1. Ultrasound Placement of Vena Cava Filters
Thomas Naslund
Vanderbilt University Medical Center

2. CONFLICT OF INTERESTS WL Gore Consultant Boston Scientific Consultant
LeMaitre Vascular Scientific Advisory Board

3. Greenfield Filter Introduced 35 years ago
Excellent safety and efficacy
Integral component of venous thromboembolism (VTE)
Initially performed in OR with cutdown
Routinely performed percutaneously - angio suites
Bedside placement with ultrasound

4. Filters for Ultrasound Placement
Greenfield, Cook Tulip, Simon Nitinol – well suited to ultrasound placement
Greenfield visualized well out of sheath
Tulip best visualized while in sheath

5. Indications for Filter
Absolute Indications
VTE with contraindication to anticoagulation
VTE with complication of anticoagulation
Recurrent VTE despite adequate anticoagulation
Concurrent with pulmonary embolectomy
Failure of alternate form of vena caval interruption
Relative Indications
Free-floating iliofemoral thrombus (>5cm) in high-risk patient
Propagating iliofemoral thrombus despite adequate anticoagulation
Septic pulmonary emboli
Pulmonary hypertension/cor pulmonale with chronic VTE
VTE in high risk patient
VTE prophylaxis in multiple trauma or malignancy

6. Ultrasound Placement Initiated in 1995 Adaptable to bedside placement
Surface or IVUS can be utilized
Eliminates patient transport
Reduced institutional cost
Efficient use of physician time

7. Technique Filter Placement with Surface Ultrasound
Preliminary duplex of femoral vein & IVC
Identify thrombus, diameter, landmarks
Establish femoral access/identify wire in IVC
Routine sheath placement/visualization
Position filter tip at right renal vein (remove wire) and deploy
Completion KUB

8. Technique Filter Placement with Surface Ultrasound
Preliminary duplex of femoral vein & IVC
Identify thrombus, diameter, landmarks

13. Technique IVUS Dual Access
Duplex femoral veins-optional
Dual femoral access (preferred bilateral)
Visualize sheath and iliac vein confluence
Advance to atrium
“Pull back” visualization/IVC diameter
Position filter tip at renal vein
Pull IVUS back and deploy
Advance IVUS to evaluate filter
Completion KUB

16. Technique IVUS single access
Interrogate atrium to iliacs (using filter sheath)
Mark location of renal vein on catheter (tie)
Translate mark onto the filter delivery catheter
Insert to mark to deploy blind
Advance IVUS to check deployment
Completion KUB

17. Overall Complication Rate
Series of Ultrasound Guided Filter Placement
Author
Year n
Modality
Location
Puncture Technique
Technical Success
Misplacement
Overall Complication Rate
Corriere1
2005
382
DUS
Bedside
Single Puncture
97% 5% 2%
Rosenthal2
2004 94
IVUS
Double Puncture 3% 6%
Garrett3 28
Single/Double Puncture
93% 8%
15%
Gamblin4
2003 36 OR
94% 0%
Wellons5 45
IR Suite/Bedside
Conners6
2002
284
98% 4%
Ashley7
2001 21
100%
Ebaugh8 26
92%
12%
Bonn9
1999 30
IR Suite
Sato10 53
Benjamin11 25
Neuzil12
1998 29
Neuzil13
1997 49
89% −
DUS, duplex ultrasound. IVUS, intravascular ultrasound. OR, operating room. IR, interventional radiology.

18. Safety Considerations Avoiding Patient Transport
Invasive monitoring lines
Pressors
Ventilators
Drains
Transportation complications risk up to 15.5%

19. Misplacement Most common 0-8% Iliac vein or suprarenal IVC
Often attributed to poor visualization or U/S misinterpretation
Suprarenal placement is satisfactory
Iliac requires fluoroscopic filter repositioning

20. Insertion Site Thrombosis
Occurs in up to 16.7% of patients
Double venous puncture technique increases exposure to risk
Incidence is related to surveillance of access site
With routine surveillance, IST may occur in up to one third of patients

21. Financial Considerations Cost Reduction
Avoid patient transport
No interventional suite
Over $2000 cost reduction per patient (2002)

22. Comparison of Techniques
Advantages
Disadvantages
Contrast Venography
Accurate deployment, detection of venous anomalies
Transportation of critically-ill patients, radiation exposure, radiocontrast exposure, cost
DUS
Portable, non-invasive, no contrast or radiation exposure, cost-effective
Imaging limited by body habitus, bowel gas, abdominal wounds, anasarca, immobilization, learning curve
IVUS
Portable, no contrast or radiation exposure, cost-effective, unlimited by gas, edema, or body habitus
Invasive, catheter expense, learning curve, need for bilateral femoral venous access*, complexity
*unless single puncture technique used
DUS, duplex ultrasonography. IVUS, intravascular ultrasound.