脳箆を用いない片側顔面痙攣手術―テープ引っ張り法による血管転移

Transposition Technique of Microvascular Decompression for Hemifacial Spasm without Using a Brain Retractor

Ⅰ．はじめに

　片側顔面痙攣手術は完全治癒，再発ゼロ，合併症ゼロを理想とする．圧迫血管と顔面神経根出口（REZ：root exit zone）の間に詰め物をする方法（interposition technique）がかつては標準手術であった．しかし現在は十分な自由空間を得る転移法（transposition technique）がより理想に近づいた手術法になってきた．われわれはこの血管転移をより完全なものにするために，テープ引っ張り法（snare technique）を考案した¹⁰⁾．この方法は特に椎骨動脈本幹による強い圧迫には有効な方法である．一方手術合併症を極力回避するために，脳箆をまったく用いない手術法に切り替えた．より高い付加価値を求めてその手術手順を述べたい．

　A unique transposition technique in microvascular decompression for hemifacial spasm (HFS) was employed in patients with compression by either the peripheral artery or the main trunk of the vertebral artery. Complete transposition that secured free space between the offending artery and the root exit zone (REZ) was accomplished by introducing GORE-TEX^® tape around the artery and suturing it to the petrous dura. An adequate working space, as if operating in a shallow basin, was essential. Throughout the procedure, it was not necessary to use a brain retractor. Instead, a gentle wrapping retraction technique using a sucker was employed over the brain covered by a sheet of Gelfoam^® (Pfizer Japan Inc., Tokyo) and cotton. All patients showed complete cure of HFS immediately after surgery with this technique. The difficulty of transposing the vertebral artery can be overcome by well-designed surgical strategy and skillfulness.