Abstract
OBJECTIVE: This study sought to investigate the changes in plasma D-dimer levels during catheter-directed thrombolysis (CDT) in patients with acute lower extremity deep venous thrombosis (DVT), analyze imaging results, and assess their clinical implications. METHODS: We retrospectively analyzed 62 patients diagnosed with acute lower extremity DVT who underwent CDT between March 2019 and December 2022. Plasma D-dimer levels were measured before CDT, at regular intervals after CDT, and at the end of CDT. Lower limb venography was performed every 2 days during CDT to assess the thrombus clearance rate and level of thrombus dissolution. Statistical analyses were conducted to observe the D-dimer concentration changes and analyze the correlation between D-dimer concentration and thrombus clearance rate. Additionally, a receiver operating characteristic curve was constructed to determine the diagnostic performance of D-dimer in assessing the efficacy of thrombolysis, including the calculation of the area under the curve, sensitivity, specificity, and optimal cut-off value. RESULTS: During CDT for acute lower extremity DVT, plasma D-dimer levels rapidly increased, peaking on CDT day 1, and then gradually decreased, followed by a rapid decline, but remained slightly elevated compared with normal levels. There was a positive correlation between D-dimer levels and thrombolysis efficacy (r = 0.809; P = .00). The linear regression equation for this correlation was Y = 0.161 + 0.028X. The area under the curve of D-dimer was 0.95, with a cut-off value of 9.935 mg/L (sensitivity, 93.2%; specificity, 95.4%). CONCLUSIONS: Plasma D-dimer concentration can serve as an indicator for evaluating the efficacy of thrombolysis during CDT in acute lower extremity DVT.