title: Cutoff values of plasma d-dimer level in patients with diagnosis of the venous thromboembolism after elective spinal surgery.
abstract: METHODS
  A prospective clinical study.
  
  
  OBJECTIVE
  Our objective in the present study was twofold. First, we sought to evaluate the relationship between postoperative venous thromboembolism (VTE) development and concentration of D-dimer to determine the cutoff value in patients who underwent elective spinal surgery. Second, we identified the predictive risk factors for postoperative VTE.
  
  
  BACKGROUND
  VTE affects the general health of patients and may even cause death. Since the complications of VTE are difficult to predict, the safest and most cost effective diagnostic method should be used in order to confirm a suspected VTE event after spinal surgery.
  
  
  METHODS
  This study was performed on 97 patients who underwent elective spinal surgery. The D-dimer assay was carried out on the day before surgery, and on days 1, 3, and 10 following surgery. VTE occurrence and D-dimer levels were compared between the VTE and the control groups.
  
  
  RESULTS
  Four patients (4.1%) were diagnosed with deep vein thrombosis and one patient (1%) was diagnosed with a pulmonary embolism. The optimum D-dimer cutoff value on day 3 following surgery in the VTE group was determined to be more than 2.1 µg/mL with a sensitivity of 100% and a specificity of 80.7%. Moreover, the duration of postoperative recumbency was a significant risk factor for the development of VTE in this study.
  
  
  CONCLUSIONS
  We have demonstrated that postoperative D-dimer measurements in patients who underwent elective spinal surgery can provide a complementary diagnostic screening for VTE during the first week after surgery.
authors.affiliation: Division of Neurosurgery, Department of Surgery, Bou-Ali Medical Educational & Clinical Center, Tehran Medical Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Hamidi
authors.affiliation: Medical Science Research Center, Tehran Medical Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Riazi
keywords: D-dimer; Risk factors; Spine; Surgery; Venous thromboembolism