Spontaneous superficial venous thrombophlebitis: Does it increase risk for thromboembolism?

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Original Research

Spontaneous superficial venous thrombophlebitis: Does it increase risk for thromboembolism?

J Fam Pract. 2006 January;55(1):52-57

By

Van H. Weert, MD, PhD

A historic follow-up study in primary care.

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References

1. Fernandez L. Superficial phlebitis. UpToDate [database]. Version 2004;12.2:4.-

2. Van der Veer G, Eekhof JAH, Van Pelt-Termeer AMM, Asselbergs RTM, Barnhoorn K, Wiersma TJ. NHG-standard varices. Huisarts Wet 1993;36:23-30.

3. Büller HR, Agnelli G, Hull RD, Hyers TM, Prins MH, Raskob GE. Antithrombotic Therapy for Venous Thromboembolic Disease. The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126:401S-428S

4. Guex JJ. Thrombotic complications of varicose veins. A literature review of the role of superficial venous thrombosis. Dermatol Surg 1996;22:378-382.

5. Verlato F, Zucchetta P, Prandomi P, et al. An unexpectedly high rate of pulmonary embolism in patients with superficial thrombophlebitis of the thigh. J Vasc Surg 1999;30:1113-1115.

6. Blumenberg RM, Barton E, Gelfand ML, Skudder P, Brennam J. Occult deep vein thrombosis complicating superficial thrombophlebitis. J Vasc Surg 1998;27:338-343.

7. Neher JO, Safranek SM. What is the best therapy for superficial thrombophlebitis? J Fam Pract 2004;53:583-585.

8. Bounameaux H, Reber-Wasem MA. Superficial thrombophlebitis and deep vein thrombosis. A controversial association. Arch Intern Med 1997;157:1822-1824.

9. The Superficial Thrombophlebitis Treated by Enoxaparin Study Group. A pilot randomized double-blind comparison of a low-molecular-weight heparin, a nonsteroidal anti-inflammatory agent, and placebo in the treatment of superficial vein thrombosis. Arch Intern Med 2003;163:1657-1663.

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12. Jorgensen JO, Hanel KC, Morgan AM, Hunt JM. The incidence of deep venous thrombosis in patients with superficial thrombophlebitis of the lower limbs. J Vasc Surg 1993;18:70-73.

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Practice recommendations

Spontaneous superficial venous thrombophlebitis (SVTP) confers a 10-fold risk of developing DVT within 6 months compared with controls.
Absolute risk of DVT following SVTP, however, is just 2.7%, and watchful waiting is probably a reasonable approach in primary care.
Swelling of a leg within 6 months after a superficial thrombophlebitis should prompt diagnostic testing for DVT.

Abstract

Objectives: To determine the risk of arterial and venous complications after a spontaneous superficial venous thrombophlebitis (SVTP) in the leg in a general practice population.
Study design: Retrospective cohort study (LOE: 2b [CEBM]). Exposure consisted of the diagnosis of SVTP of the lower limbs on an index date. The exposed cohort was compared with an (unexposed) cohort of practice-, age-, and sex-matched controls without SVTP.
Population: Patients with spontaneous SVTP in the leg were identified through diagnostic coding in the medical registers of 40,013 patients, enlisted with 5 health centers in Amsterdam, the Netherlands.
Outcomes: Primary outcomes were deep venous thrombosis (DVT), pulmonary embolism (PE), acute coronary events, or ischemic stroke over a 6-month follow-up period. Odds ratios (OR) were used to quantify the associations between SVTP and outcome events.
Results: No statistically significant odds ratios were found for PE, coronary events or stroke. DVT was the only primary outcome to show a significant relationship. DVT occurred in 2.7% of all SVTP patients as compared with 0.2% in the controls (OR=10.2; 95% confidence interval [CI], 2.0–51.6). When controlling for prior history of DVT, the OR decreased to 7.1 and the confidence interval crossed 1.0 (95% CI, 0.9–65.6).
Discussion: Spontaneous SVTP in the leg is a risk factor for DVT, but is less predictive in patients with prior DVT. Although effective treatments for the prevention of DVT are available, the absolute risk is too low to advocate prophylaxis in a general practice population. More research on prophylaxis is needed to stratify these patients at risk.

The association between spontaneous superficial venous thrombophlebitis (SVTP) and subsequent venous or arterial thromboembolic events has been studied among referred populations, but not in the primary care setting. The aim of this study was to determine this association when primary care patients experience SVTP of the leg.

We found that, although the risk of developing a deep venous thrombosis (DVT) following SVTP is real, the absolute risk is quite low. Prospective studies are needed to identify those who are at greater risk. Until they can be identified, watchful waiting with SVTP seems the best strategy in general practice, because of the sequelae of the various treatment regimens and the relative lack of benefit for primary care patients in preventing DVT.

Background

Treatment of SVTP

Spontaneous venous superficial thrombophlebitis of the leg veins is generally considered to be a benign condition. Not much is known about its natural course and prognosis,¹ except that it is usually expected to resolve spontaneously with 2 weeks.

The practice guideline of the Dutch College of General Practitioners does not recommend any specific treatment, but a recently published guideline of the American College of Chest Physicians advocates the use of an intermediate dosage of unfractioned heparin or low molecular-weight heparin for at least 4 weeks—they based this conclusion, however, on an unclear risk/benefit ratio.^2,3

Consequently, family physicians treat thrombophlebitis with any number of means, ranging from watchful waiting, analgesics, ambulant compression stockings, anticoagulants, and referral for surgical intervention.

SVTP and deep vein thrombosis/pulmonary embolism

Until the early 1990s, no relationship had been established between SVTP and either DVT or pulmonary embolism (PE). Subsequently, no standard preventive measures were recommended.²

In the late 1990s, several reports were published about concomitant or subsequent DVT or pulmonary embolism PE.^4-7 In a prospective hospital-based study, DVT occurred in approximately 2% of the patients with SVTP during 3 months of follow-up.⁸

This perceived increased risk led to trials that showed a significant reduction within 12 days in the incidence of recurrent or extended SVTP among patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs) or low-molecular-weight heparins, compared with those receiving placebo. Furthermore, the incidence of venous thromboembolism (VTE) after 10 days tended to be lower in the treatment groups compared with placebo, but this treatment effect tended to disappear after discontinuation of treatment.⁹

The primary-care population

All studies published so far, however, have been conducted in a referred population of patients, which could lead to an unknown selection of patients with relatively cumbersome symptoms or diagnostic uncertainty.¹⁰

FAST TRACK

Severe venous insufficiency, varicose veins, hypercoagulable state, male gender, older age, history of DVT predict complications of SVTP

The primary objective of the present study was to determine the association between a history of SVTP and subsequent venous or arterial thromboembolic events in patients, presenting in a primary care setting with a spontaneous episode of SVTP of the leg. Given the emphasis of recent publications on pharmacotherapy with low-molecular-weight heparin and NSAIDs to prevent DVT after SVTP, we analyzed the prescription policy of family physicians, as this could influence the primary outcome: the occurrence of venous or arterial thromboembolic events.