Superficial venous thrombosis: prevalence of common genetic risk factors and their role on spreading to deep veins

Superficial Venous Thrombosis: A Comprehensive Review

Superficial venous thrombosis (SVT), an inflammatory-thrombotic process of a superficial vein, is a relatively common event that may have several different underlying causes. This phenomenon has been generally considered benign, and its prevalence has been historically underestimated; the estimated incidence ranges from about 0.3 to 1.5 event per 1000 person-years, while the prevalence is approximately 3 to 11%, with different reports depending on the population studied. However, such pathology is not free of complications; indeed, it could extend to the deep circulation and embolize to pulmonary circulation. For this reason, an ultrasound examination is recommended to evaluate the extension of SVT and to exclude the involvement of deep circulation. Also, SVT may be costly, especially in the case of recurrence. Therefore, accurate management is necessary to prevent sequelae and costs related to the disease. This review aims to analyse the epidemiology of SVT, its complications, optimal medical treatment, and open questions with future perspectives.

Incidence and prognosis of superficial vein thrombosis during pregnancy and the post-partum period: a Danish nationwide cohort study

BACKGROUND

The incidence of superficial vein thrombosis (SVT) of the legs and the subsequent risk of venous thromboembolism during pregnancy and the post-partum period is unknown. To better understand the clinical course of SVT during these times, we aimed to estimate the incidence rate of SVT during pregnancy and in the post-partum period, as well as the risk of subsequent venous thromboembolism.

METHODS

In this nationwide cohort study, we collected data on all pregnant women who delivered between Jan 1, 1997, and Dec 31, 2017, in Denmark were extracted from the Danish Medical Birth Register, the Danish National Patient Registry, and the Danish National Prescription Registry. Data on ethnicity were not available. Incidence rates per 1000 person-years were calculated for each trimester and the antepartum and post-partum period. Among women with a pregnancy-related SVT, risk of subsequent venous thromboembolism within the same pregnancy or post-partum period were calculated and compared with a matched cohort of pregnant women without SVT using Cox proportional hazards analysis.

FINDINGS

During 1 276 046 deliveries, 710 diagnoses of lower extremity SVT occurred from conception up to 12 weeks postpartum (0·6 per 1000 person-years [95% CI 0·5-0·6]). The incidence rates of SVT per 1000 person-years were 0·1 (95% CI 0·1-0·2) during the during the first trimester, 0·2 (0·2-0·3) during the second trimester, and 0·5 (0·5-0·6) during the third trimester. The incidence rate was 1·6 per 1000 person-years (95% CI 1·4-1·7) during the post-partum period. Of the 211 women with antepartum SVT included in the analysis, 22 (10·4%) were diagnosed with venous thromboembolism, compared with 25 (0·1%) in women without SVT (hazard ratio 83·3 [95% CI 46·3-149·7]).

INTERPRETATION

The incidence rate of SVT during pregnancy and the post-partum period was low. However, if SVT during pregnancy was diagnosed, the risk of developing venous thromboembolism during the same pregnancy was high. These results might help physicians and patients to make decisions about anticoagulant management of pregnancy-related SVT.

FUNDING

None.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

Ultrasound Imaging of Superficial Venous Thrombosis in the Upper and Lower Extremities: Closing the Gap Between Clinical Management Guidelines and Ultrasound Practice Parameters

Superficial venous thrombosis (SVT) of the upper and lower extremities has long been considered a relatively benign condition. But in recent years, the literature has suggested a benefit to anticoagulation in patients with certain thrombus characteristics (size, location, and distance to deep venous system) resulting in updates to clinical guidelines for the treatment of lower extremity SVT. Despite these now well-established guidelines, there remains a paucity of guidance from national and international societies regarding the imaging of superficial veins when evaluating for venous thrombosis. We recommend potential strategies to close this gap.

Prevalence of cancer in patients with superficial vein thrombosis and its clinical importance

OBJECTIVE

The objective of the present study was to evaluate the prevalence of cancer in patients with superficial vein thrombosis (SVT) of the legs. Moreover, we evaluated the potential determinants of SVT complications by comparing a subgroup with isolated SVT and a subgroup of SVT complicated by concurrent deep vein thrombosis (DVT) and/or pulmonary embolism (PE) with respect to the presence of cancer and other clinical and laboratory characteristics.

METHODS

The present single-center, retrospective study of prospectively collected data was conducted in a tertiary care setting. We included patients who had been treated in the thrombosis clinic from 2006 to 2018 for symptomatic SVT of the legs, either isolated SVT or SVT complicated by concurrent DVT/PE. We evaluated the prevalence and type of malignancy (diagnosed ≤12 months before SVT and/or ongoing therapy), demographics, and clinical and laboratory characteristics of the patients. For statistical evaluation, we used the Student t test, Kruskal-Wallis test, Fisher exact two-sided test, and logistic regression.

RESULTS

Of 276 patients with SVT (mean age, 58.9 ± 14.7 years; 60.9% women), 191 had had isolated SVT and 85 had had SVT complicated by concurrent DVT/PE. The prevalence of malignancy was 8.7% in the whole group (mainly breast and urinary tract cancer), including 4.2% of those with isolated SVT and 18.8% of those with SVT and concurrent DVT/PE (P < .001). Between the two subgroups, no significant differences were present in the duration of leg symptoms, family or personal history of SVT and/or DVT, SVT location, and smoking. In logistic regression, several factors were significantly associated with the concurrent presence of DVT/PE: age (odds ratio [OR], 1.024; 95% confidence interval [CI], 1.004-1.044), female gender (OR, 0.545; 95% CI, 0.309-0.960), varicose vein SVT (OR, 0.42; 95% CI, 0.194-0.902), thrombophilia (OR, 1.939; 95% CI, 1.089-3.454), and cancer (OR, 4.727; 95% CI, 1.814-12.316).

CONCLUSIONS

The prevalence of malignancy in the patients with SVT was 8.7%. Age, thrombophilia, male gender, nonvaricose vein SVT, and cancer were significantly associated with the presence of concurrent DVT/PE. Cancer was the strongest determinant of concurrent DVT/PE.

Guidelines for superficial venous thrombosis

Superficial venous thrombosis (SVT) or superficial thrombophlebitis is characterized by thrombi within superficial veins, with partial involvement or occlusion of the lumen and inflammatory reaction along the course of the vein. Clinical diagnosis tends to be straightforward, but supplementary tests and examinations are needed to confirm thrombosis extension and possible thromboembolic complications. SVT can be associated with deep venous thrombosis in 6 to 40% of cases, with asymptomatic pulmonary embolism (PE) in 20 to 33%, and with symptomatic PE in 2 to 13%. Despite the morbidity and complications, there are currently no Brazilian guidelines for SVT. These guidelines cover the most important issues related to SVT definition, terminology, and etiology, and set out recommendations for diagnosis and treatment.

A haemodynamic concept in the management of superficial non-saphenous vein thrombosis

Objective

Through the analysis of the haemodynamic model in the development of superficial non-saphenous vein thrombosis, the authors propose a therapeutic approach which is based on an ultrasound study of the superficial and perforating venous system of the lower limbs.

Methods

The authors propose the development of a haemodynamic model in the evolution of superficial non-saphenous vein thrombosis. They analyse three cases to highlight the importance of venous haemodynamics in the development of this condition and its possible complications, such as the progression of thrombosis in the deep vein system through the perforating veins.

Results

The evolution of a thrombosis in the venous network of the lower limbs from the peripheral collateral veins to the deep vein can be haemodynamically explained through this model involving the perforating vein system.

Conclusions

In the management and treatment of superficial non-saphenous vein thrombosis, it is essential to perform an accurate ultrasound evaluation of the superficial venous system, the deep venous system and the perforator system, according to venous haemodynamic principles. This study proposes a new model to be used in the ultrasonic management and treatment of superficial non-saphenous vein thrombosis.

Clinical characteristics and outcomes of patients with multiple simultaneous superficial vein thrombi

BACKGROUND

Although unprovoked superficial venous thrombosis (SVT) has traditionally been considered a local, benign disorder, recent studies demonstrate that patients with SVT are at significant risk for deep venous thrombosis, pulmonary embolism, and other venous thromboembolism (VTE) events. Nevertheless, clinical management remains widely inconsistent. Moreover, patients with multiple, unprovoked SVTs of noncommunicating anatomic sites have not been previously described, and they may be at even increased risk for adverse outcomes. The objective of this study was to describe the clinical characteristics and outcomes of patients with multiple, unprovoked SVTs to elucidate whether this subset of patients possesses a higher risk of thrombophilia, cancer, recurrent VTE, or death compared with patients with unprovoked SVT at a single location.

METHODS

Twenty-four patients with multiple, unprovoked SVTs were enrolled. Blood tests and computed tomography scans were performed to detect thrombophilia and malignant disease. Patients were followed up with duplex ultrasound and clinical examination for at least 3 months. The prevalence of recurrent VTE and clinical outcomes were compared with a control group of 39 patients with unprovoked SVT in a single vein.

RESULTS

Cancer was detected in five patients (20.8%) and thrombophilia in 10 patients (41.7%). During the follow-up period, nine patients (37.5%) exhibited recurrent VTEs, and five patients (16.2%) died. The VTE recurrence rate was significantly greater than in controls (P = .03). Patients with a coexisting thrombophilia or cancer had elevated thrombotic load (4.08 vs 2.27 separate vein segments; P = .0096) and an increase in VTE recurrence (P = .038) compared with patients without any such findings.

CONCLUSIONS

The results of this study warrant further investigation into this subset of patients through a larger multicenter design, as patients with multiple SVTs are at greater risk for thrombophilia, cancer, recurrent VTE events, and death compared with patients with isolated SVT.

Reflection on the cause and avoidance of recurrent venous leg ulcers: An interpretive descriptive approach

AIMS AND OBJECTIVES

To gain insight into the experience of recurrent venous leg ulcers from the individual's perspective and provide knowledge on potential risks of recurrence not previously investigated.

BACKGROUND

Venous leg ulcers are a consequence of chronic venous disease and frequently recur. They are costly and can impact on physical and psychological health. Despite research suggesting the risk can be reduced through compression and lifestyle changes, recurrence rates are often high. This study provides an insight into individual's perceptions of the cause of their ulcers and how they try to avoid them.

DESIGN

A qualitative design guided by the Chronic Illness Trajectory Model and Social Cognitive Theory.

METHOD

A purposive sample of three males and four females were recruited from a community nursing clinic. Participants were ulcer free, had experienced at least two previous venous leg ulcers and could speak and comprehend English. An interpretive descriptive approach was taken using semi-structured interviews and thematic analysis.

RESULTS

Three themes each containing three categories emerged: The Increasing Influence of the Recurring Wound on Mind and Body, Reflection on Past Experiences and Optimism in the Face of Adversity. Most participants reported traumatic injury and lower leg surgery triggered ulcer recurrence. Failure to replace compression stockings was also deemed a cause. Compression was reported essential, but some participants were unaware of the level they were wearing and how often it should be replaced. Other preventive activities included avoiding injury and securing immediate assistance if wounding occurred.

CONCLUSION

Clinicians need to be aware that lower leg surgery may trigger recurrent venous ulceration and that individuals require ongoing emotional, physical and financial support throughout the trajectory of venous disease. The continued use of old compression stockings should be avoided and recurrence prevented by adoption of evidence-based practice rather than reflection on past experiences.

RELEVANCE TO CLINICAL PRACTICE

This research raises the awareness of factors from the individual's perspective which can influence the recurrence of venous leg ulcers.

Superficial vein thrombosis in non-varicose veins of the lower limbs and thrombophilia

Objectives

Superficial vein thrombosis in non-varicose veins of the lower limbs is rather frequent and may be underestimated. This study aims to evaluate the prevalence of inherited or acquired thrombophilia in a sample of outpatients with the disease.

Method

An observational study was conducted on 73 consecutive superficial vein thrombosis patients tested for inherited or acquired thrombophilia.

Results

Sixty of 73 patients with superficial vein thrombosis completed the testing protocol, while 13 dropped out; 46 of 60 patients were found to have a thrombophilia (76.6%). The types detected were: factor V Leiden (31/60, i.e. 51.6%), prothrombin mutation (2/60, i.e. 3.3%), MTHFR mutation (23/60, i.e. 38.3%), antiphospholipid antibodies (5/60, i.e. 8.3%), protein C deficit (1/60, i.e. 1.6%), protein S deficit (1/60, i.e. 1.6%), and antithrombin deficit (0/60, i.e. 0%).

Conclusions

Among patients with superficial vein thrombosis in non-varicose veins, testing demonstrated a high prevalence of thrombophilia. The most common form proved to be factor V Leiden. As thrombophilia was found to be a major cause of superficial vein thrombosis in non-varicose veins, the authors recommend that patients with superficial vein thrombosis in non-varicose veins be investigated for thrombophilia.

Prevalence of deep vein thrombosis and pulmonary embolism in patients with superficial vein thrombosis: a systematic review and meta-analysis

Essentials The association of superficial vein thrombosis (SVT) with venous thromboembolism (VTE) is variable. We performed a meta-analysis to assess the prevalence of concomitant VTE in patients with SVT. Deep vein thrombosis was found in 18.1%, and pulmonary embolism in 6.9%, of SVT patients. Screening for VTE may be worthy in some SVT patients to plan adequate anticoagulant treatment.

SUMMARY

Background Some studies have suggested that patients with superficial vein thrombosis (SVT) have a non-negligible risk of concomitant deep vein thrombosis (DVT) or pulmonary embolism (PE) at the time of SVT diagnosis. Unfortunately, the available data on this association are widely variable. Objectives To perform a systematic review and meta-analysis of the literature in order to evaluate the prevalence of concomitant DVT/PE in patients with SVT of the lower limbs. Methods Studies reporting on the presence of DVT/PE in SVT patients were systematically searched for in the PubMed, Web of Science, Scopus and EMBASE databases. The weighted mean prevalence (WMP) of DVT and PE was calculated by use of the random effect model. Results Twenty-one studies (4358 patients) evaluated the prevalence of DVT and 11 studies (2484 patients) evaluated the prevalence of PE in patients with SVT. The WMP of DVT at SVT diagnosis was 18.1% (95%CI: 13.9%, 23.3%) and the WMP of PE was 6.9% (95%CI: 3.9%, 11.8%). Heterogeneity among the studies was substantial. Selection of studies including outpatients only gave similar results (WMP of DVT, 18.2%, 95% CI 12.2-26.3%; and WMP of PE, 8.2%, 95% CI 3.3-18.9%). Younger age, female gender, recent trauma and pregnancy were inversely associated with the presence of DVT/PE in SVT patients. Conclusions The results of our large meta-analysis suggest that the prevalence of DVT and PE in patients presenting with SVT is not negligible. Screening for a major thromboembolic event may be worthwhile in some SVT patients, in order to allow adequate anticoagulant treatment to be planned. Other high-quality studies are warranted to confirm our findings.

[Fatal outcome of bilateral pulmonary embolism combined with ascending varicophlebitis of the lower limb: case report]

The authors review the history and risk factors of thrombophlebitis of the lower limb, and describe the main points of surgical and conservative treatment of varicophlebitis. They present the case of a 71-year-old woman who had ascending varicophlebitis and bilateral pulmonary embolism. The authors draw attention to important points: patients must be followed after phlebitis of the lower limb, and their thrombotic factors must be examined to prevent the new thromboembolic events.

Morphology and Progression in Primary Varicose Vein Disorder Due to 677C>T and 1298A>C Variants of MTHFR

Background

Clinical assessment and prognostic stratification of primary varicose veins have remained controversial and the molecular pathogenesis is unknown. Previous data have suggested a contribution of the MTHFR (methylenetetrahydrofolate reductase) polymorphism c.677C>T.

Methods

We collected blood and vein specimens from 159 consecutive patients undergoing varicose vein surgery, or autologous vein reconstruction for arterial occlusive disease as controls. We compared the frequencies of c.677C>T and another polymorphism of MTHFR, c.1298A>C, with morphology and types of complicated disease. Morphology was recorded as a trunk or perforator type and peripheral congestive complication was defined as chronic venous insufficiency (CEAP C3–6) associated with edema and skin manifestations.

Findings

Multivariate analysis of genotypes for c.677C>T and c.1298A>C indicated that c.677C>T was associated significantly with the trunk phenotype (43/53 patients, 81%, p < 0.01), while c.1298A>C was associated significantly with the perforator phenotype (18/24 patients, 75%, p < 0.01) of primary varicose veins. Accordingly, when both c.677C>T and c.1298A>C displayed a heterozygous genotype, the patients were more likely to present with both phenotypes. Additionally, c.1298A>C was found to be strongly linked to the congestive complication (34/51 patients, 67%, p < 0.01).

Interpretation

Both polymorphisms of MTHFR may be involved in the morphological specification of primary varicose veins and contribute to the development of complicated disease.

Funding

None.

•

MTHFR polymorphism c.677C>T characterizes axial trunk and c.1298A>C perforator type morphology in primary varicose veins.

•

Mutant genotypes are associated with complicated phenotypes of the disease.

•

Genetic hint for distinct perforator type morphology associating further with congestive (CEAP C3–6) disease is provided.

Association of varicosities and concomitant deep venous thrombosis in patients with superficial venous thrombosis, a systematic review

BACKGROUND

In patients with superficial venous thrombosis (SVT) co-existence of deep venous thrombosis (DVT) can be present. Varicosities are considered as a risk factor for both SVT and DVT separately. However, current evidence is contradictory whether varicosities are associated with an increased or reduced prevalence of concomitant DVT in patients with SVT.

OBJECTIVES

To determine the diagnostic value of both presence and absence of varicosities in the detection of concomitant DVT in non-hospitalized patients with SVT.

METHODS

In MEDLINE and EMBASE, a systematic search was performed to collect all published studies on this topic. The selected papers were critically appraised. By diagnostic 2 × 2 tables prior probabilities and predictive values were computed.

RESULTS

Six relevant articles were identified. The prior probability of concomitant DVT in patients referred from primary care to the outpatient clinic varied between 13 and 34%. In five studies, absence of varicosities was related to a higher probability of concomitant DVT (33-44%) compared to a presence of varicosities (3-23%). The sixth study showed an inversed, non-significant association: DVT was present in 21% of patients with SVT on non-varicose veins versus in 35% of patients with SVT on varicose veins.

CONCLUSION

In five out of six studies on patients with SVT in outpatient settings, absence of varicosities was related to a higher probability of concomitant DVT. Further research is needed to determine whether an assessment of varicosities in general practice could result in an improved selection of patients who require additional imaging to detect or exclude DVT.

Risk marker associations with venous thrombotic events: a cross-sectional analysis

OBJECTIVE

To examine the interrelations among, and risk marker associations for, superficial and deep venous events-superficial venous thrombosis (SVT), deep venous thrombosis (DVT) and pulmonary embolism (PE).

DESIGN

Cross-sectional analysis.

SETTING

San Diego, California, USA.

PARTICIPANTS

2404 men and women aged 40-79 years from four ethnic groups: non-Hispanic White, Hispanic, African-American and Asian. The study sample was drawn from current and former staff and employees of the University of California, San Diego and their spouses/significant others.

OUTCOME MEASURES

Superficial and deep venous events, specifically SVT, DVT, PE and combined deep venous events (DVE) comprising DVT and PE.

RESULTS

Significant correlates on multivariable analysis were, for SVT: female sex, ethnicity (African-American=protective), lower educational attainment, immobility and family history of varicose veins. For DVT and DVE, significant correlates included: heavy smoking, immobility and family history of DVEs (borderline for DVE). For PE, significant predictors included immobility and, in contrast to DVT, blood pressure (BP, systolic or diastolic). In women, oestrogen use duration for hormone replacement therapy, in all and among oestrogen users, predicted PE and DVE, respectively.

CONCLUSIONS

These findings fortify evidence for known risk correlates/predictors for venous disease, such as family history, hormone use and immobility. New risk associations are shown. Striking among these is an association of PE, but not DVT, to elevated BP: we conjecture PE may serve as cause rather than consequence. Future studies should evaluate the temporal direction of this association. Oxidative stress and cell energy compromise are proposed to explain and predict many risk factors, operating through cell-death mediated triggering of coagulation activation.

Clinical relevance of symptomatic superficial-vein thrombosis extension: lessons from the CALISTO study

Symptomatic extensions, whether or not reaching the SFJ, are common complications of SVT. Their frequency and associated risk of venous thromboembolic complications and medical resource consumption are reduced by fondaparinux.

Factors associated with the development of superficial vein thrombosis in patients with varicose veins

INTRODUCTION

Superficial vein thrombosis (SVT) is a common and controversial clinical entity. Recent studies have demonstrated that SVT should be seen as a venous thromboembolism (VTE). The objective of this study was to investigate the prevalence of thrombophilia defects and to estimate the role of age, sex and body mass index (BMI) in patients with varicose veins (VVs) and SVT.

MATERIALS AND METHODS

A total of 230 patients with VVs, 128 with, and 102 without SVT underwent thrombophilia testing included factor V Leiden, prothrombin G20210A, methylenetetrahydrofolate reductase and plasminogen activator inhibitor- 1 mutations, protein C, protein S (PS), anti-thrombin III and plasminogen deficiencies and levels of A2 antiplasmin, activate protein C resistance and lupus anticoagulant. According to Clinical-Etiology-Anatomy-Pathophysiology (CEAP) classification patients were categorized in two subgroups: moderate disease (C2,3) and severe disease (C4,5,6). Age and body mass index were also assessed.

RESULTS

The prevalence of thrombophilia defects was significantly higher in patients with moderate disease and SVT (p=0.002). In the C2,3 group, SVT was associated with PS deficiency (p=0.018), obesity (p<0.001), male gender (p=0.047) and age (p<0.001). There were no significant differences in patients with severe disease.

CONCLUSIONS

Age, male sex, obesity and PS deficiency are factors associated with SVT development among patients with VVs having moderate disease (C2,3).

Superficial venous thrombosis and compression ultrasound imaging

BACKGROUND

A current debate concerning suspected superficial vein thrombosis (SVT) focuses on the need of performing a compression ultrasound (CUS) exploration for confirming the diagnosis of SVT. This study was conducted to determine the clinical relevance and optimal CUS exploration in patients with symptomatic SVT.

METHODS

We analyzed the characteristics of SVT and concomitant deep vein thrombosis (DVT) in patients included in the Prospective Observational Superficial Thrombophlebitis (POST) multicenter, observational prospective study. All patients underwent complete bilateral lower limb CUS, exploring both the superficial and deep venous systems.

RESULTS

A total of 844 patients with clinical symptoms of SVT were recruited, of which 99 isolated SVTs (21.4%) had saphenofemoral/popliteal junction involvement, and 198 (23.5%) had a concomitant DVT, with 41.8% of them proximal DVTs. In 83 patients (41.9%), DVT and SVT were not contiguous. Five of 639 patients (1%) had an isolated contralateral DVT (ie, not bilateral). Age ≥ 75 years (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.6-3.4), inpatient status (OR, 5.4; 95% CI, 3.4-8.7), a personal history of DVT or pulmonary embolism (OR, 1.8; 95% CI, 1.2-2.8), and SVT on nonvaricose veins (OR, 3.3; 95% CI, 2.1-5.0) were significantly and independently associated with an increased risk of concomitant DVT. Half of the patients exhibited none of these risk factors, and the prevalence of concomitant DVT dropped to 11%.

CONCLUSIONS

In patients with symptomatic SVT, a CUS exploration screening the whole venous system of the affected limb is useful because it provides information that has important consequences for the management of these patients.

Increased risk of venous thrombosis in persons with clinically diagnosed superficial vein thrombosis: results from the MEGA study

Superficial vein thrombosis (SVT) is regarded a self-limiting disorder, although the authors of recent studies showed that ultrasonographically diagnosed SVT is a precursor for venous thrombosis. We aimed to determine whether the same holds true for clinically diagnosed SVT and to what extent it is associated with thrombophilia in a population-based case-control study (ie, Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis). We found that a history of clinical SVT was associated with a 6.3-fold (95% confidence interval [CI] 5.0-8.0) increased risk of deep-vein thrombosis and a 3.9-fold (95% CI 3.0-5.1) increased risk of pulmonary embolism. Blood group non-O and factor V Leiden showed a small increase in SVT risk in controls, with odds ratios of 1.3 (95% CI 0.9-2.0) and 1.5 (95% CI 0.7-3.3), respectively. In conclusion, clinically diagnosed SVT was a risk factor for venous thrombosis. Given that thrombophilia was only weakly associated with SVT, it is likely that other factors (varicosis, obesity, stasis) also play a role in its etiology.