A man with swelling in the inguinal region.

CASE PRESENTATION

A 54‐year‐old male with a complicated surgical history including aortobifemoral bypass complicated by right femoral artery pseudoaneurysm and eventual right external iliac‐to‐common femoral bypass presented to a tertiary referral center emergency department as a transfer for a painful left groin mass. He noticed a small “bump” 3 days before arrival, which rapidly became increasingly painful and pulsatile and eventually began oozing blood. On arrival, a large pulsatile mass was discovered with overlying necrotic skin and oozing bleeding. Point‐of‐care ultrasound was performed (Figure 1).

FIGURE 1

Ultrasound image with color doppler of the pulsatile mass

DIAGNOSIS

Multilobar spontaneous pseudoaneurysm

This was a large, multilobar spontaneous pseudoaneurysm with pulsatile, swirling blood products. Bidirectional flow seen with color Doppler results in what is commonly called the “Yin‐Yang” sign. This image shows the continuity of multiple lobules of the pseudoaneurysm with the femoral artery. The corresponding computed tomography angiography images (Figures 2, 3, 4) demonstrate the bizarre structure of the large pseudoaneurysm. The patient was taken emergently to the operating room by vascular surgery for complete excision of the pseudoaneurysm and replacement with a Dacron graft. A pseudoaneurysm arises from disruption of all layers of the arterial wall, and a hematoma forms. A pseudocapsule around the hematoma occurs as a result of pressure from arterial pulsations causing inflammation, which thickens the surrounding fibrous tissue. This encapsulation prevents exsanguination and blood freely flows within the central portion of the pseudocapsule. Bedside ultrasound is a rapid and effective means of diagnosing life‐threatening pseudoaneurysm and allows for prompt surgical consultation. ,

FIGURE 2

Computed tomography angiography with 3D reconstruction of the multiple lobules of the pseudoaneurysm extending anteriorly from the right femoral artery

FIGURE 3

Axial CT image demonstrating the multiple lobules and surrounding soft tissue inflammation forming the pseudocapsule. CT: computed tomography

FIGURE 4

Axial CT image demonstrating the very superficial nature of the outer lobule of the pseudoaneurysm at the site of oozing. CT: computed tomography

CONFLICTS OF INTEREST

The authors have no conflicts of interest. No private or grant funding was obtained for the production of this submission.