Thoracic Outlet Syndrome Vascular Case Conference WVU Dept. of Surgery

Thoracic Outlet Syndrome
Vascular Case Conference
WVU Dept. of Surgery
Mary Carolyn C. Vinson, DO PGY-1
Definition
• Thoracic outlet syndrome is a disease
of extrinsic compression of the
neurovascular structures thoracic outlet
Anatomy of Thoracic Outlet
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More Anatomy
http://intraspec.ca/images/brachialplexus.jpg
Pathophysiology
• Brachial plexus trunk & subclavian vessels
are subject to compression or irritation
• Three narrow passageways @ base of neck
toward the axilla & proximal arm.
– Interscalene Triangle
– Costoclavicular Triangle
– Subcoracoid Space
• Repetitive trauma to especially
– Lower trunk
– C8-T1 spinal nerves
Interscalene Triangle
• Triangle borders
– Anteriorly: anterior scalene muscle
– Posteriorly: middle scalene muscle
– Inferiorly: medial surface of the first rib
• Area small at rest & becomes even smaller
with certain movements
• Fibrous bands, cervical ribs, and anomalous
muscles, may further constrict this triangle
Costoclavicular Triangle
• Borders
– Anteriorly by middle 3rd of clavicle
– Posteromedially by 1st rib
– Posterolaterally by upper border of scapula
Subcoracoid Space
• Is beneath the coracoid process just
deep to the pectoralis minor tendon
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Etiology
• Anatomic Factors
– Interscalene compression
– Costoclavicular compression
– Subcoracoid compression
Congenital
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Cervical rib
Rudimentary first rib
Scalene muscle abnormalities
Fibrous bands
Bifid clavicle
First rib exostosis
Enlarged C7 transverse process
Omohyoid muscle abnormalities
Anomalous transverse cervical artery
Postfixed brachial plexus
Flat clavicle
Traumatic Factors
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Fractured clavicle
Humeral head dislocation
Upper thorax crush injury
Sudden effort of shoulder girdle
muscles
• C-spine injuries/cervical spondylosis
Clinical Presentation
• Depends on which anatomic structure is
compressed in the area of the thoracic outlet
– Axillary-subclavian artery
– Vein
• Paget-Schroetter syndrome, or effort thrombosis
– Neurogenic
• brachial plexus, or sympathetic nerves
• Clinical syndrome results from any mixture or
an isolated compression of structures
Neurologic Presentation
• More common
• Strenuous physical exercise precipitates
• Pain & paresthesias 95% of patients
– Neck, shoulder, arm & hand
– Positional: arm abduction & neck hyperextension
• True motor weakness w/ atrophy
– Usually Ulnar nerve distribution :
• hypothenar/interosseus muscles in 10%
– medial arm & hand
– 4th & 5th fingers
• Sensory fibers on outside of nerve bundles
1st affected
Arterial Presentation
• Signs:
– Distal embolization
– Post-stenotic dilation or aneurysm of subclavian a.
– True arterial occlusion
• Symptoms:
– Pain usually diffuse & assoc. w/ coldness,
weakness, easy fatigability of hand & arm
• Unilateral Raynaud's phenomenon
– 7.5% patients
– precipitated by hyperabduction or carrying heavy
objects
Venous Presentation
• Venous obstruction less common
– Effort thrombosis
– Paget-Schroetter syndrome
• Signs & Symptoms
– Edema
– Discolored
– Aches
Differential Diagnosis
• Neurologic,vascular, pulmonary,
cardiac, and esophageal disorders.
• More common Differential Diagnosis
include
– herniated cervical disk
– cervical spondylosis
– peripheral neuropathies
Clinical Diagnosis
• Positive findings for all tests:
– ⇓ or loss of the radial pulse
– reproduction of symptoms
• Adson/Scalene test:
– Deep Breath, fully extends neck, and turns head
to the side
• Costoclavicular test:
– shoulders drawn inferiorly and posteriorly
• Hyperabduction test:
– arm is hyperabducted to 180 degrees
Imaging
• CXR & C-spine films:
– detect cervical ribs & degenerative changes
• Cervical CT performed if:
– osteophytic changes & intervertebral space
narrowing present
• Angiography indicated for:
– Pulsating paraclavicular mass
– Absent radial pulse
– Paraclavicular bruit
Ulnar Nerve Conduction
Velocity
• Points of stimulation include:
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Supraclavicular fossa
Middle upper arm
Below elbow
Wrist
• Normal value across thoracic outlet: 72 m/sec
• Any value < 70 m/sec indicates compression
Angiogram
Shows compression of subclavian artery at two levels: proximally between clavicle and cervical rib (long
arrow) and distally by subclavius muscle (short arrow).
Venogram:
R subclavian vein
Venogram
Complete occlusion of Left subclavian vein (arrow) where it crosses the first rib
Treatment
• Physical therapy is initial treatment
• Many patients get relief from non-operative
therapy
– esp. for neurogenic TOS
• Simple changes in posture may result in
opening the thoracic outlet
– PT= Strengthen muscles supporting improved
posture
Surgical Treatment for TOS
• Reserved for patients w/ symptoms persisting
after aggressive physical therapy
• Equals about 5% of PTs w/ TOS require
surgery
• “There are multiple compressive forces, the
first rib is the common denominator, and
extirpation of this structure is the “gold”
standard for therapy.”
• Urschel et al. 2003
Surgical Outcomes
• > 2200 patients showed excellent or
good results after operation in over 90%
of cases
• Urschel et. al 1997
• Symptoms recur in approx 10%
• Less than 2% require re-operation
Surgical Pictures
1st thoracic rib removed to decompress
neurovascular structures of TOS
Recurrent Thoracic Outlet
Syndrome
• Approx 1-2% of PTs have persistent or
worsening symptoms after operation
– Most have recurrence within 3 months
• History, physical examination, and
nerve conduction studies should
preformed
Types of Recurrence
• Pseudorecurrence
– Cervical rib or the second rib was resected instead
of the first rib
– First rib was resected instead of the causative
cervical rib
• True recurrence
– First rib was incompletely resected
– Excessive scar development around the brachial
plexus
Re-operation for Failed
Initial Operation on TOS
• 80% of patients after re-operation =
improvement in symptoms
• 7% required a second re-operation
Summary
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TOS mimics many other processes
Compression is the causative agent
1st rib is often the culprit
History ⇒ PE ⇒ UNVC
XR ⇒ CT ⇒ Angio/Venogram
Physical therapy ⇒ Surgery
• Note: DVT and Arterial Occlusions are treated
with Anticoagulation/Thrombectomy
References
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Thomas S. Maxey, MD, T. Brett Reece, MD, Peter I. Ellman, MD, Curtis G. Tribble, MD,
Nancy Harthun, MD, Irving L. Kron, MD, John A. Kern, MD. Safety and efficacy of the
supraclavicular approach to thoracic outlet decompression.Ann Thorac Surg 2003;76:396400
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Harold C. Urschel, Jr, MD,, Amit N. Patel, MD. Surgery Remains the Most Effective
Treatment for Paget-Schroetter Syndrome: 50 Years' Experience. Ann Thorac Surg
2008;86:254-260.
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Urschel HC Jr and Razzuk MA. Upper plexus thoracic outlet syndrome: optimal therapy. .
Annals of Thoracic Surgery 1997 63(4):935-9.
•
Harold C. Urschel Jr and Amit Patel. Thoracic outlet syndromes. Current Treatment Options
in Cardiovascular Medicine. Vol 5, No 2. April 2003. 1092-8464
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Urschel HC Jr, Razzuk MA.The failed operation for thoracic outlet Syndrome: the difficulty of
diagnosis and management.Ann Thorac Surg. 1986 Nov;42(5):523-8
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http://brighamrad.harvard.edu/Cases/bwh/hcache/170/full.html
http://www.ajronline.org/cgi/content-nw/full/183/1/113/FIG9
http://www.ctsnet.org/doc/7628