Catheter-directed Venous Thrombolysis in Acute Iliofemoral Vein Thrombosis - the CaVenT Study - post-doctoral research

Following adequate conventional treatment of DVT with heparin, oral antiocoagulants and compression stockings, still 1 in 4 patients develop PTS. Systemic thrombolytic therapy reduces risk of PTS, but is associated with unacceptably high risk of bleeding complications. With CDT low dose fibrinolytic agents are delivered continuously and directly into the thrombus through a catheter until thrombus has dissolved. Although case series suggest beneficial effect of this costly treatment in terms of increased v enous patency and improved short term outcome, there are no randomized trials documenting efficacy or safety, and CDT is still an experimental therapy. The CaVenT study is a randomized, controlled, open-label, multi-center trial among hospitals in the Eas tern Southern Norway Health Authorities. Patients with acute iliofemoral DVT were randomized to receive either conventional treatment or CDT in addition to conventional treatment. Main outcome measures are patency rates at 6 months and prevalence of PTS a t 24 months. In 2009 we published the results of the first 100 patients showing that additional CDT increased patency from 36% to 64%. Our main long-term hypothesis is that CDT will improve functional outcome, i.e., reduce PTS, after 2 years, from >25% on conventional treatment to <10%. The sample size was 200 patients using a statistical significance=5% and power=80%. The CaVenT study have completed recruitment and 6 months follow-up. 2 years data will be complete by end 2011 and form the basis for this post-doctoral research. Any documentation of improved functional outcome will most likely have a significant impact on clinical practice for these patients and lead to modification of international guidelines. Hence, CaVenT is an important contribution to ward evidence-based medicine in treatment of proximal DVT.