IVCF: implants that kill

12 March 2018 (Last Updated March 12th, 2018 12:02)

IVCFs, or inferior vena cava filters, are a medical device that is implanted into the vena cava of a patient who is at a high risk of developing a pulmonary embolism (PE), a blood clot travelling to the lungs and causing damage or destroying lung tissue.

IVCF: implants that kill
Currently, there are two types of IVCFs, retrievable and permanent IVCFs. Credit: Courtesy of BozMo

IVCFs, or inferior vena cava filters, are a medical device that is implanted into the vena cava of a patient who is at a high risk of developing a pulmonary embolism (PE), a blood clot travelling to the lungs and causing damage or destroying lung tissue. This means that IVCFs can be implanted as a primary solution in patients who are suffering from vascular diseases, or as a PE prevention measure in patients who are being treated for other indications where the treatment raises their risk for PE, such as transcatheter aortic valve implantation (TAVI) or other implants in the vasculature.

Currently, there are two types of IVCFs, retrievable and permanent IVCFs. Permanent IVCFs are meant to stay in the patient’s body for the remainder of their lives, providing constant PE protection. Retrievable IVCFs are implanted in patients with a transient need for PE protection. They need to be removed after several months, after the threat of developing a PE has passed. However, in practice, they are often ignored and forgotten about. This results in a large population of patients with retrievable IVCFs permanently implanted in them, with very little chance of removal. This is due in large part to a lack of proper clinical tracking of which patients these devices are implanted in, as well as a failure to develop a reminder system for clinicians to track down previously treated patients.

Unfortunately, a retrievable IVCF left permanently in a patient can potentially result in a lot of health complications for the patient. Possible complications include IVCF migration, IVCF components detaching and causing emboli themselves, piercing of the wall of the vena cava resulting in internal bleeding, and more. These are very nasty complications that, if unexpected, can cause serious harm or death to the patient.

To curb this problem, the FDA has laid down a directive stating that all implanting physicians are responsible for tracking and removing any retrievable IVCFs, which has resulted in highly improved retrieval rates. While this is good news for newer patients, older patients from before the era of IVCF tracking may still have something to fear.