Thrombin–antithrombin III complex tests

Purpose: Patients with fractures of the pelvis and/or lower extremities are at a high risk of developing postoperative venous thromboembolism (VTE). The purpose of this study was to determine whether the thrombin–antithrombin III complex (TAT) tests could be used for postoperative screening of VTE in patients with lower limb or pelvic fractures. Methods: We enrolled 133 patients who underwent surgical treatment for fracture of the pelvis or lower extremities. TAT and D-dimer levels were compared in patients with and without VTE. Receiver operating characteristic (ROC) curve analysis was done and the appropriate TAT and D-dimer cutoff levels were determined for VTE screening. Results: VTE was diagnosed in 41 patients (30.8%). Patients with VTE had significantly higher levels of TAT and D-dimer on postoperative days 1, 3, and 7 than those without VTE, respectively. ROC curve analysis suggested that TAT test at postoperative day 7 had the highest accuracy for predicting postoperative VTE. With the optimal cutoff TAT level of 3.0 ng/mL, sensitivity and specificity were 93.3% and 70.1%, respectively. With the optimal cutoff D-dimer level of 7.4 µg/mL, sensitivity and specificity were 93.3% and 57.0%, respectively. Conclusion: TAT levels measured at postoperative day 7 could be the most useful parameter for screening postoperative VTE. TAT can be used as a screening tool for screening postoperative VTE in patients with lower limb and pelvic fractures.