A group of 21 plaintiffs is suing Cordis Corp. and Confluent Medical Technologies Inc., alleging those companies’ filter for blood clots is “defective and unreasonably dangerous.”

Each plaintiff alleges they suffered excessive complications after being implanted with one of two inferior vena cava filters designed and manufactured by Cordis and Confluent.

The two filters at issue are the TrapEase filter, designed for permanent implantation, and the OptEase filter, designed to be retrievable.

According to the plaintiffs, an IVC filter is a filter for blood clots designed to prevent them from traveling from the lower body up to the heart or lungs, where they can cause significant problems.

They were first introduced to the medical device market in the 1960s, and since then several new designs have been added to the market.

Blood clots can develop in the blood vessels within the legs in a condition known as deep vein thrombosis. These clots may travel from the legs through the inferior vena cava and lodge in the lungs, where they can cause a condition called pulmonary embolism. Pulmonary embolism creates its own set of risks for the patient.

Some patients who are at risk for deep vein thrombosis or pulmonary embolism can manage that risk by taking anticoagulant medications.

Others who are at a particularly high risk or for whom medication is not a good option may instead choose to have a filter for blood clots implanted.

The plaintiffs now claim that after several decades with these filters on the market, the medical community is now becoming aware of the lack of evidence that these filters offer any benefit.

At the same time, available evidence suggests that these filters expose patients to significant risks.

Plaintiffs cite an article published in October 2015 in which the authors concluded that IVC filters did not help prevent the occurrence of pulmonary embolism in trauma patients and in fact increased the likelihood of thrombus.

The plaintiffs allude to other studies that they say found common device failures including “migration, perforation, thrombosis, [and] fracture,” any one of which could put the patient at risk for serious injury or death.

Filter for Blood Clots Wasn’t Fully Tested, Plaintiffs Say

The plaintiffs also say that Cordis and Confluent abused an expedited FDA approval process to get their filter for blood clots on the market without going through rigorous clinical testing.

Under Section 510(k) of the Medical Device Amendments to the Food, Drug, and Cosmetic Act, the manufacturer of a new medical device can avoid formal review for safety and efficacy if the device is substantially equivalent to some other device already on the market.

Both the TrapEase and OptEase filters were approved for sale under the 510(k) process, plaintiffs say. They argue the defendants failed to conduct proper testing and evaluation that would have revealed the dangerous design flaws in the two IVC filters.

The plaintiffs’ IVC filter lawsuit includes claims for defective design and manufacture, inadequate warning, negligence, misrepresentation, fraud, fraudulent concealment, and breach of warranty.

They seek a damage award to include punitive damages based on the allegedly “willful, wanton, gross, and outrageous” conduct of the defendants.

The Blood Clot Filter Lawsuit is Case No. RG16816600 in the Superior Court of California, County of Alameda.