CHICAGO -- Big chemical companies and other manufacturers of materials used to make heart valves, artificial blood vessels and other implants have been quietly warning medical equipment companies that they intend to cut off deliveries because of fears of lawsuits.
While the suppliers' new policies have not yet forced important products from the market, medical equipment makers that are scrambling to protect themselves from the impending cutoffs say they are having trouble lining up alternate suppliers.
Industry executives and doctors say that the trend could eventually make some life-saving implants hard to come by and have a devastating effect on the development of new devices.
About 100 equipment companies have already had supply problems, according to reports received by the Health Industry Manufacturers Association, the equipment makers' Washington-based trade group.
The materials manufacturers, including giants like E. I. du Pont de Nemours and Dow Chemical Co., are dropping the medical business in response to the high risk of being dragged into lawsuits filed against implant makers by consumers who say they have been injured by defective products. Suppliers have already been named in hundreds of suits involving jaw implants, silicone breast implants and other devices.
Equipment makers say that the litigations that have spurred the suppliers' moves to withdraw have also made it harder to obtain the materials indirectly through distributors or other middlemen. In addition, some equipment companies say electronics companies and other subcontractors that assemble high-tech components for the most sophisticated implants are increasingly reluctant to take on such business.
Consumer groups say the chemical companies' moves are simply part of a broader campaign by industry to pressure Congress to limit the redress available in courts for those injured by defective products.
But one leading supporter of product-liability reform legislation is convinced that the implant makers' plight is a special case.
"This is a public health time bomb," said Sen. Joseph I. Lieberman, D-Conn., who hopes to hold hearings on the subject next month.
Mr. Lieberman said that although the proposed changes in product liability laws would reduce materials suppliers' exposure to lawsuits, the problem might have to be dealt with through specific language in the health care reform legislation being written on Capitol Hill.
The medical equipment makers fear that partial protection from litigation will not be enough to bring back the big chemical and plastics suppliers because they have so little to gain from the medical business.
Medical devices typically use small quantities of raw materials, compared with other applications.