Ultrasound Placement of Vena Cava Filters

Thomas Naslund

Vanderbilt University Medical Center

CONFLICT OF INTERESTS

WL Gore Consultant

Boston Scientific Consultant

LeMaitre VascularScientific Advisory Board

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

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

Indications for FilterAbsolute 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

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

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

Technique Filter Placement with Surface Ultrasound

• Preliminary duplex of femoral vein & IVC– Identify thrombus, diameter, landmarks

Technique IVUSDual 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

Technique IVUSsingle 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

Series of Ultrasound Guided Filter Placement

Author Year nModalit

y LocationPuncture

TechniqueTechnical Success

Misplacement

Overall Complication Rate

Corriere1 2005 382 DUS Bedside Single Puncture 97% 5% 2%

Rosenthal2 2004 94 IVUS Bedside Double Puncture 97% 3% 6%

Garrett3 2004 28 IVUS BedsideSingle/Double

Puncture93% 8% 15%

Gamblin4 2003 36 IVUS OR Single Puncture 94% 0% 0%

Wellons5 2003 45 IVUSIR

Suite/Bedside

Double Puncture 94% 3% 6%

Conners6 2002 284 DUS Bedside Single Puncture 98% 2% 4%

Ashley7 2001 21 IVUS OR Single Puncture 100% 0% 0%

Ebaugh8 2001 26 IVUS Bedside Single Puncture 92% 4% 12%

Bonn9 1999 30 IVUS IR SuiteSingle/Double

Puncture100% 0% 0%

Sato10 1999 53 DUS Bedside Single Puncture 98% 0% 2%

Benjamin11 1999 25 DUS Bedside Single Puncture 100% 4% 4%

Neuzil12 1998 29 DUS Bedside Single Puncture 100% 4% 8%

Neuzil13 1997 49 DUS Bedside Single Puncture 89% − 8%

DUS, duplex ultrasound. IVUS, intravascular ultrasound. OR, operating room. IR, interventional radiology.

Safety ConsiderationsAvoiding Patient Transport

• Invasive monitoring lines

• Pressors

• Ventilators

• Drains

• Transportation complications risk up to 15.5%

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

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

Financial ConsiderationsCost Reduction

• Avoid patient transport

• No interventional suite

• Over $2000 cost reduction per patient (2002)

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 usedDUS, duplex ultrasonography. IVUS, intravascular ultrasound.