title: Duplex ultrasound insertion of inferior vena cava filters in multitrauma patients.
abstract: BACKGROUND
  Techniques for placement of inferior vena cava (IVC) filters have undergone continued evolution from open surgical exposure of the venous insertion site to percutaneous insertion in most cases today. However, the required transport either to an operating room or interventional suite can be complex and potentially hazardous for the multiply injured trauma patient who may require ventilator support, controlled intravenous infusions, or skeletal immobilization. Increased experience with color-flow duplex scanning for routine IVC imaging and portability of ultrasound equipment have suggested the usefulness of duplex-guided IVC filter insertion (DGFI) in critically ill trauma and intensive care unit (ICU) patients.
  
  
  METHODS
  A total of 25 multitrauma/ICU patients were considered for DGIF. Screening color-flow duplex scans were performed on all patients, and obesity or bowel gas prevented ultrasound imaging in 2 cases, leaving 23 patients suitable for DGFI. In each case, the IVC was imaged in the transverse and longitudinal planes. The right renal artery was identified as it passed posterior to the IVC and was used as a landmark of the infrarenal segment of the IVC. All procedures were performed at the bedside in a monitored ICU setting using percutaneous placement of titanium Greenfield filters. Duplex scanning after insertion was used to document proper placement, and circumferential engagement of the filter struts in the IVC wall. An abdominal radiograph was also obtained in each case to confirm proper filter location. Duplex ultrasound imaging was repeated within 1 week of insertion to assess IVC and insertion site patency.
  
  
  RESULTS
  DGFI was successful in all cases. The filter was deployed at a suprarenal level in one case, as was recognized at the time of postprocedural scanning. Three patients died as a result of their injuries but there were no pulmonary embolism deaths. Repeat duplex scanning was obtained in 17 patients, and revealed no case of IVC or insertion site thrombosis.
  
  
  CONCLUSIONS
  Vena caval interruption can be safely performed under ultrasound guidance in a monitored, ICU environment. In selected multiply injured trauma patients, this will reduce the risk, complexity and cost of transport for these critically ill patients. DGFI also reduces procedural costs compared with an operating room or interventional suite, and eliminates intravenous contrast exposure. Preprocedural scanning is essential to identify patients suitable for DGFI, and careful attention must be paid to the known ultrasonographic anatomical landmarks.
authors.affiliation: Division of Vascular Surgery, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Benjamin
authors.forename: G P
authors.initials: GP
authors.lastname: Sandager
authors.forename: E J
authors.initials: EJ
authors.lastname: Cohn
authors.forename: B G
authors.initials: BG
authors.lastname: Halloran
authors.forename: M A
authors.initials: MA
authors.lastname: Cahan
authors.forename: M P
authors.initials: MP
authors.lastname: Lilly
authors.forename: T M
authors.initials: TM
authors.lastname: Scalea
authors.forename: W R
authors.initials: WR
authors.lastname: Flinn
mesh_terms: D000328:Adult; D000368:Aged; D002406:Catheterization, Peripheral; D002423:Cause of Death; D003422:Critical Care; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007103:Immobilization; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009104:Multiple Trauma / Q000150:complications*; D010360:Patient Transfer; D011859:Radiography; D012077:Renal Artery / Q000000981:diagnostic imaging; D012121:Respiration, Artificial; D012189:Retrospective Studies; D014025:Titanium; D018615:Ultrasonography, Doppler, Color; D018616:Ultrasonography, Doppler, Duplex / Q000191:economics; D018084:Ultrasonography, Interventional / Q000191:economics; D014654:Vascular Patency; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging
chemical_list: D014025:Titanium