Thoracic outlet

THORACIC OUTLET
SYNDROME
DR.Revanth Balaga

Thoracic Outlet :
• The Thoracic Outlet is called the space through which the neurovascular bundle:
subclavian vein, subclavian artery and brachial plexus (nerves) are passing from
the neck to the armpit.

Antaomy :
Ant.Scalene
Scalenus
medius

• There are three potential spaces for compression of the neurovascular structures along their
course to the upper extremity.
• These spaces are as follows:
• (l) the interscalene space or triangle
• (2) the costoclavicular space
• (3) the subpectoralis minor space

Spaces :
• INTERSCALENE TRIANGLE ( most commonly involved)
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
• PECTORALIS MINOR SPACE
Anteriorly by Pectoralis minor and posteriorly by Chest wall

• The subclavian vein follows a similar course but does not pass through the
interscalene triangle.
• It courses just medial and anterior to the anterior scalene muscle and runs
inferior and lateral to the subclavius tendon and costocoracoid ligament
• The brachial plexus is located—superior , posterior, and lateral to the
subclavian artery.
• Artery, vein, and the brachial plexus follow a similar course after passing
under the clavicle and subclavius muscle.

CAUSES:
• Causes of thoracic outlet syndrome can be divided into BONY AND SOFT-
TISSUE FACTORS.
Bony factors are abnormalities such as:
• 1. Anomalous cervical ribs,
• 2. Hypoplastic first thoracic ribs,
• 3. Exostoses of the first rib or clavicle
• The incidence of anomalous cervical ribs is believed to be 0.17-0.74% in the
general population, and the incidence of rudimentary first ribs is 0.29-
0.76%

• SOFTTISSUE FACTORS :
• Congenital anomalies such as anomalous fibrous muscular bands near
the brachial plexus
2. Hypertrophic muscles in athletes and weight lifters.
3. Space-occupying lesions (e.g., tumors, cysts)
4. Inflammatory processes also occur in the soft tissues
5.Trauma or mechanical stress to the neck, shoulders, or upper extremities
can result in thoracic outlet syndrome.
• A combination of neck trauma and anatomic predisposition (i.e., cervical
rib) is believed to be the main cause of thoracic outlet syndrome.

Post-traumatic conditions such as:
1. Hematoma,
2. Myositis ossificans
3. Scar formation,
4. A droopy shoulder secondary to trapezius muscle weakness
5.Thoracic outlet syndrome can be due to malunion of a clavicle fracture

Contributing Factors
Dynamic Factors
Static factors
Anatomic/Congenital factors
Traumatic factors
Arteriosclerotic Factors
Miscellaneous Factors

• Dynamic factors. When the arm is in full hyperabduction above the head, the
axillary artery is bent 180, thus pulling the vessel across the coracoid and
head of the humerus
• The clavicle rotates and narrows the retroclavicular space.

• Static factors.
• Vigorous occupations may result in increased muscular bulk, thereby
reducing the space through which artery, vein, and nerves must pass.
• Inactive middle-aged adults lack muscle mass and tone,
sagging shoulders,
angulate ,compress the neurovascular structures.

• Anatomic predispositions/congenital factors.
• secondary role in etiology.
• Congenital bands and ligaments are observed in a large majority of
patients with neurogenic thoracic outlet syndrome (nTOS),
• A cervical rib, will encroach on the interscalene interval and the
retroclavicular space.

• The first rib
bifid present a bony protuberance,
• the clavicle may present an anomaly such as reduction of its anterior
curvature
• All these may encroach on the space between the first rib and the clavicle

• Symptoms :
• ARTERIAL COMPROMISE
• Fatigue
• Weakness
• Coldness
• Upper limb claudication
• Thrombosis
• Paraesthesia
• Gangrene
• Raynaud's phenomenon due to thrombosis with distal embolization
• Unilateral Raynaud’s phenomenon

Venous compromise
• Edema
• Venous distension
• Collateral formation
• Cyanosis
Neural compromise
• Paraesthesia
• Pain in shoulder, arm, forearm and fingers
• Occipital headache – referred from tight
• Weakness of forearm, hand.

• The classic finding in a person with neurogenic thoracic outlet syndrome is the
Gilliatt-Sumner hand.
• This physical examination finding includes atrophy of the abductor pollicis brevis
with lesser involvement of the interossei and hypothenar muscles.
• Patients may also have decreased sensation that follows the ulnar nerve
distribution because the lower trunks of the brachial plexus are usually more
involved than the upper trunks

• The maneuvers used to detect the arterial compressions involved inTOS are the
Hyperabduction maneuver, orWright's test, (subcoracoid tunnel or retropectoralis
space),
• The Adson test (interscalene triangle) and
• Costoclavicular interval maneuver (between the clavicle and the first rib);
• However, none of these tests have been accepted as the gold standard for
diagnosis and they offer 53% mean specificity and 72% mean sensitivity.

Clinical tests :
RoosTest :
RoosTest is a common test included in the examination of the shoulder, specifically for
the presence ofThoracic Outlet Syndrome (TOS).
• It is also knows as the EAST (Elevated Arm StressTest)Test or the Hands UpTest.
Involved Structures
subclavian artery
brachial plexus
Starting Position
• In this test, the patient raises their arms to 90 degrees of abduction in the frontal plane
of the body with the arms fully externally rotated and the elbows at 90 degrees of
flexion.

Test Movement
• The patient opens and closes their hands for up to 3 minutes.
PositiveTest
• The test is considered positive if the patient is unable to hold the arms up
for the 3 minutes, or if the patient experiences pain, heaviness or
parasthesia in the shoulder, arm or hands.

Results if normal:
Only forearm muscle fatigue and minimal distress
Possible symptoms ifTOS is present:
• gradual increase in pain at neck and shoulder, progressing down the arm
• Paraesthesia in forearm and fingers

In case of arterial compression: arm pallor with arm elevated,
reactive hyperemia when limb is lowered
In case of venous compression: Cyanosis and swelling
• Inability to complete test, and patient drops arms in lap in
marked distress, recognized as reproduction of usual symptoms
• Reproduction of the usual symptoms that involve the entire
extremity!

ADSONTEST :
• The examiner locates the radial pulse in the affected arm of the seated patient.
• The patient is asked to rotate the head toward the affected side and to extend the head and
neck back.
• The shoulder and upper extremity is externally rotated and extended.
• Other versions of the test allow the arm to rest on the patient’s thigh or have it elevated as if
swearing under oath.
• The patient is asked to take a deep breath and hold it while the examiner continues to
monitor the patient’s pulse.

• The suggested mechanism of Adson’s test is that it
increases the tension of the scalene muscles
potentially compressing the neurovascular
bundle in a soft tissue tunnel or over a cervical rib.
• Historically, it has been associated with subsets of thoracic outlet
syndrome, such as scalenus anticus/anterior syndrome or cervical rib
syndrome.

A positive test
possible compromise of the neurovascular bundle somewhere
along its course through the thoracic outlet.
• positive test also suggests that the scalene muscles should be assessed
for hypertonicity and trigger points.
• It would be reasonable to pay special attention to scalene muscle
assessment.

• Positive test results can be seen as being on a continuum:
loss of pulse is the least
specific finding (and the
most likely to be positive
even in asymptomatic
subjects),
production of
paresthesia,
the most specific finding
which is pain production
in the upper extremity.
Reproduction of the patient’s familiar symptoms may be considered even a stronger positive

AllensTest
• The arm is passively elevated and the patient rapidly clenches his/her fist several times (3-5 times).
• Another option, found in the original description of the test, is to continue pumping for a full
minute.
• With the patient’s fist still clenched, the examiner compresses both radial and ulnar arteries of the
wrist
• The arm is then brought into a dependent position, the fist is opened, and one artery or the other
is released.

• Interpretation
• < 5-second refill time is considered normal.
• 6- to 15-second refill time is considered equivocal.
• >15-second refill time is considered abnormal.
• Evans (2001) suggests that an incidental finding of paresthesia may suggest an underlying
distal nerve entrapment such as carpal tunnel syndrome.

Costoclavicular test :
• Procedure
• Patient is sitting in neutral posture.
• The examiner palpates radial pulses
• The examiner extends the patient’s arms, then instructs the patient to “adopt an exaggerated
military posture with shoulders back and down and chest out.”

• An optional step is to instruct the patient to stick his/her chin out and neck forward or,
alternatively, flex the neck down.
• The patient takes in a deep breath, holds it and bears down.
• The position is held anywhere from 30 seconds
• The test can also be performed bilaterally.
• At each step, the examiner evaluates for change in pulse amplitude and reproduction of
symptoms.
• A positive test would be symptoms of upper limb neurovascular compression, such as cessation
or dampening of radial pulse with reproduction of symptoms, ischemic color changes (e.g.,
pallor, blanching), paresthesia or extremity pain

Halstead Maneuver (Reverse Adson’s)
• With the patient seated, the examiner locates
the radial pulse of the affected arm and notes
the amplitude.
• Then the examiner applies downward traction
on the patient’s extremity.
• The examiner directs the patient’s head into
• hyperextension and rotation away from the side
being tested.
• The patient is asked to take a deep breath and
hold it
• while the examiner continues to monitor the
patient’s pulse.

• A positive test suggests possible compromise of the neurovascular bundle somewhere along
its course through the thoracic outlet.

HyperabductionTest (Wright’sTest)

• If the examiner does not use enough shoulder extension keeping the arms posterior to the
patient’s ears along with abduction, then false negative results may occur.

Investigations
• To exclude systemic disease and inflammation
• blood glucose level, complete blood cell (CBC) count, erythrocyte sedimentation
rate (ESR), basic metabolic panel, thyrotropin level, and rheumatologic workup,
if indicated

I:
• Cervical spine x-ray films for assessment of arthritic or degenerative changes and presence
of cervical ribs.
• Chest x-ray film to identify apical lung pathology and superior sulcus tumor.
• Nerve conduction studies and electromyography to delineate the possible significance of
neuroforaminal or cervical disc disease, as well as median nerve compression at carpaltunnel
or ulnar nerve compression at the cubital tunnel.
• .

• Duplex scanning of subclavian artery and vein may reveal an aneurysm
orVenous thrombosis and may provide some anatomic information
before angiography.

• Arteriography:- It is performed only when the patient is suspected of
having arterial complication of thoracic outlet syndrome such as
supraclavicular bruit, a pulsatile mass or vascular symptoms and signs of
upper limb thromboembolism.
• Venography:- It can diagnose subclavian vein thrombosis or stenosis at
the level of first rib and status of the collateral circulation.

• Arteriography may reveal an angulation or stenosis of the subclavian or
axillary artery, aneurysmal widening of the artery beyond the point of
narrowing, and points of embolic occlusion,
• When venous obstruction is suspected, venography is confirmatory.
.

• A subclavian arteriography often demonstrates constriction of the artery
between the clavicle and the first rib when the arm is hyperabductcd.
• This finding is common in many asymptomatic people and is significant
only when correlated with other findings.

Nerve Conduction Studies :
• . The brachial plexus is stimulated at Erb's point in the supraclavicular
fossa.
• Erb's point is at the angle formed by the clavicle and the
posterolateral fibers of the sternocleidomastoid muscle.
• The pickup electrode is placed over the ulnar nerve or median nerve at
the elbow.
• The mean velocity Of the median nerve is 62.8 msec and that of the ulnar
nerve is 58.4 msec.
• Compression at the thoracic outlet will substantially reduce the motor
nerve conduction velocity within this nerve segment.

Treatment :
• In majority of pts conservative management will effect in improvement or
complete relief of symptoms
• Initial management consists of
• Weight reduction
• Exercise programme directed towards improving posture , strengthening
shoulder muscles and avoiding hyperabduction

Exercises :
• Stand facing a corner of the room with one hand on each wall, arms at the shoulder level, palms
forward,elbows bent, and abdominal muscles contracted.
• Slowly let the upper part of the trunk lean and press the chest into the corner.
• Inhale as the body leans forward.
• Return to the original position by pushing out both the hands.
• Exhale with this movement.

• Lie down on the back with the arms at the sides and a rolled towel or a small pillow under the
upper part of your back, between the shoulder blades.
• There should not be a pillow under your head.
• Inhale slowly and raise the arms upward and backward overhead.
• Exhale and lower the arms to the sides.
• Repeat 5-20 times

• Stand erect with the arms at the sides.
• Bend the neck to the left attempting to touch the left ear to the left shoulder without
shrugging the shoulder.
• Bend the neck to the right attempting to touch the right ear to the right shoulder without
shrugging the shoulder.
• Relax and repeat

Exercises :
Stand erect with the arms at the sides holding in each hand a 2-pound weight Shrug the
shoulders forward and upward.
• Relax.
• Shrug the shoulders backward and upward.
• Relax.
• Shrug the shoulders upward.
• Relax and repeat.
Stand erect with the arms out straight from the sides at the shoulder level; hold a 2-pound
weight in each hand (palms should be down).
• Raise the arms sideways and up until the backs of the hands meet above the head (keep elbows
straight).
• Relax and repeat.

Cervical Rib:
• The cervical rib is a supernumerary rib that arises usually from the seventh and rarely
from the sixth or fifth cervical vertebrae.
• It is frequently bilateral.

• PATHOLOGIC ANATOMY
• Whether the rib is full developed or represented by a fibrous band, the
brachial plexus and the subclavian artery must pass over a higher barrier
before passing downward to the arm . The neurovascular structures are
hung up.
• In addition, the cervical rib or band inserts anteriorly at or near the
scalene tubercle, thereby narrowing the interval through which nerves
and artery pass.
• At the point of insertion, the tubercle on the first thoracic rib may
become enlarged and add to the compression and friction.

• Plexus and artery are further embarrassed when they are pulled distally
by downward traction on the arm, such as when carrying a heavy weight.
• Normally, with advancing age, the shoulder girdle droops downward and
increases tension on the neurovascular structures.

• Pronounced drooping of the shoulder occurs in
women of middle age,
in the course of unusual lifting occupations,
and following an acute illness when muscle weakness develops.
• This explains the frequency of symptoms in these situations.

prolongation and
pointing of the
seventh cervical
transverse process
type 2, short
articulating rib
with fibrous
prolongation
type 3, jointed rib
long enough to carry
the eighth cervical
nerve
The classification proposed by Sargent

type 4, jointed rib fused
at its end withthe first
rib or articulating with
it
type 5, a complete seventh
cervical rib with
cartilaginous union to the
first costal cartilage or to the
manubrium

Symptoms :
• CLINICAL PICTURE
• Symptoms can occur at any age but are often initiated under conditions
effecting descent of the shoulder girdle.
• Symptoms and findings are characteristically ulnar in distribution, pointing
to the lower trunk of the plexus.
• Complaints referable to the median nerve distribution usually implicate a
ruptured cervical disc.

• Pain and paresthesias occur in the ulnar aspect of the hand and the little and
ring fingers.
• Less commonly, they may be felt in the whole hand.
• The pain may be dull and aching or sharp and lancinating.
• A sensation of tingling of the forearm and the hand, which the patient
describes as "falling asleep," is ascribed to circulatory deficiency and is
associated with diminution of the radial pulse.

• The patient complains of weakness of the hand, clumsiness in use of the
fingers, and dropping of objects.
• Symptoms are accentuated by downward displacement of the shoulder
girdle (e.g. when carrying a heavy object or following the fatigue brought
on by excessive activity).
• Adson's sign intensifies the symptoms by increasing tension on the
scalenus anterior and narrowing the rib-muscle interval.

SCALENUS ANTICUS SYNDROME
• Cervicobrachial compression can occur in the interval between the scalenus
anterior and the scalenus medius in the absence of a cervical rib
i. Wide Insertion
ii. Bony Prominence on insertion
iii. Tendon edge extending either forward or backward

• Similar to cervical rib
• lowermost trunk of the plexus receives the greatest amount of
compression, the neurologic symptoms are referred to the C8 andTl nerve
root
• AdsonsTest

HYPERABDUCTION SYNDROME
• The main vessels and the brachial plexus are subject to stretching and
compression at 2 points
 where they pass beneath the coracoid process posterior to the
pectoralis minor.
 The Second point of
pressure is between
Clavicle and First
rib(CostoClavicular
Syndrome)

• These structures are relaxed in adduction but are stretched about the
coracoid in hyperabduction
• Strong contraction of the pectoralis minor will pull the coracoid
downward and similarly stretch the vessels and the nerves

Symptoms :
• Numbness and paresthesias are noticed first in the fingers and progress
centripetally to involve the hands and the arms.
• Pain is not a prominent feature.The pulse is obliterated in the
hyperabducted position.
• Occasionally, gangrene of the tips of the fingers may develop.
• AllensTest
• Wright Hyperabduction test
• Costpclavicular compressionTest
• 1st Thoracic rib excision and Pectoralis minor tenotomy

• Occlussion of mainartery with insufficient collateral circulation
Recurring ulcerations,Gangrene

Complications :
• Poststenotic Dilatation of SubClavian Artery
Thrombosis Emboli
Occlude
Small
Distal
Arteries
• Paget schroetter syndrome
• Hemiplegia

Surgery :
• Indications:
• Symptoms persists with non operative treatment.
• Associated vascular compression.
• Progression of neurological symptoms.
• Nerve conduction velocity < 60m/s
• Absolute Indications:
• Expanding post-stenoticArterial Dilatation
• Embolic phenomenon in the distal extremities
• Complete Occlusion of large artery
• Specific Acquired compressive structure (malunion of clavicle )

Supraclavicular approach Transaxillary approach Infraclavicular approach Posterior approach
best route to reach all
the structures
excellent cosmesis provides excellent access to
the costoclavicular space for
first rib resection
adopted when there is
history of
previous Operation by other
approach
direct visualization of the
anatomic
relationship between bony
and myofascial structures
readily palpable and easily
visible ligaments and bony
structures
Subclavian venous
thrombosis and
first rib excision.
brachial plexus through
scalene space in the thoracic
outlet
allows access for dorsal
sympathectomy
cosmetic results are less
favourable
congenital anomalies along
with access to the first rib
and
clavicle.
Sub optimal view of surgical
field
Vascular reconstruction
possible

Trans axillary approach :
Transaxillary incision is performed
through 2nd intercoastal space

• COMPLICATIONS OF OPERATION FORTHORACIC OUTLET SYNDROME
• NERVE INJURY .VASCULAR INJURY
• Brachial plexus Subclavian artery
• Long thoracic nerve Subclavian vein
• Phrenic nerve Thoracic duct injury.
• Intercostobrachial nerve Lymphatic fistula
• Recurrent laryngeal nerve Lymphoedema
• PLEURAL COMPLICATIONS
• Chylothorax
• Pneumothorax Wound infection
• Pleural effusion Lymph collection
• Haemothorax

Complications
Method of operation
Transaxillary
(n=32)
Supraclavicular
(n=63)
Vessel injury 1 2
Hemothorax 2 3
Pneumothorax 11 25
Hemothorax with
pneumothorax
2 0
Surgical complications other than brachial plexus
Evaluation of Complications after Surgical Treatment of Thoracic
Outlet Syndrome

Complications
Method of operation
Transaxillary
(n=32)
Supraclavicular
(n=63)
Transient
paralysis due to
T1 root
compression
2 3
Permanent
paralysis due to
T1 root
compression
1 0
Remaining pain
and symptoms
after 6 months
(failure rate and
need for
reoperation)
8 0

• VATS first rib resection forTOS provides,
• unlike the classic approaches, a superior, magnified, and well-illuminated
view of the thoracic inlet.
• It allows good posterior trimming of the first rib, release of brachial plexus,
and an aesthetically pleasing result, especially in female patients
• Totally Endoscopic (VATS) First Rib Resection forThoracicOutlet Syndrome
• Presented at the GeneralThoracic Surgical Motion Picture Matinee of the Fifty-second
Annual Meeting ofThe Society ofThoracic Surgeons, Phoenix,AZ, Jan 23–27, 2016.

• Following intubation with double lumen tube,
• patients are placed in the lateral decubitus position with the arm abducted to 90 degrees and
held by a traction strap wrapped carefully around the forearm and attached to an overhead bar.
• The third to fifth ribs are marked and two 10-mm working ports are placed in the anterior third
and the lateral fourth intercostal spaces in alignment with the anterior axillary line to facilitate
conversion in case of bleeding.
• The third scope port is placed laterally in the fifth intercostal space .
• .

• While on single lung ventilation, the first rib is identified
• the parietal pleura and periosteum overlying it are stripped off using the harmonic scalpel
• Using the harmonic scalpel, both intercostal muscles are separated from the rib and the
scalenae muscles are dissected
• The first rib is then transected anteriorly near the costochondral junction and posteriorly as
close to the transverse process as possible using the modified endoscopic rib cutter
• The neurovascular bundle is gently retracted using a peanut to allow sliding of the edge under
the rib.
• Once the rib is engaged in the cutter’s groove the peanut is removed and the blade is
introduced to cut the rib
• Once the rib is cut it is removed through one of the ports

Thoracic outlet

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