Point-Of-Care Ultrasound Diagnosis of Medial Plantar Artery Pseudoaneurysm Secondary to Penetrating Injury

Background: Pseudoaneurysms of the foot are rare and can occur from a range of etiologies, including laceration from a foreign body. The majority of reported cases have been diagnosed by computed tomography, magnetic resonance imaging, or angiography. These tests require intravenous access and contrast, confer radiation, take time to perform and interpret, are expensive, and are not always readily available in the acute setting. No prior reported pseudoaneurysms of the foot have been diagnosed by point-of-care ultrasound (POCUS). Case Report: An 8-year-old boy presented to the emergency department for evaluation of left foot pain and swelling 2 weeks after stepping on small pieces of broken glass. He had a 3 × 3 cm area of painful swelling and erythema at the medial plantar aspect of his foot. A cutaneous abscess was the working diagnosis and preparations were made for an incision and drainage procedure. However, POCUS revealed a medial plantar artery pseudoaneurysm. Incision and drainage would have led to unexpected arterial bleeding. Instead, the pediatric surgery service was consulted for pseudoaneurysm excision and arterial ligation. Why Should an Emergency Physician Be Aware of This?: Incision of a pseudoaneurysm in the sole of the foot—thought to be an abscess based on clinical examination—would lead to unforeseen arterial bleeding. POCUS at the bedside can differentiate between simple abscess and pseudoaneurysm in order to guide appropriate and time-sensitive management. Historical and clinical clues to the diagnosis may include heavier-than-expected bleeding at the time of laceration and a pulsatile quality to the painful erythema and swelling.