Thromboembolic disease continues to be a cause of morbidity and mortality. Placing a filter in the inferior vena cava (IVC) is an important way to prevent significant pulmonary embolism (PE) arising from a deep vein thrombosis (DVT). This procedure is currently performed under radiological guidance via femoral vein or jugular vein access.
This article provides a step-by-step guide to jugular approach to insertion of retrievable Gunther Tulip or Celect IVC filters. For a comparison of retrievable and non-retrievable IVC filters.
IVC filters are placed endovascularly, meaning that they are inserted via the blood vessels. Historically, IVC filters were placed surgically, but with modern filters that can be compressed into much thinner catheters, access to the venous system can be obtained via the femoral vein (the large vein in the groin), the internal jugular vein (the large vein in the neck) or the arm veins with one design. Choice of route depends mainly on the number and location of any blood clot within the venous system. To place the filter, a catheter is guided into the IVC using fluoroscopic guidance, then the filter is pushed through the catheter and deployed into the desired location, usually just below the junction of the IVC and the lowest renal vein.
Review of prior cross-sectional imaging or a venogram of the IVC is performed before deploying the filter to assess for potential anatomic variations, thrombi within the IVC, or areas of stenoses, as well as to estimate the diameter of the IVC. Rarely, ultrasound-guided placement is preferred in the setting of contrast allergy, renal insufficiency, and when patient immobility is desired. The size of the IVC may affect which filter is deployed, as some (such as the Birds Nest) are approved to accommodate larger cavae. There are situations where the filter is placed above the renal veins (e.g. pregnant patients or women of childbearing age, renal or gonadal vein thromboses, etc.). Also, if there is duplication of the IVC, the filter is placed above the confluence of the two IVCs or a filter can be placed within each IVC.
While the ability to retrieve a filter does exist for many models, it cannot be guaranteed that all cases of filter placement will allow for, or be indicated for retrieval. Thus, the requirements and indications for permanent placement of filters is used to decide on when to use both permanent and temporary IVC filters.
Long-term risk factors must be considered as well, to include life expectancy of more than six months following insertion, and the ability of the patient to comply with anticoagulation therapy. The decision to use a filter that is temporary vs permanent basically is tied to the expected duration of time that protection is needed to prevent Pulmonary Emboli from passing to the heart and lungs. One such guideline is outlined below:
Contraindications to anticoagulation; e.g. a patient with DVT or PE who has another condition that puts them at risk of bleeding, such as a recent bleed into the brain, or a patient about to undergo major surgery
- Short Term Risk of PE/Short Term contraindication of anticoagulation: Usually merits a retrievable filter
- Uncertain Risk of PE and/or lack of control for anticoagulation: Usually results in permanent filters for long term management
- Long Term Risk of PE/Recurrent PE/Recurrent DVT: Permanent Filter
While many studies have been done on the efficacy of Vena Cava filters, there still have not been any major studies done on the actual placement and removal of the filters regarding standard guidelines. Which is why the Society of Interventional Radiology created a multidisciplinary panel that developed the following guidelines to see if someone qualifies for implantation:
These are patients that should strongly consider having IVC filter placement, as they are at greatest risk of pulmonary embolus.
- Proven VTE: Venous thromboembolism and contraindication or complication due to anticoagulation therapy
- Recurrent VTE: Despite adequate anticoagulation therapy
This is a maybe category; normally it represents patients who could benefit from an IVC filter, but may be just fine without one as well.
- Proven VTE: High risk of contraindication or complication to arise during anticoagulation therapy
- Large, free-floating proximal DVT's
- Poor Compliance: INR levels are not stable, not taking medicine as directed
- Thrombolysis: Iliocaval DVT's, which are emboli in the Iliac region
These are usually very controversial reasons to do an IVC filter, and most radiologists and doctors generally will not recommend an IVC filter if other options are available instead.
- No VTE: Anticoagulation therapy is not possible (high risk of bleeding)
- Transient risk of VTE: Trauma, surgical procedures or medical conditions
- Bariatric Patients: Undergoing surgery for weight control, only if BMI greater than 55, previous history of DVT/PE, hypercoagulable state, chronic venous insufficiency, truncal obesity or contraindication to anticoagulation therapy.
Indications for Removing IVC Filter
There is no current published data confirming the benefit of removing an IVC. Because of this, the Society of Interventional Radiology created a multidisciplinary panel that developed the following guidelines to see if someone qualifies for removal:
- No need for Permanent filter: Remove temporary
- Low risk of Significant PE: Continued anticoagulation is working, remove temporary
- No Expected Near-Term high risk PE: Continuation of anticoagulation therapy, remove temporary
- Life expectancy of more than six months: Remove temporary
- Ability to retrieve the filter: No complications, no tear probability, no trauma probability, if so, remove temporary
- Patient/Guardian agrees: Fully consented, fully informed, if so, remove temporary