How are blood clots treated?

Blood Clot
Blood Clot. BSIP/UIG//Getty Images

If you have been diagnosed with a blood clot, your next question is naturally, what is the treatment?  There are multiple treatments and the choice made depends on several factors including location of the clot and age of the patient.  Similar to real estate, it is all about location, location, location.  

  1. Arteries vs. Veins:  Blood clots in arteries (blood vessels that take oxygenated blood to tissues) are more serious than clots in veins (blood vessels that take unoxygenated blood back to the heart).  Without rapid intervention, arterial blood clots can result in lack of blood flow to a particular area causing tissue death. The exception to this rule is a blood clot in the pulmonary vein which can be life threatening.  
  1. Superficial vs. Deep:  The location of the clot in the venous system matters.  The venous system is broken down into a superficial venous system and a deep venous system.  Superficial clots are generally considered less serious and are treated more conservatively.  Clots in the deep venous system are more likely to enlarge (block blood flow in a larger area).  These blood clots are also more likely to break off into small pieces (emboli) which can travel in the blood supply and get stuck somewhere else, blocking blood flow.  If you have a blood clot in your leg, a small piece might break off and travel to lungs, blocking blood flow in the lungs, called pulmonary emboli.  Preventing these events is a important reason for treating blood clots.  One trivia fact: the superficial femoral vein (found in your leg) is part of the deep venous system and clots in this area require treatment despite its name.    
  1. Brain or Lungs vs. Leg or Arm:  Where in your body is the clot?  Is the clot in your brain?  Lack of blood flow in an artery of the brain is a medical emergency (ischemic stroke) and must be treated rapidly and aggressively.  Time is of the essence.  Treatment with tissue plasminogen activator (TPA) must be given within 3 hours of the first symptoms.  Blood clots in the venous system of the brain (cerebral sinus venous thrombus) can cause a different type of stroke.  If the veins are unable to drain the blood pumping into the brain, it causes pressure build up in arteries of the brain which may result in a brain bleed (hemorrhagic stroke).  Similarly, blood clots in the lungs may be life threatening (dependent on size).  These clots are usually treated with more aggressive therapy than blood clots in the leg or arm.  

    I know my clot needs treatment so what are my treatment choices?

    1. Symptomatic management:  Small blood clots in the superficial venous system (also called thrombophlebitis) are treated with heat to the area and non-steroidal anti-inflammatory medications (NSAIDs) like ibuprofen.  If pain is severe, these clots may occasionally be treated for a short period of time with blood thinner medications that we will discuss below. 
    2. Tissue plasminogen activator (tPA): tPA is used to treat limb or life threatening blood clots like ischemic strokes.  tPA is a "clot buster" that it actively breaks down the clot.  tPA works rapidly and must be administered via an IV.  Because tPA actively prevents the clotting system from working properly, bleeding is the most concerning side effect.  If you have had serious bleeding recently, you likely will not be a candidate for this treatment.  
    3. Thrombectomy or Thrombolysis:  If the blood clot is in a life threatening area, physically removing it may be recommended.  This procedure is most commonly performed by an interventional radiologist or a vascular surgeon.  A small tube (called a catheter) is placed in a large blood vessel in the leg (femoral vein) and is guided to the area of clot to remove it.  The clot can be broken down physically or with medications.   After the procedure, the catheter may stay in place for a couple of days infusing tPA directly at the site of the clot.  
    1. Heparin:  Heparin is one of the most common blood thinners used.  Often heparin is used in small doses to prevent blood clots from forming, but larger doses of heparin can be used to treat blood clots.  Heparin does not actively break down the clot like tPA but stabilizes the clot while your body removes the clot over time.  Heparin is administered via an IV as a continuous (all the time) drip (usually in the intensive care unit, ICU).  It is monitored careful with blood tests to ensure the drip is in the therapeutic range without increasing the risk of bleeding dramatically.  
    2. Low molecular weight heparin (LMWH):  LMWH goes by the brand names Enoxaparin and Fragmin among others.  LMWH is given as a subcutaneous (under the skin) injection every 12 - 24 hours.  Most children are treated every 12 hours as the medication is broken down more rapidly than in an adult.  Although not common in adults, children receiving LMWH are monitored closely to ensure the dose is correct for the individual child and is adjusted as needed.  Overall the bleeding risk is low when using LMWH and is considered one of the advantages of this treatment.   
    3. Warfarin (also known as Coumadin):  Warfarin is an oral medication used to treat or prevent blood clots.  It is used commonly in people who require lifelong prevention of blood clot secondary to other medical conditions such as after heart valve replacement.  Using warfarin can be tricky and it requires extensive laboratory monitoring to ensure the medication is in the therapeutic range.  Multiple things like dietary changes or use of antibiotics can greatly affect warfarin and often require dose adjustments. 
    4. Other oral agents:  Currently there are a slew of other oral medications used to treat or prevent clot formation.  These include rivaroxaban (Xarelto), apixaban (Eliquis), and dabigatran (Pradaxa).  Most of these medications have been approved by the Food and Drug Administration (FDA) in the last 5 years.  These medications do not require monitoring like other therapies.  

    Learning you have a blood clot can be very stressful but today you have many treatment options.  It is important to discuss with your physician how or why a particular therapy was recommended as well as possible side effects of the therapy.  Additionally, you should discuss treatment duration with your physician.  Will you only need treatment for 3 months? 6 months? Lifelong?  This often will guide you to the most appropriate treatment for you.  

    References:

    Guyatt GH, Akl EA, Crowther M, Gutterman DD, and Schünemann HJ.  Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.  Chest. 2012; 141(2)(Suppl):7S–47S. 

    Kearon C, Aki EA, Ornelas J et al. Antithrombotic Therapy for VTE Disease CHEST Guideline and Expert Panel Report. Chest. 2016; 149(2):315-352.

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