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Thrombosis

By limiting blood flow, these clots can cause damage to organs or tissues.. They also can break free from their original location and travel as blood flows to other areas to cause damage to other areas of the body.

Types of Thrombosis

An abnormal blood clot that forms in a vein is known as venous thrombosis. An abnormal clot in an artery is called arterial thrombosis. There are specific names that describe where a blood clot is located. Some examples of thrombosis seen in kids and young adults include:

• Deep vein thrombosis: a blood clot that forms in a vein deep below the skin, most often in the upper leg, arm or pelvis. These are important because they have the potential to embolize (break off) and travel to lungs causing a pulmonary embolism.
• Pulmonary embolism: a blood clot in the lung, usually caused when a deep vein thrombosis breaks off from its original location and travels through the blood in veins to the lungs.
• Cerebral embolism: a blood clot in an artery in the brain. These are often from a thrombosis that traveled there from another location.
• Cavernous sinus venous thrombosis: a blood clot in a vein that drains blood from the brain.
• Portal vein thrombosis: a blood clot in a major vein of the liver.

What Causes Thrombosis?

Thrombosis can result from multiple causes. Sometimes thrombosis occurs when the body’s anatomy doesn’t form in a normal way at birth. This leads to abnormalities in blood flow. Changes in the instructions (genes) for blood clotting proteins can make the blood clot more easily (hypercoagulable). Certain disease states can also increase the chances of thrombosis, such as cancer, inflammatory bowel disease, and certain types of infection. Some surgeries, like orthopedic procedures, increase the risk of thrombosis. Use of catheters in veins or arteries is a common thrombosis risk, particularly in children. Obesity and cigarette smoking also increase risk of thrombosis.

What are the Symptoms of Thrombosis?

Symptoms of a thrombosis can vary depending on where it is located. If a thrombosis forms in veins or arteries in the arm or leg, symptoms can include pain, swelling and redness there. Symptoms of emboli in the lungs or brain may be harder to spot.

Warning signs of blood clots in the brain can include:

• Severe headache
• Seizures
• Stroke-like symptoms, including sudden weakness, numbness, vision problems or confusion

• Shortness of breath
• Chest pain
• Pain with breathing

All blood clots need prompt medical management as they can be life-threatening.

How is Thrombosis Diagnosed?

To diagnose thrombosis, doctors will confirm there is a blood clot and its precise location using an ultrasound, a CT scan or an MRI.

How is Thrombosis Treated?

Thrombosis treatment depends on the location and severity of the clot, but also whether the patient has a high risk of bleeding if the thrombosis were treated. Treatment often involves using an anticoagulant. Anticoagulants are medicines that lessen the blood’s ability to clot. These drugs slow the formation or growth of blood clots, and allow the body’s own clot-busting system to work better. They help restore normal blood flow through the affected vein or artery.

Anticoagulants can be taken orally (by mouth), intravenously (through the vein) or subcutaneously (under the skin). Some cases of serious blood clots may need more therapies to remove the clot quickly. This could include emergency surgery or other procedures using a catheter to remove the clot. Fortunately, most children and young adults respond well to anticoagulant medication alone and do not need other procedures.

Most children diagnosed with a thrombosis can expect to be admitted to the hospital for treatment and monitoring. Those with less serious blood clots may go home after a short stay, others may require longer stays in the hospital. Many children with a thrombosis diagnosis will need to take anticoagulants at home for at least six weeks. Some patients will need anticoagulant treatment for a much longer period of time to prevent other thrombosis. During outpatient therapy doctors will monitor the patient and check that the thrombosis is getting better.

Prognosis for Thrombosis

Most young patients will recover fully from a thrombosis. Patients will have the thrombosis reimaged to make sure that it is getting better. If the underlying cause of the blood clot is no longer present (such as a surgical procedure or an infection that has been successfully treated), no additional treatment will likely be needed beyond six - 12 weeks of anticoagulation therapy.

After being diagnosed with a blood clot, some patients may be recognized as too high risk for forming another thrombosis to safely stop taking anticoagulant medications. This may be due to a risk for forming blood clots that the patient was born with (inherited thrombophilia) or another condition that is still present that increases risk for forming additional blood clots. People with these conditions will need to remain in the care of a hematologist. A hematologist is a doctor who has special training in blood diseases.

All patients taking anticoagulant medications are more likely to bleed, or bleed more than expected, if they have an injury or accident. They must avoid activities with a high risk of injury or bleeding, such as hockey or football (contact sports).