Deep Vein Thrombosis

February 1, 2017

Deep vein thrombosis (DVT, also called venous thrombosis) is a blood clot that develops in a vein deep in the body. The clot may partially or completely block blood flow through the vein. Most DVTs occur in the lower leg, thigh or pelvis, although they also can occur in other parts of the body including the arm, brain, intestines, liver or kidney.

The blood supply of the leg is transported by arteries and veins. The arteries carry blood from the heart to the limbs; veins carry blood back to the heart. The leg contains superficial veins, which are close to the surface, and deep veins, which lie much deeper in the leg. Deep vein thrombosis (DVT) is a condition in which a blood clot (a blockage) forms in a deep vein. While these clots most commonly occur in the veins of the leg (the calf or thigh), they can also develop in other parts of the body.

DVT can be very dangerous and is considered a medical emergency. If the clot (also known as a thrombus) breaks loose and travels through the bloodstream, it can lodge in the lung. This blockage in the lung, called a pulmonary embolism, can make it difficult to breathe and may even cause death. Blood clots in the thigh are more likely to cause a pulmonary embolism than those in the calf.

Studies suggest that DVTs affect approximately 1 in every 1,000 adults in America each year. Public health authorities estimate a total incidence of between 350,000 and 600,000 cases of DVT or PE annually. About 100,000 people lose their lives each year because of a DVT/PE related condition each year.

Causes

Blood clots most commonly occur when there is trauma to the vessel, hypercoagulability and stasis (Virchow’s Triad). This damage is often a result of infection, surgery, or a previous thrombosis. When damage occurs, blood clots can develop, usually starting in the veins of the calf progressing upward.

If the blockage is not treated, it can jeopardize an affected limb by obstructing blood flow. This causes leg swelling and can lead to chronic venous insufficiency (CVI), when the same clotting factors that stop external bleeding begin to function inappropriately in deep veins. The clot may grow large enough to block the vein, or become dislodged and travel to the lungs.

Less common causes of thrombosis are –

Lengthy periods of immobility (such as sitting on an airplane or confinement to bed or wheelchair). These can disrupt the balance of blood pressure in the veins, slow circulation and impair blood flow.

Clotting abnormalities associated with cancer, sickle-cell anemia, estrogen or progestin replacement therapy, dehydration and thickening of the blood.

Risk Factors

Several risk factors can affect blood flow in the deep veins and increase the risk for developing blood clots. These include –

Increasing age
Personal or family history of DVT or pulmonary embolism
Having certain types of malignant cancers
Having a vein disease, such as varicose veins
Smoking
Using birth control pills or hormone therapy
Pregnancy
Being overweight or obese
Inheriting a blood-clotting disorder

Symptoms

DVT most commonly occurs in just one leg or one arm. Not everyone with DVT will experience symptoms, although when present, they may include –

Swelling of the leg or arm (sometimes it occurs suddenly)
Pain or tenderness in the leg that may only be present when standing or walking
Feeling of increased warmth in the area of the leg or arm that is swollen or that hurts
Redness or discoloration of the skin
Enlargement of the superficial veins in the affected leg or arm

Symptoms of a pulmonary embolism include –

(Sudden) shortness of breath
Sharp chest pain, often aggravated by coughing or movement
Pain in the back
Cough with or without bloody sputum
Excessive sweating
Rapid pulse or breathing
Lightheadedness or passing out

Some people only find out they have DVT after the clot has moved from the leg or arm and traveled to the lung.

Treatment

Anticoagulants – Nonsurgical treatment usually consists of taking anticoagulants—blood thinning medications that will prevent further clotting and help dissolve existing clots. Anticoagulant medications are started immediately after the clot is diagnosed. These include –

Heparin
Warfarin
Xa inhibitors

Thrombolysis – this means the breaking down of blood clots. Drugs that break down clots are called thrombolytics or clotbusters. Patients with more serious DVT or pulmonary embolism may require such drugs. TPA (tissue plasminogen activator) is an example. Because of their risk of side effects – namely bleeding – they are only used when the patient’s life it as risk.

Compression stocking – These are worn to help reduce calf pain, swelling, and to prevent ulcers from developing. Stockings can also protect the patient from post-thrombotic syndrome.

Inferior vena cava filter – This tiny umbrella-like device is inserted into the vein to catch blood clots and stop them moving up into the lungs, while allowing blood flow to continue. It is inserted in the vena cava, a large vein.

Alternative Treatment

Vitamin E is a fat-soluble vitamin with antioxidant properties. Vitamin E has antiplatelet and possibly also anticoagulant properties, although the mechanism is speculative. The clot preventative effect of vitamin E seen in the laboratory appears to be dose dependent.

Vitamin D is a nutrient most often linked to the maintenance of strong bones, but it has also been suspected to have an anticoagulant effect by changing certain proteins involved in the clotting mechanism (upregulating thrombomodulin and downregulating tissue factor).

Fish oil is an omega-3 polyunsaturated fatty acid that comes from cold water fish, such as wild salmon, tuna, herring, and anchovies. Omega-3 fatty acids affect blood clotting by decreasing platelet aggregation, which modestly prolongs bleeding time

Garlic – Three compounds in garlic (allicin, adenosine, and paraffinic sulfide) are thought to have antiplatelet properties. There are few data on its effect on preventing venous clots.

Nattokinase is a soybean food content, produced by the bacterium Bacillus subtilis (natto) during fermentation of soybeans. It is a 275 amino acid protein. It is also called “Subtilisin NAT”. It is claimed to have clot-dissolving abilities, similar to plasmin. Plasmin is an important enzyme that we all have in our blood as our natural defense mechanism to dissolve unwanted blood clots.

Evening primrose oil, borage oil, and black currant oil all contain an unsaturated fatty acid called gamma-linolenic acid. Patients taking warfarin are sometimes advised to not take evening primrose oil because it can increase bleeding risk, but this recommendation has been based primarily upon anecdotal case reports rather than the result of clinical studies.

Lumbrokinase is an enzyme extracted from earthworms. The majority of studies involving lumbrokinase have been done in Asia and reported in medical journals not in wide circulation and involve mice, rabbits or human blood samples.

Glucosamine – Helps in suppressing platelet activation in humans, shown to effect platelet aggregation in guinea pigs.

Selenium – These supplements may affect an enzyme necessary in clot formation.

Resveratrol – Helps in inhibition of platelet adhesion, platelet aggregation .

Reference –

http://www.mayoclinic.org/diseases-conditions/deep-vein-thrombosis/basics/definition/con-20031922

https://www.nlm.nih.gov/medlineplus/ency/article/000156.htm

http://emedicine.medscape.com/article/1911303-overview

http://www.webmd.com/dvt/

http://www.sirweb.org/patients/deep-vein-thrombosis/

http://patient.info/health/deep-vein-thrombosis-leaflet

http://www.cdc.gov/ncbddd/dvt/facts.html

http://www.vascularweb.org/vascularhealth/pages/deep-vein-thrombosis-(-dvt-)-.aspx