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SplintER Series: Venous Thoracic Outlet Syndrome

Bridget Caulkins, MD |


A 29-year-old male presents with right shoulder pain, throbbing, and swelling. He states that a bulge has appeared over his right anterior shoulder recently (Image 1). While he was doing pushups today, he began to have numbness, tingling, and weakness in his right arm. While in the waiting room, his symptoms have completely resolved.

axillary varix

Image 1: Bedside ultrasound of the anterior shoulder at the site of the bulge. AA=axillary artery. AV=axillary vein. Author’s image.



This is likely vascular thoracic outlet syndrome (TOS) with high suspicion for venous TOS (vTOS).

  • Pearl: Vascular TOS is uncommon (4%). Neurogenic TOS is far more common (>95%).
  • Pearl: Vascular TOS is divided into two types- Arterial or venous involving the subclavian vessels.

Venous TOS typically results from compression of the subclavian vein in the costoclavicular space. Repetitive motion, such as pushups, results in vessel inflammation and intimal fibrosis. This can lead to blood stasis and thrombosis [1]. The bulge is likely a varix caused secondary to chronic compression of the subclavian vein. Arterial TOS is mostly likely secondary to a bony abnormality such as a cervical rib compressing the subclavian artery.

  • Pearl: Effort thrombosis or Paget-Schrötter syndrome can be an end result of venous TOS [2]. This is akin to a deep vein thrombosis of the subclavian vein which places the patient at high risk for concomitant pathology such as a pulmonary embolism.
Superficial collateralization in Paget-Schrötter syndrome

Image 2: Evident superficial collateralization in the chest, shoulder and upper right limb, which can be seen in Paget-Schrötter syndrome. Case courtesy of Dr. Julieta Crosta, Radiopaedia.org, rID: 71185

Assess the neurovascular status of the upper extremities and compare bilaterally. Order a duplex ultrasound. It is important to assess for an effort thrombosis or Paget-Schrötter syndrome [2].

  • Pearl: Plain film of the chest can assess for anatomic abnormalities such as an accessory cervical rib obstructing blood flow.

CT or magnetic resonance angiography of the chest can map the blood flow throughout the upper extremity in suspected TOS cases and determine the cause of obstruction [1]. In our patient’s case, the subclavian veins on both sides are being compressed by the first ribs ( Image 3).

MRA demonstrating bilateral stenosis of the subclavian veins

Image 3: Magnetic resonance angiography of the chest. Note the bilateral stenosis of the subclavian veins (green arrows) and the varix (yellow star). Author’s image.

Patients with acute vascular thoracic outlet syndrome (less than 6 weeks from onset) should have prompt vascular surgery referral for early catheter-directed thrombolysis or surgical decompression [1]. In this particular case, the vascular anomaly in the patient was removed surgically (Image 4).

vascular varix

Image 4: Dynamic view of the surgically-removed vascular varix in deflated (left) and inflated (right) states. Image provided with patient permission.


Resources and References:

Check out ALiEM’s SplintER Series to brush up on other can’t miss shoulder and arm injuries or our corresponding SAEM Clinical Image Series: Pinching Pain.

  1. Hussain MA, Aljabri B, Al-Omran M. Vascular thoracic outlet syndrome. Seminars in thoracic and cardiovascular surgery 2016 Mar 1 (Vol. 28, No. 1, pp. 151-157). WB Saunders. PMID: 31037504
  2. Alla VM, Natarajan N, Kaushik M, Warrier R, Nair CK. Paget-Schroetter syndrome: review of pathogenesis and treatment of effort thrombosis. Western Journal of Emergency Medicine. 2010 Sep;11(4):358. PMID: 21079709

Author information

Bridget Caulkins, MD

The post SplintER Series: Venous Thoracic Outlet Syndrome appeared first on ALiEM.

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