Superficial vein thrombosis (SVT) is a
blood clot
A thrombus ( thrombi) is a solid or semisolid aggregate from constituents of the blood (platelets, fibrin, red blood cells, white blood cells) within the circulatory system during life. A blood clot is the final product of the blood coagulatio ...
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 art ...
, a
vein
Veins () are blood vessels in the circulatory system of 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 those of the pulmonary and feta ...
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 ...
, 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 sys ...
(thickening of the skin) with
redness. SVT itself has limited significance (in terms of direct
morbidity
A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...
and
mortality) 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 enl ...
(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 ...
, 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
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 ...
(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,
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 enl ...
(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. Although usually just a cosmetic ailment, in some cases they cause fatigue, pain, itch, itching, and cramp, nighttime leg cram ...
, 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 Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
, history of
thromboembolism
Thromboembolism is a condition in which a blood clot (thrombus) breaks off from its original site and travels through the bloodstream (as an embolus) to obstruct a blood vessel, causing tissue ischemia and organ damage. Thromboembolism can affe ...
,
pregnancy
Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Conception (biology), Conception usually occurs ...
, 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. The introduction of the birth control pill ("the Pill") in 1960 revolutionized the options for contraception, ...
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. Effects of menopause can include symptoms such ...
, recent surgery, and certain
autoimmune diseases
An autoimmune disease is a condition that results from an anomalous response of the adaptive immune system, wherein it mistakenly targets and attacks healthy, functioning parts of the body as if they were foreign organisms. It is estimated that ...
(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 states 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 mutation, and
protein C
Protein C, also known as autoprothrombin IIA and blood coagulation factor XIV, is a zymogen, that is, an inactive enzyme. The activated form plays an important role in regulating anticoagulation, inflammation, and cell death and maintaini ...
,
S, and
antithrombin III
Antithrombin (AT) is a small glycoprotein that inactivates several enzymes of the coagulation system. It is a 464-amino-acid protein produced by the liver. It contains three disulfide bonds and a total of four possible glycosylation sites. α-An ...
and
factor XII deficiency.
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 with frequency, frequencies greater than 20 Hertz, kilohertz. This frequency is the approximate upper audible hearing range, limit of human hearing in healthy young adults. The physical principles of acoustic waves apply ...
.
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 dimer that is a fibrin degradation product (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 ...
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. Although usually just a cosmetic ailment, in some cases they cause fatigue, pain, itching, and nighttime leg cramps. These ve ...
(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 (or physiopathology) is a branch of study, at the intersection of pathology and physiology, concerning disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is ...
. 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, 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 stockings 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
An anticoagulant, commonly known as a blood thinner, is a chemical substance that prevents or reduces the coagulation of blood, prolonging the clotting time. Some occur naturally in blood-eating animals, such as leeches and mosquitoes, which h ...
,
NSAIDs (except
aspirin
Aspirin () is the genericized trademark for acetylsalicylic acid (ASA), a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and inflammation, and as an antithrombotic. Specific inflammatory conditions that aspirin is ...
),
antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...
, 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 invol ...
.
Anticoagulants
SVTs that occur within the
great saphenous vein
The great saphenous vein (GSV; ) or long saphenous vein is a large, subcutaneous, superficial vein of the human leg, leg. It is the longest vein in the body, running along the length of the lower limb, returning blood from the foot, human leg, le ...
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 antagonize 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 Viatris. A generic version developed by Alchemia is marketed within the US by Dr. Reddy's Laboratories.
Med ...
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 Thrombosis prevention, blood clots and, in the treatment of venous thromboembolism (deep vein thrombosis and pulmonary embolism), and ...
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 invol ...
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 of the saphenofemoral junction, ligation and
stripping of the affected veins, and local
thrombectomy
Mechanical thrombectomy, or simply thrombectomy, is the removal of a blood clot (thrombus) from a blood vessel, often and especially endovascularly as an interventional radiology procedure called endovascular thrombectomy (EVT). It thus contr ...
.
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
Intensiv ...
guidelines and the 2012
British Committee for Standards in Haematology 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