術中早期に脳腫脹を来たした頭蓋内巨大Hemangiopericytomaの2例

Two Cases of an Intracranial Large Hemangiopericytoma Associated with Brain Swelling in the Early Operative Stage

I．はじめに

　頭蓋内hemangiopericytomaは非常に血管に富んだ腫瘍として知られており，出血が多量で摘出を中止した例や術中に死亡した例が報告されている^4,5）．今回われわれが経験した2例は，出血ではなく術中早期の脳腫脹が原因で手術を中断した例である．しかし，その後の脳腫脹に対するbar-biturate療法と，再手術に際しての術前放射線療法により，両症例ともに良好な結果が得られたので，これらの症例に認められた脳腫脹の機序と，hemangiopericytomaに対する術前放射線療法の有効性について報告する．

Intracranial hemangiopericytomas are hypervascular tumors. Consequently, resection of these tumorsmust occasionally be stopped owing to profuse bleeding. We report two cases of large intracranial heman-giopericytoma whose resection had to be stopped owing not to bleeding but to brain swelling. These pa-tients were treated with large doses of barbiturate until the intracranial pressure had normalized. Afterpreoperative irradiation therapy, the residual tumors were easily removed without serious complications.

We speculate that the brain tissue around a large hemangiopericytoma might be under ischemia becauseof long-standing compression and deviation of blood to the hypervascular tumor. A large amount of bloodflowing into these brain tissues clue to external and internal decompression inverts cerebral perfusionacutely from ischemia to hyperemia. The brain swelling in the early operative stage would be evoked bythis “inverted cerebral hyperemia”.

We found that brain swelling is sometimes encountered during the resection of a large hemangiopericy-toma even in the early operative stage. If swelling occurs, tumor resection should be stopped immediatelyand intracranial pressure should be controlled. The residual tumor can then be easily removed withoutcomplications after preoperative irradiation therapy.