Japanese
English
- 有料閲覧
- Abstract 文献概要
- 1ページ目 Look Inside
- 参考文献 Reference
Ⅰ.はじめに
三叉神経痛(TN)や片側顔面痙攣(HFS)を代表とする神経血管圧迫症候群neurovascular compression syndrome (NVCS)は,脳神経のroot entry(またはexit)zone(REZ)を脳血管が直接圧迫することで生じる異常性興奮により,持続的な神経症状を呈する病態であり,微小血管減圧術microvascular decompression(MVD)はその根治的な治療法として知られる8-10).NVCSの正確な診断とMVDの確実な遂行には,患者個々における小脳橋角部の微小解剖をできる限り詳細に検討することが重要であり,この点でMR画像診断の果たしてきた役割は大きく,heavy T2強調画像やMR angiography(MRA)といった撮像条件の工夫による脳幹周囲の神経・血管構造の評価法の有用性が多数報告されてきた1-4,11,17,19,20).しかし,実際に2次元画像から脳幹周囲の3次元的な微小解剖を把握することは,慣れた脳神経外科医にとっても難しい場合が多く,コンピュータの高性能化に伴い発展してきた3次元画像処理技術に寄せられる期待は大きい.われわれは本研究で,thin-sliceで撮像した脳幹周囲のheavy T2強調画像やMRAをvolume renderingすることで作成される仮想神経内視鏡virtual endoscopy(VE)を用い,NVCSに対するMVD術前における3次元手術シミュレーションの有用性を検討した.
Objective: We conducted the present study to assess the utility of virtual endoscopy (VE) created by volume rendering of MR images in presurgical simulation for trigeminal neuralgia (TN) and hemifacial spasm (HFS).
Methods: In 12 patients (six with TN and six with HFS), we presurgically evaluated the anatomy of the cerebellopontine angle (CPA) region and simulated an appropriate surgical approach by VE of heavy T2-weighted imaging and MR angiography.
Results: The three-dimensional (3-D) relations of neurovascular structures in the CPA region were compatible between on-VE and on-the-intraoperative view in all patients. The compression sites and the major offending vessels were correctly depicted, except for two small branches as the offending vessel. The other important structures affecting the surgical procedure were identified as major petrosal veins in all patients with TN, a vertebral artery in three with HFS, and a large cerebellar flocculus in three with HFS. Transposition of the offending vessels was performed as simulated in all patients with TN and in three patients with HFS. All patients had an excellent surgical outcome.
Conclusions: Presurgical simulation by VE in patients with TN and HFS is a novel method that provides excellent visualization of the 3-D relations of neurovascular structures in the CPA region and allows us to accomplish successful and safe surgery.
Copyright © 2007, Igaku-Shoin Ltd. All rights reserved.