Presentation
Left popliteal fossa swelling. History of left total knee replacement 6 weeks ago.
Patient Data
A thick-walled cystic-like lesion measuring approximately 5 x 6 x 8 cm is seen in the left popliteal fossa, superficial to the popliteal artery. It shows turbulent forward and backward flow with a classical yin-yang sign on color Doppler ultrasound examination. These sonographic features are compatible with a pseudoaneurysm of the popliteal artery.
Partially thrombosed pseudoaneurysm measuring approximately 7.5 x 5.5 x 5.5 cm, seen communicating with the distal popliteal artery about 2 cm proximal to its bifurcation, through a defect measuring 2 mm in its posterior wall. Status post left total knee replacement. Beam hardening artifacts from the knee prosthesis, degrading the scan quality.
Case Discussion
The patient underwent open surgery. The pseudoaneurysm was excised and the defect in the posterior wall of the popliteal artery was repaired.