Arterial thoracic outlet syndrome

Last revised by Mostafa Elfeky on 10 Jul 2023

Arterial thoracic outlet syndrome (aTOS) is considered rarest from of
thoracic outlet syndrome and can result in compression of arterial structures (especially the subclavian artery) at thoracic outlet, or superior thoracic aperture.

Many of these patients may also have concurrent venous thoracic outlet syndrome and neurogenic thoracic outlet syndrome.

It is thought only to account for only 1-3% of all cases of thoracic outlet syndrome.

Patient may present with arm ischemia and effects of distal embolization. Secondary neurologic abnormalities as sequelae may also be present.

Arterial occlusion can be acute, acute on chronic or chronic.

Arterial compression can incite intimal damage, turbulent blood flow, and as times vessel dilation. (leading to aneurysm formation).

Doppler ultrasound may show dynamic changes with arm movement but can be limited in identifying specific underlying causes. Some patient's may have associated subclavian arterial aneurysms 4.

May demonstrate anatomical narrowing of the thoracic outlet and with imaging often performed in neutral and abducted positions. CT will also allow identification of factors such as

  • congenital cervical ribs

  • bony abnormality of 1st rib or clavicle (congenital anomaly, malunited fracture, callus, Paget disease, tumor etc )

  • elongated C7 transverse process

May be used to evaluate the thoracic outlet. MRI can be particularly useful in identifying soft tissue pathology such as

  • muscular hypertrophy / muscle insertional variation

  • supernumerary muscles

  • fibrous scarring

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Cases and figures

  • Case 1
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  • Case 2: arterial and venous
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  • Case 3
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