2. First clinical description was given
by A.Cooper in 1821
W. H. Willshire described about
cervical rib
H. Coote did the first resection of
cervical rib.
In 1956 Peet introduced the term
thoracic outlet syndrome.
3. De finitio n
• Thoracic outlet syndrome (TOS) is a
collection of symptoms brought about by
abnormal compression of the neurovascular
bundle by bony, ligamentous or muscular
structures in the narrow space between
clavicle and 1st
rib i.e. the thoracic outlet.
4. Introduction
• It is the compression of the lower trunk of the brachial plexus (C8 and
T1) and subclavian vessels between the clavicle and the first rib.
• The subclavian artery and lower brachial trunk pass through a triangle
based on the first rib and bordered by scalenus anterior and medius.
• These neurovascular structures are made taut when the shoulders are
braced back and the arms held tightly to the sides; an extra rib (or its
fibrous equivalent extending from a large costal process), or an
anomalous scalene muscle, exaggerates this effect by forcing the vessel
and nerve upwards.
5. • These anomalies are all congenital, yet symptoms are rare before the
age of 30. This is probably because, with increasing age, the shoulders
sag, thus putting more traction on the neurovascular bundle; indeed
drooping shoulders alone may cause the syndrome and symptoms are
characteristically posture-related.
• Stretching or compression of the lower nerve trunk produces sensory
changes along the ulnar side of the forearm and hand, and weakness of
the intrinsic hand muscles.
• The subclavian artery is rarely compressed but the lumen may contract
due to irritation of its sympathetic supply, or else its wall may be
damaged leading to the formation of small emboli.
• Even more unusual are signs of venous compression – edema, cyanosis
or thrombosis.
6. • Boundaries of TO
• posteriorly: T1 vertebral body
• laterally: first rib and costal cartilage
• anteriorly: manubrium sterni
7.
8. 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.
9.
10.
11. Contents of Thoracic Outlet
• viscera
– thymus
– trachea
– esophagus
– 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
15. • 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
16. Principal Causes of TOS
• Skeletal and bony abnormalities
Cervical rib, elongated C7 transverse process
Exostosis or tumor of the first rib or clavicle
Excess callus of the first rib or clavicle
• Soft-tissue abnormalities
Fibrous band
Congenital muscle abnormalities
Insertion variations
Supernumerary muscles
Acquired soft-tissue abnormalities
Post-traumatic fibrous scarring
Post-operative scarring
• Posture & predisposing morphotype
Poor posture and weak muscular support in thin women
17. Cervical Rib
• It is a supernumerary rib that arises from seventh
cervical vertebra or rarely from sixth or fifth
cervical vertebrae.
• Incidence is 0.5-0.6%
• Bilateral in 60-80 %
• Symptomatic in 10 -15%
19. Types of Cervical Rib
• Type 1 small projection from costal facet. 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.
21. • 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.
A) Neurogenic Type
22. • 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.
B) Venous Type
23. • 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).
C) Arterial Type
26. • Pathophysiology
– Neck trauma stretches and tears scalene
muscle fibers
– Swelling of muscle belly pain, paresthesia,
numbness, weakness
– Scarring/fibrosis of muscle belly occipital
headaches.
27. • Symptoms
– Pain, paresthesia, numbness, weakness throughout
affected hand/arm
• Not necessarily localized to peripheral nerve
distribution
– Extension to shoulder, neck, upper back
– “Upper plexus” disorders
– “Lower plexus” disorders
28. – Occipital headaches
– Perceived muscle weakness
• Actual weakness and atrophy are rare
– Vasomotor symptoms
• Vasospasm, edema, hypersensitivity
(CRPS)
29. • Pectoralis minor syndrome
– Compression of neurovascular bundle under
the pectoralis minor
– Pain over anterior chest and axilla
– Fewer head/neck symptoms
30. Venous TOS
• Etiology
– Developmental
anomalies of
costoclavicular space
– Repetitive arm activities
– throwing, swimming,
overhead activities.
31. • Predisposing Factors
– Relationship of vein to
subclavius tendon and
costoclavicular ligament
– Decrease in dimensions of
costoclavicular space
• Repetitive trauma to vein
causing stenosis, thrombosis
32. • Acute occlusion
– Pain
– Tightness
– Discomfort during exercise
– Edema
– Cyanosis
Increased venous pattern
Tenderness over the axillary vein
Gangrene rarely
38. Adson’s 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
diminution in the radial pulse
suggest compression.
39. TThheRoos testeRoos 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.
40. 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.
41. 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.
44. Diagnosis
• “the most accurate diagnosis of TOS…must
rely on a careful history and thorough,
appropriate physical examination”
• No single diagnostic test has sufficient
specificity to prove or exclude the diagnosis
45. DD of neurogenic TOS
• Carpal tunnel syndrome
• Ulnar nerve compression or neuritis.
• Rotator cuff tendinitis
• Cervical spine strain/sprain
• Fibromyositis
• Cervical disk disease
• Cervical arthritis
• Brachial plexus injury
46. DD of arterial TOS
• Other sources of emboli: Cardiac and aortic arch
causes, coagulopathies
• Vasculitis
• Radiation-induced arteritis
• Connective tissue disorders
• Arterial dissection
• Atherosclerotic disease
• Traumatic
47. Imaging
• X-rays
– Cervical rib
– Elongated C7 transverse process
– Hypoplastic 1st
rib
– Callous formation from clavicle or 1st
rib fracture
– Pseudoarthrosis of 1st
rib
• Unable to image soft tissue anomalies and fibromuscular
bands – seen only at time of surgery
48. • CT/MRI can rule out other pathologies
• Magnetic resonance (MR) angiographyMagnetic resonance (MR) angiography and
computed tomographic (CT) angiography(CT) angiography of the
thoracic outlet, especially with recently devised
techniques and protocols, are noninvasive
modalities that provide image quality comparable
to that of angiography and venography.
49. • Angiography and venographyAngiography and venography remain the criterion standards for the
radiologic diagnosis of these conditions, and they have the added benefit
of enabling potential endovascular treatment.
• MR neurography – newer technology to detect localized nerve function
abnormality
51. EMG/NCS
• Reduction in NCV and low amplitude motor
responses
• Positive results
– Confirms the clinical diagnosis
– Poor prognosis if true neural damage present
• Negative results
– Does not exclude TOS
Both EMG/NCV have low sensitivity for TOS
52. Scalene muscle block
• Most useful when diagnosis is unclear
• Patient in supine position with neck
hyperextended and turned to opposite side.
Lateral border of sternocleidomastoid is
palpated and about 1.5 inches above the
clavicle anterior scalene muscle is palpated.
53. • 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.
54. Treatment
Conservative management aims to increase the space
in the thoracic outlet area and to relieve
compression on the neurovascular structures.
Step 1 proper postural changes and correct faulty
postures.
Step 2 manipulate and mobilize and relax 1st
rib and
clavicular, scapular, pectoral muscles.
Step 3 strengthen the shoulder girdle muscles and
stretch scalene muscles
55. Pain control
• Muscle relaxants
• NSAIDS
• Ultrasonography with iontophoresis
• Transcutaneous electric nerve stimulation. (TENS)
• Local anesthetic injections.
56. Edema control
• Compressive garments
• Elevation of limb
• Active range of motion exercises
• Retrograde massages
• Phonophoresis controls pain and edema
57. Ergonomics
• Work posture related changes
• Relative adjustment of chair height so that forearm
rests comfortably and without shoulders being
elevated or depressed.
• Avoid carrying heavy weights on effected side
• Avoid hyperextension of neck and hyper abducting
postures
58. 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
60. Surgical decompression
Indications
Symptoms persists beyond 2 months of
conservative management.
Associated vascular compression with post stenotic dilatation.
Complete occlusion of a large vessel.
Progression of neurological symptoms.
Nerve conduction velocity < 60m/s
61. • 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.
62. 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, dyspnea due to
phrenic nerve irritation.
64. Trans axillary approach ( Roos approach)
• Transverse Incision at the level of third rib just below the
axillary hair line.
– Advantages
• Limited field of operative dissection
• Cosmetically placed incision
• Achieve 1st
rib resection and anterior scalenectomy
• Removal of anomalous ligaments and fibrous bands.
• Less blood loss, no muscles are divided.
65. – Disadvantages
• Incomplete exposure of entire scalene
triangle
• Difficulty achieving brachial plexus neurolysis
• Limited if vascular reconstruction is needed
66. • Supraclavicular approach
– Advantages
• Wide exposure of all anatomic structures
• Permits complete resection of anterior and
middle scalenes as well as brachial plexus
neurolysis.
• Allows resection of cervical ribs and
anomalous 1st
ribs
• Vascular reconstruction is possible
67. Infraclavicular approach
• ADVANTAGES
• Ideal for venous and arterial obstruction.
• Venous embolectomy.
• Arterial reconstruction.
• DISADVANTAGES
• Poor view of thoracic outlet.
• Poor excision of posterior part of the rib.
68. Posterior approach
• Advantages
• cervical rib can be easily resected.
• Sympathetectomy can be done
• Disadvantages
• Vascular reconstruction can not be performed.
69. Thoracoscopic First Rib Resection
• Three 10mm portal are made
-1st
anterior 3rd
ICS
-2nd
lateral 5th
ICS
- 3rd
lateral wall of 6th
ICS
Endoscopic drill is used to dissect the rib
74. Recurrent neurogenic TOS
• Postoperative scarring most common cause.
• Recurrence usually is seen within 3months.
• To minimize scar tissue formation patient is
instructed to perform active range of motion
exercises beginning the day after surgery.
Performed every 3-4 hrs for at least 6 months.
75. Initial procedure Recurrent procedure
Adequate 1st
rib resection scalenectomy
More than 1cm of first rib
stump.
Removal of the stump
Brachial plexus neurolysis
Subclavian vessel vascolysis.
Partial resection of 2nd
rib
scalenectomy
1st
rib resection +
Scalenectomy
Brachial plexus neurolysis.
Adequate coverage of plexus
with prescalene fat.
Partial 2nd
rib resection.
