特発性浅側頭動脈解離性動脈瘤の1治験例

Spontaneous Dissecting Aneurysm of the Superficial Temporal Artery:A case report

I．緒言

　浅側頭動脈に発生する動脈瘤は比較的稀であり，多くは外傷によるものである．本稿では，外傷の既往なく側頭部拍動性頭痛にて発症し，血管写にて解離性であることを確認し得た特発性浅側頭動脈解離性動脈瘤の1例を報告する．

Aneurysms of the superficial temporal artery are rare, and usually traumatic in origin. We present a very rare case of spontaneous dissecting aneurysm of the su-perficial temporal artery in a 46-year-old man. The pa-tient had pulsatile headache in the right temporal re-gion, and a pulsatile mass in the same region.

His headache gradually worsened for which he came to our hospital. On examination, there was a pulsatile mass of 1.5cm×3cm at the right temporal region, which disappeared when the main trunk of superficial temporal artery was compressed. There was no neuro-logical abnormality. On computed tomographic ex-amination, there was a spotty high density area in the right extracranial region corresponding to the right su-perficial temporal artery, which was strongly enhanced after contrast medium administration. On MRI ex-amination, the same area showed high intensity, but at inner space there was signal loss on T₁WI, T₂WI and PDWI. Angiography showed an aneurysmal dilatation at the right superficial temporal artery and both the true lumen and the false lumen were recognized. Exci-sion of the aneurysm under local anesthesia was per-formed. His complaints disappeared completely post-operatively, and the skin color of that region retained its normal texture.

Histopathological examination of the specimen showed hypertrophic intima with fibroblasts, and ab-sence of internal elastic lamina. There was hematoma outside of the intima, but no deposits of hemosiderin. On account of the above findings, the lesion was dia-gnosed as a spontaneous dissecting aneurysm of the superficial temporal artery.