Giant petrous internal carotid aneurysm causing epistaxis: A case report.

Aneurysms of the internal carotid artery (ICA) arising from the petrous portion are extremely rare, and most cases are asymptomatic or cause a mass effect leading to palsy of the adjacent cranial nerves. In rupture cases, massive nasal and ear bleeding occurs, which may cause death. We describe a 73-year-old man with a giant ICA aneurysm arising from the petrous portion and presenting as epistaxis. The patient had no history of trauma or clotting disorders. Computed tomography angiography demonstrated a giant petrous carotid aneurysm and erosion of a part of the left temporal bone. The patient was treated by trapping of the aneurysm with high-flow bypass using a radial artery. From an anatomical view point, rupture of ICA aneurysms of this portion might be caused by thinness of the bone partition between the ICA and the sphenoidal sinus. It should be noted that petrous carotid aneurysms are usually asymptomatic but may cause massive epistaxis in cases of rupture.