前頭蓋底部悪性腫瘍に対する手術—Combined transbasal ＆ transfacial approach

The operation for malignant tumors in the frontal skull base:combined transbasal & transfacial approach

I．はじめに

　頭蓋底外科手術は近年，脳外科医にとって限られた施設でなされるものではなくなり，前頭蓋底部や海綿静脈洞部などの領域においてさまざまな手術経験が報告されるようになっている^1,5,16）．このうち，前頭蓋底の領域では，種々の良性や悪性腫瘍に対して積極的に手術がなされており，特に良性腫瘍の手術術式はすでに確立されていると考えられる^{3,4,13,15,18,19）}．

　しかしながら，前頭蓋底部の悪性腫瘍においては，良性腫瘍と異なり一塊とした摘出手術が必要であることから脳神経外科にはなじみが薄く，耳鼻科などとのチームによる手術が必要とされている．このため，脳神経外科領域からの手術成績はほとんど報告されておらず^9），手術術式に対しての検討も充分ではないのが現状である．

The authors have previously reported on an exten-sive transbasal approach, through which a supraorbital bar is osteotomized. This operative technique has been applied by the authors not merely to benign but also to malignant tumors in the frontal skull base.

However, in the operation for malignant tumors of the frontal base, it is important to resect en-bloc the tumors and surrounding tissues, such as dura of the skull base and the orbital contents. The authors de-scribe the operative mode of the combined transbasal & transfacial approach and its good results in 19 cases with malignant tumors in the frontal skull base, and 3 types of en-bloc resection in this operative approach (from type A to C) are introduced.

Type A of en-bloc resection in the combined trans-basal & transfacial approach was performed in 11 cases with the tumors invading the ethmoid sinuses. Type B was performed in 4 cases with tumors ex-tending to the orbit. Type C was performed in 4 cases with tumors extending to the orbit and the maxillary sinuses on the affected side.

These operative modes are useful in skull base surgery.