コイル塞栓術後に親水コーティングに関連する脳実質変化を認め，軽快と増悪を繰り返した1例

A Case of Multiple Brain Lesions Associated with Hydrophilic Polymer Allergy after Coil Embolization that Showed Repeated Progression and Regression

Ⅰ．はじめに

　脳動脈瘤コイル塞栓術の合併症として，血栓塞栓による脳梗塞や術中破裂などが挙げられるが，カテーテルやコイルとの関連が疑われる亜急性期以降の合併症の報告も散見される．

　今回われわれは，破裂動脈瘤に対するコイル塞栓術後に軽快と増悪を繰り返した脳実質内病変の1例を経験した．これまでの報告例を含め，文献的考察を加えて報告する．

　A 41-year-old woman underwent coil embolization for subarachnoid hemorrhage associated with a ruptured anterior cerebral artery（A1）aneurysm. Approximately 3 weeks later, MRI revealed right cerebral white matter changes with extensive edema and enhancement lesions. Even though she was asymptomatic, we suspected an allergic reaction to the hydrophilic coating polymer and initiated steroid treatment. After tapering and discontinuing the steroid treatment, follow-up MRI revealed development of white matter lesions;thus, steroid treatment was reinitiated. Progression and regression of the lesions occurred repeatedly, and she was radiologically stable at almost 1 year after coiling.

　We speculated that these white matter lesions were foreign body granulomas that reacted to the hydrophilic coating of the endovascular device.

　Overall, an allergic reaction to hydrophilic coating polymer could occur as a delayed complication after coil embolization and that progression and regression of the lesions could repeatedly occur in rare cases.