Thoracic Outlet Syndrome

1. SUBCLAVIAN ARTERY
AXILLARY ARTERY
THORACIC OUTLET/INLET
THORACIC OUTLET SYNDROME
Dr. Akshai George Paul

2. Subclavian Artery

3. Origin
• Left subclavian artery: Aortic arch
• Right subclavian artery: Brachiocephalic trunk

5. Course & Parts
The subclavian artery travels laterally towards the
axilla
In relation to the anterior scalene muscles, the
subclavian artery can be divided into three segments
that include the
Prescalene
Retroscalene
Postscalene

6. • Prescalene part - the part before the medial border
of the anterior scalene muscle.
• Retroscalene part - the part located posterior to the
anterior scalene muscle.
• Postscalene part - the part after the lateral border
of the anterior scalene muscle.

7. Branches
• Vertebral artery
• Internal thoracic artery
• Thyrocervical trunk
• Costocervical trunk
• Dorsal scapular artery

9. • The subclavian artery terminates upon reaching the
lateral border of the first rib, where it becomes the
axillary artery

10. Axillary Artery

11. Origin
• Continuation of Subclavian artery that begins at the
outer border of the first rib.

13. Course & Parts
It then courses through the axilla while being
bordered by the lateral (superiorly), posterior
(posteriorly), medial (inferiorly) cords of the brachial
plexus and the ansa pectoralis (anteriorly).

14. • The artery is divided into three parts by pectoralis
minor as the muscle travels superolaterally from its
origin at the 3rd, 4th and 5th ribs to its insertion on
the medial aspect of the coracoid process.

15. • First part – proximal to pectoralis minor
• Second part – posterior to pectoralis minor
• Third part – distal to pectoralis minor

16. Branches

17. Axillary artery pass the lower border of the teres
major and continue as Brachial artery

18. Thoracic outlet/Inlet

19. Also known as the superior thoracic aperture,
connects the root of the neck with the thorax.
kidney-shaped and lies in an oblique transverse
plane, tilted anteroinferiorly to posterosuperiorly.

20. Boundaries
posteriorly: T1 vertebral body and costovertebral
joints
laterally: first ribs and their costal cartilages
anteriorly: superior border of the manubrium

22. Contents

23. Contents
1)midline from anterior to posterior
sternohyoid and sternothyroid muscles
thymic remnants
inferior thyroid veins
trachea

24. • tracheo-esophageal sulcus containing recurrent
laryngeal nerves
• esophagus
• thoracic duct displaced to the left
• longus colli muscles
• anterior longitudinal ligament

25. 2)laterally on both sides
• Sibson's fascia
• internal thoracic artery

26. 3)posteriorly from medial to lateral
• sympathetic trunk
• supreme intercostal vein
• superior intercostal artery
• ventral ramus of the first thoracic nerve

27. 4) on the left:
• left common carotid artery
• left subclavian artery
• left vagus nerve, between left common carotid and
left subclavian arteries
• left brachiocephalic vein
• left phrenic nerve

28. 5) on the right
• brachiocephalic trunk
• right vagus nerve, lateral to the brachiocephalic
trunk
• right brachiocephalic vein
• right phrenic nerve, lateral to the right
brachiocephalic vein

29. Thoracic outlet
syndrome

30. A group of clinical syndromes caused by congenital
or acquired compression of the structures as they
pass through the superior thoracic aperture

31. Causes
scalenus anticus syndrome: abnormal insertion of
scalenus anterior onto 1st rib (commonest cause)
• congenital cervical rib
• bony abnormality of 1st rib or clavicle (congenital
anomaly, malunited fracture, callus, Paget disease,
tumor)

32. • elongated C7 transverse process
• muscle hypertrophy
• fibrous bands
• supraclavicular tumor or lymphadenopathy

33. common sites of compression:
• scalene triangle: between scalenus anterior and
scalenus medius muscles
• costoclavicular space: between the clavicle and 1st
rib
• retropectoralis minor space: between pectoralis
minor and coracoid process

34. Clinical presentation
1)neurogenic thoracic outlet syndrome
• most common (90-95%)
• brachial plexus compression results in pain,
paresthesia and/or numbness of the upper limb

35. 2) venous thoracic outlet syndrome
• second most common
• subclavian vein compression causes upper limb
swelling and pain and may result in venous
thrombosis (Paget-Schroetter syndrome)
• some can present with symptoms of intermittent
venous compression in the absence of thrombosis
(McCleery syndrome)

36. 3) Arterial thoracic outlet syndrome
• rarest form (less than 3% of cases)
• subclavian artery compression causes ischemia
with coolness, pallor, claudication, paresthesia and
decreased upper limb pulses

37. Combined neurovascular symptoms and signs may
be present. The findings are exacerbated by certain
arm positions and maneuvers, particularly with the
arms raised (abducted) above the head

38. Investigation
Imaging with ultrasound, contrast-enhanced CT, MRI
or conventional angiography is useful for detecting
vascular thoracic outlet syndrome
Imaging is performed with the patient’s arms both in
the raised (abducted) and neutral (adducted)
positions for comparison.

39. • MR imaging is useful in patients with neurogenic
thoracic outlet syndrome particularly in evaluating
the brachial plexus and surrounding structures.

40. Treatment
Treatment of arterial thoracic outlet syndrome is
surgical intervention. Treatment is required to treat
or prevent acute thromboembolic events.
Stent placement is not recommended as an initial
treatment, since stent placement alone without
surgical intervention generally fails 16. The presence
of a stent can limit options for vein reconstruction
after stent failure.

41. • Treatment of venous thoracic outlet syndrome
depends primarily on the presence and extent of
associated venous thrombosis and may include
anticoagulation, thrombolysis, or surgical
decompression.