Paraclinoid carotid artery aneurysms with the dome eroding the anterior clinoid process: preoperative depiction of topography and surgical tactics--two case reports.

A 70-year-old male and a 55-year-old female presented with unruptured aneurysms in the clinoid segment of the carotid artery. Intraoperative rupture during removal of the anterior clinoid process resulted in unintended carotid artery occlusion in the former patient, causing hemispherical infarction and death. However, the aneurysm was successfully clipped due to preoperative recognition of the aneurysmal dome in the clinoid process in the latter. Magnetic resonance angiography and three-dimensional computed tomography angiography source images provide detailed visualization of the topographic anatomy around the paraclinoid aneurysms and are helpful for definite surgical planning.