1.
THORACIC OUTLET SYNDROME
Dr. N.K. CHOUDHARY
2/3/2023
Parul Institute of Medical Sciences and
Research
1

2.
Definition
• Thoracic outlet syndrome (TOS)- a collection
of symptoms brought about by abnormal
compression of the neurovascular bundle by
bony, ligamentous or muscular structers in the
narrow space between clavicle and 1st rib –the
thoracic outlet.

3.
Boundaries of TO
• posteriorly: T1 vertebral body
• laterally: first rib and costal cartilage
• anteriorly: manubrium sterni

4.
ANATOMY
Interscalene triangle
- Inferiorly : 1st rib
- Ant : scaleneus anterior
- Post : scaleneus medius.
Costoclavicular space
- Ant : clavicle, subclavius muscle
- Post medial: 1st rib
- Post lateral: superior
- border of scapula

5.
contents
• viscera
– thymus
– trachea
– oesophagus
– lung apices
• vessels, nerves and
lymphatics
– common carotid arteries
– confluences of internal
jugular and subclavian veins
– phrenic nerves
– vagus nerves
– recurrent laryngeal nerves
– thoracic duct
• prevertebral fascia
• muscles
– sternocleidomastoid
muscle
– anterior and middle
scalene muscles
– sternohyoid muscle
– sternothyroid muscle

6.
Interscalene triangle

7.
Costoclavicular space

8.
Subcoracoid area

9.
• Race
No racial predilection exists.
• Sex
Thoracic outlet syndrome is traditionally more
common in women than in men, with a female-to-
male ratio as high as 3:1.
• Age
Thoracic outlet syndrome is most common in
people aged 10-50 years

10.
Causes of TOS
• Anatomical defects-
• Bony abnormalities-
Cervical rib
Long C7 transverse process
Abnormal bands, ligaments
Fracture clavicle/ 1st rib
Exostosis

11.
• Muscle anomalies
• Anomalous insertion of scalene muscles
• Scalene muscle hypertrophy
• Scaleneus minimus
• Passage of the brachial plexus through the
substance of the anterior scalene muscle,
• A broad, excessively anterior middle scalene
muscle insertion on the first rib

12.
• Tumours
• Trauma
Brachial plexus trauma/Whiplash injury
• Poor posture.
Drooping the shoulders or holding the head in
a forward position.

13.
• Repetitive activity.
Typing on a computer,
Athletes and swimmers
Baseball pitcher
• Obesity
• Pregnancy.

14.
Cervical rib
• It is a superneumary rib that arises from seventh
cervical rib or rarely from sixth or fifth cervical
vertebrae.
• Sometimes known as "neck ribs“
• Congenital abnormality located above the normal
first rib.
• incidence 0.5-0.6%
• Bilateral in 60-80 %
• Symptomatic in 10 -15%

15.
Cervical rib

16.
TYPES
• Type1 small projection from costal faset.
Less than 2.5cm
• Type 2 projection beyond transverse
process. > 2.5cm
• Type 3 nearly complete rib which is partly
fibrous
• Type 4 complete rib with costal cartilage
attached to 1st rib or sternum.

17.
Classification

18.
Neurologic type
• 95% of cases
• This type is secondary to compression of the
brachial plexus caused by various soft tissue
and bony abnormalities at the point where the
nerves pass between the anterior and middle
scalene muscles.

19.
Venous type
• 3-4% of cases.
• Venous thrombosis may be categorized into
primary and secondary thrombosis based on the
etiology.
• Primary venous thoracic outlet syndrome, or
primary venous thrombosis, is also called Paget-
Schrötter syndrome named after the 2
individuals who first described this entity: Paget,
who described it in 1875, and von Schrötter, in
1884.

20.
Arterial type
• 1-2% of cases.
• This type is associated with the most serious
complications, including limb ischemia (which
may result in the loss of the affected upper
extremity).

21.
Neurogenic TOS
• Etiology
– Hyperextension neck
injury
(whiplash)
– Repetitive stress injuries

22.
Neurogenic TOS
• Predisposing Factors
– Scalene muscle anomalies
– Narrow scalene triangles
– Congenital ligaments/bands
– Cervical ribs

23.
Neurogenic TOS
• Pathophysiology
– Neck trauma stretches and tears scalene
muscle fibers
– Swelling of muscle belly pain,
parathesias, numbness, weakness
– Scarring/fibrosis of muscle belly occipital
headaches.

24.
Neurogenic TOS
• Symptoms
– Pain, parathesias of the neck, shoulder region, arm or hand, depending on the root
involved , numbness, weakness throughout affected hand/arm.
• Often bilateral
• Difficulty with fine motor tasks of the hand
Examination reveals :
• sensitive disorders
• muscle weakness
• muscle atrophy (long fingers flexors)
• Palpation of subclavicular area may cause pain
Not necessarily localized to peripheral nerve distribution
– Extension to shoulder, neck, upper back
– “Upper plexus” disorders
– “Lower plexus” disorders

25.
Neurogenic TOS
• Symptoms
– Occipital headaches
– Perceived muscle weakness
– Vasomotor symptoms
• Vasospasm, edema, hypersensitivity
• Pectoralis minor syndrome
– Compression of neurovascular bundle under the
pec minor muscle
– Pain over anterior chest and axilla
– Fewer head/neck symptoms

26.
Venous TOS
• Etiology
– Developmental anomalies of
costoclavicular space
– Repetitive arm activities – throwing,
swimming, overhead activities.

27.
Venous TOS
• Predisposing Factors
– Relationship of vein to
subclavius tendon and
costoclavicular ligament
– Decrease in dimensions of
costoclavicular space
• Repetitive trauma to vein
causing stenosis,
thrombosis

28.
Venous TOS
• Acute occlusion
• Pain of upper limb
• Tightness
• Discomfort during exercise
• Edema
• Cyanosis
• Swelling
• Feeling of heaviness
• Easily fatigued arm and hand
• Superficial vein distension
• Thrombophlebitis of the upper limb
• Tenderness over the axillary vein
• Gangrene rarely

29.
Arterial TOS
• Etiology
– Cervical or anomalous first rib
– Anomalous anterior scalene insertion
• Pathophysiology
– Arterial compression resulting in post-stenotic
dilatation or aneurysm
– Distal embolization of thrombus

30.
Arterial TOS
• Pathophysiology
• – Arterial compression
• resulting in post-stenotic
• dilatation or aneurysm
• – Distal embolization of
• thrombus

31.
Arterial TOS
• Symptoms
–Digital or hand ischemia
–Cutaneous ulcerations
–Forearm pain with use
–Pulsatile supraclavicular mass/bruit
--Easily fatigued arms and hands
--Rest pain of hand and fingers
--Paleness – coldness of the hand
--Raynaud’s phenomenon
--distal gangrene due to repeated embolization, or
subclavian artery thrombosis

32.
DIAGNOSIS
• Clinical maneuvers
• Radiography
• Ultrasonography
• Magnetic resonance (MR) angiography
• Computed tomographic (CT)
angiography
• Angiography and venography

33.
Adson maneuver
Patient is instructed to
take and hold a deep
breath and extend his
neck fully and then
asked to turn his head
towards the side being
examined. Obliteration
or diminuation in the
radial pulse suggest
compression.

34.
The Roos test
The patient repeatedly clenches
and unclenches the fists
while keeping the arms
abducted and externally
rotated (palms forward and
upward).
The elbows are braced slightly
behind the frontal plane for
3mins.
The test is positive when
symptoms are reproduced
with this maneuver.
A positive test is very
suggestive of the thoracic
outlet syndrome.

35.
Hyperabduction maneuver
• Evaluates compression of the neurovascular
bundle between the coracoid process and the
pectoralis minor muscle.
• The patient externally rotates the shoulders and
extends the arms out from the chest and then
above the head.

36.
Wright's hyperabdution test

37.
Halsted's Costoclavicular
maneuver
• Evaluates compression of the
neurovascular bundle between the
clavicle and the first rib.
• The patient assumes an exaggerated
military position with shoulders pushed
backward and pressed downward.

38.
ALLEN maneuver
• Patient elbow flexes to 90 degrees, while the
shoulder is extended horizontally and rotated
laterally.
• The patient is asked to turn the head away
from the tested arm. If radial pulse appears,
then the test is considered positive

39.
CERVICAL ROTATION LATERAL
FLEXION TEST
• Patient seated, Examiner passively rotates the
head away from the affected side and gently
flexes the neck forward to end range moving
the ear toward the ventral chest.
• Positive test: forward flexion part of the
movement is notably decreased with a hard
end feel.

40.
ADDITIONNAL TESTS
• Angiography and venography
--may show the compression
--explores arterial complications (stenosis,
aneurysms…)

41.
Imaging
• X-rays
– Cervical rib
– Elongated C7 transverse process
– Hypoplastic 1st rib
– Callous formation from clavicle or 1st rib
fracture
– Pseudoarthrosis of 1st rib

42.
• CT/MRI can rule out other pathologies
• Magnetic resonance (MR) angiography and
computed tomographic (CT) angiography of
the thoracic inlet, especially with recently
devised techniques and protocols, are
noninvasive modalities that provide image
quality comparable to that of angiography and
venography.
• MR neurography – newer technology to detect
localized nerve function abnormality

43.
EMG/NCV
• Reduction in NCV and low amplitude motor
responses
• Positive results
– Confirms the clinical diagnosis
– Poor prognosis if true neural damage is present
• Negative results
– Does not exclude TOS
• Both EMG/NCV have low sensitivity for TOS

44.
Scalene muscle block
• Most useful when diagnosis is unclear
• Patient in supine position with neck hyperextended and
turned to opposite side. Lateral border of
sternocledomastoid is palpated andabout 1.5 inches
above the clavicle anterior scalene muscle is palpated.
• 5- 7ml of plane bupivacaine and 1ml of
• betamethasone is injected.
• Relief of symptoms ranging from few days to weeks.
• Good relief of symptoms confirms the diagnosis.
• 2-3 injections can be given.

45.
TREATMENT
• MEDICAL TREATMENT
-- Analgesic treatment
-- Anti-inflammatory non steroid drugs
-- Muscle relaxing drugs
-- Transcutaneous electric nerve
stimulation.(TENS)
-- Local anesthetic injections.

46.
• Conservative management aims to increase the
space in the thoracic outlet area and to relieve
compression on the neurovascular structures.
(1) proper postural changes and correct faulty
postures.
(2) manipulate and mobilize and relax 1st rib and
clavicular, scapular, pectoral muscles.
(3) strengthen the shoulder girdle muscles and
stretch scalene muscles

47.
• PHYSICAL THERAPY
-- Is the key of T.O.S. treatment
-- Its purpose :
• open the costo-clavicular space
• fight against physiological shoulders falling
attitude
• Has to be progressive, painless, bilateral
• Average duration : 3 to 6 months
• If properly executed : 70 to 90% of good
• results

48.
Edema control
• Edema gloves
• Compressive garments
• Elevation of limb
• Active range of motion exercises
• Retrograde massages
• Phonophoresis controls pain and edema

49.
Exercises
• Involves relaxing shoulder girdle and
stretching the scalene and pectoral muscles.
• Neck : neck side bending exercises
neck rotation
neck flexion exercises
• Shoulder : shrugging of shoulders
pendulum exercises

50.
SURGICAL TREATMENT OF T.O.S.
• Surgical treatment is indicated:
• In case of symptomatic cervical rib Symptoms
persists beyond 2 months of conservative
management
• after failure of physiotherapy
• in T.O.S. with venous or arterial complications
(thrombosis, aneurysms…)
• Complete occlusion of a large vessel.
• Progression of neurological symptoms.
• Nerve conduction velocity < 60m/s

51.
• 1st rib resection and scalenectomy are standard
procedures for TOS
• 1st rib resection is recommended for lower
type TOS
• Scalenectomy is recommended for upper type
TOS
• Best results and less chance of recurrence with
combined 1st rib resection and scalenectomy.

52.
Scalenectomy
• Incision :8cms incision, 1.5cm above middle
third of clavicle.
• 80-90% of scalenus anterior muscle and
• 40-50% of scalenus medius muscle removed.
• Protect long thoracic nerve and phrenic nerve.
• Complications : neck hematoma, chylus
drainge, dyspnea due to phrenic nerve
irritation.

53.
1st rib resection
• 1. Transaxillary approach
• 2. Supraclavicular approach
• 3. Infraclavicular approach
• 4. Posterior approach.
• 5. Thoracoscopic First Rib Resesction
Adjunctive procedures
– Pectoralis minor tenotomy.
– Sympathectomy :

54.
Treatment vTOS
• Anticoagulation therapy with heparin and oral
anticoagulants.
• Fibrinolytics
• Catheter-directed thrombolysis.
• Thrombosis is < 3days old : Thrombectomy
• Chronic thrombosis : Venous Bypass

55.
Complications
• Nerve injury
bracial plexus injury
Long thoracic nerve of bell
Phrenic nerve
Intercostobrachial nerve.
Vagus and Reccurent laryngeal nerve
• Vascular injury
Subclavian vein and artery

56.
• Thoracic duct injury
Lymphatic fistula
Lymphocele
Chylothorax
• Pleural complication
pleural damage
Pneumotharax
Pleural effusion

57.
CONCLUSIONS
• T.O.S management requires :
• a good knowledge of the anatomy of the area
• a good patient questionning and examination
• the key of the treatment is physiotherapy
:when properly conducted it improves
symptomatology in more than 70% cases
• surgical treatment is decided only after failure
of physiotherapy

58.
2/3/2023 61
Parul Institute of Medical Sciences and
Research
Thank You!