title: Inferior vena cava filters in pulmonary embolism: A historic controversy.
abstract: OBJECTIVE
  Rationale for non-routine use of inferior venous cava filters (IVCF) in pulmonary embolism (PE) patients.
  
  
  METHODS
  Thrombosis mechanisms involved with IVCF placement and removal, the blood-contacting medical device inducing clotting, and the inorganic polyphosphate in the contact activation pathway were analyzed. In addition, we analyzed clinical evidence from randomized trials, including patients with and without cancer. Furthermore, we estimated the absolute risk reduction (ARR), the relative risk reduction (RRR), and the number needed to treat (NNT) based on the results of each study using a frequency table. Finally, we analyzed the outcome of our PE patients that were submitted to thrombolysis with short and long term follow-up.
  
  
  RESULTS
  IVCF induces thrombosis by several mechanisms including placement and removal, rapid protein adsorption, and simultaneous surface-induced activation via the contact activation pathway. Also, inorganic polyphosphate has an important role as a procoagulant, reversing the effect of anticoagulants. Randomized control trials included 904 cancer and non-cancer PE patients. In terms of ARR, RRR, and NNT, there is no evidence for routine use of IVCF. In 290 patients with proved PE, extensive thrombotic burden and right ventricular dysfunction under thrombolysis and oral anticoagulation, we observed a favorable outcome in a short- and long-term follow-up; additionally, IVCF was only used in 5% of these patients.
  
  
  CONCLUSIONS
  Considering the complex mechanisms of thrombosis related with IVCF, the evidence from randomized control trials and ARR, RRR, and NNT obtained from venous thromboembolism patients with and without cancer, non-routine use of IVCF is recommended.
authors.affiliation: Instituto de Cardiología y Medicina Vascular, TEC Salud and Centro de Investigacion Biomedica del Hospital Zambrano Hellion, Escuela de Medicina, Tecnologico de Monterrey, Mexico; Centro de Investigacion Biomedica del Hospital Zambrano Hellion, TEC Salud, Escuela de Medicina, Tecnologico de Monterrey, Mexico. Electronic address: jerjes@prodigy.net.mx.
authors.forename: Carlos
authors.initials: C
authors.lastname: Jerjes-Sanchez
authors.affiliation: Centro de Investigacion Biomedica del Hospital Zambrano Hellion, TEC Salud, Escuela de Medicina, Tecnologico de Monterrey, Mexico.
authors.forename: David
authors.initials: D
authors.lastname: Rodriguez
authors.affiliation: Escuela de Medicina, Tecnologico de Monterrey, Mexico.
authors.forename: Aline
authors.initials: A
authors.lastname: Navarrete
authors.affiliation: Escuela de Medicina, Tecnologico de Monterrey, Mexico.
authors.forename: Carolina
authors.initials: C
authors.lastname: Parra-Cantu
authors.affiliation: Escuela de Medicina, Tecnologico de Monterrey, Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Joya-Harrison
authors.affiliation: Centro de Investigacion Biomedica del Hospital Zambrano Hellion, TEC Salud, Escuela de Medicina, Tecnologico de Monterrey, Mexico.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Vazquez
authors.affiliation: Departamento de Fisiología Pulmonar, Laboratorio del Sueño y Clinica de Hipertension Pulmonar, UMAE 34 Hospital de Cardiologia, IMSS, Monterrey, Mexico.
authors.forename: Alicia
authors.initials: A
authors.lastname: Ramirez-Rivera
mesh_terms: D006801:Humans; D017410:Practice Guidelines as Topic; D011655:Pulmonary Embolism / Q000188:drug therapy / Q000601:surgery*; D012306:Risk; D015912:Thrombolytic Therapy; D013927:Thrombosis / Q000453:epidemiology / Q000209:etiology; D016306:Vena Cava Filters / Q000009:adverse effects
keywords: Deep venous thrombosis; Filtros de vena cava inferior; Inferior vena cava filters; Mexico; México; Pulmonary embolism; Tromboembolia pulmonar; Tromboembolismo venoso; Trombosis venosa profunda; Venous thromboembolism