Blood Clots – A Silent Killer

What is a Deep Vein Thrombosis (DVT)?

A DVT is a venous thromboembolism (VTE) in one of the deep veins in the human body. The terms DVT and VTE are often used interchangeably. In layman’s terms, a DVT or VTE is called a “blood clot”. Blood clots stick to the wall on the inside of a vein.  As foot and ankle surgeons, we are always on the lookout for this condition.

What are the signs/symptoms of a DVT?

Patients typically present with localized pain, swelling, redness or warmth to only one extremity. In the lower extremity is usually found in the calf muscle.

How are DVTs diagnosed?

If a clinician is suspicious of a DVT based on the patient’s signs and symptoms, a diagnostic ultrasound of the veins is commonly ordered. Blood tests may be ordered prior to the ultrasound to help aid the clinician in the diagnosis.

What causes DVTs?

There are many contributing factors to the development of DVTs.

Examples of factors which contribute to these conditions are:

Hypercoagulability of Blood

·         Malignancy (i.e. cancer)

·         Pregnancy or post-partum

·         Estrogen therapy (Oral contraceptives)

·         Trauma or surgery, especially to the lower extremity

Stasis of Blood

·         Atrial fibrillation

·         Prolonged hospitalization, cast immobilization, or paralysis

·         Venous insufficiency or varicose veins

·         Venous obstruction from tumor, obesity, or pregnancy

Vessel Wall Injury

·         Trauma or surgery in the foot or leg

·         Heart valve disease or replacement

·         Atherosclerosis

·         Venipuncture or indwelling catheters

Other risk factors include having had a previous DVT, increasing age, extended travel/prolonged sitting, being female, history of stroke, and family history of thrombosis.

Why are DVTs deadly?

DVTs have the potential to cause death. This is because when a blood clot sticks to the inside of a vein wall, there is the possibility that it breaks loose. When this happens, it can either become stuck in a more proximal portion of the vein, or it can migrate all the way to the lungs. When this happens, it is classified as a “pulmonary embolism” and, if the embolism is large enough, can interrupt the lung’s ability to effectively exchange oxygen to the blood. This can ultimately result in sudden death.

What is the treatment for DVTs?

An anticoagulant or “blood thinner” is typically prescribed for the prevention and/or treatment of DVTs. Prophylactic treatment may consist of pneumatic calf pumps, compression stockings, exercises to work the calf/leg muscles, or medications. These daily medications can either be oral or injected under the skin. The patient is typically on these medications only for as long as they are at an increased risk of DVT (e.g. after surgery and in a below knee cast).

Therapeutic treatment is treatment done after a DVT has formed in a vein. These drugs help dissolve the blood clot and prevent the formation of more clots.

A patient with a history of recurrent blood clots or has significant major risk factors for developing blood clots may be placed on chronic blood thinner therapy. Some of these medications require patients to have regular blood tests, too make sure the optimal amount of medication is being used.

Blood thinners carry a unique set of risks, namely the inability to stop bleeding. This can be fatal if bleeding were to occur intra-cranially (e.g. patient hits their head). Other possible side effects include blood in the urine or stool. It is always best to talk to you foot and ankle surgeon and your primary physician about any questions or concerns you may have before starting a new medication.