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Neurovascular Problems in the Athlete's Shoulder
Neurovascular Problems in the Athlete’s Shoulder Robert W.Thompson, MDa,*, Matt Driskill, MSPTb KEYWORDS Thoracic outlet syndrome Brachial plexus Subclavian artery Subclavian vein Effort thrombosis Digital vasospasm
Competitive athletes are subject to several neurovascular conditions that can affect the upper extremity. These conditions are relatively rare and can be difficult to recognize but are quite important because they can seriously limit athletic performance and may even have limb-threatening consequences. The purpose of this article is to review how to identify and differentiate the major neurovascular conditions affecting the upper extremity in the athlete-patient. We also wish to highlight current concepts and treatment strategies for these problems that can help avoid serious complications and promote successful outcomes. Indeed, with early recognition, proper initial treatment, and prompt referral for comprehensive surgical care, most athletes with these conditions can return to previous levels of performance within several months of diagnosis and definitive treatment. NEUROGENIC THORACIC OUTLET SYNDROME
Neurogenic thoracic outlet syndrome (TOS) is caused by compression, irritation, and chronic injury of the roots of the brachial plexus, specifically within the scalene triangle at the base of the neck and/or within the subpectoral space immediately inferolateral to the clavicle (Fig. 1).1 This condition is related to predisposing anatomic factors (such as cervical ribs, ligamentous bands, and scalene muscle abnormalities) in combination with hypertrophy and/or injury of the anterior and middle scalene muscles or the pectoralis minor muscle. Symptoms of neurogenic TOS include pain, numbness, and paresthesias in the arm and/or hand. These complaints do not correspond to the distribution of a single peripheral nerve or cervical nerve root, and they are often quite variable in intensity or duration, depending on the level of arm activity. Symptoms of neurogenic TOS are usually exacerbated by activities with the arm in an elevated
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Section of Vascular Surgery, Washington University School of Medicine, 5301 Queeny Tower, One Barnes-Jewish Hospital Plaza, Campus Box 8109, St. Louis, MO 63110, USA b The Rehabilitation Institute of St. Louis, 4455 Duncan Avenue, St. Louis, MO 63110, USA * Corresponding author. E-mail address: [email protected] (R.W. Thompson). Clin Sports Med 27 (2008) 789–802 doi:10.1016/j.csm.2008.07.008 sportsmed.theclinics.com 0278-5919/08/$ – see front matter ª 2008 Elsevier Inc. All rights reserved.
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Fig.1. Anatomy of the scalene triangle. The 5 nerve roots comprising the brachial plexus (C5, C6, C7, C8, and T1) are shown where they pass through the base of the neck within the thoracic outlet, with the scalene triangle bordered by the anterior and middle scalene muscles and the first rib. The long thoracic nerve passes through the middle scalene muscle before crossing over the first rib, and the phrenic nerve passes along the surface of the anterior scalene muscle on its passage to the mediastinum. The subclavian artery passes through the scalene triangle immediately anterior to the brachial plexus, whereas the subclavian vein crosses the first rib in front of the anterior scalene muscle.
position. Along with tenderness, muscle spasm, and reproduction of hand/arm symptoms on palpation over the scalene triangle or pectoralis muscle tendon, positional complaints on physical examination can be useful in differentiating TOS from other conditions (using the ‘‘elevated arm stress test’’). Diagnostic imaging and/or electrophysiological studies are usually negative, but they help to exclude other more common conditions that might yield similar symptoms. Anterior scalene and/or pectoralis minor muscle blocks using local anesthetics may provide useful diagnostic tests that can also predict responses to treatment.2 Treatment for neurogenic TOS is based on resting the affected extremity, physical therapy to relax and stretch the scalene muscles, and judicious use of muscle relaxants and anti-inflammatory agents.3 This should be continued for at least 4 to 6 weeks to gain maximal effect. Surgical treatment has a valuable role in neurogenic TOS when sufficient improvement has not been achieved with conservative approaches alone. This generally consists of thoracic outlet decompression through either a transaxillary or supraclavicular approach, typically with removal of the first rib, resection of the anterior and middle scalene muscles, and brachial plexus neurolysis; in cases associated with localized tenderness over the subpectoral space, pectoralis minor tenotomy is also beneficial.4,5 Although transaxillary first rib resection may offer slightly more rapid recovery and a hidden incision, the rate of symptomatic recurrence requiring reoperation has been reported to be as high as 40%.6 In contrast, recurrence rates after supraclavicular thoracic outlet decompression are approximately 5% to 10%, with other advantages including more complete anterior and middle scalenectomy, ease of identifying anatomic variations and anomalies, and ability to perform brachial plexus neurolysis with direct visual protection of the brachial plexus nerve roots.5,7 Postoperative management following thoracic outlet decompression consists of physical therapy and rehabilitation over a period of several months. This requires
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considerable patience and can often be more prolonged. Given the chronic nature of pre-existing nerve injury, there is no assurance that the patient will return to levels of physical ability experienced before the development of TOS. Because neurogenic TOS requiring surgical treatment is associated with marked upper extremity disability that has usually been refractory to conservative measures over a long period time, this condition is considered extremely uncommon in the competitive athlete. A diagnosis of neurogenic TOS in this setting, therefore, has to be made with considerable reservation, and surgical treatment considered only after all other avenues have been exhausted. SUBCLAVIAN ARTERY ANEURYSMS
Subclavian artery stenosis and aneurysm formation can occur as a result of sustained compression of the subclavian artery at the level of the first rib, almost always in association with a congenital cervical rib or aberrant first rib (Fig. 2). Aneurysm formation in this setting is the result of post-stenotic dilatation with arterial wall degeneration, leading to ulceration, mural thrombus formation, and distal embolization. Patients are usually asymptomatic until the development of distal emboli, causing occlusion of brachial, radial, ulnar, and/or digital arteries; thus, presenting complaints are typically those of exertional arm fatigue and/or acute digital ischemia. In addition to starting anticoagulation to limit the extension of arterial thrombosis, initial diagnostic studies include upper extremity blood pressures, segmental pulse waveforms, and
Fig. 2. Subclavian artery aneurysm with cervical rib. Left panel, Arch arteriogram demonstrating right subclavian artery aneurysm with ulceration and intraluminal thrombus, which had caused distal embolism to the brachial and ulnar arteries and symptoms of hand ischemia. Right upper panel, Surgical exposure of the subclavian aneurysm (*) shown after resection of the anterior scalene muscle. The phrenic nerve is seen crossing in front of the proximal subclavian artery (normal diameter) and the brachial plexus nerve roots are seen lying posterior to the subclavian artery (**). Right lower panel, Resected specimens of the cervical rib and first rib. Following thoracic outlet decompression, the subclavian aneurysm was resected and replaced with a reversed saphenous vein bypass graft.
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neck radiographs to detect the presence of a cervical rib. Contrast-enhanced arteriography is required to image the extent, location, and character of arterial occlusions and to detect the presence of subclavian artery compression and aneurysm formation. Although intra-arterial thrombolytic therapy may be considered in an effort to help resolve distal thromboembolism, operative treatment is usually preferred. Surgical treatment may consist of thromboembolectomy to clear the vessels distal to the subclavian artery, followed by specific treatment for the subclavian artery lesion. Treatment for subclavian artery aneurysms consists of supraclavicular thoracic outlet decompression with scalenectomy and removal of the cervical and first ribs, followed by excision of the aneurysmal segment of subclavian artery. Interposition bypass graft reconstruction is then used to restore flow through the subclavian artery. Although prosthetic bypass grafts may be considered for subclavian artery bypass, in young active patients, autologous conduits are strongly preferred for reconstructions in this highly mobile position (eg, saphenous vein, superficial femoral vein, or iliac artery). With early surgical treatment and restoration of flow to the hand and digits, excellent outcomes can be anticipated, with a full return to function over a period of several months. Unfortunately, due to the insidious clinical presentation of subclavian aneurysms and delays in surgical treatment, many patients with this condition have residual difficulties secondary to distal thromboembolism within the hand or digits that cannot be easily resolved. ANEURYSMS AND OCCLUSIONS OF THE AXILLARY ARTERY
Although the axillary artery is rarely affected by either aneurysmal or occlusive disease, this vessel is subject to a unique lesion that appears to occur almost exclusively in baseball pitchers (Fig. 3).8–10 This lesion is caused by compression and stretching of the axillary artery by the head of the humerus as it moves forward during extremes of arm elevation and extension, as seen in the overhead pitching motion, in combination with anatomic fixation of the axillary artery underneath the pectoralis minor tendon at the location of the circumflex humeral branch vessel origins. Repetitive vessel injury at this location can cause disruption and aneurysmal degeneration of the arterial wall, with the formation of mural thrombus and distal thromboembolism. Alternatively, the response to vessel injury may cause intimal hyperplasia and arterial stenosis, with subsequent thrombotic occlusion. A less common outcome of axillary artery compression includes arterial dissection, which may extend proximally or distally to occlude additional segments of the circulation. Presenting symptoms caused by axillary artery lesions range from exertional arm fatigue to acute digital ischemia. As with subclavian artery aneurysms, initial treatment includes anticoagulation and diagnostic studies to evaluate arterial flow to the arm, followed by imaging tests to visualize the site, extent, and character of the arterial lesion. If the artery is not completely occluded during arteriography at rest, elevation of the arm should be used to mimic the pitching motion to determine if positional obstruction occurs. Optimal treatment for all forms of these axillary artery lesions is surgical, because anticoagulation or anti-platelet therapy cannot ensure against the recurrence of distal emboli from mural thrombus. In addition, thrombolysis with balloon angioplasty and/or stent placement is unsatisfactory, because this does not correct the underlying cause. The preferred operative approach involves mobilization of the affected portion of the axillary artery to prevent future compression, interposition bypass reconstruction of the affected segment, typically using a short reversed saphenous vein graft, and preservation or reimplantation of at least 1 axillary artery branch (usually the posterior circumflex humeral artery). Recovery is typically
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Fig. 3. Axillary artery lesions in baseball pitchers. Repetitive injury of the third portion of the axillary artery occurs as a result of anterior displacement of the humeral head against the artery, at a location where it is fixed in position by the origin of the anterior and posterior circumflex humeral arteries and subscapular artery (left; green arrows). Compression and stretching of the artery result in either aneurysm formation (upper middle) or intimal hyperplasia with stenosis/occlusion (lower middle); both types of arterial lesion can cause thromboembolism to distal vessels. Treatment includes mobilization of the distal axillary artery, excision of the affected segment, and reversed saphenous vein graft reconstruction with preservation of the posterior circumflex humeral artery (right). (for interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).
complete within 3 months of operation, and a full return to previous levels of function can usually be expected. THROMBOEMBOLISM,VASOSPASM, AND DIGITAL ISCHEMIA
Digital ischemia is the most common presenting problem in patients with all upper extremity arterial conditions, typically resulting in numbness, tingling, cold, and painful sensations, cyanotic or pale discoloration, and delayed capillary refill in the fingers. In the presence of a proximal arterial occlusion, the radial and ulnar pulses may be absent or decreased and the blood pressure diminished in the affected arm. Digital ischemia may also exist with normal radial and ulnar pulses if the site of obstruction is solely within the hand, as occurs with digital artery thromboembolism from more proximal sites or digital artery thrombosis secondary to localized trauma. Digital ischemia from arterial occlusion is usually accompanied and exacerbated by local vasospasm, which may wax and wane, resulting in some day-to-day variability in symptoms. Importantly, there are also circumstances when primary vasospasm can result in digital ischemia in the absence of arterial thrombosis or embolism. Various causes of digital ischemia are summarized in Table 1. Diagnostic evaluation includes differentiation of proximal (cardiac, subclavian, or axillary artery) and distal (brachial, radial, or ulnar artery) sources of thromboembolism from isolated local digital artery occlusion (secondary to trauma) and primary vasospasm (cold exposure and tobacco use). Cardiac sources of embolism are evaluated by echocardiography; upper extremity emboli arising from the heart usually consist of
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Table 1 Differential diagnosis of digital ischemia Diagnosis
Examples
Cardiac thromboembolism
Arrhythmia, valvular disease, septal defect (paradoxical)
Proximal artery thromboembolism
Aneurysm, occlusion, stenosis, or ulceration in subclavian or axillary arteries
Distal artery thromboembolism
Radial or Ulnar Arteries (eg, Hypothenar Hammer Syndrome)
Systemic diseases with vascular component
Scleroderma, rheumatoid arthritis, polyarteritis nodosa, Takayasu’s, Buerger’s Disease
Local vascular disease
Hemangioma, arteriovenous malformation, glomus tumor, synovitis
Primary digital artery thrombosis
Localized repetitive trauma
Primary vasospasm
Raynaud’s disease, cold exposure, tobacco use, cocaine
a relatively large thrombus with occlusion of the axillary or brachial arteries. Although systemic diseases associated with digital vasospasm are extremely uncommon in young athletes, serologic tests should be performed to detect circulating markers for systemic lupus erythematosus, scleroderma, polyarteritis nodosa, or Takayasu’s arteritis. In most cases, a proximal arterial source must be considered, requiring contrast-enhanced arteriography with positional views of the neck and upper arm as well as high-resolution views of the hand. Although this may be achieved with current computed tomography (CT) or magnetic resonance imaging (MRI) techniques, subtle intimal ulcerations may still be missed with these studies, and catheter-based (transfemoral) arteriography remains the gold standard. If a proximal source of thromboembolism has been excluded, digital artery occlusion may be due to primary digital artery thrombosis and/or vasospasm. Digital artery thrombosis can be the result of localized repetitive trauma, such as that occasionally seen in baseball players, secondary to pressure exerted on a specific site in the index or middle finger when gripping or throwing the ball (Fig. 4). Another arterial lesion localized within the hand is the ‘‘hypothenar hammer’’ syndrome, in which chronic repetitive trauma to the base of the hand results in degeneration of the ulnar artery where it crosses the hamate bone. These lesions cause thromboembolism to digital arteries and have been particularly well described in baseball catchers. Finally, digital artery spasm may also be the result of localized injury in combination with cold exposure and/or use of tobacco or other vasoconstrictive agents. Treatment of digital ischemia is dictated by the findings of the initial diagnostic studies, beginning with surgical treatment for any proximal and/or distal arterial lesions identified (Table 2). Subsequent treatment specific for digital ischemia may also be required, initially consisting of controlling environmental exposure, use of anticoagulant and antiplatelet therapies, and treatment with vasodilator agents, such as nifedipine and sildenafil. These treatments are also the mainstay of management for digital ischemia not associated with a proximal source of thromboembolism. In the event of persistent symptoms refractory to conservative measures and pharmacologic management, interventions such as intra-arterial infusion of thrombolytic agents (eg, tissue plasminogen activator [TPA]), vasodilators (eg, prostaglandin E1) and/or cervical sympathetic blockade with a local anesthetic may be effective and surprisingly
Neurovascular Problems in the Athlete’s Shoulder
Fig. 4. Arterial anatomy of the hand. (A) Illustrated arterial anatomy of the hand, indicating areas prone to localized occlusive lesions in baseball players. (B) Arteriogram demonstrating localized digital artery occlusion in the medial aspect of the index finger in a baseball pitcher. (C) Arteriogram demonstrating ulnar artery aneurysm caused by repetitive local trauma in a baseball catcher, which had resulted in digital artery thromboembolism (fourth and fifth fingers).
durable. If sympathetic blockade relieves symptoms but the effects are of short duration, surgical approaches to cervical sympathectomy can also be considered, either by a supraclavicular approach or, more commonly, as a minimally invasive thoracoscopic procedure. Outcomes for digital ischemia and vasospasm are difficult to estimate, because they are largely dependent on the specific cause, extent, and duration of thrombosis and the results of specific forms of treatment. EFFORT THROMBOSIS OF THE SUBCLAVIAN VEIN
Effort thrombosis of the subclavian vein (Paget-Schro¨tter syndrome) is a relatively uncommon condition but probably the most frequently encountered vascular disorder in young competitive athletes.11 Understanding this condition is particularly important for sports medicine physicians, because delayed diagnosis and/or incomplete treatment of effort thrombosis can prevent further participation in sports and recreational activities. On the other hand, with early recognition, proper initial treatment, and prompt referral for definitive surgical care, most athletes can return to previous levels of performance within several months. Pathophysiology
Effort thrombosis is caused by compression of the subclavian vein between the clavicle and first rib and is therefore considered a form of TOS. In the past, this condition was considered to be simply the result of acute subclavian vein compression injury with superimposed thrombosis, or the result of a primary hypercoagulable disorder. However, over the past decade, effort thrombosis has become understood to be the acute clinical presentation of a chronic condition. It is also better recognized to be primarily ‘‘mechanical’’ in nature, because all patients exhibit venous compression but few have documented clotting abnormalities. According to this revised view of pathophysiology (Fig. 5), compressive injury to the subclavian vein occurs as a consequence of exertional activity with the arm in elevation, combined with underlying anatomic constraints at the level of the first rib (in the athlete, hypertrophy of the
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Table 2 Treatment options for digital ischemia Treatment
Components of Treatment
Environmental measures
Avoid cold exposure; eliminate tobacco exposure; limit arm activity
Anticoagulation
Intravenous heparin (dose adjusted to partial thromboplastin time >2.5 normal) Subcutaneous heparin (eg, enoxaparin sodium 1 mg /kg sc BID) warfarin (dose adjusted to international normalized ratio >2.0)
Antiplatelet Agents
acetylsalicylic acid (325 mg po QD); clopidogrel (75 mg po BID)
Vasodilators
Calcium channel blockers (eg, nifedipine 10 mg po QID) Angiotensin-converting enzyme inhibitors (eg, enalapril 5–10 mg po QD) Angiotensin receptor blockers (eg, losartan 25–50 mg po QD) Nitrates (eg, topical nitropaste, sublingual trinitroglycerine prn; isosorbide dinitrate 5–10 mg po QD-BID) Phosphodiesterase-5 inhibitors (eg, sildenafil citrate 5–10 mg po QD) Pentoxifylline (eg, 400 mg po TID) Endothelin-1 receptor antagonists (eg, bosentan 125 mg po BID)
Interventions
Intra-arterial thrombolytic infusions (eg, tissue plasminogen activator) Intra-arterial vasodilator infusions (eg, papaverine, prostaglandin E1) Cervical sympathetic block (local anesthetic)
Surgical treatment
Elimination of proximal source of thromboembolism Brachial/radial/ulnar artery thromboembolectomy and/or reconstruction Local digital wound care Cervical sympathectomy; digital sympathectomy
anterior scalene muscle lying immediately behind the subclavian vein may be a factor adding to positional subclavian vein compression). The initial injury to the subclavian vein stimulates a localized tissue repair response with formation of fibrosis within and around the vein wall, but without acute thrombosis, and this phase is asymptomatic. However, with repetitive cycles of injury and repair, the site of subclavian vein compression becomes gradually surrounded by a cuff of constricting scar tissue. Because venous collateral vessels also develop at the same time that the subclavian vein becomes gradually narrowed, this process occurs over many months to years and is also asymptomatic. In time, the slow and turbulent blood flow within the narrowed segment of the subclavian vein promotes formation of thrombus. This clot may completely block the subclavian vein lumen, and perhaps more importantly, it can propagate distally to the axillary vein and with further extension can obstruct critical collateral veins. The patient then experiences sudden symptoms of arm swelling, cyanotic discoloration, heaviness, pain, and/or fatigue: the ‘‘effort thrombosis’’ syndrome. Although rare, thrombus formed within the proximal portion of the subclavian vein may also lead to pulmonary embolism, leading to chest pain, shortness of breath, and fatigue. Clinical Diagnosis
Any young healthy active individual presenting with the sudden onset of arm swelling and cyanotic discoloration should be suspected of having effort thrombosis of the
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Fig. 5. Pathophysiology and treatment of subclavian vein effort thrombosis. (A) Normal anatomy of the thoracic outlet with compression of the subclavian vein during arm elevation. (B) Repetitive subclavian vein injury resulting in progressive stenosis. (C) Collateral expansion may prevent symptoms of venous obstruction; however, eventual thrombus formation with obstruction of collaterals results in the acute clinical presentation of effort thrombosis. (D) Catheter-directed venography and thrombolytic infusion improve venous flow and reveal underlying subclavian vein obstruction at the level of the first rib. Definitive treatment is achieved by thoracic outlet decompression with first rib resection and subclavian vein reconstruction.
subclavian vein. This condition should also be considered in any young individual with otherwise unexplained pulmonary embolism. Clinical suspicion of effort thrombosis is reinforced by a history of active use of the arm, especially in overhead activities (eg, throwing, weightlifting). There remains some debate over the best diagnostic studies
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to perform in confirming or excluding the possibility of effort thrombosis. Upper extremity duplex (ultrasound) imaging is non-invasive, inexpensive, and readily available and is, therefore, used most often; however, it must be emphasized that duplex imaging is not sufficiently accurate to exclude the diagnosis (w30% false-negative rate).11 Duplex studies are, therefore, of value primarily if they are positive, helping to confirm the diagnosis of axillary-subclavian vein thrombosis or obstruction, but they cannot be relied on if negative. Recently, contrast-enhanced CT or magnetic resonance (MR) venography has been frequently used to assess effort thrombosis (Fig. 6A–C). These studies are of particular value if they demonstrate axillary-subclavian vein occlusion and/or focal stenosis at the level of the first rib; because CT or MR venography provide more anatomic information than duplex imaging, they can also be used to exclude the diagnosis of venous TOS when negative (these CT or MR venographic studies should be done with positional maneuvers to avoid overlooking subclavian vein compression, which may only be evident with the arm raised overhead). Regardless of the preliminary studies that might be performed, the definitive diagnosis of effort thrombosis requires traditional catheter-directed contrast venography. This provides the most complete anatomic information regarding the site and extent of thrombosis and allows evaluation of the status of the collateral veins. Contrast venography is also required for catheter-based thrombolysis, which is the preferred initial step in treatment. Considering these factors, it is believed that the most practical and efficient approach to the patient suspected of having effort thrombosis is to go directly to catheter-based venography rather than duplex studies or other non-invasive imaging tests. Initial Treatment
As the first step in management, the patient suspected of having effort thrombosis should be systemically anticoagulated with intravenous heparin while additional diagnostic studies are performed, to prevent the extension of thrombus. Following
Fig. 6. Imaging studies and thrombolytic treatment in effort thrombosis. (A–C) Gadoliniumenhanced magnetic resonance venography demonstrating right subclavian vein occlusion at the level of the first rib with the arms down (A) and elevated (B), compared with the location of obstructive subclavian vein lesion in the same patient demonstrated by contrast venography (C). (D–F) Right subclavian vein effort thrombosis demonstrated by initial venogram (D), with improved venous flow following thrombolytic therapy along with resting stenosis and positional occlusion of the subclavian vein at the level of the first rib (E and F).
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completion of a catheter-directed venogram verifying the diagnosis of subclavian vein occlusion, thrombolytic therapy should be strongly considered in the same setting.12 In the past thrombolysis was performed by continuous infusion of a thrombolytic drug (eg, TPA) directly into the axillary-subclavian vein, often for a period of 24 to 48 hours, with follow-up by serial repeat venography. Thrombolysis is now usually performed with catheter-based mechanical thrombectomy, along with localized infusion of a much smaller amount of thrombolytic agent, which can be completed in a single stage.13,14 The goal of thrombolysis is to clear any fresh or recent clot from the axillary-subclavian and collateral veins, which will usually result in a marked improvement in venographic appearance and reduction in symptoms of venous obstruction. Following thrombolysis, a focal occlusion or high-grade stenosis of the proximal subclavian vein is usually identified at the level of the first rib; this is not composed of thrombus but represents the underlying scar tissue caused by subclavian vein compression, injury, and repair (Fig. 6D–F). Attempts to dilate these residual subclavian vein stenoses are usually unsuccessful and largely unnecessary; furthermore, vascular stents should not be placed in the subclavian vein due to an inevitably high rate of failure in the absence of venous decompression.12,15 Following thrombolysis, the patient should remain on systemic anticoagulation (intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin) and referred for surgical management. It is notable that attempts to use post-thrombolysis treatment with anticoagulation alone have been largely unsatisfactory, with a high rate of recurrent thrombosis and persistent symptoms. The proper duration for proposed anticoagulation is also unknown in this setting and would generally have to be considered lifelong in the absence of treatment to alter the underlying causes of venous compression. Furthermore, delays in referral for surgery while attempting such ‘‘conservative’’ management may eventually preclude certain therapeutic options, which might, otherwise, be considered with earlier definitive treatment. Surgical Management
Surgical treatment provides definitive management for effort thrombosis and should be considered in all patients with this condition. Operative treatment is centered on 2 goals: (1) decompression of the subclavian vein and collateral venous pathways through the thoracic outlet and (2) restoration and maintenance of normal blood flow through the subclavian vein. Thoracic outlet decompression is accomplished by removal of the first rib and division or removal of the anterior scalene and subclavius muscles. This can be performed through transaxillary, supraclavicular, or infraclavicular approaches or combinations of these incisions. The transaxillary approach typically involves partial resection of the first rib and division of its scalene muscle attachments. Because it is not feasible to expose or control the subclavian vein from this approach, these operations are often coupled with the use of intraoperative or postoperative venography and performance of balloon angioplasty and/or stent placement to deal with the subclavian vein.16,17 In contrast, anterior approaches (supraclavicular and/or infraclavicular) permit more complete first rib resection and more thorough resection of the anterior scalene and subclavius muscles as well as direct subclavian vein reconstruction, with completion of all of these steps during a single operative procedure (Fig. 7).18 The authors at Washington University have recently reviewed their results with operative treatment for venous TOS using a ‘‘paraclavicular’’ approach, which combines the advantages of both supraclavicular and infraclavicular operations.11 This experience consisted of 100 patients treated over a 10-year period, including a series of 32 high-performance athletes (29 male and 3 female; 31% in high school, 47% in
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Fig. 7. Operative treatment for venous TOS using the paraclavicular approach. (A) Operative specimen of the first rib removed during paraclavicular thoracic outlet decompression (arrow, anterior scalene tubercle). (B) Proximal left subclavian vein exhibiting chronic scar encasement (arrows). (C) Resected specimen of subclavian vein containing previously placed endoluminal stent. (D) Reconstructive technique with saphenous vein patch angioplasty (BCV, brachiocephalic vein; IJV, internal jugular vein; SCV, subclavian vein). (E) Excision of obstructed portion of subclavian vein. (F) Interposition subclavian vein bypass reconstruction using a saphenous vein panel graft.
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college, and 22% professional), with a median age of 20.3 years (range, 16–26 years). In this group of athletes, venous duplex examinations (n 5 21) had a diagnostic sensitivity of only 71% and the mean interval between symptoms and definitive venographic diagnosis was 20.2 5.6 days (range, 1–120 days). Catheter-directed subclavian vein thrombolysis was performed in 26 (81%), with balloon angioplasty in 12 and stent placement in 1. Surgical treatment consisted of paraclavicular thoracic outlet decompression (including complete scalenectomy and first rib resection), with either circumferential external venolysis alone (56%) or direct axillary-subclavian vein reconstruction (44%), using saphenous vein panel graft bypass in 8, reversed saphenous vein graft bypass in 3, and saphenous vein patch angioplasty in 3. Nineteen of these patients (59%) also had simultaneous creation of a temporary (12 weeks) adjunctive radiocephalic arteriovenous fistula.19 The mean hospital stay was 5.2 0.4 days (range, 2–11 days), with 7 patients requiring secondary procedures, and anticoagulation was maintained for 12 weeks. All 32 patients resumed unrestricted use of the upper extremity, with a median interval of 3.5 months between operation and return to participation in competitive athletics (range, 2–10 months). The overall time required to return to athletic activity was then assessed with respect to the timing and methods of diagnosis, initial treatment, operative management, and postoperative care. The overall duration of management (from symptoms to full athletic activity) was significantly correlated with the time interval from venographic diagnosis to operation (r 5 0.820, P <0.001) and was longer in patients with persistent symptoms (P <0.05) or re-thrombosis before referral (P <0.01). Our experience has thereby demonstrated that successful outcomes for the management of effort thrombosis can be achieved using an aggressive multidisciplinary approach based on (1) early diagnostic venography, thrombolysis, and tertiary referral; (2) paraclavicular thoracic outlet decompression with external venolysis and frequent use of subclavian vein reconstruction; and (3) temporary postoperative anticoagulation, with or without an adjunctive arteriovenous fistula. Optimal management of venous TOS depends on early recognition by treating physicians, prompt referral for comprehensive surgical management, and well-integrated postoperative care in conjunction with a physical therapy team with expertise, dedicated to the management of all forms of TOS. ACKNOWLEDGMENTS
We are grateful to the referring physicians, team physicians, and athletic trainers who have allowed us to participate in the care of their patients. We are indebted to Terri Moriarty, LPN, for expert surgical assistance and to Ms. Verdella F. Brink, for help in caring for all of our patients with thoracic outlet syndrome. REFERENCES
1. Thompson RW, Bartoli MA. Neurogenic thoracic outlet syndrome. In: Rutherford RB, editor. Vascular surgery. sixth edition. Philadelphia: Elsevier Saunders; 2005. p. 1347–65. 2. Jordan SE, Machleder HI. Diagnosis of thoracic outlet syndrome using electrophysiologically guided anterior scalene blocks. Ann Vasc Surg 1998;12(3):260–4. 3. Walsh MT. Therapist management of thoracic outlet syndrome. J Hand Ther 1994; 7(2):131–44. 4. Thompson RW, Petrinec D. Surgical treatment of thoracic outlet compression syndromes. I. Diagnostic considerations and transaxillary first rib resection. Ann Vasc Surg 1997;11:315–23.
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5. Thompson RW, Petrinec D, Toursarkissian B. Surgical treatment of thoracic outlet compression syndromes. II. Supraclavicular exploration and vascular reconstruction. Ann Vasc Surg 1997;11:442–51. 6. Altobelli GG, Kudo T, Haas BT, et al. Thoracic outlet syndrome: pattern of clinical success after operative decompression. J Vasc Surg 2005;42(1):122–8. 7. Sanders RJ. Thoracic outlet syndrome: a common sequelae of neck injuries. Philadelphia: J.B. Lippincott Company; 1991. 8. Rohrer MJ, Cardullo PA, Pappas AM, et al. Axillary artery compression and thrombosis in throwing athletes. J Vasc Surg 1990;11(6):761–8 [discussion: 768–9]. 9. Kee ST, Dake MD, Wolfe-Johnson B, et al. Ischemia of the throwing hand in major league baseball pitchers: embolic occlusion from aneurysms of axillary artery branches. J Vasc Interv Radiol 1995;6(6):979–82. 10. Schneider K, Kasparyan NG, Altchek DW, et al. An aneurysm involving the axillary artery and its branch vessels in a major league baseball pitcher. A case report and review of the literature. Am J Sports Med 1999;27(3):370–5. 11. Melby SJ, Vedantham S, Narra R, Paletta GA Jr, Khoo-Summers L, KhooSummers S, Driskill M, et al. Comprehensive surgical management of the competitive athlete with effort thrombosis of the subclavian vein (Paget-Schrotter syndrome). J Vasc Surg 2008;47(4):809–20. 12. Rutherford RB. Primary subclavian-axillary vein thrombosis: the relative roles of thrombolysis, percutaneous angioplasty, stents, and surgery. Semin Vasc Surg 1998;11(2):91–5. 13. Arko FR, Cipriano P, Lee E, et al. Treatment of axillosubclavian vein thrombosis: a novel technique for rapid removal of clot using low-dose thrombolysis. J Endovasc Ther 2003;10(4):733–8. 14. Schneider DB, Curry TK, Eichler CM, et al. Percutaneous mechanical thrombectomy for the management of venous thoracic outlet syndrome. J Endovasc Ther 2003;10(2):336–40. 15. Urschel HC Jr, Patel AN. Paget-Schroetter syndrome therapy: failure of intravenous stents. Ann Thorac Surg 2003;75(6):1693–6 [discussion: 1696]. 16. Kreienberg PB, Chang BB, Darling RC III, et al. Long-term results in patients treated with thrombolysis, thoracic inlet decompression, and subclavian vein stenting for Paget-Schroetter syndrome. J Vasc Surg 2001;33(Suppl 2):S100–5. 17. Schneider DB, Dimuzio PJ, Martin ND, et al. Combination treatment of venous thoracic outlet syndrome: open surgical decompression and intraoperative angioplasty. J Vasc Surg 2004;40(4):599–603. 18. Thompson RW, Schneider PA, Nelken NA, et al. Circumferential venolysis and paraclavicular thoracic outlet decompression for ‘‘effort thrombosis’’ of the subclavian vein. J Vasc Surg 1992;16:723–32. 19. Sanders RJ, Rosales C, Pearce WH. Creation and closure of temporary arteriovenous fistulas for venous reconstruction or thrombectomy: description of technique. J Vasc Surg 1987;6(5):504–5.
Competitive athletes are subject to several neurovascular conditions that can affect the upper extremity. These conditions are relatively rare and can be difficult to recognize but are quite important because they can seriously limit athletic performance and may even have limb-threatening consequences. The purpose of this article is to review how to identify and differentiate the major neurovascular conditions affecting the upper extremity in the athlete-patient. We also wish to highlight current concepts and treatment strategies for these problems that can help avoid serious complications and promote successful outcomes. Indeed, with early recognition, proper initial treatment, and prompt referral for comprehensive surgical care, most athletes with these conditions can return to previous levels of performance within several months of diagnosis and definitive treatment. NEUROGENIC THORACIC OUTLET SYNDROME
Neurogenic thoracic outlet syndrome (TOS) is caused by compression, irritation, and chronic injury of the roots of the brachial plexus, specifically within the scalene triangle at the base of the neck and/or within the subpectoral space immediately inferolateral to the clavicle (Fig. 1).1 This condition is related to predisposing anatomic factors (such as cervical ribs, ligamentous bands, and scalene muscle abnormalities) in combination with hypertrophy and/or injury of the anterior and middle scalene muscles or the pectoralis minor muscle. Symptoms of neurogenic TOS include pain, numbness, and paresthesias in the arm and/or hand. These complaints do not correspond to the distribution of a single peripheral nerve or cervical nerve root, and they are often quite variable in intensity or duration, depending on the level of arm activity. Symptoms of neurogenic TOS are usually exacerbated by activities with the arm in an elevated
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Section of Vascular Surgery, Washington University School of Medicine, 5301 Queeny Tower, One Barnes-Jewish Hospital Plaza, Campus Box 8109, St. Louis, MO 63110, USA b The Rehabilitation Institute of St. Louis, 4455 Duncan Avenue, St. Louis, MO 63110, USA * Corresponding author. E-mail address: [email protected] (R.W. Thompson). Clin Sports Med 27 (2008) 789–802 doi:10.1016/j.csm.2008.07.008 sportsmed.theclinics.com 0278-5919/08/$ – see front matter ª 2008 Elsevier Inc. All rights reserved.
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Fig.1. Anatomy of the scalene triangle. The 5 nerve roots comprising the brachial plexus (C5, C6, C7, C8, and T1) are shown where they pass through the base of the neck within the thoracic outlet, with the scalene triangle bordered by the anterior and middle scalene muscles and the first rib. The long thoracic nerve passes through the middle scalene muscle before crossing over the first rib, and the phrenic nerve passes along the surface of the anterior scalene muscle on its passage to the mediastinum. The subclavian artery passes through the scalene triangle immediately anterior to the brachial plexus, whereas the subclavian vein crosses the first rib in front of the anterior scalene muscle.
position. Along with tenderness, muscle spasm, and reproduction of hand/arm symptoms on palpation over the scalene triangle or pectoralis muscle tendon, positional complaints on physical examination can be useful in differentiating TOS from other conditions (using the ‘‘elevated arm stress test’’). Diagnostic imaging and/or electrophysiological studies are usually negative, but they help to exclude other more common conditions that might yield similar symptoms. Anterior scalene and/or pectoralis minor muscle blocks using local anesthetics may provide useful diagnostic tests that can also predict responses to treatment.2 Treatment for neurogenic TOS is based on resting the affected extremity, physical therapy to relax and stretch the scalene muscles, and judicious use of muscle relaxants and anti-inflammatory agents.3 This should be continued for at least 4 to 6 weeks to gain maximal effect. Surgical treatment has a valuable role in neurogenic TOS when sufficient improvement has not been achieved with conservative approaches alone. This generally consists of thoracic outlet decompression through either a transaxillary or supraclavicular approach, typically with removal of the first rib, resection of the anterior and middle scalene muscles, and brachial plexus neurolysis; in cases associated with localized tenderness over the subpectoral space, pectoralis minor tenotomy is also beneficial.4,5 Although transaxillary first rib resection may offer slightly more rapid recovery and a hidden incision, the rate of symptomatic recurrence requiring reoperation has been reported to be as high as 40%.6 In contrast, recurrence rates after supraclavicular thoracic outlet decompression are approximately 5% to 10%, with other advantages including more complete anterior and middle scalenectomy, ease of identifying anatomic variations and anomalies, and ability to perform brachial plexus neurolysis with direct visual protection of the brachial plexus nerve roots.5,7 Postoperative management following thoracic outlet decompression consists of physical therapy and rehabilitation over a period of several months. This requires
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considerable patience and can often be more prolonged. Given the chronic nature of pre-existing nerve injury, there is no assurance that the patient will return to levels of physical ability experienced before the development of TOS. Because neurogenic TOS requiring surgical treatment is associated with marked upper extremity disability that has usually been refractory to conservative measures over a long period time, this condition is considered extremely uncommon in the competitive athlete. A diagnosis of neurogenic TOS in this setting, therefore, has to be made with considerable reservation, and surgical treatment considered only after all other avenues have been exhausted. SUBCLAVIAN ARTERY ANEURYSMS
Subclavian artery stenosis and aneurysm formation can occur as a result of sustained compression of the subclavian artery at the level of the first rib, almost always in association with a congenital cervical rib or aberrant first rib (Fig. 2). Aneurysm formation in this setting is the result of post-stenotic dilatation with arterial wall degeneration, leading to ulceration, mural thrombus formation, and distal embolization. Patients are usually asymptomatic until the development of distal emboli, causing occlusion of brachial, radial, ulnar, and/or digital arteries; thus, presenting complaints are typically those of exertional arm fatigue and/or acute digital ischemia. In addition to starting anticoagulation to limit the extension of arterial thrombosis, initial diagnostic studies include upper extremity blood pressures, segmental pulse waveforms, and
Fig. 2. Subclavian artery aneurysm with cervical rib. Left panel, Arch arteriogram demonstrating right subclavian artery aneurysm with ulceration and intraluminal thrombus, which had caused distal embolism to the brachial and ulnar arteries and symptoms of hand ischemia. Right upper panel, Surgical exposure of the subclavian aneurysm (*) shown after resection of the anterior scalene muscle. The phrenic nerve is seen crossing in front of the proximal subclavian artery (normal diameter) and the brachial plexus nerve roots are seen lying posterior to the subclavian artery (**). Right lower panel, Resected specimens of the cervical rib and first rib. Following thoracic outlet decompression, the subclavian aneurysm was resected and replaced with a reversed saphenous vein bypass graft.
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neck radiographs to detect the presence of a cervical rib. Contrast-enhanced arteriography is required to image the extent, location, and character of arterial occlusions and to detect the presence of subclavian artery compression and aneurysm formation. Although intra-arterial thrombolytic therapy may be considered in an effort to help resolve distal thromboembolism, operative treatment is usually preferred. Surgical treatment may consist of thromboembolectomy to clear the vessels distal to the subclavian artery, followed by specific treatment for the subclavian artery lesion. Treatment for subclavian artery aneurysms consists of supraclavicular thoracic outlet decompression with scalenectomy and removal of the cervical and first ribs, followed by excision of the aneurysmal segment of subclavian artery. Interposition bypass graft reconstruction is then used to restore flow through the subclavian artery. Although prosthetic bypass grafts may be considered for subclavian artery bypass, in young active patients, autologous conduits are strongly preferred for reconstructions in this highly mobile position (eg, saphenous vein, superficial femoral vein, or iliac artery). With early surgical treatment and restoration of flow to the hand and digits, excellent outcomes can be anticipated, with a full return to function over a period of several months. Unfortunately, due to the insidious clinical presentation of subclavian aneurysms and delays in surgical treatment, many patients with this condition have residual difficulties secondary to distal thromboembolism within the hand or digits that cannot be easily resolved. ANEURYSMS AND OCCLUSIONS OF THE AXILLARY ARTERY
Although the axillary artery is rarely affected by either aneurysmal or occlusive disease, this vessel is subject to a unique lesion that appears to occur almost exclusively in baseball pitchers (Fig. 3).8–10 This lesion is caused by compression and stretching of the axillary artery by the head of the humerus as it moves forward during extremes of arm elevation and extension, as seen in the overhead pitching motion, in combination with anatomic fixation of the axillary artery underneath the pectoralis minor tendon at the location of the circumflex humeral branch vessel origins. Repetitive vessel injury at this location can cause disruption and aneurysmal degeneration of the arterial wall, with the formation of mural thrombus and distal thromboembolism. Alternatively, the response to vessel injury may cause intimal hyperplasia and arterial stenosis, with subsequent thrombotic occlusion. A less common outcome of axillary artery compression includes arterial dissection, which may extend proximally or distally to occlude additional segments of the circulation. Presenting symptoms caused by axillary artery lesions range from exertional arm fatigue to acute digital ischemia. As with subclavian artery aneurysms, initial treatment includes anticoagulation and diagnostic studies to evaluate arterial flow to the arm, followed by imaging tests to visualize the site, extent, and character of the arterial lesion. If the artery is not completely occluded during arteriography at rest, elevation of the arm should be used to mimic the pitching motion to determine if positional obstruction occurs. Optimal treatment for all forms of these axillary artery lesions is surgical, because anticoagulation or anti-platelet therapy cannot ensure against the recurrence of distal emboli from mural thrombus. In addition, thrombolysis with balloon angioplasty and/or stent placement is unsatisfactory, because this does not correct the underlying cause. The preferred operative approach involves mobilization of the affected portion of the axillary artery to prevent future compression, interposition bypass reconstruction of the affected segment, typically using a short reversed saphenous vein graft, and preservation or reimplantation of at least 1 axillary artery branch (usually the posterior circumflex humeral artery). Recovery is typically
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Fig. 3. Axillary artery lesions in baseball pitchers. Repetitive injury of the third portion of the axillary artery occurs as a result of anterior displacement of the humeral head against the artery, at a location where it is fixed in position by the origin of the anterior and posterior circumflex humeral arteries and subscapular artery (left; green arrows). Compression and stretching of the artery result in either aneurysm formation (upper middle) or intimal hyperplasia with stenosis/occlusion (lower middle); both types of arterial lesion can cause thromboembolism to distal vessels. Treatment includes mobilization of the distal axillary artery, excision of the affected segment, and reversed saphenous vein graft reconstruction with preservation of the posterior circumflex humeral artery (right). (for interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).
complete within 3 months of operation, and a full return to previous levels of function can usually be expected. THROMBOEMBOLISM,VASOSPASM, AND DIGITAL ISCHEMIA
Digital ischemia is the most common presenting problem in patients with all upper extremity arterial conditions, typically resulting in numbness, tingling, cold, and painful sensations, cyanotic or pale discoloration, and delayed capillary refill in the fingers. In the presence of a proximal arterial occlusion, the radial and ulnar pulses may be absent or decreased and the blood pressure diminished in the affected arm. Digital ischemia may also exist with normal radial and ulnar pulses if the site of obstruction is solely within the hand, as occurs with digital artery thromboembolism from more proximal sites or digital artery thrombosis secondary to localized trauma. Digital ischemia from arterial occlusion is usually accompanied and exacerbated by local vasospasm, which may wax and wane, resulting in some day-to-day variability in symptoms. Importantly, there are also circumstances when primary vasospasm can result in digital ischemia in the absence of arterial thrombosis or embolism. Various causes of digital ischemia are summarized in Table 1. Diagnostic evaluation includes differentiation of proximal (cardiac, subclavian, or axillary artery) and distal (brachial, radial, or ulnar artery) sources of thromboembolism from isolated local digital artery occlusion (secondary to trauma) and primary vasospasm (cold exposure and tobacco use). Cardiac sources of embolism are evaluated by echocardiography; upper extremity emboli arising from the heart usually consist of
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Table 1 Differential diagnosis of digital ischemia Diagnosis
Examples
Cardiac thromboembolism
Arrhythmia, valvular disease, septal defect (paradoxical)
Proximal artery thromboembolism
Aneurysm, occlusion, stenosis, or ulceration in subclavian or axillary arteries
Distal artery thromboembolism
Radial or Ulnar Arteries (eg, Hypothenar Hammer Syndrome)
Systemic diseases with vascular component
Scleroderma, rheumatoid arthritis, polyarteritis nodosa, Takayasu’s, Buerger’s Disease
Local vascular disease
Hemangioma, arteriovenous malformation, glomus tumor, synovitis
Primary digital artery thrombosis
Localized repetitive trauma
Primary vasospasm
Raynaud’s disease, cold exposure, tobacco use, cocaine
a relatively large thrombus with occlusion of the axillary or brachial arteries. Although systemic diseases associated with digital vasospasm are extremely uncommon in young athletes, serologic tests should be performed to detect circulating markers for systemic lupus erythematosus, scleroderma, polyarteritis nodosa, or Takayasu’s arteritis. In most cases, a proximal arterial source must be considered, requiring contrast-enhanced arteriography with positional views of the neck and upper arm as well as high-resolution views of the hand. Although this may be achieved with current computed tomography (CT) or magnetic resonance imaging (MRI) techniques, subtle intimal ulcerations may still be missed with these studies, and catheter-based (transfemoral) arteriography remains the gold standard. If a proximal source of thromboembolism has been excluded, digital artery occlusion may be due to primary digital artery thrombosis and/or vasospasm. Digital artery thrombosis can be the result of localized repetitive trauma, such as that occasionally seen in baseball players, secondary to pressure exerted on a specific site in the index or middle finger when gripping or throwing the ball (Fig. 4). Another arterial lesion localized within the hand is the ‘‘hypothenar hammer’’ syndrome, in which chronic repetitive trauma to the base of the hand results in degeneration of the ulnar artery where it crosses the hamate bone. These lesions cause thromboembolism to digital arteries and have been particularly well described in baseball catchers. Finally, digital artery spasm may also be the result of localized injury in combination with cold exposure and/or use of tobacco or other vasoconstrictive agents. Treatment of digital ischemia is dictated by the findings of the initial diagnostic studies, beginning with surgical treatment for any proximal and/or distal arterial lesions identified (Table 2). Subsequent treatment specific for digital ischemia may also be required, initially consisting of controlling environmental exposure, use of anticoagulant and antiplatelet therapies, and treatment with vasodilator agents, such as nifedipine and sildenafil. These treatments are also the mainstay of management for digital ischemia not associated with a proximal source of thromboembolism. In the event of persistent symptoms refractory to conservative measures and pharmacologic management, interventions such as intra-arterial infusion of thrombolytic agents (eg, tissue plasminogen activator [TPA]), vasodilators (eg, prostaglandin E1) and/or cervical sympathetic blockade with a local anesthetic may be effective and surprisingly
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Fig. 4. Arterial anatomy of the hand. (A) Illustrated arterial anatomy of the hand, indicating areas prone to localized occlusive lesions in baseball players. (B) Arteriogram demonstrating localized digital artery occlusion in the medial aspect of the index finger in a baseball pitcher. (C) Arteriogram demonstrating ulnar artery aneurysm caused by repetitive local trauma in a baseball catcher, which had resulted in digital artery thromboembolism (fourth and fifth fingers).
durable. If sympathetic blockade relieves symptoms but the effects are of short duration, surgical approaches to cervical sympathectomy can also be considered, either by a supraclavicular approach or, more commonly, as a minimally invasive thoracoscopic procedure. Outcomes for digital ischemia and vasospasm are difficult to estimate, because they are largely dependent on the specific cause, extent, and duration of thrombosis and the results of specific forms of treatment. EFFORT THROMBOSIS OF THE SUBCLAVIAN VEIN
Effort thrombosis of the subclavian vein (Paget-Schro¨tter syndrome) is a relatively uncommon condition but probably the most frequently encountered vascular disorder in young competitive athletes.11 Understanding this condition is particularly important for sports medicine physicians, because delayed diagnosis and/or incomplete treatment of effort thrombosis can prevent further participation in sports and recreational activities. On the other hand, with early recognition, proper initial treatment, and prompt referral for definitive surgical care, most athletes can return to previous levels of performance within several months. Pathophysiology
Effort thrombosis is caused by compression of the subclavian vein between the clavicle and first rib and is therefore considered a form of TOS. In the past, this condition was considered to be simply the result of acute subclavian vein compression injury with superimposed thrombosis, or the result of a primary hypercoagulable disorder. However, over the past decade, effort thrombosis has become understood to be the acute clinical presentation of a chronic condition. It is also better recognized to be primarily ‘‘mechanical’’ in nature, because all patients exhibit venous compression but few have documented clotting abnormalities. According to this revised view of pathophysiology (Fig. 5), compressive injury to the subclavian vein occurs as a consequence of exertional activity with the arm in elevation, combined with underlying anatomic constraints at the level of the first rib (in the athlete, hypertrophy of the
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Table 2 Treatment options for digital ischemia Treatment
Components of Treatment
Environmental measures
Avoid cold exposure; eliminate tobacco exposure; limit arm activity
Anticoagulation
Intravenous heparin (dose adjusted to partial thromboplastin time >2.5 normal) Subcutaneous heparin (eg, enoxaparin sodium 1 mg /kg sc BID) warfarin (dose adjusted to international normalized ratio >2.0)
Antiplatelet Agents
acetylsalicylic acid (325 mg po QD); clopidogrel (75 mg po BID)
Vasodilators
Calcium channel blockers (eg, nifedipine 10 mg po QID) Angiotensin-converting enzyme inhibitors (eg, enalapril 5–10 mg po QD) Angiotensin receptor blockers (eg, losartan 25–50 mg po QD) Nitrates (eg, topical nitropaste, sublingual trinitroglycerine prn; isosorbide dinitrate 5–10 mg po QD-BID) Phosphodiesterase-5 inhibitors (eg, sildenafil citrate 5–10 mg po QD) Pentoxifylline (eg, 400 mg po TID) Endothelin-1 receptor antagonists (eg, bosentan 125 mg po BID)
Interventions
Intra-arterial thrombolytic infusions (eg, tissue plasminogen activator) Intra-arterial vasodilator infusions (eg, papaverine, prostaglandin E1) Cervical sympathetic block (local anesthetic)
Surgical treatment
Elimination of proximal source of thromboembolism Brachial/radial/ulnar artery thromboembolectomy and/or reconstruction Local digital wound care Cervical sympathectomy; digital sympathectomy
anterior scalene muscle lying immediately behind the subclavian vein may be a factor adding to positional subclavian vein compression). The initial injury to the subclavian vein stimulates a localized tissue repair response with formation of fibrosis within and around the vein wall, but without acute thrombosis, and this phase is asymptomatic. However, with repetitive cycles of injury and repair, the site of subclavian vein compression becomes gradually surrounded by a cuff of constricting scar tissue. Because venous collateral vessels also develop at the same time that the subclavian vein becomes gradually narrowed, this process occurs over many months to years and is also asymptomatic. In time, the slow and turbulent blood flow within the narrowed segment of the subclavian vein promotes formation of thrombus. This clot may completely block the subclavian vein lumen, and perhaps more importantly, it can propagate distally to the axillary vein and with further extension can obstruct critical collateral veins. The patient then experiences sudden symptoms of arm swelling, cyanotic discoloration, heaviness, pain, and/or fatigue: the ‘‘effort thrombosis’’ syndrome. Although rare, thrombus formed within the proximal portion of the subclavian vein may also lead to pulmonary embolism, leading to chest pain, shortness of breath, and fatigue. Clinical Diagnosis
Any young healthy active individual presenting with the sudden onset of arm swelling and cyanotic discoloration should be suspected of having effort thrombosis of the
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Fig. 5. Pathophysiology and treatment of subclavian vein effort thrombosis. (A) Normal anatomy of the thoracic outlet with compression of the subclavian vein during arm elevation. (B) Repetitive subclavian vein injury resulting in progressive stenosis. (C) Collateral expansion may prevent symptoms of venous obstruction; however, eventual thrombus formation with obstruction of collaterals results in the acute clinical presentation of effort thrombosis. (D) Catheter-directed venography and thrombolytic infusion improve venous flow and reveal underlying subclavian vein obstruction at the level of the first rib. Definitive treatment is achieved by thoracic outlet decompression with first rib resection and subclavian vein reconstruction.
subclavian vein. This condition should also be considered in any young individual with otherwise unexplained pulmonary embolism. Clinical suspicion of effort thrombosis is reinforced by a history of active use of the arm, especially in overhead activities (eg, throwing, weightlifting). There remains some debate over the best diagnostic studies
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to perform in confirming or excluding the possibility of effort thrombosis. Upper extremity duplex (ultrasound) imaging is non-invasive, inexpensive, and readily available and is, therefore, used most often; however, it must be emphasized that duplex imaging is not sufficiently accurate to exclude the diagnosis (w30% false-negative rate).11 Duplex studies are, therefore, of value primarily if they are positive, helping to confirm the diagnosis of axillary-subclavian vein thrombosis or obstruction, but they cannot be relied on if negative. Recently, contrast-enhanced CT or magnetic resonance (MR) venography has been frequently used to assess effort thrombosis (Fig. 6A–C). These studies are of particular value if they demonstrate axillary-subclavian vein occlusion and/or focal stenosis at the level of the first rib; because CT or MR venography provide more anatomic information than duplex imaging, they can also be used to exclude the diagnosis of venous TOS when negative (these CT or MR venographic studies should be done with positional maneuvers to avoid overlooking subclavian vein compression, which may only be evident with the arm raised overhead). Regardless of the preliminary studies that might be performed, the definitive diagnosis of effort thrombosis requires traditional catheter-directed contrast venography. This provides the most complete anatomic information regarding the site and extent of thrombosis and allows evaluation of the status of the collateral veins. Contrast venography is also required for catheter-based thrombolysis, which is the preferred initial step in treatment. Considering these factors, it is believed that the most practical and efficient approach to the patient suspected of having effort thrombosis is to go directly to catheter-based venography rather than duplex studies or other non-invasive imaging tests. Initial Treatment
As the first step in management, the patient suspected of having effort thrombosis should be systemically anticoagulated with intravenous heparin while additional diagnostic studies are performed, to prevent the extension of thrombus. Following
Fig. 6. Imaging studies and thrombolytic treatment in effort thrombosis. (A–C) Gadoliniumenhanced magnetic resonance venography demonstrating right subclavian vein occlusion at the level of the first rib with the arms down (A) and elevated (B), compared with the location of obstructive subclavian vein lesion in the same patient demonstrated by contrast venography (C). (D–F) Right subclavian vein effort thrombosis demonstrated by initial venogram (D), with improved venous flow following thrombolytic therapy along with resting stenosis and positional occlusion of the subclavian vein at the level of the first rib (E and F).
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completion of a catheter-directed venogram verifying the diagnosis of subclavian vein occlusion, thrombolytic therapy should be strongly considered in the same setting.12 In the past thrombolysis was performed by continuous infusion of a thrombolytic drug (eg, TPA) directly into the axillary-subclavian vein, often for a period of 24 to 48 hours, with follow-up by serial repeat venography. Thrombolysis is now usually performed with catheter-based mechanical thrombectomy, along with localized infusion of a much smaller amount of thrombolytic agent, which can be completed in a single stage.13,14 The goal of thrombolysis is to clear any fresh or recent clot from the axillary-subclavian and collateral veins, which will usually result in a marked improvement in venographic appearance and reduction in symptoms of venous obstruction. Following thrombolysis, a focal occlusion or high-grade stenosis of the proximal subclavian vein is usually identified at the level of the first rib; this is not composed of thrombus but represents the underlying scar tissue caused by subclavian vein compression, injury, and repair (Fig. 6D–F). Attempts to dilate these residual subclavian vein stenoses are usually unsuccessful and largely unnecessary; furthermore, vascular stents should not be placed in the subclavian vein due to an inevitably high rate of failure in the absence of venous decompression.12,15 Following thrombolysis, the patient should remain on systemic anticoagulation (intravenous unfractionated heparin or subcutaneous low-molecular-weight heparin) and referred for surgical management. It is notable that attempts to use post-thrombolysis treatment with anticoagulation alone have been largely unsatisfactory, with a high rate of recurrent thrombosis and persistent symptoms. The proper duration for proposed anticoagulation is also unknown in this setting and would generally have to be considered lifelong in the absence of treatment to alter the underlying causes of venous compression. Furthermore, delays in referral for surgery while attempting such ‘‘conservative’’ management may eventually preclude certain therapeutic options, which might, otherwise, be considered with earlier definitive treatment. Surgical Management
Surgical treatment provides definitive management for effort thrombosis and should be considered in all patients with this condition. Operative treatment is centered on 2 goals: (1) decompression of the subclavian vein and collateral venous pathways through the thoracic outlet and (2) restoration and maintenance of normal blood flow through the subclavian vein. Thoracic outlet decompression is accomplished by removal of the first rib and division or removal of the anterior scalene and subclavius muscles. This can be performed through transaxillary, supraclavicular, or infraclavicular approaches or combinations of these incisions. The transaxillary approach typically involves partial resection of the first rib and division of its scalene muscle attachments. Because it is not feasible to expose or control the subclavian vein from this approach, these operations are often coupled with the use of intraoperative or postoperative venography and performance of balloon angioplasty and/or stent placement to deal with the subclavian vein.16,17 In contrast, anterior approaches (supraclavicular and/or infraclavicular) permit more complete first rib resection and more thorough resection of the anterior scalene and subclavius muscles as well as direct subclavian vein reconstruction, with completion of all of these steps during a single operative procedure (Fig. 7).18 The authors at Washington University have recently reviewed their results with operative treatment for venous TOS using a ‘‘paraclavicular’’ approach, which combines the advantages of both supraclavicular and infraclavicular operations.11 This experience consisted of 100 patients treated over a 10-year period, including a series of 32 high-performance athletes (29 male and 3 female; 31% in high school, 47% in
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Fig. 7. Operative treatment for venous TOS using the paraclavicular approach. (A) Operative specimen of the first rib removed during paraclavicular thoracic outlet decompression (arrow, anterior scalene tubercle). (B) Proximal left subclavian vein exhibiting chronic scar encasement (arrows). (C) Resected specimen of subclavian vein containing previously placed endoluminal stent. (D) Reconstructive technique with saphenous vein patch angioplasty (BCV, brachiocephalic vein; IJV, internal jugular vein; SCV, subclavian vein). (E) Excision of obstructed portion of subclavian vein. (F) Interposition subclavian vein bypass reconstruction using a saphenous vein panel graft.
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college, and 22% professional), with a median age of 20.3 years (range, 16–26 years). In this group of athletes, venous duplex examinations (n 5 21) had a diagnostic sensitivity of only 71% and the mean interval between symptoms and definitive venographic diagnosis was 20.2 5.6 days (range, 1–120 days). Catheter-directed subclavian vein thrombolysis was performed in 26 (81%), with balloon angioplasty in 12 and stent placement in 1. Surgical treatment consisted of paraclavicular thoracic outlet decompression (including complete scalenectomy and first rib resection), with either circumferential external venolysis alone (56%) or direct axillary-subclavian vein reconstruction (44%), using saphenous vein panel graft bypass in 8, reversed saphenous vein graft bypass in 3, and saphenous vein patch angioplasty in 3. Nineteen of these patients (59%) also had simultaneous creation of a temporary (12 weeks) adjunctive radiocephalic arteriovenous fistula.19 The mean hospital stay was 5.2 0.4 days (range, 2–11 days), with 7 patients requiring secondary procedures, and anticoagulation was maintained for 12 weeks. All 32 patients resumed unrestricted use of the upper extremity, with a median interval of 3.5 months between operation and return to participation in competitive athletics (range, 2–10 months). The overall time required to return to athletic activity was then assessed with respect to the timing and methods of diagnosis, initial treatment, operative management, and postoperative care. The overall duration of management (from symptoms to full athletic activity) was significantly correlated with the time interval from venographic diagnosis to operation (r 5 0.820, P <0.001) and was longer in patients with persistent symptoms (P <0.05) or re-thrombosis before referral (P <0.01). Our experience has thereby demonstrated that successful outcomes for the management of effort thrombosis can be achieved using an aggressive multidisciplinary approach based on (1) early diagnostic venography, thrombolysis, and tertiary referral; (2) paraclavicular thoracic outlet decompression with external venolysis and frequent use of subclavian vein reconstruction; and (3) temporary postoperative anticoagulation, with or without an adjunctive arteriovenous fistula. Optimal management of venous TOS depends on early recognition by treating physicians, prompt referral for comprehensive surgical management, and well-integrated postoperative care in conjunction with a physical therapy team with expertise, dedicated to the management of all forms of TOS. ACKNOWLEDGMENTS
We are grateful to the referring physicians, team physicians, and athletic trainers who have allowed us to participate in the care of their patients. We are indebted to Terri Moriarty, LPN, for expert surgical assistance and to Ms. Verdella F. Brink, for help in caring for all of our patients with thoracic outlet syndrome. REFERENCES
1. Thompson RW, Bartoli MA. Neurogenic thoracic outlet syndrome. In: Rutherford RB, editor. Vascular surgery. sixth edition. Philadelphia: Elsevier Saunders; 2005. p. 1347–65. 2. Jordan SE, Machleder HI. Diagnosis of thoracic outlet syndrome using electrophysiologically guided anterior scalene blocks. Ann Vasc Surg 1998;12(3):260–4. 3. Walsh MT. Therapist management of thoracic outlet syndrome. J Hand Ther 1994; 7(2):131–44. 4. Thompson RW, Petrinec D. Surgical treatment of thoracic outlet compression syndromes. I. Diagnostic considerations and transaxillary first rib resection. Ann Vasc Surg 1997;11:315–23.
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5. Thompson RW, Petrinec D, Toursarkissian B. Surgical treatment of thoracic outlet compression syndromes. II. Supraclavicular exploration and vascular reconstruction. Ann Vasc Surg 1997;11:442–51. 6. Altobelli GG, Kudo T, Haas BT, et al. Thoracic outlet syndrome: pattern of clinical success after operative decompression. J Vasc Surg 2005;42(1):122–8. 7. Sanders RJ. Thoracic outlet syndrome: a common sequelae of neck injuries. Philadelphia: J.B. Lippincott Company; 1991. 8. Rohrer MJ, Cardullo PA, Pappas AM, et al. Axillary artery compression and thrombosis in throwing athletes. J Vasc Surg 1990;11(6):761–8 [discussion: 768–9]. 9. Kee ST, Dake MD, Wolfe-Johnson B, et al. Ischemia of the throwing hand in major league baseball pitchers: embolic occlusion from aneurysms of axillary artery branches. J Vasc Interv Radiol 1995;6(6):979–82. 10. Schneider K, Kasparyan NG, Altchek DW, et al. An aneurysm involving the axillary artery and its branch vessels in a major league baseball pitcher. A case report and review of the literature. Am J Sports Med 1999;27(3):370–5. 11. Melby SJ, Vedantham S, Narra R, Paletta GA Jr, Khoo-Summers L, KhooSummers S, Driskill M, et al. Comprehensive surgical management of the competitive athlete with effort thrombosis of the subclavian vein (Paget-Schrotter syndrome). J Vasc Surg 2008;47(4):809–20. 12. Rutherford RB. Primary subclavian-axillary vein thrombosis: the relative roles of thrombolysis, percutaneous angioplasty, stents, and surgery. Semin Vasc Surg 1998;11(2):91–5. 13. Arko FR, Cipriano P, Lee E, et al. Treatment of axillosubclavian vein thrombosis: a novel technique for rapid removal of clot using low-dose thrombolysis. J Endovasc Ther 2003;10(4):733–8. 14. Schneider DB, Curry TK, Eichler CM, et al. Percutaneous mechanical thrombectomy for the management of venous thoracic outlet syndrome. J Endovasc Ther 2003;10(2):336–40. 15. Urschel HC Jr, Patel AN. Paget-Schroetter syndrome therapy: failure of intravenous stents. Ann Thorac Surg 2003;75(6):1693–6 [discussion: 1696]. 16. Kreienberg PB, Chang BB, Darling RC III, et al. Long-term results in patients treated with thrombolysis, thoracic inlet decompression, and subclavian vein stenting for Paget-Schroetter syndrome. J Vasc Surg 2001;33(Suppl 2):S100–5. 17. Schneider DB, Dimuzio PJ, Martin ND, et al. Combination treatment of venous thoracic outlet syndrome: open surgical decompression and intraoperative angioplasty. J Vasc Surg 2004;40(4):599–603. 18. Thompson RW, Schneider PA, Nelken NA, et al. Circumferential venolysis and paraclavicular thoracic outlet decompression for ‘‘effort thrombosis’’ of the subclavian vein. J Vasc Surg 1992;16:723–32. 19. Sanders RJ, Rosales C, Pearce WH. Creation and closure of temporary arteriovenous fistulas for venous reconstruction or thrombectomy: description of technique. J Vasc Surg 1987;6(5):504–5.