THORACIC OUTLET
SYNDROME
Dr. Nanda gopal
Velagapudi
Dr. Avinash Katkam
Dr Giridhar Boyapati

First clinical description given by
A.Cooper 1821
W H Willshire described about
cervical rib
H Coote first resection of cervical rib.
In 1956 Peet introduced the term
thoracic outlet syndrome.

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.

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

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.

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

Interscalene triangle

Costoclavicular space

Subcoracoid area

Anatomic sections show the compartments of tthhee tthhoorraacciicc oouuttlleett
Fig. (b) Section obtained after removal of
the pectoralis minor muscle shows the
neurovascular bundle. C = clavicle, straight
black arrow = axillary artery, curved black
arrow = axillary vein, white arrow = brachial
plexus.
Demondion X et al. Radiographics 2006;26:1735-1750

Anatomic sections show the compartments of the thoracic outlet
Fig. Anatomic sections show the
compartments of the thoracic outlet.
(a) Section obtained after removal of
the pectoralis major muscle shows the
costoclavicular space (red oval) and
retropectoralis minor space (yellow
oval). Pmi = pectoralis minor muscle.
Demondion X et al. Radiographics 2006;26:1735-1750

• 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

Principal Causes of TOS

Cervical rib

Cervical rib
• It is a superneumary rib that arises from
seventh cervical rib or rarely from sixth or
fifth cervical vertebrae.
• incidence 0.5-0.6%
• Bilateral in 60-80 %
• Symptomatic in 10 -15%

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.

Classification

SSuubbggrroouupp 11 -- ((nneeuurroollooggiicc
ttyyppee))
• –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.

Subgroup 2 - (the 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.

SSuubbggrroouupp 33 ((the 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).

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

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

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.

• Symptoms
– Pain, parathesias, 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

Neurogenic TOS
• Symptoms
– Occipital headaches
– Perceived muscle weakness
• Actual weakness and atrophy are rare
– Vasomotor symptoms
• Vasospasm, edema, hypersensitivity
(CRPS)

Neurogenic TOS
• Pectoralis minor syndrome
– Compression of neurovascular bundle
under the pec minor
– Pain over anterior chest and axilla
– Fewer head/neck symptoms

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

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

• Acute occlusion
– Pain
– Tightness
– Discomfort during exercise
– Edema
– Cyanosis
Increased venous pattern
Tenderness over the axillary vein
Gangrene rarely

Arterial TOS
• Etiology
– Cervical or anomalous first rib
– Anomalous anterior scalene insertion

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

Interscalene triangle Artery , Nerves
Costoclavicular space Vein
Subcoracoid area Artery, Vein , Nerves

Arterial TOS
• Symptoms
–Digital or hand ischemia
–Cutaneous ulcerations
–Forearm pain with use
–Pulsatile supraclavicular
mass/bruit

DIAGNOSIS
• CClliinniiccaall mmaanneeuuvveerrss
• RRaaddiiooggrraapphhyy
• UUllttrraassoonnooggrraapphhyy
• MMaaggnneettiicc rreessoonnaannccee ((MMRR)) aannggiiooggrraapphhyy
• Computed tomographic ((CCTT))
aannggiiooggrraapphhyy
• AAnnggiiooggrraapphhyy aanndd vveennooggrraapphhyy

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.

TThhee RRooooss tteesstt
• 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.

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.

Wright's hyperabdution test

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.

Diagnosis and
Treatment

Diagnosis
• “the most accurate diagnosis of TOS…must
rely on a careful history and thorough,
appropriate physical examination”
» David B Roos, MD
• No single diagnostic test has sufficient
specificity to prove or exclude the diagnosis

DD nTOS
• Carpal tunnel syndrome
• Ulnar nerve compression or neuritis.
• Rotator cuff tendinitis
• Cervical spine strain/sprain
• Fibromyositis
• Cervical disk disease
• Cervical arthritis
• Brachial plexus injury

DD aTOS
• Other sources of emboli: Cardiac and aortic
arch causes, coagulopathies
• Vasculitis
• Radiation-induced arteritis
• Connective tissue disorders
• Arterial dissection
• Atherosclerotic disease
• Traumatic

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

• CT/MRI can rule out other pathologies
• Magnetic rreessoonnaannccee ((MMRR)) aannggiiooggrraapphhyy and
computed tomographic ((CCTT)) aannggiiooggrraapphhyy 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.

• an Angiography andd vveennooggrraapphhyy 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

• aTOS
– Segmental arterial pressures
– Angiography
• vTOS
– Duplex U/S
– Venography
• Consider bilateral studies

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 lo sensistivity for TOS

Electrophysiology Testing
• Medial antebrachial cutaneous nerve (MAC)
– Lowest branch of inferior trunk of brachial
plexus
– More sensitive to compression than other
branches
• Higher sensitivity and specificity with
EMG/NCS

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.

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

Pain control
• Muscle relaxants
• NSAIDS
• Ultrasonography with ionatophorosis
• Transcutaneous electric nerve stimulation.
(TENS)
• Local anesthetic injections.

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

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 hyperabducting
postures

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

Treatment nTOS
• Neck stretching
• Posture correction
• Avoid neck traction,
weights, resistance
exercises,
strengthening
exercises

Surgical decompression
Symptoms persists beyond 2 months of
conservative management.
 Associated vascular compression with
poststenotic dialatation.
Complete occlusion of a large vessel.
Progression of neurological symptoms.
Nerve conduction velocity < 60m/s

• 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.

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.

1st rib resection
1. Transaxillary approach
2. Supraclavicular approach
3. Infraclavicular approach
4. Posterior approach.

Transaxillary 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.

– Disadvantages
• Incomplete exposure of entire scalene triangle
• Difficulty achieving brachial plexus neurolysis
• Limited if vascular reconstruction is needed

• 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

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.

Posterior approach
• Advantages
• cervical rib can be easily resected.
• Sympathetectomy can be done
• Disadvantages
• Vascular reconstruction can not be
performed.

Thoracoscopic First Rib Resesction
• Three 10mm portal are made
-1st anterior 3rd ICS
-2nd lateral 5th ICS
- 3rd lateral wall of 6th ICS
Endoscopic drill is used to dissesct the rib

Adjunctive procedures
– Pectoralis minor tenotomy.
– Sympathectomy :

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

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

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

Recurrent nTOS
• 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 atleast 6 months.

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 prescelene fat.
Partial 2nd rib resection.

Thank you.