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.