title: Efficacy and safety of weight-adjusted heparin prophylaxis for the prevention of acute venous thromboembolism among obese patients undergoing bariatric surgery: a systematic review and meta-analysis.
abstract: BACKGROUND
  The bariatric surgical population is a particularly high risk population for VTE. It is unclear if standard (i.e. non-adjusted) thromboprophylaxis doses of low-molecular weight or unfractionated heparin provide adequate protection for obese patients undergoing bariatric surgery, or if higher doses are required. We sought to determine whether a weight based thromboprophylactic dosing regimen is safe and effective in the post-operative period for obese patients undergoing bariatric surgery.
  
  
  METHODS
  A systematic literature search strategy was conducted using MEDLINE, EMBASE, the Cochrane Register of Controlled Trials and all EBM Reviews. Pooled proportions for the different outcomes were calculated.
  
  
  RESULTS
  A total of 6 studies (1 RCT, 4 cohort studies and one quasi experimental trial) containing 1,858 patients were include in the systematic review. Post bariatric surgery patients receiving weight-adjusted prophylactic doses of heparin products, had an in hospital rate of VTE of 0.54% (95% CI: 0.2 to 1.0%) compared to 2.0% (95% CI: 0.1 to 6.4%) for those that did not weight adjust doses. Rates of major bleeding were similar for both groups: 1.6% (95% CI: 0.6 to 3.0%) for patients receiving weight-adjusted dosing compared to 2.3% (95% CI: 1.1% to 3.9%) for those receiving standard doses of heparin products.
  
  
  CONCLUSIONS
  Adjusting the dose of heparin products for thromboprophylaxis post-bariatric surgery seems to be associated with a lower rate of in hospital VTE compared to a strategy of not adjusting the dose, although this did not reach statistical significance. This practice does not lead to an increase in adverse major bleeding events.
authors: Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors: Rick
authors: R
authors: Ikesaka
authors: Département de Médecine Interne, EA3878, University of Brest, Brest, France.
authors: Aurélien
authors: A
authors: Delluc
authors: Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Clinical Epidemiology Program, The Ottawa Health Research Institute, Ottawa, Ontario Canada; Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors: Grégoire
authors: G
authors: Le Gal
authors: Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada; Clinical Epidemiology Program, The Ottawa Health Research Institute, Ottawa, Ontario Canada; Thrombosis Program, Division of Hematology, Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada. Electronic address: mcarrier@toh.on.ca.
authors: Marc
authors: M
authors: Carrier
mesh_terms: D000208:Acute Disease; D050110:Bariatric Surgery / Q000009:adverse effects / Q000379:methods*; D015331:Cohort Studies; D006470:Hemorrhage / Q000139:chemically induced; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects*; D006801:Humans; D009765:Obesity / Q000097:blood / Q000601:surgery*; D015995:Prevalence; D054556:Venous Thromboembolism / Q000209:etiology / Q000517:prevention & control*
chemical_list: D006493:Heparin
keywords: Bariatric surgery; Hemorrhage; Heparin; Low-molecular weight; Mortality; Venous thromboembolism