DVT Intervention


Why Anticoagulation Isn't Enough

  • Does not dissolve the clot
  • Waits for the body’s own internal mechanism to dissolve the thrombus which can take several months
  • Residual clot in the veins can lead to post-thrombotic syndrome (PTS)
  • Anticoagulation, when combined with early thrombus removal can greatly reduce the chances of developing post-thrombotic syndrome

Anticoagulation is the current front-line and standard treatment for deep vein thrombosis (DVT).  Studies have consistently shown that anticoagulation prevents the propagation of the thrombus and protects against embolization. 


Anticoagulation does not remove or break up the thrombus, rather it ‘keeps it in check’ until the body’s own internal mechanisms can dissolve the clot which, depending on the size of the thrombus, can take up to several months.


The management of DVT has been studied extensively.  There are clear correlations between residual thrombus or venous occlusion and the development of long term sequelae, most frequently post-thrombotic syndrome. 


The goal of treating a DVT is to avoid early and late complications of venous thrombosis – the prevention of pulmonary embolism and the restoration of blood flow with the preservation of venous valve function. 


Multiple clinical studies consistently show that a strategy of early thrombus removal combined with anticoagulation therapy can result in rapid resolution of symptoms and a significant reduction in long term aftereffects.

 

Iliofemoral Deep Vein Thrombosis: Conventional Therapy Versus Lysis and Percutaneous Transluminal Angioplasty and Stenting


Conventional therapy for iliofemoral DVT is systemic heparinization followed by oral anticoagulants.  This therapy has not been associated with rapid resolution of symptoms or removal of thrombus.  Secondary complications such as venous inefficiency and PTS are common to this treatment modality.


In this study 51 patients with extensive iliofemoral DVT were treated and followed over a 10 year period.  Patients were able to choose whether they wanted anticoagulation therapy alone or a multimodal therapy option including catheter directed thrombolysis (CDT), percutaneous transluminal balloon angioplasty (PTA) and stenting if needed.


The mean follow-up was four to five years.  Long-term symptom resolution was shown in only 30% of the anticoagulation group versus 78% of the multi-modality group.


The authors concluded that immediate lysis when combined with PTA or stenting (as indicated) is more effective than conventional anticoagulation treatment in patients with iliofemoral DVT.


Reference: AbuRahma, Ali, Perkins, Samuel, Wulu, John, Ng, Hong.  Iliofemoral Deep Vein Thrombosis: Conventional Therapy Versus Lysis and Percutaneous Transluminal Angioplasty and Stenting.  Ann Surg 2001; 233:752-760


Catheter-directed Thrombolysis for Lower Extremity Deep Venous Thrombosis: Report of a National Multicenter Registry

Deep Vein Thrombosis (DVT) of the lower extremity is a recognized cause of post-thrombotic syndrome (PTS) and pulmonary embolism.


The authors analyzed data from a National Multicenter Venous Registry which included interventional data on 303 limbs of 287 patients in an effort to evaluate catheter directed thrombolysis (CDT) as an effective treatment for symptomatic lower extremity DVT. 


Mean time to lysis was 48 hours using CDT.  Eighty-three percent of patients experienced Grade II or Grade II lysis (as defined by the National Venous Registry), representing a minimum venous patency of 50%.  Primary patency was maintained in 65% and 60% of patients at six months and one year respectively.


Anticoagulation is the current standard of care and is effective at mitigating the risk of pulmonary embolism (PE) but it does not promote lysis to reduce the thrombus nor does it contribute to restoration of venous valve function.

Thrombolysis provides immediate restoration of venous patency and preserves valve function thereby reducing the potential for long term DVT associated sequelae and PTS.


Mewissen, Mark, Seabrook, Gary, Meissner, Mark, Cynamon, Jacob, Labropoulos, Nicos, Haughton, Signs.  Catheter-directed Thrombolysis for Lower Extremity Deep Venous Thrombosis: Report of a National Multicenter Registry. Radiology 1999; 211:39-49


Society of Interventional Radiology Position Statement: Treatment of Acute Iliofemoral Deep Vein Thrombosis with Use of Adjunctive Catheter-directed Intrathrombus Thrombolysis


“The Society of Interventional Radiology (SIR) considers the use of catheter-directed intrathrombus thrombolysis (CDT) as an adjunct to anticoagulant therapy to represent an acceptable initial treatment strategy for carefully selected patients with acute iliofemoral deep vein thrombosis (DVT).”


Any treatment for acute iliofemoral DVT must be able to: prevent pulmonary embolism (PE) and DVT propagation; provide early symptom relief; prevent post-thrombotic syndrome (PTS). 


Stand-alone anticoagulant therapy fails to sufficiently clear the burden associated with a proximal DVT leading to significant disability, reduced quality of life and socioeconomic costs.  The direct cost of treatment of chronic venous disease is estimated to exceed $300 million annually in the United States with approximately 2 million workdays lost as a result of DVT-associated sequelae.


The value of CDT is in its ability to deliver intrathrombus lytic at a higher concentration which reduces the dose of lytic.  Endovascular access to the venous system enables the operator to utilize adjunctive procedures – PTA, stenting – to treat underlying venous disease and prevent recurrence of DVT.


Reference: Vedantham, Suresh, Millward, Steven, Cardella, John, Hofmann, Lawrence, Razavi, Mahmood, Grassi, Clement, Sacks, David, Kinney, Thomas. “Society of Interventional Radiology Position Statement: Treatment of Acute Iliofemoral Deep Vein Thrombosis with use of Adjunctive Catheter-directed Intrathrombus Thrombolysis.  J Vasc Interv Radiol 2006; 17:613-616