2. DEFINITION
• Refers to compression of subclavian vessels and
the brachial plexus at the superior aperture of
the chest.
• Most compressive factors operate against the
first rib.
3. Surgical
Anatomy
• The subclavian vessels and the brachial
plexus traverse the cervicoaxillary canal
to reach upper extremity.
• The first rib divides the canal into two
parts –
• Proximal – Scalene triangle and
costoclavicular space (more critical
for neurovascular compression)
• Distal – Axilla
• The scalaneus anterior muscle divides
costoclavicular space into two parts –
• Anteromedial
• Posterolateral – known as Scalene
triangle
8. Causes of Neurovascular Compression
Anatomic –
Potential site of neurovascular compression –
• Interscalene triangle
• Costoclavicular space
• Subcoracoid area
Traumatic –
SUDDEN UNACCUSTOMED MUSCULAR EFFORTS
INVOLVING SHOULDER GIRDLE MUSCLES.
Fracture of clavicle
Dislocation of head of humerus
Crushing injury of upper thorax
Cervical SPONDYLOSIS and injury to Cervical
spine
9. Causes of Neurovascular Compression
• CONGENITAL –
• CERVICAL RIB
• RUDIMENTARY FIRST THORACIC RIB
• SCALENE MUSCLES ANOMALY
• FIBROUS BANDS
• BIFID FIRST RIB
• EXOSTOSIS OF FIRST RIB
• ENLARGED PROCESS OF C7
• FLAT CLAVICLE
• ABNORMAL INSERTION OF SOTOCLAVICULAR LIGAMENT
10. SIGNS AND
SYMPTOMS
Neurogenic
manifestations more
common.
•Pain
•Paraesthesia
•Motor weakness
•Atrophy of hypothenar
and interosseous muscles
Symptoms occurs
most commonly in
area supplied by
ulnar nerve.
Upper type involves
C5-C6 – pain usually
in deltoid area and
lateral aspect of the
arm – Must exclude
herniated cervical
disc.
C7-C8 entrapment
produces symptoms
in distribution of
median nerve.
11. SIGNS AND SYMPTOMS
• PSEUDOANGINA –
• Atypical pain, in the area of anterior chest wall or parascapular area.
• Symptoms of arterial compression –
• Coldness, weakness, easy fatiguability of arm and hand
• Diffuse pain – Raynauds phenomenon in 8% patients.
• May be precursor of arterial thrombosis.
• Palpation in parascapular area may reveal prominent pulsation indicating
post-stenotic dilatation of subclavian artery.
• Less commonly symptoms are due to venous compression – known
as effort thrombosis or PAGET – SCHROETTER SYNDROME
20. INDICATIONS
FOR SURGERY
AREA OF COMPRESSION SYMPTOMS INDICATING NEED FOR
SURGERY
NERVE SENSORY :- PERSISTENT SYMPTOMS
INSPITE OF PHYSICAL THERAPY
MOTOR : WEAKNESS OR ATROPHY
ARTERY ANEURYSM OR SYMPTOMATIC
INSUFFICIENCY
VEIN OCCLUSION (PAGET – SCHROETTER)
MULTIPLE THEAPEUTIC TRAIL
21. APPROACHES
TYPE OF PROBLEM SURGICAL APPROACH
NERVE COMPRESSION TRANSAXILLARY
VENOUS COMPRESSION TRANSAXILLARY
ARTERIAL COMPRESSION SUPRA & INFRACLAVICULAR
RECURRENT TOS POSTERIOR HIGH THORACOPLASTY
22. TRANSAXILLARY
APPROACH (ROOS
et al)
• Return the arm to the
neutral position every 20
minutes during the course
of the operation to further
minimize positioning-
related brachial plexopathy
• The incision is located just
above the lower border of
the axillary hair line and
extends from the border of
the latissimus to the border
of the pectoralis.
• Preserve the thoracodorsal
and long thoracic nerves
23. Operative
exposure by this
approach.
• Blunt dissection cephalad exposes
first rib and permit palpation of
subclavian artery.
• Wylie vein retractor permits
focused deep retraction
• Subclavian pulse is used to guide
the retractor placement to avoid
compressing brachial plexus
24. Division of
anterior scalene
muscle
• The phrenic nerve courses laterally to
medially across the anterior surface of
the muscle at the cephalad extent of the
field of exposure.
• In general, the phrenic nerve courses
posterior to the subclavian vein, but in
rare cases it will pass anterior to the vein.
• Divide the muscle carefully as cephalad as
it may be adequately visualized,
permitting an effective resection or
scalenectomy at the time of first rib
removal, rather than a simple division or
scalenotomy.
• This additional effort is of importance in
averting the portion of persistent or
recurrent TOS that is attributed to
inadequate resection of this muscle
25. Division of
middle scalene
• A periosteal elevator or the Metzenbaum
scissors may then be used to separate the
middle scalene from its insertion on the
first rib, a technique that preserves the
long thoracic nerve that courses rather
variably through the belly of this muscle,
thus avoiding denervation of the serratus
anterior muscle and the attendant
complication of “winged scapula”
• If a scalenus minimus is present between
the subclavian artery and the brachial
plexus, it should be resected at this stage,
as should any other ligamentous bands
encountered constraining the plexus.
• These may insert on the first rib or even
extend to insert into Sibson’s fascia over
the pleural cupola
26. Dissection of
inferior border of
first rib
• Dissect the inferior border of
the first rib free from the
intercostal musculature,
exposing the underlying
parietal pleura.
• The parietal pleura should be
gently bluntly dissected free of
the posterior surface of the rib,
with care taken to avoid
entering the pleural space.
• The rib should be dissected
free from the level of the
costochondral junction
medially to the lateral-most
extent of the middle scalene
posteriorly
27. Resection of first
rib using Roos
first rib shear
• Roos bone shear is inserted
carefully, with the surgeon’s
finger placed between the
shear and the brachial
plexus.
• The rib should be divided
just beyond the divided
insertion of the middle
scalene muscle.
• Anteriorly,the Roos bone
shear should be used to
resect the first rib segment
as close as possible to the
costochondral junction
28. Complete medial
rib removal by
Kerrison rongeur
• Kerrison rongeur is
used to smooth the
rib end posteriorly
and extend the
resection to the level
of the costochondral
junction anteriorly to
permit full
decompression
29. Complete lateral
rib removal by
Kerrison rongeur.
• complete resection of the
costoclavicular ligament
and the subclavius tendon
and muscle to permit full
venolysis and
decompression of the
vein at this key point of
entrapment.
• Air leak should be
checked, wound should
then be closed over a
chest drain.
31. SUPRACLAVICULAR
APPROACH
• A sandbag is placed
between the scapulae
and the neck extended
to the nonoperative
side.
• Long-acting paralytic
agents are avoided.
• An incision is made in
the supraclavicular
fossa, in a neck crease
parallel to and 2 cm
above the clavicle
33. Division of
omohyoid
• The omohyoid is divided
• the supraclavicular fat pad is
elevated, after which the scalene
muscles and the brachial plexus
are palpated.
• The lateral portion of the clavicular
head of the. sternocleidomastoid
is divided and at the end of the
procedure is repaired.
• The phrenic nerve is seen on the
anterior surface of the anterior
scalene muscle; the brachial
plexus is noted at the interscalene
position, and the long thoracic
nerve is noted on the posterior
aspect of the middle scalene
muscle.
34. Anterior
scalene division
• The anterior scalene muscle
is divided from the first rib,
and the subclavian artery is
noted immediately behind
this.
• An umbilical tape is placed
around the subclavian
artery. The phrenic nerve is
not mobilized, but rather is
protected by direct
visualization, while the
anterior scalene muscle is
divided
35. Middle scalene
division
• The upper, middle, and lower
trunks of the brachial plexus
are visualized and gently
mobilized.
• The middle scalene muscle is
now divided from the first rib.
• It has a broad attachment to
the first rib, and care must be
taken to avoid injury to the
long thoracic nerve, which in
this position may have multiple
branches and may pass
through or posterior to the
middle scalene muscle
36. Division of
congenital bands
• With division of the
middle scalene muscle,
the brachial plexus is
visualized and mobilized,
and the lower trunk is
identified with the C8 and
T1 nerve roots resting
above and below the first
rib, respectively.
• Congenital bands and
thickening in Sibson’s
fascia are divided.
37. Exposure &
division of first
rib
• The first rib is then
encircled and divided
where it is easily visible
with bone-cutting
instruments.
• Note the relationship of
the C8 and T1 nerve roots
with the head of the first
rib.
• These roots are reflected
and protected to allow
maximum exposure of the
first rib.
38. Division of
posterior part of
1st rib
• The posterior segment of the
divided first rib is removed back to
its spinal attachments by rongeur
technique.
• The posterior edge of the first rib
is grasped firmly with a rongeur,
and a rocking and twisting motion
is used to remove the entire
aspect of the rib.
• This technique facilitates removal
of the entire posterior portion of
the rib to ensure residual bone
does not remain, thereby
preventing new bone formation
and the potential for production of
recurrent compression.
39. Division of
anterior part of
first rib
• The anterior portion of
the first rib is removed
in a similar fashion to
decompress the
neurovascular
elements.
• Cervical ribs or long
transverse processes
are removed by the
same technique.
40. Completed
dissection
• The brachial plexus, subclavian
artery, phrenic nerve, and long
thoracic nerve are protected.
• Open the pleura, facilitating
drainage of any postoperative
blood collection into the chest
cavity rather than allowing the
blood to collect in the operative
site around the brachial plexus.
• When opening the pleura, care is
taken to protect the intercostal
brachial nerve, which is noted on
the dome of the pleura.
• The sternocleidomastoid muscle is
repaired
42. RECURRENT THORACIC OUTLET SYNDROME
• Recurrent symptoms, primarily neurogenic, should be documented by
objective NCVs.
• When NCVs are depressed in a patient whose symptoms are unrelieved by
prolonged conservative therapy, a posterior procedure should be
considered.
• Removal of any rib remnants or regenerated fibrocartilage and neurolysis
of C7, C8, and T1 nerve roots and the brachial plexus are performed .
• Dorsal sympathectomy is added to minimize the contribution of causalgia
to symptoms.
• Methylprednisolone acetate and hyaluronic acid are employed to minimize
recurrent scarring