Thoracic Outlet Assessment

There are three different types of thoracic outlet syndrome, these include:

​

1. Neurogenic TOS

        o Compression of the nerves​

2. Venous​​ TOS

        o Compression of the vein​

3. Arterial TOS

        o Compression of the artery​

 

This ultrasound study focuses on vascular TOS. Vascular thoracic outlet syndrome (TOS) is a condition caused by compression or constriction of the blood vessels that pass through the thoracic outlet (a narrow space between the neck and the upper chest)

 

1. Venous Thoracic Outlet Syndrome: This type of vascular TOS occurs when the subclavian vein is compressed, resulting in reduced venous blood flow from the arms. The compression can occur at different locations within the thoracic outlet, such as between the scalene muscles in the neck or under the clavicle (collarbone). Common causes of venous TOS include anatomical abnormalities, muscle or soft tissue abnormalities, or trauma.

2. Arterial Thoracic Outlet Syndrome: This typeof vascular TOS involves the compression or constriction of the subclavian artery, which carries oxygenated blood to the arms. Arterial TOS is less common than venous TOS but can have signifiant implications for blood flow to the upper extremities. It is often caused by anatomical abnormalities such as cervical ribs or abnormal muscles structures which compress on the artery.

This scan usually takes between 20 minutes to complete.

​

A Thoracic Outlet study involves the arteries around your clavicle. This ultrasound requires direct contact with your skin. We will require you to remove any jackets and jumpers. We can often scan around a loose fitting T-shirt, however if we happen to need this removed we will provide you with a disposable gown. We also recommend you remove any necklaces to avoid getting gel on them.

We will ask you to sit on our examination bed. During the scan we will apply gel around the clavicle and use the ultrasound machine to look at the the arteries and veins. You will hear noises from the ultrasound machine; this is all normal and is the sound of the blood flow moving through your arteries.

A Thoracic Outlet ultrasound looks at the subclavian artery and subclavian vein. This scan is predominately looking for any kind of blood flow restriction/s to your arms both at rest, and in a number of positions which may bring on your symptoms. This scan looks for a narrowing or complete occlusion of the vessel during the arm movements (arterial and venous thoracic outlet syndrome). The most common type of narrowing or occlusion we see is caused by the compression of the vessel by a rib.

 

A thoracic outlet ultrasound is performed to evaluate the structures within the thoracic outlet, which is the narrow space between the neck and the upper chest. It is used to diagnose or assess various conditions that can affect the blood vessels and nerves in this area.

 

The thoracic outlet contains important structures such as the subclavian artery, subclavian vein, and brachial plexus (a network of nerves that control the movement and sensation of the upper limbs). Compression or impingement of these structures can lead to thoracic outlet syndrome (TOS) and result in symptoms such as pain, numbness, tingling, weakness, and circulation problems in the upper extremities.

 

The ultrasound images provide real-time information about the anatomy, blood flow, and potential abnormalities within the thoracic outlet.

​

The primary goals of a thoracic outlet ultrasound include:

​

Assessment of anatomy

The ultrasound helps visualise the structures within the thoracic outlet, including the subclavian artery, subclavian vein, and brachial plexus. It can identify any anatomical variations or abnormalities such as compression by muscles, bony structures, or other soft tissues.

 

Evaluation of blood flow

The ultrasound allows for the assessment of blood flow through the subclavian artery and subclavian vein. It can help identify any narrowing (stenosis) or blockage (occlusion) of these vessels, which can contribute to symptoms and complications.

 

Visualisation of nerves

The ultrasound can provide information about the position and integrity of the brachial plexus nerves, helping to identify any impingement or compression that may be causing nerve-related symptoms.

 

Based on the ultrasound findings, healthcare professionals can make a more accurate diagnosis of thoracic outlet syndrome and determine the underlying cause. This information is essential in guiding treatment decisions, which may involve physical therapy, medication, or, in severe cases, surgical intervention.

Vascular thoracic outlet syndrome (TOS) is a condition characterised by the compression or constriction of blood vessels, particularly the subclavian vein, as they pass through the thoracic outlet. While the exact cause of vascular TOS is often multifactorial, there are several risk factors that may increase the likelihood of developing the condition. These risk factors include:

 

Anatomical variations

Certain anatomical variations or abnormalities in the thoracic outlet region can predispose individuals to vascular TOS. These variations may include cervical ribs (extra ribs in the neck), elongated transverse processes (bony projections), or abnormal muscle or ligament structures.

​

Repetitive arm movements or trauma

Engaging in repetitive overhead arm movements, such as those involved in certain occupations (e.g., overhead athletes, construction workers) or activities (e.g., weightlifting, swimming), can increase the risk of vascular TOS. Trauma or injuries to the shoulder or neck area, such as fractures or dislocations, can also contribute to the development of the condition.

 

Poor posture

Maintaining poor posture over extended periods can put stress on the thoracic outlet and potentially lead to vascular TOS. Slouching, rounded shoulders, and forward head posture can contribute to compression or impingement of blood vessels in the area.

 

Muscle imbalances or tightness

Imbalances or tightness in the muscles surrounding the thoracic outlet can contribute to vascular TOS. For example, tightness or hypertrophy of the scalene muscles in the neck or the pectoralis minor muscle in the chest can compress the blood vessels passing through the area.

 

Congenital or developmental factors

Some individuals may have congenital or developmental factors that increase their susceptibility to vascular TOS. This can include abnormalities in the development or positioning of structures within the thoracic outlet.

 

Poor vascular health

Conditions that affect vascular health, such as atherosclerosis (hardening and narrowing of the arteries) or blood clotting disorders, can increase the risk of vascular TOS. These conditions can predispose individuals to the development of blood vessel compression or compromise.

Arterial TOS

 

Arterial thoracic outlet syndrome (TOS) refers to a condition in which the subclavian artery, a major blood vessel that supplies the arms, is compressed or constricted as it passes through the thoracic outlet. This compression can result in a variety of symptoms, which may include:

 

Arm pain

Individuals with arterial TOS often experience pain in the arm, typically described as aching, throbbing, or sharp. The pain may be present at rest but is more commonly triggered or worsened by arm movement or physical activity.

 

Arm weakness

Weakness in the affected arm may occur due to compromised blood flow to the muscles. It can range from mild to severe and may impact the ability to perform tasks requiring strength or coordination.

 

Arm fatigue

Fatigue or a sense of heaviness in the arm is a common symptom of arterial TOS. The affected arm may feel tired quickly during activities, and individuals may find it challenging to sustain or repeat arm movements.

 

Coldness or numbness

Reduced blood flow to the arm can lead to sensations of coldness or numbness. The affected arm may feel cooler to the touch compared to the unaffected arm, and numbness or tingling may be experienced in the fingers, hand, or forearm.

 

Color changes

In some cases, arterial TOS can cause changes in the colour of the affected arm. The skin may appear pale or bluish (cyanotic) due to inadequate blood supply.

 

Pulse abnormalities

Compression of the subclavian artery may lead to diminished or weakened pulses in the affected arm. The pulse may be difficult to palpate or may feel significantly weaker compared to the unaffected arm.

 

 

Venous TOS

 

Venous thoracic outlet syndrome (TOS) refers to a condition in which the subclavian vein, one of the major veins that carries blood from the arms back to the heart, is compressed or obstructed as it passes through the thoracic outlet. This compression can result in a variety of symptoms, which may include:

 

Arm and hand swelling

Swelling in the affected arm and hand is a common symptom of venous TOS. The impaired blood flow due to vein compression can lead to fluid buildup and cause noticeable swelling, particularly after activities or with prolonged arm elevation.

 

Heaviness and aching

Individuals with venous TOS often experience a sense of heaviness, aching, or discomfort in the affected arm, shoulder, or neck. The pain may be described as a deep ache and may worsen with activities that increase venous pressure, such as overhead movements or carrying heavy objects.

 

Cyanosis

Compression of the subclavian vein can result in reduced blood flow and oxygenation, leading to discoloration of the affected arm and hand. Cyanosis, characterized by bluish or purplish skin, may be observed in severe cases.

 

Visible superficial veins

In some instances, venous TOS can cause the dilation and prominence of superficial veins in the affected arm, shoulder, or chest. These veins may become more visible or engorged due to the increased pressure within the venous system.

 

Sensation changes

Compression of nerves accompanying the subclavian vein can lead to sensory changes in the arm, hand, and fingers. This can include numbness, tingling, or a sensation of pins and needles. The affected area may also exhibit decreased sensitivity to touch.

 

History of blood clots

Venous TOS may be associated with a history of blood clots, particularly in the upper extremities. This is because the compression or obstruction of the subclavian vein can increase the risk of blood clot formation (deep vein thrombosis) in the affected arm.

Vascular Thoracic Outlet Syndrome (TOS) is a condition characterised by compression or irritation of the nerves and blood vessels in the thoracic outlet, which is the space between the collarbone and the first rib. The treatment for TOS typically involves a combination of conservative measures and, in some cases, surgical intervention. Here are the treatment options commonly used for Vascular TOS:

 

Conservative management:

• Physical therapy: Physical therapy plays a crucial role in managing TOS. Specific exercises are designed to improve posture, strengthen muscles, increase flexibility, and correct any muscular imbalances that may contribute to compression in the thoracic outlet. Manual therapy techniques may also be used to relieve muscle tension and improve blood flow.

• Postural adjustments: Modifying posture and ergonomics can help reduce symptoms. This may involve adjustments in sitting or standing positions, using ergonomic supports, and avoiding activities that worsen symptoms.

• Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) or

• muscle relaxants may be prescribed to alleviate pain and reduce inflammation in the affected area.

• Lifestyle modifications: Making certain lifestyle changes can be beneficial, such as managing stress, maintaining a healthy weight, avoiding repetitive arm movements, and taking regular breaks during activities that involve prolonged arm positions.

 

Interventional procedures:

• Nerve blocks: Local anesthetic injections or nerve blocks may be used to provide temporary pain relief by numbing the affected nerves.

 

Surgical intervention:

In cases where conservative measures fail to provide relief, surgery may be considered. Surgical options for Vascular TOS include:

 

• First rib resection: The removal of a portion or the entire first rib to create more space in the thoracic outlet, relieving pressure on the blood vessels and nerves.

• Arterial repair or reconstruction: If blood vessels are compressed or damaged, surgical techniques may be used to repair or reconstruct the affected arteries to restore proper blood flow.