Mycotic Pseudoaneurysm Associated with Skull Base Osteomyelitis Treated with Endovascular Embolization

Pseudoaneurysms occur due to malformations in arterial wall uniformity, leading to blood collection between the outer arterial layers and resultant outpouching of the vessel. Unlike true aneurysms, pseudoaneurysms do not involve all layers of the blood vessel. Mycotic pseudoaneurysms can occur after associated vessel adventitia infection, leading to transmural dissection. Here we present a case of a 78-year-old man with a history of chronic otitis externa and osteomyelitis who presented with increasing right ear pain with bloody discharge and associated headache. Catheter angiography demonstrated a large pseudoaneurysm in the right middle meningeal artery (MMA) at the base of the skull. Based on the clinical findings and the patient's history, the patient was ultimately diagnosed with mycotic pseudoaneurysms of the MMA. The patient was subsequently treated with antibiotics as well as endovascular embolization and recovered without any complications.