This article has a companion Counterpoint by Poston and Garcia.Lower extremity deep vein thrombosis (DVT) is a common disorder associated with disabling symptoms and significant clinical sequelae. 1 In the acute phase, clot extension and embolization may result in limb ischemia and pulmonary embolism, whereas recurrent venous thromboembolism and postthrombotic syndrome (PTS) are frequent long-term consequences.PTS is a heterogeneous condition ranging in severity from mild discomfort to chronic leg pain, intractable edema, stasis dermatitis, and skin ulceration. The Villalta scale is a validated tool for defining the presence and grading the severity of PTS.2 Moderate to severe PTS results in disability, impaired quality of life (QOL) and high economic burden.3,4 Up to 50% of DVT patients develop PTS despite anticoagulation and compression therapy; 5% to 10% of cases are severe, suggesting that additional strategies are needed to prevent this potentially debilitating complication.3 Patients with iliofemoral DVT (IFDVT), defined as DVT involving any part of the iliac vein and/or the common femoral vein, with or without involvement of the more distal veins, are at especially high risk due to a lack of collateral drainage. Catheter-directed thrombolysis (CDT) allows direct delivery of a fibrinolytic drug to the thrombus site. By means of more rapid and effective clot clearance, CDT has the potential to reduce the risk of PTS. To date, the role of CDT in acute IFDVT remains controversial given conflicting data from published clinical trials. In this article, we describe the rationale for CDT as a means of preventing PTS, summarize CDT techniques, review recent evidence on clinical outcomes, argue for consideration of CDT in selected patients, and summarize factors involved in identifying appropriate candidates for CDT.
Rationale for thrombolytic therapy in DVTIn the most extreme form of acute DVT, phlegmasia cerulea dolens, acute thrombosis in the proximal deep vein(s) causes total or near-total occlusion of venous drainage from the lower extremity. The resultant venous congestion leads to compromised circulation, jeopardizing viability of the affected limb. In such cases, it is well-accepted that immediate clot degradation, either by thrombectomy or thrombolysis, is necessary to restore venous patency and avoid limb gangrene and amputation. 6 Thrombolysis is also indicated in less extreme instances in which DVT is not limb-threatening, but results in severe symptoms that are persistent or progressive despite initial treatment with anticoagulation.The role of routine thrombolytic therapy in unselected cases of DVT, in contrast, is controversial. Rather than limb salvage, the desired goal in this setting is prevention of PTS. PTS results from venous hypertension, which is a consequence of incomplete clot lysis, residual venous obstruction, and venous valvular reflux.7-9 Anticoagulation prevents thrombus formation and propagation, effectively reducing the risk of pulmonary embolism and recurrent venous thromboembolism....