title: Prospective study of venous thromboembolism in patients with head and neck cancer after surgery: interim analysis.
abstract: OBJECTIVE
  To prospectively determine the incidence of venous thromboembolism (VTE) following major head and neck surgery. At the midpoint of enrollment, an interim analysis was performed to determine if it was ethical to continue this study as an observational study without routine anticoagulation.
  
  
  METHODS
  Prospective, observational cohort study.
  
  
  METHODS
  Academic surgical center.
  
  
  METHODS
  The interim analysis comprised 47 subjects.
  
  
  METHODS
  The total number of new cases of VTE (superficial and deep) identified within 30 days of surgery and confirmed on diagnostic imaging. These cases were further categorized as clinically relevant and nonclinically relevant. Clinically relevant VTEs were those requiring more than 6 weeks of anticoagulation or were associated with any negative impact on clinical course. On postoperative day 2 or 3, subjects were clinically examined and received duplex ultrasonography. Subjects with negative findings from examination and ultrasonography were followed up clinically; subjects with evidence of deep venous thrombus or pulmonary embolism were given therapeutic anticoagulation. Subjects with superficial VTE received repeated ultrasonography on postoperative days 4 to 6. Subjects were monitored for 30 days after surgery.
  
  
  RESULTS
  Three subjects (6%) were identified as having clinically significant VTE: 2 cases of deep venous thrombus and 1 case of pulmonary embolism. Two additional subjects had lower extremity superficial VTE without clinical findings, which were detected by ultrasonography alone. No statistically significant differences were seen between patients with VTE and those without VTE.
  
  
  CONCLUSIONS
  This interim analysis of the first prospective study of the incidence of VTE in patients with head and neck cancer showed a VTE rate slightly higher than previously estimated in retrospective studies. There have been no unexpected serious adverse events and no rationale for early termination of the study.
authors: Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, OR 97239, USA.
authors: Daniel
authors: D
authors: Clayburgh
authors: Will
authors: W
authors: Stott
authors: Teresa
authors: T
authors: Kochanowski
authors: Renee
authors: R
authors: Park
authors: Kara
authors: K
authors: Detwiller
authors: Maria
authors: M
authors: Buniel
authors: Paul
authors: P
authors: Flint
authors: Joshua
authors: J
authors: Schindler
authors: Peter
authors: P
authors: Andersen
authors: Mark
authors: M
authors: Wax
authors: Neil D
authors: ND
authors: Gross
mesh_terms: D000367:Age Factors; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000601:surgery*; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000209:etiology*; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex; D020246:Venous Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000209:etiology*
chemical_list: D000925:Anticoagulants