Yin and Yang in the groin.

True, this is a Yin & Yang on the groin,
but not quite what we're aiming for...

 

 

The case 
The patient had undergone emergent angiography and PCI for a STEMI. Access for the PCI was gained through the radial artery, which is associated with fewer complications than femoral artery access. Unfortunately, they also required placement of an intra-aortic balloon pump, which was placed through the right femoral artery.
At a follow-up appointment soon after discharge, examination revealed swelling in the right inguinal crease. The swelling was both pulsatile and had a sharp systolic bruit.

Point-of-care ultrasound (POCUS) of the area of pulsatility was conducted with both B-mode and color Doppler.

The physical exam, of course, had been strongly suggestive of a pseudoaneurysm of the femoral artery. The POCUS is diagnostic!

The B-mode image shows a large pulsatile hypoechic structure, but a post-operative hematoma might have the same appearance (e.g. if an adjacent artery was causing pseudo-pulsation). 

Color Doppler is required to exclude hematoma by demonstrating pulsatile flow within the structure. Such flow may appear as a "swirling" or "to and fro" pattern.

Even more "colorfully" (pun intended), the pattern has been described as the Yin-Yang sign.

Treatment can be as simple as ultrasound-directed compression of the pseudoaneurysm sac, or as invasive as surgical management. The majority of post-cathetererization pseudoaneurysms, however, are managed with injection of thrombin into the sac. This is almost always successful.

And lastly, speaking of things that required fixing...

Perfect!

Open-access references:
Contemporary Management of Postcatheterization Pseudoaneurysms
Sonographic Evaluation of Vascular Injuries