Axillo-subclavian vein thrombosis (ASVT) occurs when blood clots form in your upper arm due to compression of certain veins. It’s usually the result of repetitive stress on your upper arms. Medication and surgery are the primary treatments for ASVT.
Axillo-subclavian vein thrombosis (ASVT) occurs when a blood vessel in your upper arm gets compressed by a nearby rib or muscle and blood clots develop. ASVT may develop in the subclavian vein in your shoulder or the axillary vein in your armpit. It usually results from injury or repeated stress to one or both of your upper arms.
Other terms for the condition are Paget-Schroetter syndrome or “effort-induced thrombosis.”
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ASVT is a form of deep vein thrombosis (DVT). DVT is a blood clot that forms in a vein deep in your body, usually in your legs. But DVT risk factors include obesity, inactivity, advanced age and underlying blood vessel disorders.
ASVT, on the other hand, is usually the result of sudden injury or overuse. The two conditions present with different symptoms and need different treatment.
Anyone can get ASVT, but it’s most common in people who:
ASVT is a type of upper extremity DVT. Primary ASVT is the result of strenuous arm movements. Secondary ASVT is the result of medical devices implanted in your upper chest like:
ASVT isn’t common. It affects 1 to 2 people out of every 100,000 per year. But it accounts for 10% to 20% of all instances of upper extremity DVT.
Symptoms of ASVT may include:
In 10% to 20% of cases, the clots can dislodge from upper arm veins and travel to your lungs. This clot is called a pulmonary embolism (PE). A PE can cause serious lung damage or even death.
Repetitive arm movements can cause inflamed muscles around your shoulder or armpit to put pressure on and injure veins. This may cause scar tissue to form, narrowing your blood vessels and reducing blood flow. This type of thoracic outlet syndrome (TOS) might not cause problems initially. But over time, clots can form in the subclavian or axillary veins and lead to serious problems.
Sometimes abnormalities in your first rib bone, muscles or ligaments surrounding the axillary and subclavian veins contribute to ASVT.
A healthcare provider typically notices signs of ASVT during a physical examination. Your provider may order tests to examine your blood vessels, such as:
Thrombolysis, or thrombolytic therapy, is the main treatment for ASVT. Your healthcare provider delivers a clot-dissolving drug directly to the blocked vein through a catheter (thin, flexible tube). They may combine this with a thrombectomy, a procedure to physically remove blood clots. After thrombolysis, you receive blood-thinning medication for several months to prevent new clots.
Your healthcare provider will also likely have you:
In some cases, you may need surgery to decompress the affected veins completely. The surgery may involve removing a portion of the muscle or rib nearest the vein to restore blood flow.
You can reduce your risk of ASVT by:
Most people have excellent outcomes after ASVT treatment. Studies show success rates of 90% to 95% if the condition is diagnosed and treated soon after symptoms start. But some people develop a complication called post-thrombotic syndrome (PTS). PTS can cause chronic pain, heaviness and swelling in your affected arm.
Contact your healthcare provider right away at the first signs of ASVT, or if you experience:
If you have ASVT, you may want to ask:
A note from Cleveland Clinic
Axillo-subclavian vein thrombosis (ASVT) occurs when you develop blood clots in the veins in your upper arm. It’s usually the result of repeated overhead arm movements. Symptoms can include sudden pain, swelling or skin discoloration in one or both arms. The primary treatments are thrombolytic therapy (drugs that dissolve clots) and thrombectomy (surgery to remove blood clots).
Last reviewed by a Cleveland Clinic medical professional on 05/02/2022.
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