An IVC filter is a small metal device that can stop blood clots in your veins from moving. It’s used for conditions in which there’s a chance that a blood clot could enter your lungs, such as deep vein thrombosis (DVT). It’s placed in your body’s main vein, called the inferior vena cava (IVC). This vein runs through your belly. It sends blood from the lower half of your body back to the heart. A doctor inserts the filter during a short surgery.
How Are IVC Filters Used for DVT?
DVT happens when a blood clot forms in a vein deep within your body, usually in the leg. In some cases, this clot breaks off and travels to your heart and lungs. It can block a blood vessel in the lung. This dangerous condition is called a pulmonary embolism. It can lead to chest pain, shortness of breath, and death.
If you have DVT, your doctor may recommend an IVC filter. These devices look like tiny upside-down umbrella frames. Blood from the lower half of your body must pass through the filter to reach your heart and lungs. It traps blood clots before they cause a pulmonary embolism.
An IVC filter is only used to prevent pulmonary embolisms. It doesn’t protect against DVT, or treat the condition itself.
Who Gets an IVC Filter?
Not everyone who has DVT needs an IVC filter. Doctors usually prescribe other treatments first. The most common are blood thinners, also called anticoagulants. They’re given as pills or shots. They help prevent clots from forming.
But some people can’t take blood thinners. They may have another condition that gets worse because of the drugs. If you have DVT along with one of these issues, your doctor may recommend an IVC filter:
- Hemorrhagic, or bleeding, stroke
- Bleeding in your digestive tract. Many things can cause this, including tumors, ulcers, inflammatory bowel disease, and more.
- Malignant hypertension, or very high blood pressure
- Bleeding in your brain because of a fall or accident
- Recent brain, eye, or spinal cord surgery
IVC filters are also sometimes recommended for these reasons:
- Blood thinner failure: These drugs don’t work for some people.
- Circulation problems, which your doctor might call hemodynamic instability
- Serious injuries to your spinal cord or other organs: They can raise your risk for blood clots.
- Blood clots that move from place to place (mobile thrombus)
- DVT in your inferior vena cava and iliac veins: These are the veins that run from your heart down to your lower body and pelvis.
Who Shouldn’t Get an IVC Filter?
If you have DVT and you take blood thinners to prevent clotting, you don’t need to get an IVC filter. You should avoid the device if you have:
- A too-small inferior vena cava vein
- Bacteria in the blood or sepsis, a dangerous condition caused when your body reacts to an infection
- Blood clotting problems
- A blood clot that clogs the entire vena cava vein
How Do You Get an IVC Filter?
In most cases, the procedure to insert a filter takes around an hour. You’ll go home on the same day.
Before the surgery, you’ll likely get blood tests. If you have kidney issues, the doctor will prescribe a medicine to protect them. They’ll also give you instructions on how to take your medications, including blood thinners and diabetes drugs. You can’t eat or drink in the hours before the procedure.
In the hospital, the doctor will put a medication that makes you feel sleepy and relaxed into a vein in your arm. You’ll also receive a shot to numb the area at the base of your neck or near your groin. This is where the doctor will make a small cut and insert a thin, flexible plastic tube called a catheter into your vein.
Your doctor will use X-rays to see inside your body. They may put special dye, called contrast media, into the tube. This helps them better see your IVC. Then they’ll use the catheter to thread the filter into place into the vein. The IVC filter will expand and attach to the walls of the vein.
After the surgery, you’ll spend time in the recovery room. Your doctor will watch over you. You may need pain medicine. When it’s time to go home, you’ll need a friend or family member to drive you.
What Are the Risks?
For the most part, IVC filters appear to be safe. Serious problems happen in less than 1% of cases, but other issues are more common.
The risks and complications of IVC filters include:
- Bleeding: In up to 15% of cases, there’s bleeding at the vein where the doctor inserts the catheter.
- Problems placing the filter: If it’s put in the wrong part of the vein or at an incorrect angle, your doctor may need to do the surgery again.
- The filter moves or breaks: It may travel to your heart or lungs, which can lead to injury or even death. You’ll need surgery to remove it.
- Infection: As with all surgeries, there’s a risk of an infection.
- The filter breaks the vein: It may pierce the inferior vena cava walls. This can damage one of the nearby organs.
- Blood flow blockage: The filter may slow or stop the blood flow in the inferior vena cava. This may cause your legs to swell.
- DVT: Although IVC filters protect against pulmonary embolisms, they may lead to DVT. One study found that they raised the risk of DVT by 40%.
How Long Do IVC Filters Last?
There are two types of IVC filters: One stays in your body permanently. The other is designed to be removed. Your doctor may use a removable IVC filter if there’s a chance that your risk of a pulmonary embolism risk will drop. For example, you may be able to start taking blood thinners.
Your doctor will take out a removable filter in a short surgery. It’s much like the one used to insert the IVC filter. In some cases, your doctor won’t be able to remove it. Reasons include:
- Tissue in your veins may grow around the filter. This can cause it to become stuck.
- It’s filled with large blood clots.
If this happens, the IVC filter will remain in your body for the rest of your life. In most cases, this doesn’t lead to any issues.