This letter is to inform you about serious problems that have occurred with two endovascular prosthetic graft devices used to treat infrarenal AAA, and to make recommendations concerning their continued use. The two products, both of which were approved for marketing in the U.S. in September 1999, are:
AncureEndograft System (Guidant Endovascula r Solutions, Menlo Park, CA) and AneuRx Stent Graft System (Medtronic AVE, Santa Rosa, CA).
Endovascular repair of AAA is an important new technology. It represents a useful therapeutic option for carefully selected patients whose only previous treatment alternative was open surgical repair of their aneurysm. For patients who are at high risk for adverse outcomes with conventional open surgery, endovascular repair provides an alternative to watchful waiting.
Since this is a rapidly evolving technology, it is critical that physicians who evaluate and treat AAA patients have the information needed to make informed decisions on patient selection, device selection, and follow-up management.
Specific Problems with Endovascular Grafts
The two devices have very different designs, and there are different reasons for the current concerns focused on each.
Ancure System (Guidant)
This device has a flexible, unsupported fabric graft prosthesis that is actively fixed in place on the ends by wire hooks that penetrate the vascular tissue. On 3/16/01, Guidant suspended production and announced a recall of all existing inventory. The company reported to the FDA that they had failed to report many device malfunctions and adverse eve nts, including severe vessel damage associated with problems with the deployment of the device. There were also manufacturing changes that were not properly reported to the FDA. The manufacturer told FDA that an internal audit revealed problems with their complaint handling system, manufacturing quality systems, documentation procedures and training.
The FDA is reviewing the firms Corrective Action Plan that addresses these problems.
Once we receive evidence that the firm has appropriately changed their systems and procedures, and the FDA has reviewed their regulatory submissions, we will assess whether the product can be returned to the market.
AneuRx System (Medtronic AVE)
This device has a fabric graft supported along its entire length by a series of metal rings sutured to the graft. The endograft is held in place by the radial force applied by the rings to the patients aorta. FDA is concerned about reports of approximately 25 aneurysm ruptures, as well as other serious adverse events, in patients who have received AneuRx. Factors thought to be associated with the adverse events, including aneurysm ruptures, include:
sub-optimal placement of the graft; endoleak (inadequate proximal seal, collateral vessel retrograde flow, persistent perigraft flow); migration of the main body of the device as well as any attachment cuffs, possibly associated with continuing aortic dilatation; problems with device integrity, due to metal frame fractures, suture breaks, or fabric tears; and aneurysm anatomy. We are working with Medtronic AVE to obtain relevant data that will help us understand how these problems affect the overall risk/benefit assessment of this product.