Clinical Trials

Post-thrombotic syndrome (PTS) is a common and burdensome complication of deep venous thrombosis (DVT). Previous trials suggesting benefit of elastic compression stockings (ECS) to prevent PTS were small, single-centre studies without placebo control. We aimed to assess the efficacy of ECS, compared with placebo stockings, for the prevention of PTS. Read More on PubMed

Calf muscle pump is the motive force enhancing return of venous blood from the lower extremity to the heart. It causes displacement of venous blood in both vertical and horizontal directions, generates ambulatory pressure gradient between thigh and lower leg veins, and bidirectional streaming within calf perforators. Ambulatory pressure gradient triggers venous reflux in incompetent veins, which induces ambulatory venous hypertension in the lower leg and foot. Bidirectional flow in calf perforators enables quick pressure equalization between deep and superficial veins of the lower leg; the outward (into the superficial veins) oriented component of the bidirectional flow taking place during calf muscle contraction is no pathological reflux but a physiological centripetal flow streaming via great saphenous vein into the femoral vein. Calf perforators are communicating channels between both systems making them conjoined vessels; they are not involved in the generation of pathological hemodynamic situations, nor do they cause ambulatory venous hypertension. The real cause why recurrences develop has not as yet been cleared. Pressure gradient arising during calf pump activity between the femoral vein and the saphenous remnant after abolition of saphenous reflux triggers biophysical and biochemical events, which might induce recurrence. Thus, abolition of saphenous reflux removes the hemodynamic disturbance, but at the same time it generates precondition for reflux recurrence and for the comeback of the previous pathological situation; this chain of events has been called hemodynamic paradox. Read More on PubMed

Deep vein thrombosis (DVT) is a blood clot that occurs in a deep vein of the body; pulmonary embolism (PE) occurs when a clot breaks free and enters the arteries of the lungs. DVT and PE comprise venous thromboembolism (VTE), an important and growing public health concern. Hospitalization is a major risk factor for VTE, and many VTE events that occur among hospitalized patients can be prevented. A new program of the U.S. Department of Health and Human Services (Partnership for Patients: Better Care, Lower Costs) aims to reduce the number of preventable VTE cases in hospitals. To estimate the number of hospitalizations with VTE each year in the United States, CDC analyzed 2007-2009 data from the National Hospital Discharge Survey (NHDS). The results of that analysis determined that an estimated average of 547,596 hospitalizations with VTE occurred each year among those aged ≥18 years in the United States. DVT was diagnosed in an estimated annual average of 348,558 hospitalizations, and PE was diagnosed in 277,549; both DVT and PE were diagnosed in 78,511 hospitalizations. Estimates of the rates of hospitalizations with VTE were substantially higher among adults aged ≥60 years compared with those aged 18-59 years. These findings underscore the need to promote implementation of evidence-based prevention strategies to reduce the number of preventable cases of VTE among hospitalized patients. Read More on PubMed

Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise (SE), or stent revascularization (ST). Read More on PubMed

Catheter-directed thrombolysis (CDT) is a promising treatment of acute proximal deep vein thrombosis (DVT) to prevent the postthrombotic syndrome by early removal of thrombus. During CDT for DVT patients, the calf muscle pump is compromised because of immobility. Intermittent pneumatic compression (IPC) can be used to increase venous flow during bed rest. The CDT with IPC may lyse venous thrombus better than CDT alone. The purpose of this study was to evaluate the efficiency and safety of IPC during CDT for DVT using low-dose urokinase. Read More on PubMed

To determine whether increased physical activity 1 month after deep vein thrombosis (DVT) led to worsening of venous symptoms and signs within the subsequent 3 months. Read More on PubMed

The postthrombotic syndrome (PTS) occurs frequently after deep venous thrombosis (DVT) and is believed to worsen with upright posture and physical activity. However, the effects of exercise in patients with previous DVT have not been studied. Read More on PubMed

The subsequent course of residual abnormalities after an acute deep vein thrombosis (DVT) can vary within individual venous segments. To investigate the pattern of response within the individual venous segment, we used sequential duplex scanning to determine whether certain segments are more likely to recanalize or remain occluded. Read More on PubMed

Recanalization after acute lower limb deep venous thrombosis (DVT) is well documented, but the precise mechanism and timing of these events has not been well characterized. Regression of DVT has been presumed to result from activation of the endogenous fibrinolytic system. This study was performed to compare measurements of the enzymatic components of the intrinsic fibrinolytic system (tissue plasminogen activator [tPA], plasminogen activator inhibitor [PAI-1]) with the observed morphologic changes in thrombosed venous segments using venous duplex ultrasound scanning (VDUS) at intervals after diagnosis of acute DVT. Read More on PubMed

To determine the lower-limb venous hemodynamics in patients with varying grades of chronic venous insufficiency (CVI), not due to deep vein thrombosis, when matched for age and duration of disease. Read More on PubMed

The purpose of this study was to evaluate the rate of resolution of deep vein thrombosis (DVT) in the leg, by means of duplex imaging, in patients with symptoms during a 6-month period after initial diagnosis. Read More on PubMed

Thrombus regression in heparin-treated, acute deep venous thrombosis of the lower extremity is poorly documented in the literature; different rates of thrombus resolution and recanalization are reported. Read More on PubMed

Ultrasonic duplex scanning was used to study the rates at which lysis of thrombi, valvular incompetence, and symptoms of the postthrombotic syndrome (edema) developed in 21 patients after deep venous thrombosis (DVT). Lysis of thrombi occurred rapidly in most patients. In 11 of 21 patients (53%), recanalization occurred in all segments by 90 days after presentation. In four patients, extension of the initial DVT occurred between 30 and 180 days, despite treatment with warfarin. Valvular incompetence developed in 13 patients during the study period. The number of patent venous segments with incompetent valves increased from the initial presentation to 180 days, at which time 25% of patent segments contained incompetent valves. Valvular incompetence developed in previously thrombosed segments that were initially competent after recanalization and in segments not previously thrombosed. This suggested that although incompetence may occur as a result of a direct effect of the thrombus on the valve, other mechanisms must also be involved. Patients with edema early after DVT (from 7 to 30 days) were more likely to have residual occlusion than valvular incompetence. The late development of edema (from 90 to 270 days) was more closely correlated with valvular incompetence. Read More on PubMed