Sonographic findings of a recannalised femoral pseudoaneurysm: What happened next?
Ellen Cronin, Maria O Brien, Therese Herlihy, University College, Dublin
Background
A femoral pseudoaneurysm is one of the most common complications following cardiac catheterisation. In this case a 90 year old lady presented to the ultrasound department for a 4 week follow up of a left superficial femoral artery (SFA) pseudoaneurysm. This developed as a complication of a coronary angiogram and was treated initially with ultrasound guided thrombin injection which appeared to result in complete thrombosis of the pseudoaneurysm.
Ultrasound Findings
The ultrasound examination incorporated a B-mode, colour Doppler and spectral Doppler assessment of the left SFA. An echolucent sac adjacent to the SFA was identified on B-mode. Colour Doppler identified a tract connecting the pseudoaneurysm chamber to the SFA. The “yin-yang” sign was also visualised within the chamber, indicating bidirectional flow. Spectral Doppler demonstrated a “to-and-fro” waveform in the communicating neck between the SFA and the pseudoaneurysm chamber, indicating blood entering and exiting during systole and diastole respectively.
Discussion
Ultrasound findings indicated a recannalised pseudoaneurysm due to a persistent defect in the proximal SFA. Surgical correction was deemed necessary for the patient. In anticipation of this, a computed tomography lower limb angiogram was performed. This demonstrated a haematoma anterior to the proximal SFA with no visible arterial flow, indicating that the pseudoaneurysm had spontaneously thrombosed. Therefore, no further intervention was required. This case study demonstrates an unusual outcome in the management of a femoral pseudoaneurysm. Although ultrasound guided thrombin injection was successful initially, the pseudoaneurysm recannalised. Additionally, the recannalised pseudoaneursym spontaneously thrombosed.
Conclusion
Ultrasound plays an essential role in the diagnosis and monitoring of a pseudoaneurysm. Diagnostic confidence is achieved when the triad of classical ultrasound findings are identified, including an echolucent sac adjacent to a vessel on B-mode, the “yin-yang” sign on colour Doppler and the “to-and-fro” waveform on spectral Doppler.