The case
A young male with a history of intravenous drug use presents to the ED of POCUS General Hospital with bleeding from a sinus in his groin. The bleeding was minor and there is none at present.
- really quite broad at this point. IDUs often resort to groin injection due to lack of peripheral veins. There are several well described complications
- abscess
- sinus formation
- DVT
- AV fistula
- pseudoaneurysm
A bedside ultrasound is obtained
- it is difficult to tell if this is artery or vein but there is some turbulence visible and some pulsatility.
- in other words it isn’t hugely helpful…
- get your colour on!
The following image is obtained
- the flow in the artery could be mistaken for a Yin Yang sign – which suggests a pseudoaneurysm
Yin Yang Sign via Andrew Dixon on Radiology Signs (click for source)
However there seems to be a separate vessel above the artery and there seems to be flow communicating between the two.
He is referred to the vascular team and has further formal ultrasound and CT imaging showing that he had developed an AV fistula
Longitudinal view of the common femoral vein (top) showing high velocity flow and communication with the artery (bottom)
This is tricky stuff and it would be easy to confuse the two and an important lesson here is to recognise when something isn’t normal and to pursue further formal imaging or expert advice.