Thoracic Outlet Syndrome
Thoracis Outlet Syndrome
Thoracic Outlet Syndrome (TOS) is a group of conditions where nerves or blood vessels are compressed in the space between your collarbone and first rib, known as the thoracic outlet. Vascular TOS refers specifically to the compression of arteries or veins in this area, leading to various symptoms related to blood flow.
Why we do this scan
Ultrasound can effectively identify vascular thoracic outlet syndrome (TOS) by visualizing compression or abnormalities in blood flow within the subclavian artery or vein as the arm is moved through various positions. It is particularly useful in detecting changes in blood flow with arm movements that reproduce symptoms, such as abduction and hyperabduction, which can indicate arterial or venous TOS.
Why choose us
Vascular sonographers know how to optimize ultrasound settings for imaging the deep structures of the thoracic outlet and ensure high-quality images. They can differentiate normal anatomical variations from true abnormalities, minimizing false positives or negatives. Our accomplished sonographer can integrate ultrasound findings with the patient's clinical presentation to arrive at an accurate diagnosis and degree of compression.
Risk factors
Thoracic Outlet Syndrome (TOS) risk factors can be categorized into anatomical, traumatic, and functional/behavioral factors. Anatomical abnormalities, like an extra rib or a narrow thoracic outlet, can predispose individuals. Trauma, such as from a car accident, and repetitive overhead movements, common in certain sports or jobs, are also significant risk factors. Additionally, poor posture, weight gain, and pregnancy can contribute to TOS development.
Symptoms
Specific to Arterial TOS:
Coldness, numbness, or tingling: in the fingers, hand, or arm.
Pain: that worsens with arm use and improves with rest.
Pale discoloration: of the fingers, hand, or arm.
Slow-healing sores: on the fingers.
Specific to Venous TOS:
Edema (swelling) of the arm and hand.
Bluish discoloration of the arm and hand.
Prominent veins: in the shoulder, neck, and hand.
Pain and tingling.
Complications
Arterial Thoracic Outlet Syndrome Complications:
Blood Clots (Thrombosis): can cause blood clots to form in the arteries, particularly the subclavian artery, restricting blood flow to the arm and hand.
Embolism: These clots can break loose and travel to smaller arteries in the hand and arm, potentially leading to tissue damage or even gangrene.
Stroke: In rare cases, clots can travel to the brain, causing a stroke.
Aneurysms: In some cases, TOS can lead to the formation of aneurysms (bulges in the artery wall).
Venous Thoracic Outlet Syndrome Complications:
Blood Clots (Thrombosis): can lead to blood clots in the subclavian vein, causing swelling, pain, and bluish discoloration of the arm.
Pulmonary Embolism: If a clot breaks loose and travels to the lungs, it can cause a pulmonary embolism, a serious and potentially life-threatening condition.
Chronic Arm Swelling and Pain: Even without a major clot, chronic compression can lead to persistent arm swelling and pain.
Preparation for the ultrasound
There is no patient preparation needed for this scan which will take up to 30 minutes for each arm. You will be asked to remove clothing to expose the neck, shoulder, and arm, however a loose thin strapped singlet may be left on. We will ask for you to sit on the edge of our examination bed and the sonographer will apply a gel to the skin and move the transducer over the area. The scan assesses the entire arm from the neck to the wrist, with particular attention around the clavicle, while the patient performs various arm movements. The ultrasound examination is generally painless, although some patients may experience mild discomfort due to probe pressure or arm positioning.
