Thoracic Outlet Syndrome & Subclavian Steal Syndrome😍

Thoracic Outlet Syndrome

Description:

• Entrapment of neurovascular structures
• as they pass through the thoracic outlet.

Thoracic Outlet Boundaries:

• Anterior scalene muscle

• Posterior scalene muscle

• Clavicle

• First rib

Contents:

• Brachial plexus
• Most Common to be compressed
• Ulnar N more (C8, T1 Nerve root)

• Subclavian vessels (Artery > vein).

Causes of Compression:

• Abnormal positioning of neck/upper limb.

• Lung tumor (upper lobe).

Clinical Features:

• C8 - T1 > SCV > SCA

• Compression of Brachial Plexus:
• Pain Along Ulnar Border
• Paraesthesia
• tingling

• Arterial Occlusion: Gangrene/Claudication

• Venous Occlusion: Subclavian Vein Thrombosis

• Poor Muscle Tone

• Cervical Rib

Diagnosis:

• Clinical evaluation (More important than MRI):
• Positive test if
• pain/neurological symptoms
• decreased pulse.
• Mnemonic:
• Thoraxil (TOS) adichitt (Adson) Hall (Halstead) nte right (wright) sidil roomil (Roos) itt

Specific Tests:

Adson's Test:

• Head turned towards affected side,

• neck extended,

• abduct and externally rotate shoulder,

• extend elbow.

• Mnemonic: Adichapo → head turn

Reverse Adson's/Halstead's Test:

• Head turned to opposite side,

• same as Adson's test positioning otherwise.

Roo's Test:

• Abduct shoulder + flex elbow.

• Open & close hands for 3 mins.

• Reproduces symptoms of vascular claudication.

• Mnemonic: Roo roo rooo → Kayyi adakkuka nuukuka

Wright's Hyperabduction Test:

• Hyperabduction of shoulders,

• extension of neck.

Treatment:

• Conservative:
• Rest, Splint, Physiotherapy.

• Surgical:
• Excision of first rib/cervical rib/tumor (Lung).

• Physiotherapy

• Angioplasty / Grafting for Thrombosis

Subclavian Steal Syndrome

Pathophysiology

• Subclavian Artery (1st Part) Stenosis

• Retrograde Blood Flow
• from Vertebral/Basilar Artery

Clinical Feature

• Syncopal Attack

• After Upper Limb Exercise

Management

• IOC: CT Angiography

• Rx: Angioplasty

Aberrant Right Subclavian Artery (ARSA)

 

• Right 4th arch artery obliterates (Normally persists)

• Persisting Arteries
• Right caudal dorsal aorta +
• Right 7th cervical intersegmental artery
• = abnormal right subclavian artery.

• Compresses the esophagus
• "dysphagia lusoria" (difficulty swallowing)

Double aortic arch

Persistence of both sides.

• 4th arch arteries &

• Dorsal aorta.