An inferior vena cava (IVC) filter is a small device that can stop blood clots from going up into the lungs. The inferior vena cava is a large vein in the middle of your body. The device is put in during a short surgery.

Veins are the blood vessels that bring oxygen-poor blood and waste products back to the heart. Arteries are the blood vessels that bring oxygen-rich blood and nutrients to the body. A deep vein thrombosis (DVT) is a blood clot that forms in a vein deep inside the body. A clot occurs when blood thickens and clumps together. In most cases, this clot forms inside one of the deep veins of the thigh or lower leg.

The veins in your legs have tiny valves that help keep blood moving back up toward the heart. But a DVT may damage one or more of these valves. This causes them to weaken or become leaky. When this happens, blood starts to collect in your legs. This can also happen if you are immobile for a long time. Normally, muscles in the leg help blood move up in the veins when the muscles contract. When blood flows very slowly through the veins, this increases the risk that cells in the blood will stick together and form a clot.

DVT is a serious medical condition that can cause swelling, pain, and soreness in your leg. In some cases, a deep clot in a leg vein can break free and move through the blood to the lungs. This can cause a blockage in the vessel called a pulmonary embolism. Pulmonary embolism can cause severe shortness of breath and even sudden death.

An IVC filter is one method to help prevent pulmonary embolism. Your inferior vena cava (IVC) is the major vein that brings oxygen-poor blood from the lower body back to the heart. The heart then pumps the blood to the lungs to pick up oxygen. An IVC filter is a small, wiry device. When the filter is placed in your IVC, the blood flows past the filter. The filter catches blood clots and stops them from moving up to the heart and lungs. This helps to prevent a pulmonary embolism.

The IVC filter is placed through a small cut (incision) in a vein in your groin or neck. A thin, flexible tube (catheter) is inserted into this vein. The catheter is then gently moved into your IVC. A collapsed IVC filter is sent with the catheter. The filter is left in place, and the catheter is removed. The filter then expands and attaches itself to the walls of the IVC. It may be left in place permanently. In some cases, it may be removed after a period of time.

It's important to understand that an IVC filter does not protect against DVT. You may still get a DVT. The filter helps to protect you from a life-threatening pulmonary embolism if you have a DVT.

You might need an IVC filter if you have a DVT or pulmonary embolism now, or had either of these in the past. You might need an IVC filter if you have a high risk of getting a DVT. Anything that slows the movement of blood through your veins increases your risk of DVT. A variety of conditions can increase your chance of getting a DVT, such as:

• Recent surgery, which decreases your mobility and increases inflammation in the body, which can lead to clotting
• Health conditions that limit your mobility, such as an injury or stroke
• Long periods of travel, which limit your mobility
• Injury to a deep vein in the leg
• Inherited blood disorders that increase clotting
• Pregnancy
• Cancer treatment
• Smoking
• Obesity
• Older age

A blood-thinning medicine such as warfarin is also used to treat people who are at risk of pulmonary embolism. Blood thinners may be used alone to prevent pulmonary embolism. But in some cases, they may be used along with the IVC filter.

However, some people have conditions that make this kind of medicine unsafe for them. They may have dangerous bleeding when taking blood thinners. This may include someone who has bleeding in the brain from an injury or fall. Or someone who has bleeding in the digestive tract. Excess bleeding in these areas can be life-threatening. In these cases, your doctor may instead advise an IVC filter alone to protect against pulmonary embolism.

All procedures have risks. The risks of this procedure include:

• Infection.
• Excess bleeding.
• An allergic reaction.
• Damage to the blood vessel at the insertion site.
• The blockage of blood flow through the vena cava, which can cause leg swelling.
• A filter that travels to the heart or lungs, causing injury or death.
• A filter that pierces through the inferior vena cava, causing pain or damage to other organs.
• A problem with the placement of the filter.
• The continued risk of a blood clot that travels to the lungs.
• Death.

Your risks may vary based on your overall health, the severity of your condition, and other factors. Ask your doctor about which risks apply most to you.

Talk with your doctor about how to prepare for your surgery.

• Your doctor will explain the procedure to you. Ask any questions you may have.
• You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if anything is not clear.
• Talk with your doctor about the type of IVC filter that you will have. Some filters can be taken out when your risk of DVT is lower. Others are meant to stay in your IVC permanently.
• Tell your doctor about all the medicines you take. This includes over-the-counter medicines such as aspirin and all prescription medicines. It also includes herbs, vitamins, and other supplements. You may need to stop taking some medicines before the surgery, such as blood thinners.
• If you smoke, you'll need to stop before your surgery. Smoking can delay healing. Talk with your doctor if you need help to stop smoking.
• Follow all directions you are given for not eating or drinking before your surgery.

Before the procedure, make sure to tell the health care team if you:

• Have any allergies.
• Have had any recent changes in your health, such as a fever.
• Are pregnant or think you might be pregnant.
• Have ever had a problem with sedation.

Follow any other instructions from your doctor.

Talk with your doctor about what to expect during your procedure. It usually takes about 1 hour. The procedure is done by an interventional radiologist and a team of specialized nurses. A typical procedure may go like this:

1. An I.V. (intravenous) line will be put in your arm or hand before the procedure starts. You'll be given sedation through the I.V. line. This will make you relaxed and sleepy during the procedure.
2. Hair in the area of your procedure may be removed. The area may be numbed with a local anesthesia.
3. Your doctor will make a small incision in this region to access a major vein leading to the IVC.
4. A long thin tube (catheter) will be inserted into this vein.
5. Using continuous X-rays (fluoroscopy), this tube will be moved up into the IVC. X-ray dye (contrast material) may be sent through into the catheter. This helps show the IVC clearly on the X-rays.
6. Your doctor will release the filter into the IVC. Here the filter will expand and attach itself to the walls of your IVC.
7. The catheter will be removed.
8. The incision on your neck or groin will be closed and bandaged.

After the procedure, you will spend a few hours in a post-anesthesia care unit (PACU). You may be sleepy and confused when you wake up. Your health care team will watch your vital signs, such as your heart rate, blood pressure and breathing. You'll be given pain medicine if you need it. You may have a headache or nausea, but these should go away quickly.

You may be able to go home the same day. Your doctor will tell you more about what to expect. When you're ready to go home, you will need to have a family member or friend drive you.

You may have some pain after the procedure. You may notice a bruise where the catheter was inserted. You can take over-the-counter pain medicines if you need to as prescribed. Get some rest and don't do strenuous exercise for at least 24 hours.

Contact your doctor right away or get medical care right away if you have any of these:

• Coldness or numbness in one of your limbs
• Bleeding at the site that doesn't stop with pressure
• Swelling or pain at the incision site that gets worse
• Fluid leaking from the incision site
• Redness or warmth at the incision site
• Fever
• Chest pain
• Headache or nausea that doesn't go away

Follow all of your doctor's instructions. This includes any advice about medicines, exercise, and wound care. Your doctor may prescribe blood-thinner medicine to help prevent blood clots.

You will need continued monitoring after your treatment. You may need follow-up imaging tests to make sure your filter is still in the correct location. If you have the type of IVC filter that can be removed, you may have a similar procedure in the future to remove the filter. This may be done after your risk of DVT has decreased. In some cases, a removable filter is left in place. This may happen if scar tissue grows around the filter and it cannot be removed.

Before you agree to the test or the procedure, make sure you know:

• The name of the test or procedure.
• The reason you are having the test or procedure.
• What results to expect and what they mean.
• The risks and benefits of the test or procedure.
• What the possible side effects or complications are.
• When and where you are to have the test or procedure.
• Who will do the test or procedure and what that person's qualifications are.
• What would happen if you did not have the test or procedure.
• Any alternative tests or procedures to think about.
• When and how you will get the results.
• Who to call after the test or procedure if you have questions or problems.
• How much you will have to pay for the test or procedure.