In the United States alone, venous thromboembolism (VTE) affects some 900,000 individuals. Acute lower extremity deep venous thrombosis (DVT) has significant associated long-term morbidity. Postthrombotic syndrome (PTS) may occur in 40% to 80% of patients with DVT, leading to significant healthcare costs in its long-term management. Prevention is of paramount importance in reducing the long-term complications that may arise after lower extremity DVT. The basis of preventing DVT stems from Virchow’s initial observations over 150 years ago that the pathogenesis of DVT is related mainly to hypercoagulability, venous stasis, and endothelial damage. Methods of DVT prevention are either mechanical, with the goal of improving venous flow and reducing stasis, or pharmacologic, based on agents that act as anticoagulants.

The traditional mainstay therapy for acute DVT has been anticoagulation with unfractionated heparin (UFH) or low molecular weight heparin (LMWH) with conversion to oral warfarin for a specified period of time. Anticoagulation alone significantly decreases the risk of subsequent pulmonary embolism (PE) and reduces the incidence of symptomatic leg swelling in patients with DVT. Despite the dramatic decrease in subsequent PE development with anticoagulation, significant lower extremity venous valvular dysfunction occurs and leads to the development of PTS. Markel et al. demonstrated that despite recanalization of a high percentage of extremity veins treated with anticoagulation, up to 50% of patients had residual chronic thrombus. This leads to a significant inflammatory response resulting in valvular incompetence and dysfunction. Faulty venous valve function and residual venous obstruction despite anticoagulation leads to ambulatory venous hypertension resulting in PTS.

The development of PTS has a significant impact on healthcare costs and leads to a significant decreased quality of life. PTS leading to recalcitrant edema, pain, color changes, and ulcerations can be very problematic to manage. Given this, aggressive treatment of acute DVT with catheter-directed thrombolysis (CDT) is now recognized as an option in first-line therapy. Not all DVTs require treatment with CDT. Patients who derive the greatest benefit are those with extensive iliofemoral DVT. To a lesser extent femoropopliteal DVT may be treated with CDT, whereas DVT in the popliteal segment alone does not warrant treatment with CDT. CDT is most efficacious if initiated shortly after development of iliofemoral DVT, ideally within 1 week.

All patients with iliofemoral DVT should be evaluated for possible CDT. A thorough history should be obtained to identify those patients with relative or absolute contraindications for CDT. Patients with known malignancy, those who are nonambulatory, and postsurgical patients are likely not optimal candidates for thrombolytic therapy. Other absolute contraindications to thrombolytic therapy include active bleeding disorder, gastrointestinal (GI) bleeding within 10 days, stroke within 6 months, head injury within 3 months, and intracranial or spine surgery within 3 months.

The initial management of patients with iliofemoral DVT is therapeutic anticoagulation. We prefer the use of UFH, as it has a shorter half-life than LMWH, can be turned on and off with ease, and can be reversed if need be. A bolus dose of intravenous heparin is administered at 80 units/kg and subsequently, a continuous infusion of IV heparin is administered at 18 units/kg/hr with the goal of keeping the aPTT between 60 and 90 seconds. Alternatively, LMWH therapy may be used with an initial bolus dose of 1 unit/kg followed by twice-daily injections of 1 unit/kg. In preparation for initiating CDT, a Foley catheter should be placed to monitor for hematuria as a complication of thrombolysis. An intensive care unit (ICU) bed should be arranged for the patient. Baseline coagulation labs should be sent off including a CBC, PT, aPTT, INR, and fibrinogen. The vast majority of thrombolysis cases can be performed under local anesthesia with minimal sedation. General anesthesia is usually unnecessary.