A recent study is raising doubts about the value of inferior vena cava (IVC) filters following catheter-directed thrombolysis for deep vein thrombosis (DVT).
Catheter-directed thrombolytic therapy is used to dissolve acute DVT, a serious type of blood clot that typically occurs in the leg, thigh, or pelvis. If untreated, these clots can break loose and travel to the heart or lungs (this is known as pulmonary embolism), leading to shortness of breath, chest pain, and even death.
IVC filters are used in about 1/3 of patients who undergo catheter-directed thrombolysis for DVT. The small, wire devices look like cages and are designed to intercept traveling blood clots before they reach the heart and lungs. However, insertion of IVC filters following DVT catheter procedures is controversial, as there is little in the way of long-term data to support their use.
The authors of this study, which appears in the July 23rd issue of JACC: Cardiovascular Interventions, identified more than 138,000 patients from the National Inpatient Sample (NIS) database who had been treated in the hospital for proximal or caval DVT between 2005 and 2013. The dataset included 7,119 patients who had undergone catheter-directed thrombolysis, including 2,421 who received an IVC filter.
The analysis found:
“Practicing physicians treating patients should be very, very careful putting these IVC filters in because for the vast majority of patients they are unnecessary,” the study’s lead author said in an interview with TCTMD. “We don’t think there is a strong reason for us to be putting them in unless the patient is actively bleeding.”
IVC filters were controversial long before the publication of this study.
In 2010, for example, the U.S. Food & Drug Administration (FDA) warned that its adverse event database had logged more than 900 IVC filter complication reports, including incidents of migration, filter fracture, and embolization, as well as cases where pieces of an IVC filter perforated organs and blood vessels. Among other things, the agency expressed concerns that retrievable IVC filters weren’t being removed in a timely manner.
In May 2014, the FDA issued a second alert to remind doctors of the importance of IVC filter retrieval.
More than 8,000 people across the United States have filed IVC filter lawsuits against C.R. Bard, Inc. and Cook Medical, Inc. over injuries and complications that allegedly resulted from the malfunction of a retrievable blood clot filter.
Federally-filed claims involving Bard’s products have been consolidated in the U.S. District Court, District of Arizona. The litigation’s first bellwether trial concluded in March, after a jury awarded $3.6 million to a recipient of Bard’s G2 IVC filter.
C.R. Bard won the second bellwether trial in May. The IVC filter lawsuit selected for the proceeding’s third trial was dismissed earlier this month, after a judge found that the plaintiff had waited too long to file the case.
Federally-filed IVC filter lawsuits involving Cook Medical’s devices are centralized in the U.S. District Court, Southern District of Indiana. The company won the litigation’s first bellwether trial in November 2017, while the second bellwether case was dismissed 4 months later.
In May, a Texas state court jury awarded $1.2 million to firefighter who suffered serious complications after a Cook Celect filter tilted, migrated, and perforated his aorta and duodenum.