Using POCUS to Identify Vascular Structures in Soft-Tissue Presentations in the ED:Tale of 2 cases
Himanshu Gul Mirani , Rena Darbar
Midland Metropolitan University Hospital, United Kingdom
Case Presentation:
Soft tissue swellings are a common presentation in the emergency department (ED), often attributed to abscesses or cellulitis. However, in patients with vascular risk factors or histories of recent arterial interventions, the differential must be broadened to include vascular complications such as pseudoaneurysms. This case series demonstrates the critical role of point-of-care ultrasound (POCUS) in differentiating pseudoaneurysms from soft tissue infections, thereby guiding safe and timely management.
CASE 1 – Complex abscess with no vascular connection seen in transverse and longitudinal planes; CASE 2 – Image 1 - Pseudoaneurysm with swirling blood, Image 2 shows - Yin-Yang Sign on Doppler
Management and Outcome:
Case 1: A male in his early 30s with a history of intravenous drug use (IVDU) presented with a painful, firm swelling in the left groin. He admitted to injecting in the femoral region. There were injection track marks. Initial clinical impression was that of a groin abscess. Given the anatomical location and history of repeated vascular trauma, POCUS was performed to assess for vascular involvement and its proximity to the lesion. Ultrasound revealed a complex, loculated fluid collection distinct from the femoral artery and vein. This allowed for confident exclusion of a pseudoaneurysm, facilitating prompt and safe incision and drainage (I&D). Given the known risk of pseudoaneurysm formation in IVDU, particularly in high-flow vascular territories, this bedside vascular assessment was pivotal in ensuring procedural safety.
Case 2: A 31-year-old male with a known prothrombotic disorder of unclear etiology, on warfarin and clopidogrel following PCI for myocardial infarction three months prior, and previous history of deep veinous thrombosis and pulmonary embolism (with no known intracardiac shunt) presented with a progressively enlarging, painful swelling over the right forearm at the site of previous radial artery access. The lesion was tender without signs of infection or overt hemorrhage. POCUS revealed a hypoechoic lesion with characteristic bidirectional “yin-yang” Doppler flow, and a narrow neck arising from the radial artery, consistent with a pseudoaneurysm. This prompt identification enabled urgent vascular referral and avoided inappropriate attempts at drainage or delayed intervention. Radial artery pseudoaneurysms are rare but potentially serious complications of catheter-based interventions and may rupture if not recognized early. They also carry the risk of getting infected.
Key Learnings and Points:
These cases underscore the diagnostic value of POCUS in the ED for differentiating pseudoaneurysms from infectious or inflammatory soft tissue masses. Pseudoaneurysms can mimic abscesses in appearance and symptomatology, particularly if infected, but inappropriate intervention can lead to catastrophic hemorrhage. Conversely, excluding vascular involvement with bedside ultrasound can expedite appropriate procedural intervention. These cases advocate for routine consideration of pseudoaneurysm in the differential diagnosis of soft tissue swellings in high-risk patients and reinforce the importance of POCUS in emergency medicine practice.
Conclusion:
POCUS serves as a rapid, non-invasive, bedside tool with high utility in identifying pseudoaneurysms in undifferentiated soft tissue swellings, directly impacting diagnostic accuracy, procedural safety, and patient outcomes in the ED.