title: The use of intravascular ultrasound imaging to improve use of inferior vena cava filters in a high-risk bariatric population.
abstract: OBJECTIVE
  Pulmonary embolism is the leading cause of death after gastric bypass procedures for obesity, approximating 0.5% to 4%. All bariatric patients, but especially the super-obese, which have a body mass index (BMI) >50 kg/m(2), are at significant risk for postoperative venous thromboembolism (VTE). Visualization and weight limitations of fluoroscopy tables exclude most bariatric and all super-obese patients from inferior vena cava (IVC) filter placement using fluoroscopy. Intravascular ultrasound (IVUS)-guided IVC filter placement is the only modality that allows these high-risk patients to have an IVC filter placed.
  
  
  METHODS
  Hospital and outpatient records of the 494 patients who underwent gastric bypass procedures from January 1, 2004, to May 31, 2006, were reviewed. All patients who had concurrent IVC filter placement with the use of IVUS guidance were selected. Comorbidities, outcomes, and complications were recorded.
  
  
  RESULTS
  We identified 27 patients with mean BMI of 70 +/- 3 kg/m(2); of these, 25 were super-obese (BMI >50 kg/m(2)). Procedures included five laparoscopic and 22 open gastric bypass operations. All patients underwent concurrent IVC filter placement using IVUS guidance. In addition to super-obesity, indications for IVC filter placement included history of VTE (n = 4), known hypercoagulable state (n = 2), and profound immobility (n = 21). Mean follow up was 293 +/- 40 days. Technical success rate was 96.3%. There were no catheter site complications. In one surviving patient, a nonfatal pulmonary embolism was detected by computed tomography 2 months postoperatively. Two patients died, and autopsy excluded VTE as the cause of death in both.
  
  
  CONCLUSIONS
  This study suggests efficacy of IVUS-guided IVC filter placement in preventing mortality from pulmonary embolism in high-risk bariatric patients, including the super-obese. IVUS-guided IVC filter placement can be safely performed with an excellent success rate in all bariatric patients, including the super-obese, who otherwise would not be candidates for IVC filter placement due to the limitations imposed by their large body habitus.
authors.affiliation: Division of Vascular and Endovascular Surgery, East Carolina University, Brody School of Medicine, Greenville, North Carolina 27834, USA.
authors.forename: Clark M
authors.initials: CM
authors.lastname: Kardys
authors.forename: Michael C
authors.initials: MC
authors.lastname: Stoner
authors.forename: Mark L
authors.initials: ML
authors.lastname: Manwaring
authors.forename: William M
authors.initials: WM
authors.lastname: Bogey
authors.forename: Frank M
authors.initials: FM
authors.lastname: Parker
authors.forename: Steve
authors.initials: S
authors.lastname: Powell
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D018579:Patient Selection; D011655:Pulmonary Embolism / Q000209:etiology / Q000517:prevention & control*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging*; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*