About IVC filters

An IVC is a small metal filter, shaped like the spokes of an umbrella.

We place it in the large vein that drains blood from your pelvis and legs back to your heart. This vein is known as the inferior vena cava (IVC).

Why we offer IVC filter insertion

If there are blood clots in your pelvic or leg veins (known as deep vein thrombosis or DVT), these clots can break free and get swept along in your blood flow.  They can travel up through your IVC and heart to lodge in the vessels supplying your lungs. This is known as pulmonary embolism (PE) and it is a serious, potentially fatal condition.

An IVC filter is designed to stop this happening.

Generally, we treat DVT and PE with blood thinning medicines called anti coagulants.  These help your body dissolve away the clots. This treatment may not be appropriate in the following situations:

  • Some patients cannot take blood thinning medicines as they may be at risk of serious bleeding.
  • Some patients may have tried anti coagulants, but they failed to work satisfactorily.

In these situations, we use an IVC filter to trap any moving clots and hold them in the IVC which stops them from reaching the patient's heart and lungs.

Why you need an IVC filter insertion

The consultant in charge of your case and your interventional radiologist feel this is the best treatment option for you.  Other experts, including a haematologist (who specialises in disorders of the blood) and a vascular surgeon (who specialises in arteries and veins) may also have contributed to the decision.

Your doctors will discuss their recommendation with you and they will take your opinion into account. You will have the chance to ask questions.  If, after discussion with your doctors, you do not want us to carry out the procedure, you can decide against it.

We will only go ahead with this procedure after you have given us your written consent.

Who performs the procedure and where it takes place

Your procedure will be performed by a consultant interventional radiologist. This is a doctor who specialises in performing percutaneous (through the skin) procedures under imaging guidance.  They are experienced in manipulating equipment remotely from outside the body, using X ray and scanning equipment.  They use images on screen to guide the procedure and move the IVC filter into the correct place.

We will perform the procedure in the Interventional Screening Room, part of the Kingston Hospital Radiology Department.

Preparing for your procedure

If you are an inpatient, to prepare for the procedure, do the following.

  • You can take sips of water up to 2 hours before the procedure.
  • You can take your normal medicines up until the procedure.

If you are an outpatient, do the following.

  • You can take sips of water up to 2 hours before the procedure.
  • You can take your normal medicines up until the procedure.
  • When you receive your appointment letter, tell the Interventional Radiology Unit if you have previously had allergies to foods, medicines or intravenous contrast medium (the dye used for kidney X rays and CT scans).
  • When you receive your appointment letter, tell the Interventional Radiology Unit if you have been on blood thinning tablets such as warfarin, aspirin or clopidogrel.

If you are an outpatient

You must have a responsible adult go home with you.
You must also have a responsible adult to stay with you for 24 hours (including overnight).

On the day of the procedure you can expect the following.

We will introduce you to the consultant interventional radiologist who will answer any questions. 

  • We will ask you to change into a hospital gown and lie on the X ray table.
  • We will make sure you are as comfortable as possible before continuing. We will wrap a cuff around your arm to monitor your blood pressure and put a clip on your finger to measure your pulse and breathing.
  • We will place an intravenous cannula (a small flexible tube with a needle on the end) in a vein on your arm to give you medicines you might need.
  • The radiologist may perform a further ultrasound scan if necessary.
  • Usually we insert the IVC filter from the right groin but we can also insert it from the left groin or neck.
  • We will clean the skin with antiseptic solution at the insertion point and inject local anaesthetic to make it go numb. The radiologist will pass a long thin wire into your vein, through this numb patch, via a needle. This wire maintains a route into your vein from the outside and we use it as a guide to slide the IVC filter into position.
  • When the radiologist is satisfied with the position of the filter, they will release it the wire and the delivery system.  They will apply pressure to your skin at the needle entry point for a few minutes, to prevent any bleeding.

How long it takes

Every patient’s situation is different, but you can expect to be in the room for approximately 1 hour.

Pain

When we anaesthetise your skin and deeper tissues with local anaesthetic, this will sting for a few seconds, after which the area will go numb. The procedure is likely to be almost pain free.

A nurse or another member of clinical staff will stand next to you and look after you. If the procedure does become uncomfortable for you, they can arrange for you to have painkillers through a needle in your arm, directly into your blood stream.

After the procedure

We will transfer you back to your ward [Amanda: if they are outpatient do they go to Radiology Recovery Ward?]. It is important that you remain comfortable and lie quietly in bed for a few hours until you have recovered. Your nurse will monitor your pulse, blood pressure and breathing, to ensure you are recovering as expected.

You must take it easy for the next few days and avoid any unnecessary straining or lifting.

Risks

IVC filter insertion is usually a straightforward, safe procedure, but there are some possible risks and complications. These include the following.

  • The most serious risk is the filter itself slipping out of position and ending up in your heart.  This can happen if your inferior vena cava (IVC) is particularly wide and prevents the spring-loaded legs of the filter to gain a satisfactory grip. The radiologist will check the filter is a suitable fit before finally inserting it.
  • Sudden movements and excessive straining (for example, whilst opening your bowels) can cause the filter to move within the first few days after insertion. This is rare, but you must avoid sudden movements and excessive straining. After a few days, the filter legs bed down into your body and the filter position becomes more stable.
  • Blood clots can become trapped within the IVC, blocking the IVC and causing pressure on your back and swelling of both legs. This is rare and happens to about 1 in 20 patients. This means the filter is doing its job.  It is better for clots to form a blockage in the IVC, instead of forming them in your heart and lungs. We may put you on a small dose of blood thinning tablets to help prevent this.
  • You may have an unusual arrangement of veins which provides an alternative route for clots to get to the heart, bypassing the IVC. This is rare.
  • An IVC filter does not completely protect you against pulmonary embolism.  Small blood clots can sometimes pass through the filter.

Despite these risks, IVC insertion is an important part of the overall health management for some patients who are at risk of life-threatening pulmonary embolism.

If you have concerns or questions about this procedure, you can discuss these with your medical team and your interventional radiologist at any time.

How long the IVC filter stays in place

For many patients, we leave the filter in place permanently.

For some patients it is more appropriate for us to remove the filter after a few weeks. This is more likely to apply to younger patients for are temporarily at risk of pulmonary embolism.

Your doctors will discuss the best option with you.

Even if your IVC filter stays in, we will try to keep you on a small dose of blood thinning tablets for the rest of your life.  This will help prevent further clots developing.

Contact information

Interventional Radiology Unit
 

Interventional Radiology Unit Charge Nurse​​​​​​​

Telephone:

Interventional Radiology Unit: 020 8934 6206

Interventional Radiology Unit Charge Nurse: 020 8934 2758