Deep Vein Thrombosis (DVT)

Arteries bring oxygen-rich blood from the heart to the rest of your body, whereas the veins are the blood vessels that return oxygen-poor blood back to the heart. There are three kinds of veins. Superficial veins lie close to the skin, and the deep veins lie in groups of muscles. Perforating veins connect the superficial veins to the deep veins with one-way valves. Deep veins lead to the vena cava, the body's largest vein, which runs directly to the heart. Deep vein thrombosis (DVT) is a blood clot in one of the deep veins. Usually, DVT occurs in the pelvis, thigh, or calf, but it can also occur less commonly in the arm, chest, or other locations.

DVT can cause sudden swelling, pain or a sensation of warmth. DVT can be dangerous because it can cause a complication known as pulmonary embolism. In this condition, a blood clot breaks free from the deep veins, travels through the bloodstream, and lodges in the lungs. This clot can block blood flow in the lungs, which can strain the heart and lungs. A pulmonary embolism is a medical emergency. A large embolism can be fatal in a short time.

Symptoms

About half of all DVT cases do not cause symptoms. The symptoms you feel can depend on the location and size of your blood clot. They include swelling, tenderness, leg pain that may worsen when you walk or stand, a sensation of warmth, and skin that turns blue or red.

Risk Factors

Often, poor blood flow, or stagnation of blood flow, in your leg veins increases the risk for DVT. This poor flow can occur when you are not able to move for long periods of time. As a result, when your blood pools in your veins, clots are more likely to form. Some specific causes of DVT include:

  • Major surgery on your hip, knee, leg, calf, abdomen, or chest
  • A broken hip or leg
  • Prolonged travel
  • Inherited blood clotting abnormalities
  • Cancer


Most cases of DVT affect the legs, but DVT in the upper body is becoming more commonly recognized. Some factors that increase your chances of developing DVT in the upper body include:

  • Having a long, thin flexible tube called a catheter inserted in your arm vein. Catheters can irritate your vein wall and cause clots to form
  • Having a pacemaker or implantable cardioverter defibrillator (ICD) for the same reason
  • Cancer
  • Performing vigorous repetitive activities with your arms. This type of DVT is rare and occurs mostly in athletes such as weight lifters, swimmers and baseball pitchers. This disease is known as Paget-Schroeter syndrome, and can often be associated with other anatomic abnormalities

Diagnosis

  • History and Physical Examination
  • Duplex ultrasound
  • Intravascular Ultrasound
  • CT Scan
  • A venogram is an x ray that allows your physician to see the anatomy of your veins and sometimes the clots within them

Treatment

Medications

  • Heparin - IV medication used in the hospital
  • Lovenox - Recombinant heparin related drug, this is usually given subcutaneously
  • Coumadin - Oral medication, taken on a daily basis. This requires weekly monitoring of blood levels called INR
  • Other drugs - Newer oral agents are now available for treatment of DVT. Most of these drugs would be used as replacement for Coumadin and do not require weekly monitoring

Surgical Options

  • Thrombolysis
  • This procedure is used to dissolve and break the clot endovascularly. In this procedure, the vascular surgeon injects clot-dissolving drugs through a catheter directly into the clot. Thrombolysis has a higher risk for bleeding complications and stroke than anticoagulant therapy. However, thrombolysis can also dissolve very large clots.
  • Open Thrombectomy
  • Rarely, physicians recommend surgery to remove a deep vein clot. The procedure is called venous thrombectomy. You may need this surgery if you have a severe form of DVT, which does not respond to adequate non-surgical treatment and thrombolysis.
  • Vena Caval filter
  • A special metal filter can protect you from a pulmonary embolism if you are unable to take anticoagulants. This device is called a vena cava filter. The vena cava is a large vein in your abdomen. It carries blood back to your heart and lungs. The vascular surgeon may recommend a vena cava filter if you are not a candidate for drug therapy for DVT or if drugs didn't reduce your clots. Vena cava filters trap the clots that break away from your leg veins before they can reach your lungs.

Risks of Intervention

Risks of thrombolysis include high risk of bleeding, need for additional procedures, stroke, and very small risk of death. May need to be monitored in ICU.