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

CONFLICT OF INTERESTS WL Gore Consultant Boston Scientific Consultant LeMaitre Vascular Scientific 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 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

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 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

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

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.

Safety Considerations Avoiding 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 Considerations Cost 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 used DUS, duplex ultrasonography. IVUS, intravascular ultrasound.