Summary
Thromboangiitis obliterans (TAO), also known as Buerger disease, is an inflammatory, nonatherosclerotic, vasoocclusive disease affecting small and medium-sized vessels of the extremities. TAO most commonly affects adult males with a significant history of tobacco consumption (e.g., smoking, chewing, vaping). In susceptible individuals, tobacco exposure causes inflammation of the tunica intima, with the formation of a highly cellular thrombus that occludes the affected vessel. Patients frequently present with intermittent claudication, Raynaud phenomenon, and migratory superficial thrombophlebitis. Eventually, critical limb ischemia develops and the patient presents with rest pain, absent pulse in the extremities, and/or digital ulcerations. Angiography can determine the extent of the disease and differentiate TAO from other causes of peripheral vasculopathy. The most important therapeutic measure is the complete avoidance of tobacco exposure. Additionally, prostaglandin analogues (e.g., iloprost) may be used to improve ulcer healing and decrease rest pain. Patients with TAO who develop gangrene require amputation.
Epidemiology
- Prevalence: up to 20 cases per 100,000 individuals [1]
- Sex: : ♂ > ♀ (3:1)
- Age of onset: before the age of 45 years [2]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
- The exact etiology of TAO is unknown.
- Tobacco consumption is the single most important risk factor for TAO. [3]
Pathophysiology
TAO is an inflammatory, nonatherosclerotic, vasoocclusive disease affecting small and medium-sized vessels of the extremities.
Histopathological phases [4]
-
Acute phase
- Inflammation of the tunica intima (i.e., endarteritis) with neutrophilic infiltration and microabscess formation
- Inflammation may extend to the tunica media but the internal elastic lamina usually remains intact.
- Formation of a highly cellular inflammatory thrombus
-
Intermediate (subacute) phase
- Mononuclear cells, fibroblasts, and giant cells replace neutrophils
- Thrombus organization
- Chronic phase
Clinical features
TAO affects the small and medium vessels of the extremities. Other systems are only very rarely involved.
Extremities [2][5]
- Migratory superficial thrombophlebitis (recurrent): often seen prior to the onset of limb ischemia ; [3][6]
- Raynaud phenomenon
-
Chronic or acute limb ischemia: may progress from distal to proximal vessels
- Intermittent claudication
- Pain at rest, cool extremities, and/or diminished or absent pulses
- Ulceration and/or gangrene of fingertips and/or toes (digits may autoamputate)
TAO typically affects more than one limb. [2][6]
Upper extremity ischemia is often asymptomatic; perform an Allen test in all patients with TAO. [2][6]
Systemic symptoms [1][6]
- Joints: nonerosive arthritis of large joints
- Organ ischemia (very rare) : e.g., manifesting as colon stricture or perforation in the GI tract, stroke in CNS involvement [2][6]
Diagnostics
General principles
-
TAO is a clinical diagnosis that requires:
- Typical clinical features in a patient with a history of tobacco consumption
- Exclusion of differential diagnoses of TAO
- Imaging studies (i.e., angiography and echocardiography) can be obtained to rule out other embolic sources and support the diagnosis.
- A biopsy may be indicated in patients with atypical presentations.
- Consultation with vascular surgery and/or rheumatology is often required.
Suspect TAO in a patient < 45–50 years old with signs of distal limb ischemia and a history of tobacco consumption.
Laboratory studies [2][3]
The following studies are normal in patients with TAO and should be obtained in all patients to rule out alternative diagnoses:
- CBC
- Liver studies
- BMP
- ESR and CRP
- Autoantibodies (e.g., ANA, RF, anticentromere antibodies)
- Coagulation studies (see “Hypercoagulable states”)
ESR and CRP remain within normal limits, which helps differentiate TAO from vasculitides.
Imaging studies [2][3]
-
Angiography
- Indications
- Findings
- Segmental occlusions in the distal vessels of the extremities
- Corkscrew-shaped collateral vessels around the site of occlusion
- Normal proximal arteries without evidence of atherosclerosis
- Echocardiography: indicated in patients with a suspected cardiac source of emboli
An angiography is preferred over CTA and MRA because of its higher sensitivity for detecting small vessel disease in the extremities. [3] 
Additional studies
- Ankle-brachial index (ABI): may be decreased [3]
- Additional laboratory studies: Consider based on the patient's clinical features (e.g., urine drug screen, serum cryoglobulins). [2][3]
-
Biopsy
- May be considered in patients with tender nodules and/or superficial thrombophlebitis, atypical locations (e.g., large vessel involvement), or age of onset > 45 years [2][5]
- Typically shows acute inflammation of all layers of the vessel wall accompanied by occlusive thrombosis [6]
Differential diagnoses
The following alternate diagnoses are typically investigated in a patient with suspected TAO. [2][3][5]
- Peripheral artery disease; see “Differential diagnosis of claudication.”
- Hypercoagulable states
- Diabetes mellitus
- Deep vein thrombosis
- Autoimmune diseases
The differential diagnoses listed here are not exhaustive.
Treatment
General principles
- There is no specific treatment for TAO.
- Tobacco abstinence is the most important therapeutic measure.
- Pharmacotherapy may improve ulcer healing.
- Revascularization procedures are rarely performed.
- Consult a vascular surgeon and/or a rheumatologist for all patients.
Prevention and supportive care [2][3]
- Abstinence from tobacco in any form (e.g., smoking or chewing tobacco, nicotine patches or gum)
- Most effective measure for reducing symptoms
- Decreases the risk of amputation if started early in the disease course
- Protection of fingers and toes from cold and mechanical injuries (e.g., wearing gloves and appropriate footwear)
- Basic wound and skin hygiene (e.g., cleaning with soap and water, covering wounds with clean bandages) contributes to ulcer healing and prevents infections. [1]
Complete cessation of tobacco consumption in any form is the single most effective therapeutic measure. [1][3]
Even nicotine patches can reactivate TAO. Bupropion and varenicline are the preferred agents for assisting in tobacco cessation. [2][3]
Symptomatic therapy [2][6]
- Calcium channel blockers (nifedipine, amlodipine): commonly prescribed, but evidence of effectiveness is lacking [1]
- Iloprost improves resolution of trophic changes and may reduce the amputation rate.
Surgical therapy [4][6]
- Patients with ulcers may require debridement and antibiotic therapy for soft tissue infections. [1]
- Patients who develop gangrene require amputation.
- Revascularization procedures (e.g., bypass grafting, angioplasty) are rarely feasible because vascular involvement tends to be diffuse and distal.
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