術野外硬膜外血腫—天幕上開頭術にて反対側に硬膜外血腫を来たした5症例

Postoperative Epidural Hematoma:Five cases of epidural hematomas developed after supratentorial craniotmy on the contralateral side

I．はじめに

　脳室腹腔シャント術，脳室ドレナージあるいは後頭下開頭術後急激な脳圧の低下を来たし，その手術部位と異なる部位に硬膜外血腫を発生することが文献上に散見される^{1-9,13,16,18-20,22-25）}．これに対して，天幕上開頭術において手術野と直接関係のない反対側に硬膜外血腫が生じることは非常に稀と考えられる^14,15,17）．われわれは過去15年間に，このような症例を5例経験したので，ここに報告する．

Postoperative epidural hematomas developed far from the operative field are generally recognized as a complication of ventriculo-peritoneal shunt, ventricular drainage or suboccipital craniotomy. It is very rare but may occur after supratentorialcraniotomy on the contralateral side. Five such cases are presented with a review of the relevant literature.

The mechanism of this complication is not clearly understood. In hydrocephalus, these massive epidural hematomas are probably caused by dura-skull detachment when the brain volume is strikingly reduced by a decompressive procedure.