下顎離断経口腔到達法を施行した頭蓋底陥入症の1例

A case of basilar impression treated with mandible splitting transoral approach

I．はじめに

　頭蓋頸椎移行部病変に対する治療は，手術アプローチ・手術術式についていまだ議論の多いところである^{1,2,4,6-9,12,14,16）}．

　今回われわれは，開口制限のため通常の経口腔的なアプローチによる手術では十分な効果が得られなかったために，下顎離断術を追加することによって良好な結果を得た頭蓋底陥入症例を経験したので報告する．

We report a case of basilar impression treated with mandible splitting transoral approach surgery.

A 39-year-old man presented a ten-year history of gait disturbance. He had experienced acceleration of his spastic paraparesis for the past few years. Neurological examination on admission demonstrated tetraparesis (MMT4/5), severe hyperreflexia in his arms and legs, severe sensory loss below C2, urinary retention and in-ability to open his mouth widely. Radiological findings showed the dens and the body of C2 are deeply in-vaginated to the atlas and the foramen magnum and medulla and upper cervical cord were markedly com-pressed by this basilar invagination.

After carrying out posterior decompression and occi-pito-cervical fixation, we attempted to remove the inva-ginated dens and the C2 vertebral body using a conven-tional transoral approach. But limitation of mouth open-ing made operative fields narrow. Consequently be-cause of insufficient anterior decompression his neu-rological deficits could not be alleviated.

Employment of mandible splitting procedure brought about a wide operative view so that complete removal of the residual dens and 70% drilling out of the C2 body was made possible. Postoperative complications were negligible. Finally, great alleviation of his deficits was achieved.

Mandible splitting procedure is effective for obtain-ing a wide operative field on the anterior approach to the craniocervical junction.