Venous
Procedure Guide
Indications
IVC Filter Placement
Absolute indications
Acute proximal (at least popliteal) DVT or PE with inability to achieve therapeutic anticoagulation or contraindication such as recent surgery, intracranial hemorrhage, active bleeding, vascular brain tumor
CTEPH prior to pulmonary thromboendarterectomy
Recurrent embolization despite anticoagulation
Relative indications
Iliocaval DVT or large residual “widow-maker” thrombus in IVC/iliacs
Massive PE treated with catheter directed therapy
VTE with limited cardiopulmonary reserve
High risk of bleeding from anticoagulation, e.g., recurrent falls
Trauma with high VTE risk
Surgical patient with high risk for VTE
IVC Filter Removal
Indwelling filters should be removed as soon as it is safe to do so, i.e., once tolerating anticoagulation or recovered from trauma or surgery.
For insurance coverage for advanced removal techniques, it is important to assess for and document filter-related anxiety and/or symptoms (e.g. back/abdominal pain)
Contraindications
Device allergy
Total IVC occlusion
INR > 3.0, Plts < 25K
Bacteremia, *NOT sepsis*
HIT per Hematology 2018 guidelines but studies suggest this may be over blown
Pregnancy is debated. The mass effect from the uterus can theoretically serve as a physiologic IVC filter and is higher risk requiring suprarenal placement.
Efficacy and alternatives
Successful deployment >99%. Retrieval rates very high if removed within 3 months and nearly 100% with ancillary techniques even for prolonged dwell times.
PREPIC1: RCT of 400 pts with proximal DVT assigned to anticoagulation alone or with IVC filter. During first 12d, PE lower with filter (1 v. 5%). At 8 yrs, no difference in survival, PE less with filter (6 v. 15%) but DVT higher (21 v. 12%).
PREPIC2: RCT of 399 pts with severe PE assigned to anticoagulation alone or with IVC filter. No difference in PE, mortality, or DVT at 3mo.
PRESERVE: multicenter, prospective, non-randomized, followed 1429 pts. Filter removed in 44%, post-filter VTE occurred in 6.5% (1.6% PE, 5.2% DVT, 1.1% cava thrombosis/obstruction), no PE in pts who received the filter for prophylaxis. Successful filter removal in 99% of those attempted, 97% at first attempt.
Pre-procedure care
Review imaging and VTE/filter history as applicable
Aberrant IVC anatomy: circumferential left renal (7%), duplicated IVC (1%), megacava (1%), left IVC (<1%)
Labs: coags, CBC, BMP for INR <3, Plt >25K, Cr <1.5 (debatable)
Meds: No need to hold anticoagulation
Some give prophylactic antibiotics for retrieval if filter leg penetration of adjacent bowel.
Procedures
Filter Placement
Obtain access: Internal jugular > external jugular, femoral > subclavian, translumbar.
NOTE: Need to select appropriate filter designed for approach, e.g., IJ vs femoral. Some allow either with same device set, e.g., Option Elite (Argon).
Advance working wire (e.g. Amplatz) into IVC.
Advance sheath - often the filter comes with a delivery sheath, which can be used for venography.
IVC venogram to identify caval anomalies and level of renal venous inflow to plan placement. Helpful to “prime” sheath by filling with contrast and then inject for the venogram with a second syringe, particularly for larger sheaths. This can be done with a 3-way with both syringes attached.
Classic teaching is to place below the level of the renal veins (infrarenal) with filter apex near the level of the renal veins.
Suprarenal placement can be done in the setting of renal venous thrombus, duplicated IVC, or pregnancy. This comes with increased risks.
Some will use a retrievable filter for all [e.g. Gunther-Tulip (Cook), Option Elite (Argon)]. Others will use permanent filters (e.g. Vena Tech) if highly unlikely to be removed such as a patient with end-stage malignancy due to some evidence that permanent filters have less long-term complications.
If megacava (>28 mm), most filters are too small and may require placing bilateral common iliac vein fitlers.
Exchange for deployment system and deploy
(Optional) Repeat venogram.
Spot image of the filter to document positioning and appearance at the end of the case.
Achieve hemostasis
Filter Retrieval
Magnified spot image of the filter to assess for and document fracture or missing struts prior to manipulation.
Obtain access - often just right internal jugular but concurrent femoral access can be helpful for advanced, challenging retrievals.
Advance working wire passed the filter in the IVC.
Advance a long sheath large enough to accommodate the filter as well as any devices to be used, often 9-16 Fr. Leave sheath tip near filter apex.
IVC venogram to assess for filling defects in the filter, fibrin cap, and filter positioning relative to the cava.
Helpful to “prime” sheath by filling with contrast and then inject for the venogram with a second syringe, particularly for larger sheaths. This can be done with a 3-way with both syringes attached.
If large amount of intrafilter thrombus, many will terminate the procedure and bring the patient back after further anticoagulation. Some have described attempting aspiration thrombectomy and proceeding.
(Optional) Some use IVUS for further assessment, e.g., relationship between an embedding apex and the right renal artery.
Basic retrieval
Advance EnSnare or device-specific retrieval device. Often engaging a small hook at the apex allowing the sheath to be advanced over the filter and freeing it from the caval wall.
Advanced retrieval
Loop-snare technique - use a curved catheter through the sheath (e.g. C2, RIM, Kumpe) to advance a glidewire through the filter interstices near the apex. Advance a snare to snare the end of the glidewire and pull through the sheath so both ends of the wire are out of the patient. Pull wire to help straighten a tilted filter and engage the apex with the sheath. Also good for filters with no hook.
Forceps - good for microdissection of a fibrin cap and to engage the apex. Can then pull to straighten the filter and engage it with the sheath.
Excimer laser - good for scarring and penetration of filter legs with the caval wall to carefully strip the filter legs off the wall.
Unsuccessful retrieval
Many will abort the procedure and consider referral to high volume center or attempting again on a different day.
Otherwise, a stent can be placed to crush the filter against the caval wall and exclude it. Should be done cautiously as these prohibits further retrieval attempts.
Post-removal venogram to assess the caval injury.
Venoplasty/stenting if significant caval injury.
Small irregularities and pseudoaneurysms often resolve without intervention.
A soft sizing balloon can be used to assess for significant narrowing by inflating it caudal to the prior filter site and pulling it across the prior filter site.
Larger pseudoaneurysms and stenoses often respond to venoplasty alone. Large volume extravation may require stent placement.
Achieve hemostasis
Complications
Overall, highly safe and effective in the PRESERVE study
Adverse events in ~2% during implantation, e.g., tilted filter, migration, fracture, hematoma, tachycardia, groin pain
IVC perforation (>5 mm, 15%)
Post-filter VTE 6.5% (1.6% PE, 5.2% DVT, 1.1% cava thrombosis/obstruction)
Other studies report rate of caval thrombus of 2% (risk factors: male gender, neurologic dx, implantation >6mo)
Pericardial tamponade (2%, SVC placement) - not recommended any more
One patient died during attempted removal in PRESERVE study
Post-procedure care and follow up
Start anticoagulation as soon as not contraindicated
Some suggest abdominal XR every 3-5 yrs to monitor position for permanent filters.
Additional Resources
Decision Aids for Patients and Consent
Backtable Articles and Podcasts on IVC Filters