Why do I need a filter?
Blood clots that develop in the veins of your legs or pelvis may break up and large pieces can travel to the lungs causing so-called pulmonary thrombo-embolism. It may result in severe damage of the lungs, pressure on your heart and even death. The purpose of the filter is to trap large fragments and prevent them from travelling to the lungs. The filter will be retrieved when your doctors decide that there is no more danger of clot propagation.
What will happen?
The procedure can be done on an outpatient basis. However, in most cases, venous thrombosis is a complex health condition, which necessitates hospitalization. You will be brought to the Interventional Radiology Suite where the interventional radiologist (a doctor specially trained in these procedures) and radiographer will explain the procedure and answer your questions. The intervention usually takes about 60 minutes. After completion, you will be monitored for 2-3 hours for possible complications or if admitted, transferred to your ward.
Do I need any blood results?
We will need to give you contrast (X-ray dye), so you should discuss any allergy history (particularly to Iodine) with the radiologist prior to booking a procedure.
You will need to have your U&E checked to assess if your kidneys can handle the contrast.
The vena cava filter placement
The procedure is similar to general angiographv.
No sedation is usually required. Under ultrasound guidance and local anesthetic, a tiny incision will be made in your groin or neck and a small soft tube (catheter) will be introduced into the vein. Contrast (X-ray dye) will be injected and series of X-rays will demonstrate inferior vena cava and identify the best spot for the filter placement. Filter delivery system will be advanced to that level and the filter will be deployed.
The procedure of filter retrieval is practically identical.
What will I feel? Does it hurt?
You will feel a bee sting when the doctor numbs the entry site. You may feel slight pressure when the delivery device is inserted in your vein, but most patients feel little or no discomfort during the procedure.
What are the risks?
The possibility of bleeding or damage of your vein is minimized by the used of ultrasound guidance.
The chance that the filter may break loose and dislodge into the heart or lung is minimal and is avoided by the careful assessment of the size of inferior vena cava and most appropriate lending zone. Follow up abdominal radiograph in 24 hours time will confirm that the filter is stable.
Very seldom, the filter may get clogged with clots resulting in swelling of the legs.
The risk of infection is very low.
When will I get my results?
The radiologist will be able to talk to you after the procedure.
When will I resume my normal activities?
This will depend on your general health condition and the interventional radiologist and your attending physician will give you proper advice.
When will the filter be removed?
It will also depend on your general condition and particularly on the results of the treatment of legs or pelvic clots. Newly manufactured filters can stay in your vein for a couple of months. Sometimes the your doctors may decide that it is unsafe to remove it, in which case it will be converted into a permanent one.