大後頭孔前半部腫瘍の摘出手術—Lateral Approachの経験

Lateral Approach to the Anterior Foramen Magnum Tumor: Report of two cases

I．はじめに

　大後頭孔部の延髄や脊髄の前方に位置する腫瘍に対してposterior approachが一般に用いられている．この場合，延髄や脊髄が前方の腫瘍に覆い被さり，直視下に摘出することが困難である．このためにanteriorapproachが時として用いられるが後に述べる種々の欠点のため一般的ではない^2）．一方この部位の腫瘍に対して真横から到達するlateral approachに関してはあまり記載がない^6）．われわれは最近この方法を用いて2例の大後頭孔前半部腫瘍を摘出したのでその経験を述べる．

A procedure for lateral approach to the ventral por-tion of the foramen magnum and the upper cervical canal is described. The patient was placed in the lateral position and a curvilinear skin incision was made from the retoroauricular area down to the lateral neck across the sternocleidomastoid muscle, and underlying muscle layers were divided. A suboccipital hemicraniectomy and hemilaminectomies were performed with an air drill. Because the medulla and the cervical cord are dis-placed posteriorly by the tumor, there is no need to re-tract those structures and all the tumors can be re-moved under direct vision.