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Understanding Coagulopathy in Vascular Anomalies


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Below is the webinar in it’s entirety. A special thanks to the M-CM Network, CLOVES Syndrome Community, and the Klippel Trenaunay Support Group for organizing this informative presentation.

Vascular anomalies is an “old-school” umbrella term

  1. Tumors generally benign
  2. Malformations
    1. Slow flow.
    2. High flow.

Visit ISSVA for the most recent outline of vascular anomalies. Click on the word “HERE”  in first sentence.


What happens when a vascular injury occurs?

  1. Vasoconstriction to reduce blood flow
  2. Platelet plug formation creates coagulation (fibrin formation)
  3. Fibrinolysis leads to the repair process
  4. And finally wound healing

Two Sides to coagulopathy

  1. Hemostasis
    1. Control and stop bleeding.
    2. Involves multiple structures.
      1. Blood vessels, supporting structures, platelets, interaction with injured vessels, formation of fibrin or the cessation of blood flow from or within a blood vessel.
  2. Thrombosis
    1. Regulation of clot with remodeling and repair to the injured site following the cessation of bleeding.
    2. Resolving the clot.
      1. All dependent on blood vessel, flow, and platelet response
  3. Bleeding and clotting can happen simultaneously

Vascular Anomalies

  1. Bleeding
  2. Clotting
  3. Abnormal muscles within the vasculature
    1. Slow flow allows proteins to get sticky creating a clot.

Coagulopathy is multifactorial:

  1. Virchow’s Triad:
    1. A trio of elements essential to thrombosis; i.e. blood stasis (secondary to immobility, congestive heart failure, vein compressions), alteration to a vein wall (secondary to previous thrombosis, vein inflammation/infection, direct vein wall trauma, varicose veins) and blood hypercoagulability (e.g. antiphospholipid syndrome, hyperhomocysteinaemia, lower-limb surgery/trauma, childbirth, polycythaemia, neoplastic disease, oral contraceptives); thrombosis requires a minimum of two of the three elements
        • Vessel Injury
        • Blood flow
        • Blood composition
  2. Abnormal endothelium lining
  3. Abnormal size of the vessels and blood flow
  4. Localized intravascular coagulopathy (LIC)
    1. Low fibrinogen, FV, FVIII, FXIII, and antithrombin III. Elevated D-dimers and fibrin split products. Mild thrombocytopenia.

It is important to realize the vascular anomalies are at an increased risk for hematological complications, such as bleeding and clotting. And this risk is increased more following surgical or invasive radiological prodedures. The pathogenesis is poorly understood, as the incidence is not well-documented. Coagulopathy is regularly labeled incorrectly leading to a misdiagnosis and improper treatment plans. It is important to prepare high risk patients for surgeries and/or radiologic intervention so there are less side effects.

Once someone has had a clot, DVT, you are at increased risk of other clots.

Who is at high risk?

  1. Coagulopathy/malformations:
    1. Venous
    2. Capillary/lymphatic/venous
    3. Venous/lymphatic
    4. Lymphatic
    5. Diffuse/multiple lesions
      1. Covers the span of an extremity.
      2. Multifocal.
  2. Another risk:
    1. Venous ectasia (expansion, dilatation, or distension of a vein).
    2. Embrionic veins: veins that should not be there and are dilated causing Virchow’s Triad to occur.

Localized Intra-lesional Coagulopathy

  1. Not disseminated
    1. Disseminated means; scattered or spread widely.
  2. In the vascular lesion
  3. Can have normal laboratory parameters
  4. Can have abnormal parameters
  5. Can become a more disseminated problem


A hematologic analysis should be performed with a patient presents with extensive lesions, symptomatic lesions, and prior to any surgical or interventional procedure. All patients with abnormal labs should have a consult in hematology prior to surgeries, interventional procedures, or if their labs are severely abnormal.


When to worry:

  1. Surgery to vascular malformation
    1. Coagulation system can be activated more easily.
    2. Low molecular weight heparin (Lovenox) is often ordered.
  2. Interventional radiology
  3. Trauma to vascular malformation
  4. Puberty
    1. Can worsen coagulopathy.
  5. Infection and illness
    1. Due to inflammation.
  6. Immobility
  7. Pregnancy
  8. Birth control
    1. Especially those containing the hormones estrogen and/or progestin.
  9. Smoking
    1. Increases risk due to it increases hemoglobin.
  10. Weight
  11. Family history
    1. Hereditary factors for clotting.
      1. History of dangerous blood clots (DVTs).
      2. Repeated blood clots before the age of 40.
      3. Frequent nose bleeds.
      4. Unexplained miscarriages.

What can I do?

  1. Stay hydrated
  2. Increase mobility
    1. Avoid sitting or lying for long periods of time.
      1. If this is unavoidable, work the lower leg muscle by pumping (flexing and extending) the feet to enhance the circulation and propel the blood to flow
  3. Exercise
    1. Walking
    2. Doing anything that works the muscles

Medical treatment:

These drugs prevent more clots from forming by reducing the viscosity (stickiness) of blood.

  1. Aspirin – antiplatelet agent
    1. Not certain if helpful for vascular malformations.
    2. Should also avoid in children.
  2. Low molecular weight heparin (Lovenox)
    1. Specific for those with vascular malformations.
    2. Used for:
      1. Abnormal blood work.
      2. Prior to surgery or interventional procedure.
      3. Chronic pain.
      4. Patient with a history of LTT (life threatening thrombosis).
  3. Coumadin – Vit. K antagonist
    1. Not used regularly with vascular malformations.
    2. Metabolism of this drug is complicated, and can be affected by foods containing vitamin K.
  4. Direct thrombin inhibitors (dabigatran)
  5. Direct factor Xa inhibitors (rivarozaan, apixaban)
    1. Not certain if this drug increases bleed in patients.
  6. Vena Caval Filter
    1. For extreme risk patients, and when medications are not sufficient.
    2. These catch a clot if embolism occurs.
    3. Will remain on anti-coagulation drugs after placement of the filter.
  7. Antifibrinolytic drugs
    1. These are to prevent bleeding.
    2. Must be careful with these as clotting can remain a concern related to possible slow blood flow some patient experience.

Non-pharmacological treatment options:

  1. Compression garments
    1. Compression stockings consistently squeeze the legs assisting the veins and leg muscles to enhance the flow of blood by efficiently.
  2. Massage
    1. There are varying levels of massage that are useful for stimulating better vascular response in affected areas.
  3. Physical therapy
    1. Specific exercises that can help to re-tone damaged muscles and even specialized compression techniques that help the body recover from the stresses of a thrombosis.
  4. Hydrotherapy
    1. Promotes blood flow in sluggish veins.

Patients require a multidisciplinary approach. It is important to understand the risk factors related to coagulopathy and vascular malformations. We also understand further research is required, to develop prospective trials, find evidence-based plans of care through outcome studies to finally lead to new agents.