Upper Extremity Arterial Disease

Atherosclerosis

Atherosclerotic disease is the most common etiology of chronic upper extremity arterial occlusive disease in older adults and typically involves the proximal great vessels, particularly the ostial/proximal subclavian artery (and less commonly the innominate), followed by axillary/brachial disease. (Shadman 2004)📄 (Martin 2025)

Clinical clues suggesting hemodynamically significant subclavian/innominate disease

• Inter-arm systolic blood pressure (BP) difference >=15-20 mmHg, diminished pulses, supraclavicular bruit. (Shadman 2004)📄
• Vertebrobasilar symptoms with arm exertion suggests subclavian steal (see 7Ch. 7). (Shadman 2004)📄
• Angina/ischemia in patients with a left internal mammary artery (LIMA) coronary graft suggests coronary-subclavian steal and warrants prompt evaluation. (Angle 2003)

Indications for revascularization (typical)

Revascularization is generally recommended for symptomatic lesions (rather than asymptomatic stenosis) and should be individualized based on anatomic severity, symptom mechanism, and procedural risk. (Aboyans 2017)📄

Common indications include:

1. Lifestyle-limiting arm claudication attributable to subclavian/innominate stenosis/occlusion. (Aboyans 2017)📄
2. Critical hand ischemia (rest pain, ulcers, tissue loss) when due to correctable proximal inflow disease. (Aboyans 2017)📄
3. Embolization from a proximal lesion (ulcerated plaque or aneurysmal disease) with recurrent distal ischemic events. (Aboyans 2017)📄
4. Subclavian steal syndrome with reproducible vertebrobasilar symptoms and confirmed hemodynamic steal physiology. (Shadman 2004)📄
5. Coronary-subclavian steal in patients with LIMA grafts (symptomatic or high-risk anatomy). (Angle 2003)
6. Pre-emptive left subclavian artery (LSA) revascularization may be indicated in selected patients undergoing 6thoracic endovascular aortic repair (TEVAR) when coverage risks posterior circulation or spinal cord ischemia. (Matsumura 2009)📄

Treatment strategy (overview)

• Best medical therapy (antiplatelet therapy, statin therapy, smoking cessation, BP/diabetes control) is mandatory in all patients because upper extremity atherosclerosis is a marker of systemic cardiovascular risk. (Hiatt 2015)📄 (Aboyans 2017)📄 (Martin 2025)
• Endovascular-first (angioplasty +/- stenting) is commonly favored for focal proximal stenoses due to high technical success and low morbidity; open reconstruction is reserved for long occlusions, failed endovascular therapy, complex anatomy, or specific operative contexts. (Angle 2003) (Rutherford 2018)

Trauma

Hypothenar hammer syndrome (HHS) results from repetitive blunt trauma to the hypothenar eminence, injuring the ulnar artery at the hamate with intimal disruption, thrombosis, aneurysm formation, and distal embolization. It is classically seen in manual laborers using impact tools and in athletes with repetitive hand impact. (Illig 2016)📄

Workup

• Focused history (occupation, repetitive trauma, tobacco, vasospastic symptoms) and exam (ulnar-sided ischemia, hypothenar tenderness/mass).
• Allen test (screening) plus digital pressures/photoplethysmography to quantify ischemia; consider cold challenge if vasospasm suspected. (Illig 2016)📄
• Duplex ultrasound to assess ulnar artery patency/aneurysm and palmar arch flow; computed tomography angiography (CTA)/magnetic resonance angiography (MRA)/digital subtraction angiography (DSA) for operative planning and to define distal embolic burden. (Illig 2016)📄 (White 2006)📄

Management

• Initial: eliminate inciting trauma, smoking cessation, protective padding, and antiplatelet therapy (particularly in embolic presentations). (Illig 2016)📄
• Acute embolic ischemia: consider catheter-directed thrombolysis or thrombectomy in appropriately selected patients, with attention to ischemia duration and distal target vessel size. Principles parallel 10PAD acute limb ischemia management. (White 2006)📄
• Operative: resection of diseased ulnar segment with vein interposition graft is preferred when the palmar arch is incomplete or when durable inflow is required. If the palmar arch is complete and distal perfusion is adequate, ligation may be reasonable. (Illig 2016)📄
• Avoid stenting across the wrist because of motion-related failure and fracture risk. (Illig 2016)📄

When to broaden the differential

If symptoms are bilateral, episodic, or triggered by cold/stress, consider vasospastic disease (see "Raynaud phenomenon") or inflammatory vasculitis (see "Other"). (Wigley 2016)

Thoracic Outlet Syndrome

Arterial thoracic outlet syndrome (arterial TOS) is caused by chronic extrinsic compression of the subclavian artery in the scalene-costoclavicular space, most often due to a cervical rib, anomalous first rib, or fibrous bands. Repetitive trauma can lead to intimal injury, post-stenotic dilatation/aneurysm, mural thrombus, and distal embolization. (Durham 1995)📄

Diagnostic standards

• Diagnosis requires correlation of symptoms (hand ischemia, digital emboli, exertional arm fatigue) with objective imaging.
• Recommended imaging includes dynamic duplex ultrasonography and computed tomography angiography (CTA)/magnetic resonance angiography (MRA) performed in neutral position and with provocative positioning (abduction/external rotation) to document compression and associated arterial pathology (aneurysm, thrombus). (Demondion 2006) (Illig 2016)📄

Treatment principles

• Definitive management is thoracic outlet decompression (first rib and/or cervical rib resection with scalenectomy), combined with arterial reconstruction when aneurysm, thrombus, or fixed arterial damage is present (patch angioplasty, endarterectomy, or interposition graft). (Illig 2016)📄 (Durham 1995)📄
• Isolated endovascular stenting across the thoracic outlet without decompression is not recommended due to persistent external compression and risk of stent deformation/fracture and recurrent embolization. (Illig 2016)📄
• Distal embolization should be treated with thrombectomy or thrombolysis when clinically indicated; the embolic source must be addressed to prevent recurrence. (White 2006)📄 (Illig 2016)📄

Other

This section highlights non-atherosclerotic causes of upper extremity ischemia. A structured approach is to determine whether ischemia is primarily due to: 1) inflammatory arterial wall disease, 2) embolism/thrombosis, 3) extrinsic compression, or 4) iatrogenic/radiation injury.

Vasculitis

Examples include Takayasu arteritis, giant cell arteritis, and Buerger disease.

• Workup typically includes inflammatory markers and targeted rheumatologic evaluation plus vascular imaging.
• In large-vessel vasculitis, FDG-PET/CT can support diagnosis and map inflammatory activity when available and clinically appropriate. (Slart 2018)
• Revascularization is generally preferred during disease quiescence, with concomitant immunosuppression coordinated with rheumatology; restenosis risk is higher in active inflammatory disease. (Rutherford 2018)

Embolic disease

Common sources include atrial fibrillation, valvular disease, mural thrombus, aortic arch atheroma, and proximal arterial lesions such as subclavian aneurysm (including aneurysms associated with arterial TOS). (Paraskevas 2015)

• Initial management of suspected acute arterial embolism includes immediate systemic anticoagulation unless contraindicated, while defining the source and limb threat. (White 2006)📄
• Definitive therapy aligns with acute limb ischemia principles (open embolectomy, catheter-directed thrombolysis, or endovascular therapy based on timing and thrombus burden). See 10PAD. (White 2006)📄

Radiation-induced injury

Consider in patients with prior thoracic/neck radiation. Dense fibrosis and long-segment disease may reduce endovascular durability; open reconstruction may be required in selected cases. (Rutherford 2018)

Buerger disease (thromboangiitis obliterans)

Buerger disease is a distal, segmental inflammatory vaso-occlusive disease strongly linked to tobacco exposure, often presenting with digital ischemia and superficial thrombophlebitis.

• Absolute tobacco cessation is the only proven disease-modifying therapy. (Olin 2000)
• Revascularization is rarely feasible due to distal target limitations; consider sympathectomy or vasodilator strategies only in carefully selected refractory cases. (Olin 2000)

Upper Extremity Pathophysiology

• Atherosclerotic lesions: cause flow-limiting stenosis/occlusion.
• Trauma: disruption of intima → thrombosis, pseudoaneurysm, arteriovenous fistula.
• TOS: repeated compression → intimal hyperplasia, mural thrombus, distal embolization.
• Vasculitis: chronic inflammation, wall thickening, stenosis, or aneurysm.
• Embolism: distal ischemia, often digital gangrene.

Upper Extremity Clinical Presentation

Upper extremity arterial disease presents along a spectrum from asymptomatic disease to acute and chronic ischemic syndromes. Because upper extremity atherosclerosis often reflects systemic vascular disease, symptoms should trigger a cardiovascular risk assessment and optimization. (Hiatt 2015)📄 (Aboyans 2017)📄

Common clinical patterns

1. Proximal inflow disease (subclavian/innominate)
2. - Arm claudication, fatigue, exertional pain.
3. - Subclavian steal: vertebrobasilar symptoms provoked by arm exertion due to retrograde vertebral flow. (Shadman 2004)📄
4. - Coronary-subclavian steal: angina/ischemia in patients with LIMA grafts. (Angle 2003)

1. Distal occlusive/embolic disease (brachial/forearm/digital)
2. - Blue finger syndrome, digital ulcers/gangrene, acute pain with pallor/coolness and neurologic deficits (advanced ischemia).

1. Extrinsic compression syndromes
2. - Arterial TOS: exertional symptoms and recurrent distal embolization. (Illig 2016)📄

1. Dialysis access-related ischemia ("steal syndrome")
2. - Hand pain, numbness, coolness, tissue loss, often improved with access compression during bedside testing. (Lok 2020)

Terminology

The term chronic limb-threatening ischemia (CLTI) is reserved for lower extremity disease; upper extremity ischemia is described by etiology and severity (e.g., chronic ischemia, acute embolic ischemia, TOS-related embolization). See 10PAD. (Gerhard 2016)📄

Clinical examination

A focused vascular exam should define inflow (subclavian/axillary), outflow (brachial/forearm), and hand perfusion.

Key elements

• Palpate brachial, radial, and ulnar pulses; assess capillary refill, temperature gradient, and digital perfusion.
• Auscultate for supraclavicular/subclavian bruits and evaluate for cervical rib/space-occupying findings when TOS is suspected. (Illig 2016)📄

Blood pressure

Measure bilateral brachial pressures. An inter-arm systolic BP difference >=15-20 mmHg suggests hemodynamically significant subclavian stenosis in an appropriate clinical context. (Shadman 2004)📄

Hand collateral assessment

Perform Allen test as a bedside screen of palmar arch adequacy when planning radial artery harvest, catheterization, or interventions impacting the forearm circulation; abnormal results should be confirmed with duplex/PPG-based testing. (Illig 2016)📄

Non-invasive

Duplex ultrasound (first-line)

Duplex ultrasound is the usual first-line test for suspected upper extremity occlusive disease because it can:

• Localize stenosis/occlusion and characterize plaque.
• Identify vertebral artery flow direction in suspected subclavian steal. (Shadman 2004)📄
• Provide validated velocity criteria for grading subclavian stenosis severity. (Mousa 2017)📄

Physiologic testing

Physiologic studies help quantify ischemia and are especially useful for distal/digital disease:

• Wrist-brachial index and segmental pressures (interpretation principles parallel ankle-brachial index (ABI) methodology). (Aboyans 2012)📄
• Digital pressures/photoplethysmography (PPG), including cold challenge when vasospasm is suspected (see "Raynaud phenomenon"). (Wigley 2016)
• Dialysis access ischemia: compare digital pressures and waveforms with and without access compression to support steal physiology. (Lok 2020)

Imaging

computed tomography angiography (CTA)/magnetic resonance angiography (MRA) are preferred noninvasive modalities for anatomic mapping and procedural planning when intervention is being considered.

• CTA: high spatial resolution, rapid acquisition; useful for calcified ostial lesions and for mapping arch/subclavian origins.
• MRA: alternative in iodinated contrast allergy or when minimizing radiation; interpret with awareness of flow-related artifacts. (Prince 2016)

Dynamic protocols

In suspected arterial TOS, perform CTA/MRA with arm positioning (neutral and provocative) to demonstrate compression and post-stenotic changes. (Demondion 2006)

digital subtraction angiography (DSA)

Digital subtraction angiography (DSA) remains the reference standard for luminal assessment and is typically performed when endovascular treatment is planned or when noninvasive studies are discordant. (White 2006)📄

Special investigations

When to consider specialized testing

• Arterial TOS: use standardized dynamic duplex and cross-sectional imaging (neutral vs abduction/external rotation) to document compression and arterial sequelae (aneurysm, thrombus). (Demondion 2006) (Illig 2016)📄
• Complex ostial subclavian lesions: consider adjunctive intraprocedural imaging (e.g., IVUS) to optimize stent sizing/landing in ostial disease where angiography may underestimate vessel diameter due to overlap and eccentric plaque. (Evidence base is extrapolated from broader endovascular practice.) (White 2006)📄

Medical therapy

Medical therapy serves two goals in upper extremity arterial disease:

1. Reduce systemic cardiovascular risk (myocardial infarction (MI), stroke, cardiovascular death)
2. Reduce limb events and maintain patency after revascularization

(Aboyans 2017)📄 (Hiatt 2015)📄

Baseline therapy for atherosclerotic upper extremity disease

• Antiplatelet therapy: single antiplatelet therapy is standard for symptomatic atherosclerotic disease. Clopidogrel demonstrated benefit over aspirin in atherosclerotic vascular disease populations (including peripheral arterial disease (PAD) subgroups). (CAPRIE 1996)
• High-intensity statin therapy: reduces major cardiovascular events in high-risk atherosclerotic populations. (Heart Protection 2002)
• Smoking cessation: associated with improved outcomes and reduced mortality in symptomatic PAD populations (extrapolated to systemic atherosclerosis management). (Armstrong 2014)
• Intensively manage blood pressure (BP), diabetes, and lifestyle according to general vascular prevention standards. (Aboyans 2017)📄

Antithrombotic therapy after subclavian/innominate stenting (pragmatic approach)

Evidence for dual antiplatelet therapy (DAPT) duration in subclavian stenting is limited; practice is typically extrapolated from peripheral and carotid stenting experience.

• DAPT (aspirin + clopidogrel) for 1-3 months, then single antiplatelet therapy long term, individualized by bleeding risk and competing indications (e.g., atrial fibrillation). (Aboyans 2017)📄
• Consider dual-pathway inhibition (low-dose rivaroxaban plus aspirin) in selected patients with polyvascular atherosclerosis and acceptable bleeding risk; this strategy reduced cardiovascular and limb events in PAD populations and may be considered after non-coronary peripheral interventions on an individualized basis. (Eikelboom 2017)📄 (Bonaca 2020)📄

Lipid intensification for very high-risk disease

In very high-risk atherosclerotic disease with persistent low-density lipoprotein (LDL) elevation despite statin therapy, consider additional lipid-lowering therapy based on cardiovascular outcome trials. (Sabatine 2017)📄 (Schwartz 2018)📄 Additionally, lipoprotein(a) (Lp(a)) should be measured at least once in a lifetime to identify patients at high risk for atherosclerotic cardiovascular disease (ASCVD). (Yang 2026)

Embolic disease

For suspected acute arterial embolism, initiate systemic anticoagulation unless contraindicated while definitive source evaluation proceeds. (White 2006)📄

Endovascular therapy

Endovascular therapy (angioplasty +/- stenting) is commonly used for symptomatic subclavian/innominate stenosis because of high technical success and low peri-procedural morbidity in appropriately selected patients. (Patel 2008) (Rutherford 2018)

Typical indications

• Lifestyle-limiting arm claudication attributable to inflow stenosis.
• Subclavian steal with reproducible vertebrobasilar symptoms and documented hemodynamic steal.
• Coronary-subclavian steal in LIMA graft patients.
• Embolic manifestations from proximal lesions when anatomy is suitable (often alongside treatment of the embolic source). (Angle 2003) (Shadman 2004)📄

Technical considerations (proximal subclavian)

• Ostial lesions require precise stent positioning to cover the plaque while avoiding protrusion into the aortic arch when possible.
• Assess vertebral origin and dominance; manage embolic risk and neurologic symptoms in coordination with cerebrovascular evaluation (see 7Ch. 7). (White 2006)📄
• Report outcomes using standardized definitions (technical success, primary/assisted/secondary patency, target lesion revascularization). (Illig 2016)📄

Outcomes (typical)

• Technical success for subclavian stenosis interventions is commonly reported as >90% in contemporary practice.
• Mid-term patency varies by lesion type and location; restenosis and reintervention remain expected failure modes requiring surveillance. (Angle 2003) (Rutherford 2018)

Special context: thoracic endovascular aortic repair (TEVAR) and the left subclavian artery

When TEVAR requires LSA coverage, selective LSA revascularization is recommended to reduce risks of posterior circulation ischemia and spinal cord ischemia in appropriately selected patients. (Matsumura 2009)📄

Upper Extremity Open Surgery

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Open reconstruction remains an essential option for upper extremity inflow disease, particularly when lesions are long, occlusive, recurrent after endovascular therapy, or when clinical context favors durable reconstruction (e.g., younger patients, complex anatomy, or concomitant open procedures). (Rutherford 2018)

Common proximal reconstructions

1. Carotid-subclavian bypass (CSB)
2. Subclavian-carotid transposition (SCT)

These procedures are also used to preserve LSA flow when required for 6thoracic endovascular aortic repair (TEVAR) or to treat coronary-subclavian steal in LIMA graft patients. (Matsumura 2009)📄 (Angle 2003)

Additional options (selected settings)

• Axillo-axillary bypass (selected inflow patterns or reoperative fields).
• Endarterectomy for focal lesions in selected anatomic segments.
• Embolectomy/thrombectomy (Fogarty catheter) for acute embolic occlusion when appropriate, with evaluation and treatment of the embolic source. (White 2006)📄

Outcomes (general expectations)

Open reconstructions are generally durable with good long-term patency when appropriately selected, but carry higher perioperative morbidity than endovascular therapy and require careful stroke risk mitigation for carotid-based inflow procedures. (Rutherford 2018)

Upper Extremity Hybrid Procedures

Hybrid approaches combine open exposure/reconstruction with endovascular therapy and are useful when:

• There is multilevel disease requiring both inflow correction and distal optimization.
• Open access improves endovascular safety (e.g., difficult arch anatomy, need for controlled access).
• Concomitant procedures are planned (e.g., left subclavian artery (LSA) revascularization plus endovascular arch/descending thoracic work). (Matsumura 2009)📄
• Complex aneurysmal disease involves the subclavian-axillary-brachial axis, where hybrid exclusion and bypass maintain distal perfusion. (Mendes 2022)

Planning principles

• Define the dominant failure risk (inflow vs outflow vs embolic source) and sequence steps accordingly.
• Use standardized reporting (primary/assisted/secondary patency and reintervention). (Illig 2016)📄

Hybrid revascularization is established in peripheral arterial practice; outcomes depend on lesion complexity and patient selection. (Bisdas 2013)📄 (Jung 2018)📄

Upper Extremity Follow-up

Follow-up should combine clinical assessment, risk-factor optimization, and hemodynamic surveillance tailored to the treated segment.

Suggested surveillance after subclavian/innominate revascularization

(Adapted from general vascular surveillance principles.) (Almasri 2018)📄

• Baseline exam and duplex ultrasound within 4-6 weeks post-procedure.
• Repeat duplex at 6 months, 12 months, then annually if stable.
• Earlier assessment for recurrent claudication, neurologic symptoms suggestive of recurrent steal, loss of pulses, or recurrent BP differential. (Shadman 2004)📄

Registry benchmarking

National and international registries (e.g., Swedvasc, Vascunet) support benchmarking of reintervention and patency outcomes across vascular procedures and can inform quality improvement. (Mani 2020)📄 (Vascunet Collaboration 2019) (Swedvasc Annual 2022)

Long-term medical therapy reinforcement

Ensure long-term antiplatelet therapy and lipid-lowering therapy consistent with systemic atherosclerosis management, and smoking cessation counseling at every visit. (CAPRIE 1996) (Heart Protection 2002) (Armstrong 2014)

Upper Extremity Tables

Table 9.1. Treatment options for proximal upper extremity inflow disease (subclavian/innominate) (Angle 2003) (Matsumura 2009)📄 (Rutherford 2018)

Table 9.2. Evidence-based medical therapy (systemic atherosclerosis focus) (CAPRIE 1996) (Heart Protection 2002) (Eikelboom 2017)📄 (Bonaca 2020)📄 (Sabatine 2017)📄 (Schwartz 2018)📄 (Armstrong 2014) (Aboyans 2017)📄

Table 9.3. Dialysis access-induced hand ischemia (steal): evaluation clue (Lok 2020)

Table 9.4. Etiology-specific management (selected) (Illig 2016)📄 (Olin 2000) (Wigley 2016)

Arterial thoracic outlet syndrome (TOS): diagnostic standards and surgical decompression

Arterial thoracic outlet syndrome (aTOS) requires differentiation from neurogenic and venous forms. Standardized diagnostic imaging includes dynamic duplex ultrasonography and computed tomography angiography (CTA) or magnetic resonance angiography (MRA) performed in both neutral position and with abduction/external rotation to document arterial compression, morphologic lesions such as post-stenotic dilatation or aneurysm, and thrombus. It is critical to distinguish pathological compression from physiological variants, as positional arterial compression can be observed in up to 20% of asymptomatic individuals; thus, a diagnosis of aTOS typically requires evidence of structural arterial damage or distal complications (Dengler 2022). Indications for surgical intervention include documented arterial compression with aneurysm or thrombus formation, or recurrent ischemia with distal embolization. The surgical approach consists of first rib or cervical rib resection combined with scalenectomy, which forms the cornerstone of treatment for aTOS. When aneurysm or focal intimal disease is present, concomitant arterial reconstruction is performed using endarterectomy, patch angioplasty, or interposition vein grafting. Isolated stenting across the thoracic outlet without decompression is not recommended due to persistent external compression and the risk of stent fracture. Evaluation and management of distal embolization with thrombectomy or catheter-directed thrombolysis should be performed as clinically indicated. (Demondion 2006) (Durham 1995)📄 (Dengler 2022)

Hypothenar hammer syndrome (HHS): workup and management

Hypothenar hammer syndrome results from repetitive blunt trauma to the hypothenar eminence, causing injury to the ulnar artery at the level of the hamate bone and the superficial palmar arch. This condition predominantly affects manual laborers, mechanics, jackhammer operators, and athletes such as baseball players, tennis players, and cyclists. Patients typically present with ulnar-sided digital ischemia, cold sensitivity, and characteristic corkscrew appearance of the ulnar artery on imaging. The diagnostic workup begins with a focused physical examination including the Allen test to assess palmar arch competency. Duplex ultrasonography evaluates for ulnar artery irregularity, aneurysm formation, or thrombosis. Digital pressures and photoplethysmography, optionally with cold challenge testing, assess the severity of digital ischemia. Computed tomography angiography (CTA), magnetic resonance angiography (MRA), or digital subtraction angiography provides detailed anatomic information for operative planning. Management strategies include risk-factor modification, occupational counseling, smoking cessation, and antiplatelet therapy. Surgical treatment is indicated for aneurysm formation or ongoing distal embolization and consists of resection of the diseased ulnar artery segment with interposition vein grafting or, when the palmar arch is complete, simple ligation. Catheter-directed thrombolysis or open thrombectomy may be considered for acute embolic events. Stenting across the wrist joint is contraindicated due to high rates of motion-related failure (Illig 2016)📄.

Buerger disease (Thromboangiitis obliterans) in upper extremity disease

Buerger disease, also known as thromboangiitis obliterans (TAO), is an inflammatory vaso-occlusive disorder that predominantly affects young tobacco users. The disease is characterized by distal, segmental arterial occlusions and frequently associated superficial thrombophlebitis. Upper extremity involvement occurs in a substantial proportion of affected patients, manifesting as digital ischemia and tissue loss. Diagnosis relies on clinical criteria (young smoker, distal ischemia, exclusion of autoimmune diseases) and angiographic findings of corkscrew collaterals. Management mandates absolute smoking cessation, as no other therapy prevents progression. While revascularization is often challenging due to the distal nature of the disease, endovascular angioplasty has emerged as a feasible option for patients with chronic limb-threatening ischemia (CLTI), showing reasonable early and late outcomes in systematic reviews (Galyfos 2022). Sympathectomy or iloprost may also provide symptomatic relief in select cases (Olin 2000).

Raynaud phenomenon: diagnostic approach and evidence-based therapy

The diagnostic approach to Raynaud phenomenon begins with differentiation between primary and secondary forms. Nailfold capillaroscopy and autoantibody screening should be performed when clinical features suggest secondary causes. Initial management emphasizes nonpharmacologic measures including cold avoidance and smoking cessation, which are recommended for all patients. First-line pharmacotherapy consists of dihydropyridine calcium channel blockers such as amlodipine or nifedipine. For refractory cases, adjunctive therapies include topical nitrates, phosphodiesterase-5 inhibitors, and in highly selected cases, botulinum toxin injection. Digital sympathectomy has a limited role and should be reserved for severe refractory ischemia unresponsive to medical therapy. Digital photoplethysmography with cold challenge testing may provide supportive diagnostic information (Wigley 2016).