Vena cava filter
Vena cava filter is an endovascular device which is typically placed in the infrarenal inferior vena cava (IVC) to prevent pulmonary embolism in selected patients. This procedure is most often performed by interventional radiologists under fluoroscopic guidance.
- contraindication to anticoagulation, eg active gastrointestinal bleed or recent neurosurgery
- pulmonary embolism despite anticoagulation
- poor patient compliance with antiocoagulation treatment
- large iliocaval or floating IVC thrombus “widow-maker” thrombus
A temporary (i.e. retrievable) vena cava filter is typically placed for a short duration, usually weeks to a few months. The design of the temporary filter permits subsequent endovascular retrieval. In certain patients vena cava filters are left in situ indefinitely, these devices may be called permanent filters.
Circumstances when a vena cava filter cannot be placed are rare.
- complete vena cava thrombosis
- vena cava is too small or too large to safely admit a filter
- septic thromboembolism
- review all available imaging to establish indication for the procedure; previous studies can help assess IVC patency, size and presence of anomolies such as duplicated IVC and circumaortic renal vein
- whilst departmental practices vary, interventionists often place IVC filters without stopping anticoagulation therapy
- obtain informed consent for the procedure
- arrange analgesia and sedation according to patient comfort
Positioning/room set up
The procedure is usually performed in the angiography suite with the patient in supine position. Regular monitoring of the vital signs by a suitably trained staff member is recommended during the procedure. Clean skin with antiseptic solution and drape to maintain sterility for the procedure.
- ultrasound machine
- 18 gauge needle. Alternatively 22 or 21 gauge needle and a micro-puncture access set
- 0.035" vascular guide wire
- multisidehole straight or pigtail catheter
- commercially available vena cava filter set
Specific technical steps may vary according to personal preference and on the type of filter being used. Generally, internal jugular or femoral vein is punctured under ultrasound guidance and a guide wire is placed in the IVC. A venogram is obtained by injecting contrast through a multisidehole catheter positioned in lower IVC or distal common iliac vein. The venogram is used to reassess the IVC for patency, size and anomalies. The location of the renal veins is often indicated by the presence of contrast reflux or flow voids. The venous access is dilated using a dilator. The vena cava filter is subsequently deployed in a suitable location through a delivery sheath, typically the infra-renal IVC. Another venogram is obtained to ensure satisfactory deployment of the filter. The delivery sheath is removed. Haemostasis is secured using manual compression.
Post procedure care
Regular monitoring of vital signs is performed for the first few hours after the procedure.
- 1. Kandarpa K, Machan L. Handbook of Interventional Radiologic Procedures. Lippincott Williams & Wilkins. (2010) ISBN:0781768160. Read it at Google Books - Find it at Amazon
- 2. Smillie RP, Shetty M, Boyer AC et-al. Imaging evaluation of the inferior vena cava. Radiographics. 2015;35 (2): 578-92. doi:10.1148/rg.352140136 - Pubmed citation
- 3. Smoot RL, Koch CA, Heller SF et-al. Inferior vena cava filters in trauma patients: efficacy, morbidity, and retrievability. J Trauma. 2010;68 (4): 899-903. doi:10.1097/TA.0b013e3181d3cbdc - Pubmed citation