Duplex ultrasonography (DUS) does pick up alternative diagnoses (AD) including Baker's cyst, muscle hematomas, old deep vein thrombosis (DVT), and superficial vein thrombosis. The sequential use of DUS followed by a sensitive D-dimer test and a clinical score assessment is a safe and effective noninvasive strategy to exclude and diagnose DVT and AD in patients with suspected DVT.
DVT patients are recommended to wear medical elastic stockings (MECS) for symptomatic relief of swollen legs during the acute phase of DVT, or when postthrombotic syndrome (PTS) is present. In routine daily practice, discontinuation of anticoagulation at 6 months post-DVT is followed by a subsequent 20%-30% DVT recurrence rate; this is the main cause of PTS after 1-5 years of follow-up.
To bridge the gap between DVT and PTS, the frequent occurrence of PTS is best prevented by prolonged anticoagulation, if indicated, based on objective risk factors for DVT recurrence. Post-DVT rapid and complete recanalization on DUS within 1-3 months and no reflux is associated with no development of PTS, obviating the need of MECS; furthermore, anticoagulation can be discontinued after 3-6 months post-DVT.
Absence of residual venous thrombosis (complete recanalization) at 3 months post-DVT with no reflux and with a low PTS score is associated with no recurrence of DVT (1.2% of 100 patient/years). The presence of reflux due to valve destruction, irrespective of the degree of recanalization on DUS at 3-6 months post-DVT, is associated with a high risk of DVT recurrence and symptomatic PTS, indicating the need to wear MECS and extend anticoagulation.
Appearance of reflux on DUS at 6 months or 9 months post-DVT in symptomatic PTS patients is associated with increased DVT recurrence in about one-third of post-DVT patients after the discontinuation of anticoagulation. We designed a prospective safety outcome management study to bridge the gap between DVT and PTS, with the aim of reducing the overall DVT recurrence rate to ,3% patient/years during long-term follow-up.