[Posttraumatic aneurysm-like shadow at the supraclinoid portion of the internal carotid artery--a case report].

Traumatic cerebral aneurysms occupy less than 1% in all cerebral aneurysms and the onset usually occurs two to three weeks after the head injury. The authors present a case revealing an aneurysm-like shadow at the supraclinoid portion of the internal carotid artery immediately after the head injury. A 45-year-old man was admitted in a semi-comatose state, with bleeding from the nose and the ear. He presented anisocoria, with the left pupil larger, and absence of light reflex of the pupil. Roentgenographic examinations revealed fractures of the skull, the left radius, and the pelvis. CT disclosed subarachnoid hemorrhage and intrasylvian and intracerebral hematoma, with midline shift to the right. Left carotid angiograms revealed an aneurysm-like shadow projecting medially at the supraclinoid portion of the left internal carotid artery, and an emergency operation was performed. A left fronto-temporo-parietal craniectomy was done. Incision of the dura disclosed a thin subdural hematoma and subarachnoid hemorrhage on the surface of the brain. Following removal of the intrasylvian and intracerebral hematoma and slight retraction of the left frontal lobe, a bone fracture and dural tear of the anterior cranial fossa were found. During exposure of the internal carotid artery, a heavy bleeding occurred from the supraclinoid internal carotid artery. Under control of the bleeding by temporary clipping of the internal carotid artery, the bleeding point was proved to be a longitudinal tear of the infero-medial wall of the internal carotid artery, and its length was about 5 mm. Because it was difficult to suture the tear, the internal carotid artery was doubly clipped.(ABSTRACT TRUNCATED AT 250 WORDS)