Residual thrombosis after a first episode of proximal deep venous thrombosis.

: The aim of this study was to analyse the normalization rate of compression ultrasonography after a first episode of proximal deep venous thrombosis (DVT). Patients underwent compressive ultrasound (C-US) examinations during the 3-6 months following the first proximal DVT episode. Normalization rate of compressive ultrasound (C-US) during the follow-up period was 26.4% [95% confidence interval, 16.3-37.3]. Allelic variation in factor XIII gene (Val34Leu) significantly affected the improvement of popliteal residual thrombi (P = 0.019). We also observed a significant negative correlation between D-dimer levels at 3 months and improvement of popliteal residual thrombi (P = 0.016). There was a significant positive correlation between baseline lumen diameter of the femoral thrombi and IL-8 cytokine (P = 0.015). A significant difference was also found between 1 month-tumor necrosis factor (TNF)-α levels and improvement of residual thrombi (P = 0.047). Our results show that normalization after a standard period of anticoagulation is not frequent and procoagulant and inflammatory biomarkers and also some genetic variations might be related to the resolution of thrombosis.