脳機能温存を目指した深部腫瘍に対するアプローチ選択—視床後半部病変の2例

Selection of Appropriate Approaches to Preserve Brain Function for Deep Seated Brain Tumors:Our Experience of Two Posterior Thalamic Cases

Point

・深部腫瘍に対して脳機能を極力温存して適切な腫瘍摘出を行うためには，発生母地に対してなるべく手術早期に直接到達できるアプローチを選択することが重要である．

・そのために，主要な基盤的白質線維束群を含めた脳解剖の3次元的な術前検討が有用である．

・視床後半部・低位病変が外側に進展する場合には，対角線に対側から進入する2つのアプローチ，テント上からのoccipital transtentorial/falcine approach，テント下からのinfratentorial supracerebellar transtentorial approachが有用である．

＊本論文中、［Video］マークのある図につきましては、関連する動画を見ることができます（公開期間：2027年4月まで）。

　What is the most important factor to achieve successful surgery for deep-seated brain tumors with preservation of brain functions? Definitely, it is to identify the tumor origin site at which a tumor arose and select appropriate surgical approaches that immediately lead directly to the site in the early stage of surgery, minimizing damages of cortices and important white matter bundles, and controlling main arterial supply to the tumor. For this, neurosurgeons must have thorough knowledge of brain anatomy and function, and tailor the best surgical approach for each patient, based on three-dimensional anatomical simulation. For lesions situated in the posterior and lower part of the thalamus and extending to the lateral part, two “cross-court” approaches; the occipital transtentorial/falcine and infratentorial supracerebellar transtentorial approaches, provide a wide corridor to even the lateral aspect of the thalamus and early access to the posterior choroidal arteries, usually main feeders of this territory tumors, without damaging any cerebral cortices and major white matter bundles. Here, we describe the selection of approaches for two representative cases and demonstrate surgical procedures and postoperative courses.