Screening for Deep Vein Thrombosis Using D-dimer Levels Based on Surgical Patients' Characteristics.

Purpose Owing to the shortage of surgeons and the decrease in medical staff in regional medical care, reducing unnecessary tests can limit the burden on the staff. In this study, we aimed to examine the predictors of deep vein thrombosis (DVT), such as D-dimer levels in patients who underwent surgery at our hospital, and determine the feasibility of screening in these patients. Knowledge of D-dimer levels can indicate the risk of DVT in patients about to undergo surgery. Methods We retrospectively analyzed 310 of 1,059 surgical cases in which preoperative lower extremity ultrasonography was performed in our department between April 2021 and June 2024. We compared 46 patients with thrombi and 264 patients without thrombi. Results Patients with low body mass indices (<18.5 kg/m) and high D-dimer levels (> 2 μg/mL) had a significantly higher risk of DVT, whereas patients taking oral antiplatelet drugs or anticoagulants had a significantly lower risk of DVT. The area under the curve for D-dimer levels in predicting DVT was 0.779. D-dimer levels of 2 μg/mL had high sensitivity - (1 - specificity). However, there were three false-negative cases, and the highest D-dimer level that resulted in 100% sensitivity was 1.4 μg/mL. Conclusion Predicting DVT using D-dimer levels may be effective, and considering additional testing based on D-dimer levels and patient background may reduce excessive preoperative testing.