鉄筋による頭蓋底穿通の後に発生した外傷性前大脳動脈動脈瘤の1例

A Case of a Traumatic Anterior Cerebral Artery Aneurysm Following the Penetration of the Skull Base by an Iron Rod

I．はじめに

　穿通性頭部外傷は戦時下に多く，一般市民生活には比較的稀な外傷である^20）．今回，建築現場の鉄筋による頭蓋底穿通の後に発生した外傷性脳動脈瘤の1例を経験したので報告する．

A 61-year-old male fell from a position lm high when building a house. An iron rod, which protrudedupward from a solid base in cement, penetrated this patient's neck 15 cm to the head and was successfullyextracted by himself. On admission, he complained of headache and vomiting. General examination dis-closed nasal bleeding, intraoral bleeding, and L figured skin laceration in the left side of his neck at thelevel of the thyroid cartilage. Mild disorientation (JCS2) was noted. Otolaryngological examination dis-closed hyperemia on the left side of the vocal cord as well as at the dome of the superior pharynx. Plainskull film disclosed pneumocephalus and that a piece of bone fragment of the planum sphenoiclale hadpenetrated the brain. CT demonstrated air in the subarachnoicl space, ventricular hemorrhage, intracerebralhematoma in the right frontal lobe, and subarachnoid hemorrhage in the anterior interhemispheric:fissure.CAG detected neither cerebral vascular abnormalities nor cerebral aneurysm. While staying in our depart-ment, he developed mild fever and CSF rhinorrhea. The diagnosis of bacterial meningitis was made fromthe CSF finding and was well controlled with conservative therapy. CSF rhinorrhea stopped spontaneouslywith conservative treatment. Sagittal MRI continuously demonstrated contusional hematoma in the base of the right frontal lobe just above the fractured planum sphenoidale and genu of the corpus callosum follow-ing the course of the intracranially invading iron rod.

The right CAG on Day 10 demonstrated vasospasm on the Al and a 1 cm sized saccular cerebralaneurysm at the proximal right fronto-polar artery. CAG on Day 17 again showed the persistent presenceof the aneurysm. For the purpose of preventing delayed rupture of the aneurysm, radical surgical treatmentwas planned. Microsurgical dissection disclosed that the aneurysm was located just behind the elevatedfracture of the planum sphenoiclale. Severe arachnoid adhesion was noted around the aneurysm. The aneu-rysm was successfully clipped with preservation of the parent artery without inducing new neurological