Risk for Post-Thrombotic Syndrome after Lower-Limb Deep Vein Thrombosis: Location of the Thrombus or Residual Thrombi?

BACKGROUND:Many works aimed to determine factors that influence the onset of postthrombotic syndrome after an acute episode of deep venous thrombosis. We aimed to compare the prognostic value of the most proximal extent of thrombus (proximal and distal DVT) versus the residual thrombosis as identified by venous ultrasonography performed during follow-up.METHOD:We conducted a retrospective study of prospectively collected 1183 consecutive cohort patients in the RIETE registry after a first episode of deep venous thrombosis and assessed for postthrombotic syndrome after 12 months.RESULTS:Multivariate analysis revealed that: residual thrombosis (OR 1.40; 95% CI 0,88-2,21), the presence of cancer (OR 1.38; 95% CI: 0,64-2,97), immobility (OR 1.31; 95% CI 0,70-2,43) and estrogen-containing drugs use (OR 2.08, 95% CI 0,63-6,83), all had a predictive value for the occurrence of PTS.CONCLUSION:Our study results revealed that ultrasound finding of residual thrombosis is more predictive than proximal location of thrombus for postthrombotic syndrome after episode of deep venous thrombosis. Real life data from a large group of patients from the RIETE registry substantiates that.