title: Vena caval filter placement by intravascular ultrasound.
abstract: OBJECTIVE
  Placement of vena caval filters under fluoroscopic surveillance incurs significant expense and potential risks associated with the transportation of critically ill patients. Intravascular ultrasound (IVUS) allows direct intraluminal visualization of the vena cava and the renal veins. The purpose of this study is to evaluate the accuracy of vena caval filter placement under IVUS in an animal model.
  
  
  METHODS
  Fifteen Simon-Nitinol venal cava filters (C.R. Bard, Inc., Covington, GA) were placed under IVUS guidance into four anesthetized sheep. Twelve were placed transfemorally, and three were placed transjugularly. Accuracy of placement was confirmed with fluoroscopy by measurement between the filter tip and the targeted side branch.
  
  
  RESULTS
  The vena caval filters placed femorally averaged 0.33+/-0.42 cm distance from the target vein side branch. Jugular approach filter placement was less accurate. Although two out of three filters placed from the jugular vein were correctly positioned, the distance from the target vein side branch was much greater averaging 2.5+/-1.04 cm.
  
  
  CONCLUSIONS
  Femoral placement of vena caval filters under IVUS is extremely accurate. The transjugular route, however, was technically challenging and standard fluoroscopic vena caval filter placement appears to be more appropriate. Our success with the femoral approach merits further clinical investigation in the use of IVUS for critically ill patients that would benefit from bedside vena caval filter placement.
authors.affiliation: Department of Surgery, Atlanta Medical Center, Medical College of Georgia, Atlanta, GA, USA. docmt@mindspring.com
authors.forename: J H
authors.initials: JH
authors.lastname: Matsuura
authors.forename: R A
authors.initials: RA
authors.lastname: White
authors.forename: G
authors.initials: G
authors.lastname: Kopchok
authors.forename: G
authors.initials: G
authors.lastname: Nishinian
authors.forename: J D
authors.initials: JD
authors.lastname: Woody
authors.forename: D
authors.initials: D
authors.lastname: Rosenthal
authors.forename: M D
authors.initials: MD
authors.lastname: Clark
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D023421:Models, Animal; D012756:Sheep; D018084:Ultrasonography, Interventional; D016306:Vena Cava Filters