Vena cava filters associated with device fracture, embolization that may cause life-threatening complications

Nicholson W. Arch Intern Med. 2010;doi:10.1001/archinternmed.2010.316.

Recently published data suggesting that Bard’s Recovery and G2 vena cava filters are associated with an increased incidence of fracture and embolization has resulted in the FDA’s initiation of quantitative decision analysis modeling to assess the devices’ post-implantation risk/benefit profiles.

Since 2005, 921 adverse events involving inferior vena cava filters have been reported to the FDA. Of these, 328 involved device migration, 146 involved embolization, 70 involved perforation of the device and 56 involved filter fracture. Based on these reports and the current data, the FDA is concerned that these filters, which are intended for short-term use, are left in too long after the risk for pulmonary embolism is gone.

In the current study, researchers conducted a retrospective, single-center, cross-sectional study that included 80 patients who underwent inferior vena cava implantation between 2004 and 2009. Fluoroscopy was performed to assess the filter’s integrity and locate embolized struts. Patients with fragment embolization to the heart underwent echocardiography and cardiac CT.

Sixteen percent of patients had at least one nitinol arm or leg fracture, and the average time from implantation to evaluation was 37.8 months.

Of the 28 Recovery filters placed, at least one in seven (25%) fractured and embolized, and at least one fragment embolized to the right ventricle of the heart in five of the seven cases (71%). Three patients experienced life-threatening symptoms of ventricular tachycardia and/or tamponade; one of these patients experienced sudden death at home, according to the researchers. Overall, 86% of those who received the Recovery filter had a fragment embolize to the right ventricle of the heart or continue moving throughout the venous system through the heart and into the pulmonary arteries.

Although the prevalence of fracture and embolization was not as high for the G2 filters, it was still significant. Of the 52 G2 filters placed, six fractured (12%); two of these cases involved asymptomatic end-organ fragment embolization to the hepatic vein and the lung.

“It is essential that patients and their treating physicians be educated about this previously under-recognized and potentially life-threatening complication of these devices,” the researchers wrote. “Armed with this knowledge, educated patients can be alert to the presence of pleuritic chest pain and other symptoms that should prompt immediate evaluation. Such early awareness and evaluation could certainly be life-saving. In addition, the propensity for filter fragmentation may be directly related to the duration of implantation. Patients and their physicians should be educated about this fact so that they have the opportunity to consider having the filter removed.”

Currently, the FDA recommends that physicians consider removing inferior vena cava filters as soon as protection from pulmonary embolism is no longer needed. In addition, physicians are encouraged to weigh the risks and benefits of filter removal for each patient.

Follow CardiologyToday.com on Twitter.