Thoracic Outlet Syndrome - WVU School of Medicine

Thoracic Outlet SyndromeVascular Case ConferenceWVU Dept. of SurgeryMary Carolyn C. Vinson, DO PGY-1

Definition• Thoracic outlet syndrome is a diseaseof extrinsic compression of theneurovascular structures thoracic outlet

Anatomy of Thoracic OutletQuickTime and aTIFF (LZW) decompressorare needed to see this picture.

More Anatomyhttp://intraspec.ca/images/brachialplexus.jpg

Pathophysiology• Brachial plexus trunk & subclavian vesselsare subject to compression or irritation• Three narrow passageways @ base of necktoward 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 smallerwith certain movements• Fibrous bands, cervical ribs, and anomalousmuscles, 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 justdeep to the pectoralis minor tendonQuickTime and aTIFF (LZW) decompressorare needed to see this picture.QuickTime and aTIFF (LZW) decompressorare needed to see this picture.

• Anatomic FactorsEtiology– Interscalene compression– Costoclavicular compression– Subcoracoid compression

Congenital• 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• Fractured clavicle• Humeral head dislocation• Upper thorax crush injury• Sudden effort of shoulder girdlemuscles• C-spine injuries/cervical spondylosis

Clinical Presentation• Depends on which anatomic structure iscompressed 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 oran 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 bundles1st 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 heavyobjects

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 Diagnosisinclude– 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 headto 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 spacenarrowing present• Angiography indicated for:– Pulsating paraclavicular mass– Absent radial pulse– Paraclavicular bruit

AngiogramShows compression of subclavian artery at two levels: proximally between clavicle and cervical rib (longarrow) and distally by subclavius muscle (short arrow).

Venogram:R subclavian vein

VenogramComplete occlusion of Left subclavian vein (arrow) where it crosses the first rib

Treatment• Physical therapy is initial treatment• Many patients get relief from non-operativetherapy– esp. for neurogenic TOS• Simple changes in posture may result inopening the thoracic outlet– PT= Strengthen muscles supporting improvedposture

Surgical Treatment for TOS• Reserved for patients w/ symptoms persistingafter aggressive physical therapy• Equals about 5% of PTs w/ TOS requiresurgery• “There are multiple compressive forces, thefirst rib is the common denominator, andextirpation of this structure is the “gold”standard for therapy.”• Urschel et al. 2003

Surgical Outcomes• > 2200 patients showed excellent orgood results after operation in over 90%of cases• Urschel et. al 1997• Symptoms recur in approx 10%• Less than 2% require re-operation

Surgical Pictures1st thoracic rib removed to decompressneurovascular structures of TOS

Recurrent Thoracic OutletSyndrome• Approx 1-2% of PTs have persistent orworsening symptoms after operation– Most have recurrence within 3 months• History, physical examination, andnerve conduction studies shouldpreformed

Types of Recurrence• Pseudorecurrence– Cervical rib or the second rib was resected insteadof the first rib– First rib was resected instead of the causativecervical rib• True recurrence– First rib was incompletely resected– Excessive scar development around the brachialplexus

Re-operation for FailedInitial Operation on TOS• 80% of patients after re-operation =improvement in symptoms• 7% required a second re-operation

Summary• 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 treatedwith Anticoagulation/Thrombectomy

References• 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 thesupraclavicular approach to thoracic outlet decompression.Ann Thorac Surg 2003;76:396-400• Harold C. Urschel, Jr, MD,, Amit N. Patel, MD. Surgery Remains the Most EffectiveTreatment for Paget-Schroetter Syndrome: 50 Years' Experience. Ann Thorac Surg2008;86:254-260.• 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 Optionsin Cardiovascular Medicine. Vol 5, No 2. April 2003. 1092-8464• Urschel HC Jr, Razzuk MA.The failed operation for thoracic outlet Syndrome: the difficulty ofdiagnosis and management.Ann Thorac Surg. 1986 Nov;42(5):523-8• 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