Superficial vein thrombosis (SVT) is a

blood clot A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of c ...

formed in a

superficial vein Superficial veins are veins that are close to the surface of the body, as opposed to deep veins, which are far from the surface. Superficial veins are not paired with an artery, unlike the deep veins, which are typically associated with an arte ...

, a

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...

near the surface of the body. Usually there is

thrombophlebitis Thrombophlebitis is a phlebitis (inflammation of a vein) related to a thrombus (blood clot). When it occurs repeatedly in different locations, it is known as thrombophlebitis migrans (migratory thrombophlebitis). Signs and symptoms The following s ...

, which is an inflammatory reaction around a thrombosed vein, presenting as a painful

induration A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this sy ...

(thickening of the skin) with redness. SVT itself has limited significance (in terms of direct

morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

and

mortality Mortality is the state of being mortal, or susceptible to death; the opposite of immortality. Mortality may also refer to: * Fish mortality, a parameter used in fisheries population dynamics to account for the loss of fish in a fish stock throug ...

) when compared to a

deep vein thrombosis Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enla ...

(DVT), which occurs deeper in the body at the deep venous system level. However, SVT can lead to serious complications (as well as signal other serious problems, such as genetic mutations that increase one's risk for clotting), and is therefore no longer regarded as a benign condition. If the blood clot is too near the saphenofemoral junction there is a higher risk of

pulmonary embolism Pulmonary embolism (PE) is a blockage of an pulmonary artery, artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include dyspnea, shortness of breath, chest pain p ...

, a potentially life-threatening complication. SVT has risk factors similar to those for other thrombotic conditions and can arise from a variety of causes. Diagnosis is often based on symptoms. There are multiple possible treatments, with the goal of providing symptomatic relief and preventing complications.

Signs and symptoms

SVT is recognized by the presence of pain, warmth, redness, and tenderness over a superficial vein. The SVT may present as a "cord-like" structure upon palpation. The affected vein may be hard along its entire length. SVTs tend to involve the legs, though they can affect any superficial vein (e.g. those in the arms).

Complications

SVT in the lower extremities can lead to a dangerous complication in which the clot travels to the lungs, called

(PE). This is because lower limb SVTs can migrate from superficial veins into deeper veins. In a French population, the percent of people with SVTs that also suffered from PEs was 4.7%. In the same population,

(DVT) was found in 24.6% of people with SVTs. However, because superficial veins lack muscular support, any clots that form are far less likely to be squeezed by muscle contraction, dislodged, and induce a PE. SVTs can recur after they resolve, which is termed "migratory thrombophlebitis." Migratory thrombophlebitis is a complication that may be due to more serious disorders, such as cancer and other hypercoagulable states.

Causes

SVTs of the legs are often due to

varicose veins Varicose veins, also known as varicoses, are a medical condition in which superficial veins become enlarged and twisted. These veins typically develop in the legs, just under the skin. Varicose veins usually cause few symptoms. However, some indi ...

, though most people with varicose veins do not develop SVTs. SVTs of the arms are often due to the placement of intravenous catheters. Many of the risk factors that are associated with SVT are also associated with other thrombotic conditions (e.g. DVT). These risk factors include age,

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

, history of thromboembolism,

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

, use of

oral contraceptive Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control. Female Two types of female oral contraceptive pill, taken once per day, are widely available: * The combin ...

medications (containing estrogen),

hormone replacement therapy Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. These symptoms can include hot flashes, vaginal ...

, recent surgery, and certain

autoimmune diseases An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...

(especially Behçet's and Buerger's diseases). Other risk factors include immobilization (stasis) and

laparoscopy Laparoscopy () is an operation performed in the abdomen or pelvis using small incisions (usually 0.5–1.5 cm) with the aid of a camera. The laparoscope aids diagnosis or therapeutic interventions with a few small cuts in the abdomen.Medli ...

Hypercoagulable state Thrombophilia (sometimes called hypercoagulability or a prothrombotic state) is an abnormality of blood coagulation that increases the risk of thrombosis (blood clots in blood vessels). Such abnormalities can be identified in 50% of people who ...

s due to genetic conditions that increase the risk of clotting may contribute to the development of SVT, such as

factor V Leiden Factor V Leiden (rs6025 or ''F5'' p.R506Q) is a variant (mutated form) of human factor V (one of several substances that helps blood clot), which causes an increase in blood clotting (hypercoagulability). Due to this mutation, protein C, an anticoa ...

prothrombin 20210A Prothrombin G20210A is a genetic condition that increases the risk of blood clots including from deep vein thrombosis, and of pulmonary embolism. One copy of the mutation increases the risk of a blood clot from 1 in 1,000 per year to 2.5 in 1,000. ...

mutation, and

protein C Protein C, also known as autoprothrombin IIA and blood coagulation factor XIX, is a zymogen, that is, an inactive enzyme. The activated form plays an important role in regulating anticoagulation, inflammation, and apoptosis, cell death and ...

, S, and

antithrombin III Antithrombin (AT) is a small glycoprotein that inactivates several enzymes of the coagulation system. It is a 432-amino-acid protein produced by the liver. It contains three disulfide bonds and a total of four possible glycosylation sites. α-Ant ...

and

factor XII deficiency Factor XII deficiency is a deficiency in the production of factor XII (FXII), a plasma glycoprotein and clotting factor that participates in the coagulation cascade and activates factor XI. FXII appears to be not essential for blood clotting, as ...

Mechanism

The mechanism for the development of an SVT depends upon the specific etiology of the SVT. For example, varicose veins and prolonged bed rest both may induce SVTs due to slowing the flow of blood through superficial veins.

Diagnosis

SVTs may be diagnosed based upon clinical criteria by a healthcare professional. A more specific evaluation can be made by

ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible limit of human hearing range, hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hea ...

. An ultrasound can be useful in situations in which an SVT occurs above the knee and is not associated with a varicose vein, because ultrasounds can detect more serious clots like DVTs. The diagnostic utility of

D-dimer D-dimer (or D dimer) is a fibrin degradation product (or FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. It is so named because it contains two D fragments of the fibrin protein joined by a cross ...

testing in the setting of SVTs has yet to be fully established.

Classification

SVTs can be classified as either

varicose vein Varicose veins, also known as varicoses, are a medical condition in which superficial veins become enlarged and twisted. These veins typically develop in the legs, just under the skin. Varicose veins usually cause few symptoms. However, some indiv ...

(VV) or non-varicose (NV) associated. NV-SVTs are more likely to be associated with genetic procoagulable states compared to VV-SVTs. SVTs can also be classified by

pathophysiology Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is the ...

. That is, primary SVTs are characterized by inflammation that is localized to the veins. Secondary SVTs are characterized by systemic inflammatory processes. A subclass of SVTs are

septic thrombophlebitis Septic thrombophlebitis refers to venous thrombosis and inflammation associated with bacteremia. Causes It can occur following throat infections, dental procedures, gingivitis Gingivitis is a non-destructive disease that causes inflammation o ...

, which are SVTs that occur in the setting of an infection.

Treatment

The goal of treatment in SVT is to reduce local inflammation and prevent the SVT from extending from its point of origin. Treatment may entail the use of compression, physical activity, medications, or surgical interventions. The optimal treatment for many SVT sites (i.e. upper limbs, neck, abdominal and thoracic walls, and the penis) has not been determined.

Compression

Multiple compression bandages exist. Fixed compression bandages, adhesive short stretch bandages, and graduated elastic

compression stocking Compression stockings (Flight Socks, Support Bandage) are a specialized hosiery designed to help prevent the occurrence of, and guard against further progression of, venous disorders such as edema, phlebitis and thrombosis. Compression stockings ...

s have all be used in the treatment of SVTs. The benefit of compression stockings is unclear, though they are frequently used.

Physical activity

Inactivity is contraindicated in the aftermath of an SVT. Uninterrupted periods of sitting or standing may cause the SVT to elongate from its point of origin, increasing the risk for complications and clinical worsening.

Medications

Medications used for the treatment of SVT include

anticoagulants Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where the ...

, NSAIDs (except

aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...

, and

corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involve ...

Anticoagulants

SVTs that occur within the

great saphenous vein The great saphenous vein (GSV, alternately "long saphenous vein"; ) is a large, subcutaneous, superficial vein of the leg. It is the longest vein in the body, running along the length of the lower limb, returning blood from the foot, leg and thig ...

within 3 cm of the saphenofemoral junction are considered to be equivalent in risk to DVTs. These high risk SVTs are treated identically with therapeutic anticoagulation. Anticoagulation is also used for intermediate risk SVTs that are greater than 3 cm from the saphenofemoral junction or are greater than 4–5 cm in length. Anticoagulation for high risk SVTs includes the use of

vitamin K antagonists Vitamin K antagonists (VKA) are a group of substances that reduce blood clotting by reducing the action of vitamin K. The term "vitamin K antagonist" is technically a misnomer, as the drugs do not directly antagonise the action of vitamin K in t ...

or novel oral anticoagulants (NOACs) for 3 months. Anticoagulation for intermediate risk SVTs includes

fondaparinux Fondaparinux (trade name Arixtra) is an anticoagulant medication chemically related to low molecular weight heparins. It is marketed by GlaxoSmithKline. A generic version developed by Alchemia is marketed within the US by Dr. Reddy's Laboratories. ...

2.5 mg daily for 45 days or the use of intermediate to therapeutic dose

low molecular weight heparin Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention of blood clots and treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism) and in the treatment of myocardial in ...

for 4–6 weeks.

NSAIDs

NSAIDs (non-steroidal anti-inflammatory drugs) can be used in both oral or topical formulations for the relief of SVT symptoms. The British Committee for Standards in Haematology guidelines recommend the use of NSAIDs for low-risk SVTs (thrombus <4–5 cm in length, no additional risk factors for thromboembolic events). NSAIDs are used for treatment durations of 8–12 days.

Other

Antibiotics are used in the treatment of septic SVT.

Corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involve ...

are used for the treatment of SVTs in the setting of vasculitic and autoimmune syndromes.

Surgery

Surgical interventions are used for both symptomatic relief of the SVT as well as for preventing the development of more serious complications (e.g. pulmonary embolism). Surgical interventions include

ligation Ligation may refer to: * Ligation (molecular biology), the covalent linking of two ends of DNA or RNA molecules * In medicine, the making of a ligature (tie) * Chemical ligation, the production of peptides from amino acids * Tubal ligation, a meth ...

of the saphenofemoral junction, ligation and stripping of the affected veins, and local

thrombectomy Mechanical thrombectomy, or simply thrombectomy, is the interventional procedure of removing a blood clot (thrombus) from a blood vessel. It is commonly performed in the cerebral arteries (interventional neuroradiology). The effectiveness of throm ...

. Because of the risk of symptomatic pulmonary embolism with surgery itself, surgical interventions are not recommended for the treatment of lower limb SVTs by the 2012

American College of Chest Physicians The American College of Chest Physicians (CHEST) is a medical association in the United States consisting of physicians and non-physician specialists in the field of chest medicine, which includes pulmonology, critical care medicine, and sleep med ...

guidelines and the 2012

British Committee for Standards in Haematology British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

guidelines. The use of surgery for the treatment of SVT is controversial.

Prognosis

SVT is often a mild, self-resolving medical condition. The inflammatory reaction may last up to 2–3 weeks, with possible recanalization of the thrombosed vein occurring in 6–8 weeks. The superficial vein may continue to be hyperpigmented for several months following the initial event.

Epidemiology

In a French population, SVT occurred in 0.64 per 1000 persons per year.

History

SVTs have been historically considered to be benign diseases, for which treatment was limited to conservative measures. However, an increased awareness of the potential risks of SVTs developing into more serious complications has prompted more research into the diagnosis, classification, and treatment of SVTs.

Research

A Cochrane review recommends that future research investigate the utility of oral, topical, and surgical treatments for preventing the progression of SVTs and the development of thromboembolic complications.

Footnotes

References

{{reflist, 30em Coagulopathies Diseases of veins, lymphatic vessels and lymph nodes Hematology Vascular-related cutaneous conditions Angiology Vascular diseases