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Thoracic outlet syndrome
Neurovascular symptoms in the upper extremities due to pressure on the nerves and vessels in the thoracic outlet area
The specific structures compressed are usually the nerves of the branchial plexus and occasionally the subclavian artery or subclavian vein
Anatomy
Thoracic outlet
Entrance/ Exit region of the upper limb
The thoracic outlet is defined as the interval from the supraclavicular fossa to the axilla that passes between the clavicle and the first rib
Anatomy - Scalane triangle
Anatomy of the costoclavicular space
Pectoralis minor space
Located inferior to the coracoid process
anterior to the second through fourth ribs
posterior to the pectoralis minor muscle
The cords of the brachial plexus
Axillary artery
Axillary vein.
Soft-tissue Causes (70%)
Scalene muscle
Variations in insertion
Hypertrophy
Accessory scalenus minimus muscle
Anomalous ligaments or bands
Soft-tissue tumors
Osseous Causes
Cervical rib
Prominent C7 transverse process
Displacement or callus from first rib fracture
Malunited clavicle or first rib fracture
AC or SC joint injury or dislocation
Osseous tumor
Poor posture
Drooping the shoulders
Holding the head in a forward position
Repetitive activity
Athletes and swimmers
Neurogenic TOS
Compression – scalene triangle and costoclavicular space
May be associated with normal anatomy
Traction of the lowest trunk of the brachial plexus
Often in association with arterial TOS
Features of Lower brachial plexus compression - Common
Female predominance
Appearance of Amedio Modigliani painting
Complains of pain and paresthesia extending from the shoulder /down the ulnar aspect of the arm into the medial two fingers
Neurogenic TOS
Upper brachial plexus compression C5,C6 and C7
Less common
Compression mainly occurs in scalene triangle
Symptoms
Unilateral occipito-frontal headache
Facial or jaw pain
The Gilliatt-Sumner hand
A characteristic finding of neurogenic TOS, is described as atrophy of the abductor pollicis brevis and, to a lesser degree, the hypothenar musculature and the interossei.
Venous TOS
Causes
Hypertrophy of the subclavius muscle,
Chondroma formation
Clinical presentation
Most patients are sportsmen, musicians or manual workers undertaking repetitive arm movements.
The condition occurs more commonly in the dominant limb
Male predominance
Clinical presentation
Acute presentation -
Swollen and tensed upper limb
Upper limb aching pain
blueish- purple arm due to venous engorgement
Collateral veins may be visible
Feeling of heaviness that is worse after activity
Symptoms are precipitated by working with the arms elevated and are relieved by dependency, a pathognomonic feature of vTOS.
Arterial TOS
Rare but has more devastating consequences
Caused by
Intermittent subclavian arterial compression - Costoclavicular compression with normal anatomy.
2. Introduction
Definition
• Neurovascular symptoms in the upper extremities due to
pressure on the nerves and vessels in the thoracic outlet area
• The specific structures compressed are usually the nerves of
the branchial plexus and occasionally the subclavian artery or
subclavian vein
3. Anatomy
Thoracic outlet
• The thoracic outlet is defined as the interval from the
supraclavicular fossa to the axilla that passes between
the clavicle and the first rib
7. Pectoralis
minor space
• Located inferior to the coracoid
process
• anterior to the second through
fourth ribs
• posterior to the pectoralis minor
muscle
• Contents
1. The cords of the brachial
plexus
2. Axillary artery
3. Axillary vein.
9. Etiology
Osseous Causes
• Cervical rib
• Prominent C7 transverse process
• Displacement or callus from first rib fracture
• Malunited clavicle or first rib fracture
• AC or SC joint injury or dislocation
• Osseous tumor
10. Etiology
Other causes
Poor posture
Drooping the shoulders
Holding the head in a forward position
Repetitive activity
Athletes and swimmers
Obesity
Pregnancy
12. Neurogenic TOS
• Compression – scalene triangle and costoclavicular space
• May be associated with normal anatomy
• Traction of the lowest trunk of the brachial plexus
• Often in association with arterial TOS
Features of Lower brachial plexus compression - Common
• Female predominance
• Appearance of Amedio Modigliani painting
• Complains of pain and paresthesia extending from the
shoulder /down the ulnar aspect of the arm into the
medial two fingers
13. The Gilliatt-
Sumner hand
• A characteristic finding of neurogenic TOS, is described as atrophy
of the abductor pollicis brevis and, to a lesser degree, the
hypothenar musculature and the interossei.
14. Neurogenic TOS
Upper brachial plexus compression C5,C6 and C7
• Less common
• Compression mainly occurs in scalene triangle
• Symptoms
• Unilateral occipito-frontal headache
• Facial or jaw pain
16. Clinical presentation
• Most patients are sportsmen, musicians or
manual workers undertaking repetitive arm
movements.
• The condition occurs more commonly in the
dominant limb
• Male predominance
17. Clinical presentation
Acute presentation -
• Swollen and tensed upper limb
• Upper limb aching pain
• blueish- purple arm due to venous engorgement
• Collateral veins may be visible
• Feeling of heaviness that is worse after activity
Symptoms are precipitated by working with the arms
elevated and are relieved by dependency, a pathognomonic
feature of vTOS.
18. Arterial TOS
Rare but has more devastating consequences
Caused by
1. Intermittent subclavian arterial compression - Costoclavicular compression with normal
anatomy.
2. Prolonged subclavian arterial compression - Always associated with a bony abnormality
A-TOS often coincides with minor paraesthesia in the C8/T1 distribution because the
lowest trunk of the brachial plexus lies alongside the subclavian artery and is subject
to the same compressive mechanisms.
19. Clinical features
• Pallor that worsens in cold temperatures
• Non radicular pain
• Coolness
• Numbness
Compression over time leads to intimal damage, eventual aneurysm formation,
thrombosis, embolic events, and even potentially limb-threatening ischemia
21. Physical examination
• Comparing the upper extremity with cotra lateral limb
1. Skin colour – Cyanosis
2. Temperature
3. Hair distribution
4. Muscle atrophy
5. Odema
• Palpation of the supraclavicular region - Mass
• Quality and location of pain with movements of the neck, shoulder, and upper limb
should be recorded
• The vascular examination documents the presence and quality of the radial pulse
with the arm in different positions
• Listen for bruits
• Should include evaluation of shoulder, cervical spine and upper extremity
22. The Adson test
• Bringing the arm into extension turning
the head toward the affected side and
taking a deep breath.
• The test is positive if there is a marked
decrease, or disappearance, of the radial
pulse.
• It is important to check the patient's radial
pulse on the other arm to recognize the
patient's normal pulse
23. Provocative
tests
A decrease in the radial pulse with the arm in
hyperabduction
and external rotation, with the head turned in the opposite
direction.
With this maneuver, the radial pulse dampens or
obliterates
But in up to 7% of the normal population shows positive
finfing
24. Roos test / The
elevated arm
stress test
The patient places both arms in the 90 abducted position with the elbows flexed to 90. The
hands are then opened and closed for a 3-minute period.
Normal persons may have minor discomfort due to muscular fatigue, but patients with TOS
have more discomfort
• Carpal tunnel syndrome,
• Ulnar neuropathy fibromyalgia
25. Differential diagnosis
Pancoast’s syndrome
• Due to apical carcinoma of the bronchus with
infiltration of the structures at the root of the neck
pain, numbness and weakness of the hand.
• A hard mass may be palpable in the neck
• X-ray of the chest shows a characteristic opacity
Cervical spondylosis –
• Constant neck and shoulder pain presents in a
radicular distribution
• Pain aggravated by position of the neck
26. Differential diagnosis…..
Rotator cuff lesions
• Sometimes cause pain radiating down the arm
• There are no neurological symptoms
• Shoulder movement is likely to be abnormal.
Distal compression neuropathies ( carpal tunnel cubital tunnel syndrome)
• Symptoms isolated to nerve distributions
• Pain aggravated by position of the wrist or elbow
27. Investigations
Imaging
Chest and cervical spine radiographs
1. Cervical ribs
2. Prominent C7 transverse processes
3. Low-lying shoulder girdles
CT and MRI - has not been well studied, it may be effective in the setting of
1. Identifiable congenital anomaly
2. A space-occupying lesion (eg, a pancoast tumor)
3. Metastatic disease
4. Malunited fractures of ribs or the clavicle
28. Investigations ……
Angiography -
• CTA / MRA or traditional angiography can be utilized to identify more clearly the
• Occlusion
• Aneurysm
• Distal embolization.
Nerve conduction study, electromyography
• Confirm neurogenic TOS
• Localize the area of compression- r/o CTS
31. Botulinum toxin A
• Botulinum toxin A (botox) can be used for temporary symptom relief.
• Botox takes two weeks to work but can last three months and can help patients
progress with physical therapy.
• Botulinum toxin injection with ultrasound guidance is safe and well tolerated in
subjects with suspected nTOS .
33. Surgical options and Approaches
• First rib resection
• Anterior scalenectomy
• Cervical Rib/fibrous band resection
• Costoclavicular ligament resection
• C7,C8 and T1 root neurolysis
Trans axillary approach
Commonly performed approach
Provides superior exposure for
first rib resection, as well as for
removal of cervical ribs and
fibrous bands, with a more
cosmetic scar.
Supraclavicular approach
Favorable exposure for upper
brachial plexus
Posterior approach
Favorable exposure for upper
brachial plexus