The vena cava is the largest vein in the body and receives blood from the body and takes it directly back toward the heart. The inferior vena cava specifically receives blood from the lower half of the body. Inferior vena cava filters, also called IVC filters are a specialized device that is surgically placed within the inferior vena cava, either in the abdomen or pelvis.
"In the past, IVC filters were permanent, but due to the concern of the eventual clogging of the vena cava, IVC filters are now used for only a short duration." - Dr. Almeida
DVT and IVC Filters
Deep vein thrombosis, or DVT, is the formation of blood clots within the deep veins in the legs. There are multiple risk factors for the development of DVTs including obesity, sedentary lifestyle, recent surgery, long airline flight or car ride, and conditions that cause the blood to be thicker, such as Factor V Leiden Disorder. DVTs typically cause symptoms of swelling, pain, and redness in the affected leg.
Although DVTs can occur in the arms, this is rare and they are typically found in the legs, usually only on one side. DVTs can either be acute or chronic. With chronic DVTs, the clot sits within the vein, causing scarring with swelling and eventual ulceration of the leg, which is known as post-thrombotic syndrome. With acute DVTs, the clot increases in size and eventually can break off from the vein and travel through the veins to the lungs, where it lodges within the pulmonary veins causing a pulmonary embolism, or PE. Pulmonary embolisms can be fatal, which is why treatment of DVTs is necessary.
An initial treatment for DVTs is anticoagulation, which is a group of specialized medication used to reduce the size of the clot to prevent both PE and post-thrombotic syndrome. In some cases, more aggressive treatment is necessary with the use of an IVC filter, such as patients that are unable to take anticoagulation due to other medical conditions or recent procedures, or those who are on appropriate doses of anticoagulation and still form blood clots.
What does an IVC Filter do & how does it work?
An IVC filter is a metal mesh device that is placed within the vena cava in order to trap clots and prevent them from traveling to the lungs. In the past, IVC filters were permanent, but due to the concern of the eventual clogging of the vena cava, IVC filters are now used for only a short duration. Due to their use in the past for long duration, there are a lot of people that may still have an IVC filter in place. This is because the filters more recently have been used as a way to prevent any pulmonary embolism in patients having surgery, such as bariatric surgery. As no clots were present and it was to prevent pulmonary embolism, these filters have been left in place in people for several years. It is not until it causes a problem that the IVC filter is addressed.
Symptoms of a Clogged IVC Filter
Those with an occluded vena cava filter will begin to have problems, such as increased swelling in the legs and damage in the legs due to the increase in blood volume and pressure within the veins in the legs. As there is less blood flow toward the heart, many patients also experience fatigue.
How to Treat / Replace a Clogged IVC Filter
Surgical intervention is necessary to address the clogged IVC filter. There are different filters available and depending on the type of filter, will determine the ease of removal. The filter is usually removed via endovascular catheter-based techniques - but sometimes it must be removed surgically and the vena cava must be repaired, along with opening of some of the veins that feed into the vena cava to move blood from the legs, back toward the heart.
Based on the duration of time that the IVC filter has been in place, there are other complications that may occur, such as fracturing of the filter, which is a breakdown of the filter and even erosion of the filter into nearby organs, that may make the removal more difficult.
What to do if you an Old or Potentially Clogged IVC Filter
If you have an IVC filter that has been present for many years, it is important to find a surgeon that is skilled to remove this type of filter in order to have it removed before symptoms develop or before complications arise from the IVC filter. If there has been discussion of placing an IVC filter, please be sure to understand the reasons behind the placement and when there are intentions for removal to prevent clogging or other complications.