Predictable factors of deep venous thrombosis in patients undergoing spine surgery

Background: DVT is one of the major postoperative complications of joint replacement surgery of the lower extremity which can cause catastrophic complications such as pulmonary embolism. However, little is known about the incidence of DVT after spine surgery. The purpose of this study was to examine predictable factors of DVT after spine surgery. Methods: This study included 194 patients who underwent spine surgery (104 males, 90 females, mean age 65.7 years). Postoperative DVT was detected using duplex ultrasonography (DUS). Age, sex, BMI, operation time, amount of bleeding, preoperative ambulatory status, usage of instrumentation, and preoperative serum levels of D-dimer were compared between the DVT(+) and DVT(-) groups to establish predictors for postoperative DVT. Cut-off value of the preoperative level of D-dimer was calculated using ROC analysis. Results: Postoperative DVT was detected in 57 patients (29.4%). No patients showed clinical signs of DVT or pulmonary embolism. Sex, age, BMI, preoperative non-ambulatory status, and preoperative levels of D-dimer were significantly different between the DVT(+) and DVT(-) groups. However, age and BMI was not significantly different factor in logistic regression analysis. Cut-off value of preoperative D-dimer was 1.4 mu g/ml. Conclusion: It was suggested that perioperative application of DUS for detecting DVT in the lower extremities should be performed on patients undergoing spine surgery who are female, non-ambulatory, and with higher preoperative D-dimer serum level. (C) 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.