title: PROOF trial: protection from pulmonary embolism with the OptEase filter.
abstract: OBJECTIVE
  A postmarketing surveillance registry was conducted to monitor the safety and effectiveness of the OptEase vena cava filter when used as a permanent filter.
  
  
  METHODS
  This study was a nonrandomized, multicenter prospective trial with all patients receiving the OptEase vena cava filter for the prevention of pulmonary embolism (PE). A total of 11 clinical sites in the United States enrolled patients. A 1-month postimplantation follow-up examination was performed to determine potential filter migration and the presence of symptomatic thrombosis of the inferior vena cava (IVC) or lower extremities. At 6-month postimplantation follow-up, patients were again assessed for the safety and stability of the filter and any clinical evidence of symptomatic thrombosis.
  
  
  RESULTS
  One hundred fifty patients were enrolled in this study. Fifty-five patients (36.6%) were unable to complete all of the necessary follow-up at 6 months. At 1 month, filter migration and filter-related symptomatic deep vein thrombosis was observed in one patient each (0.9% and 0.8%, respectively). At 6 months, no new cases of filter migration or filter-related symptomatic thrombosis were observed. Filter tilting (> or = 15 degrees off the IVC axis) was observed in one patient at baseline (0.7%), four patients at 1-month follow-up (3.6%), and three patients (11.4%) at 6-month follow-up. Incidental findings on follow-up radiographs included filter fracture in two patients (1.8%) at 1 month and in one additional patient (4.3%) at 6 months. There were no clinical sequelae associated with the filter fracture.
  
  
  CONCLUSIONS
  The co-primary endpoints of filter migration and symptomatic thrombus formation at 1 month had an observed frequency of 0.9% and 0.8%, respectively. These co-primary endpoints were stable and unchanged at 6 months.
authors.affiliation: Department of Radiology, Sunrise Medical Center, 3186 S Maryland Pkwy, Las Vegas, NV 89109, USA. wernerziegler@yahoo.com
authors.forename: J Werner
authors.initials: JW
authors.lastname: Ziegler
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Dietrich
authors.forename: Sidney A
authors.initials: SA
authors.lastname: Cohen
authors.forename: Keith
authors.initials: K
authors.lastname: Sterling
authors.forename: James
authors.initials: J
authors.lastname: Duncan
authors.forename: Michael
authors.initials: M
authors.lastname: Samotowka
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D011655:Pulmonary Embolism / Q000517:prevention & control*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D016306:Vena Cava Filters / Q000706:statistics & numerical data*