title: Chemoprophylaxis for venous thromboembolism in otolaryngology.
abstract: OBJECTIVE
  Venous thromboembolism (VTE) causes significant morbidity and mortality in surgical patients. Despite strong evidence that thromboprophylaxis reduces the incidence VTE, guidelines for prophylaxis in otolaryngology are not well established. Key to the development of VTE prophylaxis recommendations are effective VTE risk stratification and evaluation of the benefits and harms of prophylaxis.
  
  
  OBJECTIVE
  To evaluate the effectiveness and safety of VTE chemoprophylaxis among a population of otolaryngology patients stratified by risk.
  
  
  METHODS
  Retrospective cohort study of 3498 adult patients admitted for otolaryngologic surgery at a single-institution academic tertiary care medical center between September 1, 2003, and June 30, 2010.
  
  
  METHODS
  Patients were stratified into 2 groups based on whether they received VTE chemoprophylaxis.
  
  
  METHODS
  Incidence of VTE and bleeding-related complications within 30 days after surgery.
  
  
  RESULTS
  Of 1482 patients receiving VTE chemoprophylaxis, 18 (1.2%) developed a VTE compared with 27 of 2016 patients (1.3%) who did not receive prophylaxis (P = .75). Patients with Caprini VTE risk scores greater than 7 were less likely to have a VTE with perioperative chemoprophylaxis (5.3% vs 10.4%; P = .06). Of patients with VTE chemoprophylaxis, 3.5% developed a bleeding complication compared with 1.2% of patients without prophylaxis (P < .001). Bleeding complications were associated with concomitant use of antiplatelet medications and chemoprophylaxis. Among patients undergoing free tissue transfer, chemoprophylaxis significantly decreased the incidence of VTE (2.1% vs 7.7%; P = .002) and increased bleeding complications (11.9% vs 4.5%; P = .01). In all other patients, VTE chemoprophylaxis did not significantly influence the likelihood of VTE (1.0% vs 0.6%; P = .12) or bleeding (1.5% vs 0.9%; P = .15).
  
  
  CONCLUSIONS
  Effectiveness and safety of VTE chemoprophylaxis differed between patient subgroups, defined by Caprini risk score and by procedure. Effectiveness was most evident in patients with high Caprini risk scores and microvascular free tissue reconstruction. Bleeding complications were associated with VTE chemoprophylaxis administered in close proximity to potent antiplatelet therapy. The Caprini risk assessment model appears to be an effective tool to stratify otolaryngology patients by risk for VTE. Patients undergoing free tissue reconstruction merit further study before developing recommendations for VTE prophylaxis because of their higher risk of both VTE and bleeding.
authors.affiliation: Office of Clinical Affairs, Department of Performance Assessment and Clinical Effectiveness, University of Michigan Health System, Ann Arbor.
authors.forename: Vinita
authors.initials: V
authors.lastname: Bahl
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Shuman
authors.affiliation: Office of Clinical Affairs, Department of Performance Assessment and Clinical Effectiveness, University of Michigan Health System, Ann Arbor.
authors.forename: Hsou Mei
authors.initials: HM
authors.lastname: Hu
authors.affiliation: Department of Otolaryngology, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Jackson
authors.affiliation: Division of Plastic Surgery, Department of Surgery, University of Pennsylvania, Philadelphia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Pannucci
authors.affiliation: College of Pharmacy and Pharmacy Services, University of Michigan Health System, Ann Arbor.
authors.forename: Cesar
authors.initials: C
authors.lastname: Alaniz
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Chepeha
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor.
authors.forename: Carol R
authors.initials: CR
authors.lastname: Bradford
mesh_terms: D000925:Anticoagulants / Q000008:administration & dosage; D017984:Enoxaparin / Q000008:administration & dosage; D000077425:Fondaparinux; D058752:Free Tissue Flaps; D006470:Hemorrhage / Q000453:epidemiology; D006493:Heparin / Q000008:administration & dosage; D006801:Humans; D015994:Incidence; D010036:Otolaryngology; D013517:Otorhinolaryngologic Surgical Procedures; D011134:Polysaccharides / Q000008:administration & dosage; D012189:Retrospective Studies; D018570:Risk Assessment; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000517:prevention & control*
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D011134:Polysaccharides; D006493:Heparin; D000077425:Fondaparinux