Intracranial internal carotid artery aneurysm associated with extracranial occlusion of the ipsilateral internal carotid artery in a patient with polycystic kidney disease

We report a rare case with polycystic kidney disease (PKD) having an intracranial internal carotid artery aneurysm associated with extracranial occlusion of the ipsilateral internal carotid artery. A 55-year-old man with chronic renal failure due to PKD presented with headache. CT scan and MRI showed no abnormal findings. MRA showed cervical occlusion of the right internal carotid artery and an ipsilateral intracranial carotid aneurysm. At surgery, the saccular aneurysm protruded anterolaterally at the C2 portion of the right internal carotid and was clipped. Hemodynamic stress of the blood flow through the posterior communicating artery and the fragility of arteries because of PKD were considered to be two main causes of aneurysmal formation in this case.