A thrombosis is a blood clot that develops within veins or sometimes arteries in the body. Thrombosis may be serious or inconvenient and often occurs as a complication of a procedure, medication or other
disease. Left untreated, a thrombosis can cause long-term problems, such as chronic swelling, pain or even permanent damage to internal organs.
Thrombophilia refers to anything
that increases one’s tendency to develop blood clots. Thrombosis in children is
uncommon, and is most often seen in children with complex medical problems or
procedures. Thrombophilia can be considered the opposite of hemophilia, a
disorder that prevents blood from clotting.
Children and young adults with blood
clots are treated through the Dana-Farber/Boston Children’s Thrombosis and Anticoagulation Program. Through our unique
program, we can quickly identify children who need anticoagulation medications
(or “blood-thinners”) using established monitoring and risk identification
guidelines. Children outside of the hospital visit our outpatient center
staffed by pediatric hematologists and pediatric hematology nurse practitioners
with specialized expertise in the diagnosis and treatment of thrombosis.
Thrombophilia refers to a group of disorders that increases
a child’s tendency to develop dangerous blood clots. There are two main types
Thrombosis symptoms in children can
vary significantly depending on the size and location of the blood clot, and
each child may experience symptoms differently. A thrombosis may occur anywhere
in a child’s body, but most are in the legs or arms (deep vein thrombosis or
DVT) or lungs (pulmonary embolism). Other types of thrombosis include sinus
venous thrombosis and arterial thrombosis.
Children with a thrombosis in the legs
or arms may have the following symptoms:
If a child has a pulmonary
embolism, he/she may experience:
It is important to understand that some thrombosis symptoms may
resemble those of other more common medical problems. Because some of these
symptoms can also point to other conditions, it’s important to have your child
evaluated by a qualified medical professional for an accurate diagnosis and
prompt treatment. If you have a family history of thrombosis, it is important
to bring this up during evaluation for these symptoms.
There are three categories of
causes of thrombosis: damage to the blood vessel (e.g. catheter or surgery),
slowed blood flow (e.g. immobility) and/or thrombophilia (e.g. if the blood
itself is more likely to clot).
Causes of thrombosis depend
on whether your child has inherited or acquired thrombosis. Inherited
thrombophilia is caused by certain genetic conditions including Factor V Leiden, Prothrombin gene
mutation or deficiencies
of protein C, protein S or antithrombin. While we do not always
recommend blood testing for these conditions, we will discuss this with you.
Acquired thrombophilia is caused by lifestyle factors or
medical conditions including immobility, obesity, a sedentary lifestyle or trauma. In teens and adults, risk factors
also may include smoking
or oral contraceptive use. Some patients with chronic inflammation or
rheumatologic disorders may develop antiphospholipid antibody syndrome, a
disorder where antibodies produced by the patient cause thrombosis to occur.
The first step in treating your child is forming an accurate
and complete diagnosis. If thrombosis is suspected, imaging is done to confirm
the diagnosis and to define where the blood clot starts and ends. Thrombosis is sometimes found accidentally, but mostly because patients develop signs and symptoms of a blood clot.
If your child is suspected of having a thrombosis, diagnostic tests may include:
There may be other diagnostic tests that your doctor will discuss with
you depending on your child's individual situation. After we complete all
necessary tests, our experts meet to review and discuss what they have learned
about your child's condition. Then we will meet with you and your family to
discuss the results and outline the best possible treatment options.
Your child’s treatment team will
determine a specific care plan. In most
cases, thrombosis is treated with anticoagulation medications (“blood
thinners”). These medications prevent the clot from growing, and decrease the risk
of its breaking apart and causing further complications. Your child may need to
continue taking these medications for several months after initial treatment.
Examples of anticoagulation medication your child’s physician may prescribe include:
Other treatments may include
wearing compression stockings, remaining active and applying warm packs to improve
blood flow and pain caused by the clot.
Of course, your child's team of doctors will help determine the best
approach for your child's unique situation, based on a number of factors
Thrombosis Clinical Trials
For many children with rare or
hard-to-treat conditions, clinical trials provide new options.Participation in any clinical trial is
completely voluntary. We will take care to fully explain all elements of the
treatment plan prior to the start of the trial, and you may remove your child
from the medical study at any time. Currently, our hematology team is studying
several new oral blood thinners in children for treatment and prevention of
blood clots. We are also involved in an
international study of the length of anticoagulation needed to treat
thrombosis. Your hematologist may
mention opportunities to participate in these studies, but you should feel free
to ask about current research studies relevant to your child.
Researchers at Dana-Farber/Boston
Children’s perform scientific and clinical research on platelets and related
aspects of hemostasis and thrombosis. A particular focus is antiplatelet
therapy, including the characterization of:
Some deep vein thromboses may resolve without treatment. Treatment is
given to help get rid of the blood clot and to minimize complications of
thrombosis. If blood clot remains, other
veins will enlarge to bypass the blockage (like side road traffic after a car
accident). Sometimes these veins are
visible, like varicose veins. After a
blood clot, however, some people develop long-term pain and swelling in the leg
called post-thrombotic syndrome, which is caused by reduced blood flow and
damage to the affected vein. Some patients also have changes in skin color,
which may not develop for a year or more afterward.
Blood clots in the thigh are more likely to break off and travel to
the lungs than blood clots below the knee or in the arms. A pulmonary embolism can
be a life-threatening emergency, requiring immediate medical attention.
We have a number of resources at
Dana-Farber/Boston Children’s to help you and your family through this time.
From the first visit through follow-up care, our nurses will be on hand to walk
you through your child’s treatment and help answer any questions you may have.
Want to talk with someone whose
child has been treated for thrombosis? We can often put you in touch with
other families who have been through the same experience that you and your
child are facing, and can share their experience.
If you are in need of spiritual
support, we will help connect you with the chaplaincy
at Boston Children's Hospital. Our program includes nearly a dozen clergy
representing Episcopal, Jewish, Lutheran, Muslim, Roman Catholic, Unitarian and
United Church of Christ traditions who will listen to you, pray with you and
help you observe your own faith practices during your hospital experience.
Our social workers and mental
health clinicians have helped many other families in your situation. We can
offer counseling and assistance with issues such as coping with your child’s
diagnosis, stresses relating to coping with illness and dealing with financial