What is IVC Filter?IVC filter insertion is a medical technique which involves placing the filter into inferior vena cava to avoid the formation of blood clots in the pelvic area or legs which pass to the lungs. A small thin catheter and a needle are placed in the neck or groin area for inserting a filter. Inferior vena cava filter is a 25mm long tool, also called vascular filter, used for preventing pulmonary embolism or blockage in the artery in the lungs. It is considered effective if anticoagulation fails.
IVC filter typesIVC filters are broadly two types namely permanent filters and temporary retrievable filters. Permanent filters were in use since the 1970s, they are mostly used in patients who require defensive mechanisms against pulmonary emboli for a long time. Whereas retrievable filters came into use in the 1990s and applied with the purpose of hindering the flow of blood clots temporarily. Temporary filters strike out possibilities of developing complications frequent in permanent filters. These complications include inferior vena cava occlusion or stenosis, embolization filtering and high-risk DVT. Optional filters increased the rate of insertion to a great extent. Optional filters are widely used in case of prophylactic indications which envelopes a high risk of trauma. Benefits of optional filters- During pregnancy chances of developing VTE are considerably high as compared to other patients. The first phase of pregnancy is associated with hypercoagulability. In the third phase, the uterus causes altered flow through iliac veins and inferior vena cava which further increases the risk of VTE. Anticoagulation can lead to hemorrhage. This proves optional filters a better and safe procedure as compared to permanent filters. Permanent filters are also not used in pediatric patients. In patients with bariatric surgery, there is a chance of VTE development because of endothelial and immobility injury. According to a study, VTE is the leading cause of death only after sepsis from anastomotic leakage in patients going through bariatric surgery. This condition makes optional or retrievable filters highly preferred.
Greenfield filter placementGreenfield filter is a type of IVC filter which captures blood clot in the vessels. It has been a widely used device for almost 30 years now. It is a small device with stainless steel. This filter is in the shape of a cone having six legs from the base. These legs consist of small hooks which help during insertion and with stability. This filter encourages the flow of blood around the tool. It hinders the flow of blood clots by capturing them through its widely spread legs. Greenfield filters are usually placed near the kidney to capture the flow of blood clots along the veins. However, Greenfield filter insertion is not in use due to severe side effects in some patients.
IVC filter placement indicationsTypes of IVC filter indications are relative indications, prophylactic indications, absolute indications and other indications.
- Prophylactic indications- in case of a high chance of bleeding, anticoagulation is not preferred. It indicates the application of IVC filters. If conditions of trauma or other surgical or medical treatment are present then IVC filter is recommended.
- Absolute indications- usually, IVC is recommended by patients to reduce the risk of pulmonary embolism. Anticoagulation therapy may cause venous thromboembolism or complications despite proper treatment.
- Relative indications- there are certain benefits in opting IVC filter above other surgeries like less risk of complication after surgery, stable procedure and medicines prescribed after treatment are very effective, no freely flowing proximal DVTs and thrombolysis that is no emboli present in the iliac area.
- Other indications- these indications include a reduction in risks of obesity, complications if weight controlling surgery is done, insufficiency of the chronic venous system, and hypercoagulable state.
IVC insertion techniqueInferior vena cava filters are inserted through blood vessels. Earlier, inferior vena cava filters are inserted through the surgical procedure but with advancement, filters are redesigned as thin catheters. These catheters provide easy access to the venous system through the veins in the arms, a large vein in the neck that is an internal jugular vein or the femoral vein, the large vein of the groin. The path of insertion depends on the amount and location of a blood clot in the system. With the help of fluoroscopy, a catheter is guided through the inferior vena cava. Then filter and catheter are pressed towards each other and adjusted at the required position. The common site of insertion is the lowest renal vein and inferior vena cava junction. Before extending a filter to check for thrombi in the inferior vena cava, stenoses areas, a diameter of inferior vena cava and potential variations of anatomy, venogram or cross-sectional imaging is performed. In the case of immobility of a patient, chronic disease of kidney and contrast allergy placement with the help of ultrasound is recommended. The type of filter to be inserted depends on the size of the inferior vena cava. In some cases like gonadal vein thrombosis and pregnant patients, a filter is fixed above renal veins. Another case involves the placement of a filter either between two inferior vena caves or a separate filter in each inferior vena cava if duplication of IVC occurs. Removal of filters- the removal procedure was first performed in 1967. However, retrievable filters were approved by the United States Food and drug administration in 2003 and 2004. Temporary filters are placed with the help of a device which makes their retrieval easy. It is removed from the body by pulling out in a catheter, generally through the internal jugular vein. Initially, the removal of filters considered suitable within three weeks to avoid injury to the inferior vena cava. Now, it is safe to leave the filter for at least one year before retrieval. These filters constitute tulip, bard G2 and G2x, celect, ALN and option filters.
Risks of IVC insertionSome complications are blood clot at the operated site, allergy to drugs injected; damage to adjacent organs, blood vessels and muscles, swelling in legs and it may be inefficient in filtering out small blood clots which travel to lungs without obstruction. The risk from anesthesia includes nausea, vomiting, weakness, dizziness, low blood pressure, worsening of previous medical conditions, other lung problems like pneumonia, stroke, heart attack and brain damage. Few rare risks are cardiac arrest; x-rays may lead to cancer and displacement of IVC filter which needs another surgery to be treated or for removal.
Recovery time for IVC filter insertionImmediate recovery for a few hours is necessary to overcome the effect of anesthesia. One to two days rest must be provided for faster recovery and to avoid any strain on the area. Total recovery takes 5 to 6 days before the patient returns to work. Drinking water is necessary for clearing the dye used in the process. Consult a doctor if bleeding or redness, swelling, increasing tenderness, and fever is spotted.
Indications for removing IVC insertionThere is no need for a permanent filter and it can be removed after 24 to 54 days, if anticoagulation is working properly then removal of temporary treatment is preferred, life expectancy is more and temporary detached is acceptable, no risk of developing pulmonary emboli in near future and if there is no risk of tear, complications or trauma then removal can be done.
• the abrupt onset of ascites
• fluid retention below the diaphragm with edema of the lower extremity
• Proteinuria can be associated with these symptoms.
The blood clots of deep vein thrombosis can be caused by anything that prevents your blood from circulating or clotting normally, such as injury to a vein, surgery, certain medications and limited movement.
What is IVC filter insertion cost?
The cost of IVC filter insertion ranges from $2,246 to $5,234. Retrieval of filters can cost more along with other hospital formalities such as medications and injections. This cost differs depending on hospital facilities and several clinic visits. However, insurance cover can help with cost reduction.
How long does the IVC filter insertion take place?
The procedure takes almost 30 minutes or 1 hour to complete. Preparation for surgery takes a few hours and recovery is 2-3 weeks long. However, an overnight stay is recommended in the hospital before surgery.
What are the side effects of IVC filter insertion?
Common side effects of IVC filter insertion are bruising or bleeding from the area, infections mostly from IV cannula which requires antibiotics for treatment, infection from anaesthesia and temporary nerve damage.
How to prepare for IVC filter insertion?
Avoiding all previous medications are necessary, diet intake and consumption of prescribed medicines are important, do not eat anything for at least 8-10 hours and required tests should be completed beforehand.
Is IVC filter insertion painful?
No, IVC filter insertion is not painful as it is performed through the administration of anaesthesia to numb the pain. However, after the effect of anaesthesia lessens slight discomfort or minor pain is experienced.