False aneurysm of the radial artery

Case contributed by Mark Hall
Diagnosis certain


Smoker presented to ED 12 days ago with an acute exacerbation of COPD. Following admission to the high dependency unit for BiPAP he developed an ovoid soft tissue mass overlying the volar and radial aspect of his right wrist at the site of previous arterial cannulation. The ultrasound request read "Soft tissue mass ? collection".

Patient Data

Age: 60 years
Gender: Male

Right radial wrist mass


Erythematous swelling overlying the volar aspect of the right radius.

USS radial aspect of wrist


Ultrasound of the radial aspect of the wrist was performed. On examination there was an erythematous mass overlying the distal radius on the volar aspect of the wrist.

Ultrasound demonstrated that this mass was a radial artery aneurysm measuring 14 mm in length with a diameter of 6 mm (normal size 2 mm). The aneurysm had a broad neck and was partially thrombosed. Doppler signal showed the classic "yin and yang" flow. Thrombus is seen extending proximally up the radial artery.

CT upper limb angiogram


Wide necked radial artery aneurysm.  

Note the narrow ulnar artery.  This is important regarding surgical planning and collateral perfusion.

Case Discussion

This case demonstrates a radial artery aneurysm following multiple attempts at radial arterial line insertion in the medical high dependency unit. Given the traumatic nature it was felt that this was almost certainly a false aneurysm although several features such as the wide neck and thrombus within are more in keeping with a true aneurysm. 

The standard initial treatment for small peripheral arterial false aneurysms is ultrasound guided thrombin injection however, given the wide neck and overlying erythema/cellulitis it was treated surgically by tying off the vessel, as the risk of graft infection and peripheral embolization was deemed too great. In theater the radial artery was clipped for 10 minutes before tying off to ensure that perfusion by the ulnar artery was adequate.  

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