A Mycotic Common Iliac Artery Pseudoaneurysm of Indeterminate Etiology.

We present the unusual case of a mycotic right common iliac artery pseudoaneurysm caused by the methicillin-susceptible Staphylococcus aureus (MSSA) of indeterminate etiology in a healthy 57-year-old man with no risk factors for infection, trauma, or malignancy. The patient initially presented with worsening subacute right lower quadrant pain and was found to have a pseudoaneurysm of the right common iliac artery. Given concern for rupture on a computed tomography angiogram (CTA), he underwent exclusion of the pseudoaneurysm with a covered stent. At the time of presentation, he had no signs or symptoms of infection. However, the patient developed fever, chills, and worsening right lower quadrant pain 13 days after the index operation and was found to have a leukocytosis, blood cultures positive for MSSA, and progressive soft-tissue changes involving the right common iliac artery on CTA consistent with infection. He was definitively treated with stent explantation, aggressive debridement and replacement with an in situ cryopreserved bypass, and short-term suppressive antibiotic therapy.