Significance of preoperative screening of deep vein thrombosis and its indications for patients undergoing urological surgery

Purpose Preoperative deep vein thrombosis (pre-DVT) is a risk of symptomatic venous thromboembolism (VTE) and a serious postoperative surgical complication. However, little is known about pre-DVT in patients undergoing surgery. This study aimed to investigate the incidence and screening criteria of pre-DVT in patients undergoing urological surgery. Materials and methods Between 2015 and 2017, 320 patients admitted to our hospital for urological surgery were included in this retrospective study. All patients underwent preoperative D-dimer testing. Patients with elevated D-dimer (≥1.0 μg/mL) levels underwent lower-limb compression ultrasonography (CUS). Clinical parameters were analyzed as predictors of pre-DVT, and modest cutoff value of D-dimer to predict pre-DVT were evaluated. Results Of 320 patients, preoperative elevated D-dimer levels and DVT were found in 81 (25.3%) and 20 (6.3%) patients, respectively. The positive predictive value (PPV) was 24.7% (20/81). ROC curve analysis revealed a cutoff D-dimer level of 1.8 μg/mL, yielding a PPV of 40.7% for pre-DVT among patients with elevated D-dimer levels. Preoperative DVT was detected in 16 (7.6%, n=210) patients with malignancy, 3 (5.7%, n=53) with adrenal tumors, and in 1 (1.8%, n=57) kidney donor. An age of >70 years was significantly associated with risk for pre-DVT (odds ratio, 2.81; 95% confidence interval, 1.12-7.19; p=0.0270). During a postoperative follow-up period of 90 days, no patient developed symptomatic VTE. Conclusions The incidence of pre-DVT was 6.3% in patients undergoing urological surgery. Elderly patients and/or a cutoff D-dimer level of 1.8 μg/mL might be good indications for pre-DVT screening by CUS.