ASSESSMENT VASCULAR/SHOULDER INJURIES

FROM ARTERIAL COMPRESSION TO

ENDOTHELIAL INJURY Theoretically, the effects of arterial compression on the vessel’s diameter and blood-flow velocity alter the stress inflicted on the vessel wall, which has the potential to be detrimental to the health of the tissue. The inner lining of the vessel wall (endothelium), in particular, plays a key role in determining the health of the vessel. Normal stresses, specifically shear stress, result from the friction created by blood cells flowing over the endothelium. Normal laminar flow induces sufficient shear stress to align the endothelial cells in the direction of flow and maintain a balance between the release of vasodilating (eg. nitric oxide, NO) and vasoconstricting (eg. endothelin, ET-1) substances. The reciprocal regulation of NO and ET-1 and the integrity of the endothelium are vital for counteracting inflammatory events and for maintaining vascular tone and antithrombotic and anti-atherogenic properties (36–38). In circumstances where abnormally low or high shear stresses persist (ie. with constant or possibly repeated compression), the capacity of the endothelium to produce NO diminishes and its counterbalancing role to ET-1 is lost, described as endothelial dysfunction (38). Any dysfunction of the endothelium adversely affects vascular tone and the anti-inflammatory, antithrombotic and anti-atherogenic properties of the endothelium, predisposing the tissue to more serious vascular injury, such as thrombus and aneurysm formation. More research is required to determine whether the intermittent compression observed with, for instance, the hyperabduction manoeuvre, or the similar dynamic action of overhead throwing, is capable of disrupting the integrity of endothelium and, as such, initiating an inflammatory and thrombotic process that results in more serious vascular damage.

SUMMARY In summary, arterial compression syndromes affecting the subclavian, axillary artery and posterior humeral circumflex artery have been identified in young, fit and healthy athletes. Specific to the third portion of the axillary artery, the overhead-throwing motion in combination with excessive anterior

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THEIR DIFFERENTIAL DIAGNOSIS OF SHOULDER INJUIRES

CLINICIANS MUST CONSIDER THE VASCULAR SYSTEM IN

translation of the humeral head has been implicated as a possible cause of vascular damage. Whether this finding is related to the development of arterial injury and a deterioration of the health of the vessel, or whether it is an innocuous finding that should be regarded as a false positive, has yet to be ascertained.

References 1. Neunteufl T, Heher S, Katzenschlager R, Wolfl G, et al. Late prognostic value of flow- mediated dilation in the brachial artery of patients with chest pain. American Journal of Cardiology 2000;86:207–210 2. Bender MHM, Schep G, de Vries WR, Hoogeveen AR, Wijn PFF. Sports-related flow limitations in the iliac arteries in endurance athletes: aetiology, diagnosis, treatment and future developments. Sports Medicine 2004;34:427–442 3. Cohn SL, Taylor WC. Vascular problems of the lower-extremity in athletes. Clinics in Sports Medicine 1990;9:449–470 4. Lee AW, Hopkins SF, Griffen WO, Jr. Axillary artery aneurysm as an occult source of emboli to the upper extremity. American Surgeon 1987;53:485–486 5. Vlychou M, Spanomichos G, Chatziioannou A, Georganas M, Zavras GM. Embolisation of a traumatic aneurysm of the posterior circumflex humeral artery in a volleyball player. British Journal of Sports Medicine 2001;35:136–137 6. Casey RG, Richards S, O’Donohoe M. Exercise induced critical ischaemia of the upper limb secondary to a cervical rib. British Journal of Sports Medicine 2003;37:455–456 7. Fields WS, Lemak NA, Benmenachem Y. Thoracic outlet syndrome: review and reference to stroke in a major- league pitcher. American Journal of Neuroradiology 1986;7:73–78 8. Jackson MR. Upper extremity arterial

injuries in athletes. Seminars in Vascular Surgery 2003;16:232–239 9. Roos DB, Owens JC. Thoracic outlet syndrome. Archives of Surgery 1966;93:71–74 10. Durham JR, Yao JS, Pearce WH, Nuber GM, McCarthy WJ, 3rd. Arterial injuries in the thoracic outlet syndrome. Journal of Vascular Surgery 1995;21:57–69 11. Roos DB. Historical perspectives and anatomic considerations: thoracic outlet syndrome. Seminars in Thoracic and Cardiovascular Surgery 1996;8:183–189 12. Ault J, Suutala K. Thoracic outlet syndrome. Journal of Manual and Manipulative Therapy 1998;6:118–129 13. Harris J, Huang W, Tyrer P, Burnett A, May J. Clinical and photoplethysmographic assessment of thoracic outlet arterial compression. Journal of Vascular Technology 1989;13:20–23 14. Lee AD, Agarwal S, Sadhu D. Doppler Adson’s test: predictor of outcome of surgery in non-specific thoracic outlet syndrome. World Journal of Surgery 2006;30:291–292 15. Plewa MC, Delinger M. The false-positive rate of thoracic outlet syndrome shoulder maneuvers in healthy subjects. Academic Emergency Medicine 1998;5:337–342 16. Wright I. The neurovascular syndrome produced by hyperabduction of the arm. American Heart Journal 1945;29:1–19. 17. Arko FR, Harris EJ, Zarins CK, Olcott C. Vascular complications in high-performance athletes. Journal of Vascular Surgery 2001;33:935–942 18. Ishitobi K, Moteki K, Nara S, Akiyama Y, et al. Extra-anatomic bypass graft for management of axillary artery occlusion in pitchers. Journal of Vascular Surgery 2001;33:797–801 19. Todd GJ, Benvenisty AI, Hershon S, Bigliani LU. Aneurysms of the mid axillary artery in major league baseball pitchers: a report of two cases. Journal of Vascular Surgery 1998;28:702–707 20. Rohrer MJ, Cardullo PA, Pappas AM,

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