Development of the postthrombotic syndrome: its management at different stages

A Prospective Study of the Long-Term Efficacy of Two Different Venoactive Drugs in Patients with Post-Thrombotic Syndrome

Objective:

In an open cross-over study, the effect of two different venoactive drugs was prospectively studied in a series of patients with post-thrombotic syndrome.

Design:

Prospective, open cross-over study.

Patients:

Twenty-nine patients with established unilateral deep venous insufficiency of at least 12 months duration, and a history of venography-proven deep venous thrombosis in the affected leg.

Interventions:

On entering the study, patients were randomly assigned to receive either Hidrosmina (Venosmil, FAES SA, Spain) 600 mg daily, or 0-(β-hydroxyethyl)-rutosides (Venoruton, Zyma SA, Switzerland) 900 mg daily. The drugs were taken for 6 months. At the end of this period, the drug was discontinued, and patients taking Hidrosmina changed to rutosides, or vice versa, for a further 6-month period. Finally, both drugs were discontinued, and patients were re-examined 3 and 6 months later.

Results:

During the first 6-month period, 12 out of 29 patients showed reduced tiredness and/or pain in the leg in comparison to the control visit. Furthermore, a slight reduction was found in mean circumferences of both the ankle and calf during this study period. During the second 6-month period of therapy, six additional patients improved their subjective symptoms, but there were three patients in whom these symptoms had increased. Six months after discontinuation of therapy, subjective symptoms increased in 10 out of 29 patients, and mean circumferences of both the ankle and calf returned to baseline values.

Conclusions:

In this pilot study our findings demonstrate that venoactive drugs may improve both objective and subjective symptoms in patients with post-thrombotic syndrome, and that these effects disappear after drug therapy is discontinued.

Economic burden of long-term complications of deep vein thrombosis after total hip replacement surgery in the United States

BACKGROUND

Estimates of the cost of long-term complications of a primary deep vein thrombosis (DVT), including the post-thrombotic syndrome (PTS) and recurrent venous thromboembolism (VTE), may be relevant for resource allocation decisions.

OBJECTIVE

The objective of this study was to provide US cost estimates of the long-term complications of a primary DVT, which occurs in approximately 5% to 20% (with adequate thromboprophylaxis) and 50% (in the absence of thromboprophylaxis) of total hip replacement surgeries (THRS).

METHODS

A literature-based model was used to project the excess long-term complication costs of DVT following THRS. The model simulated the natural history of DVT complications using published estimates of the incidence and prognosis of PTS and recurrent VTE. Each complication was assigned a cost obtained by multiplying the amount of resources used in its management by the unit price of these resources.

RESULTS

The annual per-patient cost of each complication was as follows: mild-to-moderate PTS, 839 dollars in the first year and 341 dollars in subsequent years; severe PTS, 3817 dollars in the first year and 1677 dollars in subsequent years; DVT, 3798 dollars; and pulmonary embolism, 6604 dollars. The average discounted lifetime cost of DVT complications was estimated to be 3069 dollars (95% interval 2091 dollars-4279 dollars).

CONCLUSIONS

The long-term complications of a primary DVT represent a significant economic burden. Preventing a DVT could arguably lead to substantial savings in long-term DVT complications.

Pediatric thrombosis

Although thrombosis is less frequent in children than in adults, it represents a significant source of morbidity and mortality. Multiple factors. both genetic and acquired. contribute to the development of thrombosis in chiidren. Thrombosis in a child warrants investigation of potential underlying prothrombotic conditions. The risk of thrombosis in children with heterozygous deficiencies is not clearly defined, but it appears that children who are heterozygous for more than one risk factor or who have a combination of inherited and acquired defects are at higher risk for thrombosis. Treatment of thrombosis primarily involves a rapidly acting anticoaguiant such as heparin or LMWH to prevent extension, and long-term anticoagulation with warfarin may be instituted to prevent recurrence. Thrombolytic therapy with recombinant tissue plasminogen activator also appears to be safe and effective in children. Prospective and multicenter studies are still needed to clarify the contribution of specific prothrombotic disorders to childhood TE so that evidence-based treatment recommendations can be made.

The venous stasis syndrome after deep venous thrombosis or pulmonary embolism: a population-based study

OBJECTIVES

To estimate the incidence and determine predictors of venous stasis syndrome and venous ulcers after deep venous thrombosis and pulmonary embolism.

PATIENTS AND METHODS

This population-based retrospective cohort study reviewed medical records of 1527 patients with incident deep venous thrombosis or pulmonary embolism between 1966 and 1990. We recorded baseline characteristics, event type (deep venous thrombosis with or without pulmonary embolism or pulmonary embolism alone), leg side and site of deep venous thrombosis (proximal with or without distal deep venous thrombosis vs distal deep venous thrombosis alone), and venous stasis syndrome and venous ulcer.

RESULTS

Two hundred forty-five patients developed venous stasis syndrome. One-year, 5-year, 10-year, and 20-year cumulative incidence rates were 7.3%, 14.3%, 19.7%, and 26.8%, respectively. By 20 years the cumulative incidence of venous ulcers was 3.7%. Patients with deep venous thrombosis with or without pulmonary embolism were 2.4-fold (95% confidence interval, 1.7-fold-3.2-fold) more likely to develop venous stasis syndrome than patients with pulmonary embolism and no diagnosed deep venous thrombosis. In patients aged 40 years or younger with proximal compared with distal-only deep venous thrombosis, venous stasis syndrome was 3.0-fold more likely (95% confidence interval, 1.6-fold-4.7-fold). In patients with unilateral leg deep venous thrombosis, venous stasis syndrome usually developed in the concordant leg (P < .001). There was a 30% (95% confidence interval, 2%-62%) increased risk for venous ulcer per decade of age at the incident venous thromboembolism.

CONCLUSIONS

The cumulative incidence of venous stasis syndrome continues to increase for 20 years after venous thromboembolism. Pulmonary embolism alone is less likely to cause venous stasis syndrome.

Thrombosis with outflow obstruction delays thrombolysis and results in chronic wall thickening of rat veins

PURPOSE

An in vivo model of acute deep venous thrombosis was developed in rats to assess the role of venous thrombosis and outflow obstruction in recanalization and development of secondary wall changes.

METHODS

The left femoral veins of male Sprague-Dawley rats were thrombosed either by means of proximal ligation (obstruction, group A, n = 38) or by means of temporary 24-hour occlusion with a microvascular clamp (unobstructed, group B, n = 20). Right femoral veins served as controls. The rats were killed at intervals over 5 weeks. Wall thickness was compared among groups by means of counting of cells on representative sections through the midvein area. Thrombi were indirectly quantitated with a radiolabeled fibrinogen assay in a parallel series of rats.

RESULTS

Control veins showed no evidence of cellular or structural changes. Early thrombus extension was seen in group A (peak at day 4) followed by recanalization after 2 weeks. Group A veins had marked wall thickening (27 +/- 7 vs 6 +/- 2 cells, p < 0.01, peak at 10 days) consisting of smooth muscle-type, neointimal, and medial cellular proliferations. Within 2 to 3 weeks, local neovascular channels had grown to bypass the outflow obstruction, and resumption of normal cephalad flow was seen. At the same time neointimal proliferation regressed, but medial cellular growth persisted, resulting in chronic wall thickening (11 +/- 3 vs 5 +/- 1 cells, p < 0.01, after 21 days). In contrast, group B veins exhibited no thrombus extension, had significantly less wall thickening (13 +/- 2 vs 5 +/- 1 cells, p < 0.01, peak at 4 days), and did not induce growth of local collateral blood vessels. Within 2 weeks, group B veins regained normal appearance and resumed normal flow.

CONCLUSIONS

Thrombosis of rat femoral veins without chronic obstruction results in rapid lysis of thrombus and transient proliferative changes. In contrast, thrombosis with chronic outflow obstruction results in delayed recanalization, early extension of thrombus, and development of vigorous and persistent proliferative cellular responses. Thrombus-induced chronic wall thickening may be an important factor in development of postthrombotic venous insufficiency.

A technique for venography in chronic venous syndromes

The technique of venography presented here is given in detail and is intended to distinguish between the specific requirements of venography of chronic and acute venous syndromes. At each of four major sections of the venous return from the lower limb, the major veins requiring evaluation are identified together with variations in technique needed to ensure that no artefacts develop. Central to the technique is the use of sustained, large volume injections of low-osmolality ionized contrast medium. The technique was used in over 2000 examinations without significant complications.

Complications and failure of anticoagulation therapy in the treatment of venous thromboembolism in patients with disseminated malignancy

Thirty-one patients with malignancy, anticoagulated for the treatment of venous thromboembolism (VTE) are reported. Complications of treatment included major bleeding (35%), redevelopment of VTE whilst on therapeutic levels of anticoagulants (13%) and recurrent VTE following cessation of anticoagulant (42%). Forty-two per cent of patients died within three months of initiating anticoagulant therapy. The cause of death was progressive malignancy, except in one patient who died of anticoagulant-related bleeding. The high incidence of bleeding is frequently associated with over-anticoagulation and indicates the need for improved monitoring. The frequent recurrence of VTE is associated with chronic disseminated intravascular coagulation, for which warfarin is ineffective and heparin is indicated.