the first recall, of 200 stents, on July 2 after finding three with narrow holes. They expanded the recall last week after discovering the defects were not limited to individual batches.

Dr. Daniel G. Schultz, acting director of the FDA’s office of device evaluation, said the agency felt a total recall of Boston Scientific stents made before the May 5 manufacturing change would have left some patients waiting for stents.

If the agency were to require a total recall, ‘‘These stents would not be available for a long period of time,’’ he said.

FDA inspectors will continue to monitor Boston Scientific’s two plants.

‘‘I can’t provide a 100 percent assurance that the problem is over at this point,’’ Schultz said. ‘‘But we feel reasonably comfortable the problem has been corrected and that moving forward we won’t see these problems clinically.’’

Ross Kerber can be reached at kerber@globe.com; Jeffrey Krasner, at krasner@globe.com.