Preoperative deep vein thrombosis in patients with cervical spondylotic myelopathy scheduled for spinal surgery

Introduction: The prevalence of deep vein thrombosis (DVT) and its risk factors in patients with cervical spondylotic myelopathy (CSM) before spinal surgery are poorly understood. We investigated this association with a retrospective cross-sectional study. Patients concerns: The study cohort consisted of all consecutive patients with CSM who were scheduled for spinal surgery at our institution from 2013 to 2015. DVT was defined as an intraluminal filling defect in a lower extremity vein identified by Doppler ultrasonography. Outcomes: Of the 396 patients with CSM, 16 (4%) had DVT. Compared with patients without preoperative DVT, patients with preoperative DVT were older (62.75 +/- 8.79 vs 53.03 +/- 10.95 years, P=0.001), had higher D-dimer concentrations (2.23 +/- 4.15 vs 0.43 +/- 0.90 mg/L, P=0.04), had experienced longer duration of CSM (7.56 +/- 7.08 vs 4.01 +/- 6.37 months, P=0.03), had lower Japanese Orthopaedic Association lower limb motor dysfunction scores (1.68 +/- 1.25 vs 2.54 +/- 0.91, P=0.01), and had a history of ischemic cardiovascular events (33.3% vs 2.1%, P=0.02). The area under the curve for the ability of D-dimer levels to predict DVT was 0.858 (95% confidence interval: 0.764-0.951; P<0.0001). A D-dimer level of 0.54mg/L detected DVT with a sensitivity and specificity of 87.5% and 83.2%, respectively. Abnormal D-dimer levels and ischemic cardiovascular events history were independent predictors of DVT. Conclusion: Patients with CSM who were scheduled for surgery often presented with preoperative DVT. Preoperative vascular screening should be considered for patients with CSM, especially for those who are older, have had longer duration of CSM, have poor lower limb mobility, and have a heart disease history. Inferior vena cava filter insertion and anticoagulation treatments should be considered for CSM patients with preoperative DVT.