腰椎椎間孔狭窄症の診断と顕微鏡的除圧術

Lumbar Foraminal Stenosis: Diagnosis and Microsurgical Decompression

Point

・腰椎椎間孔狭窄症に対する現状の診断と外科治療は不十分であり，有効な診断技術と手術手技の開発が急務である．

・1 mm sliceの連続切片とmultiplanar reconstructionを用いたthin-slice MRIで，すべての神経根を3方向から観察することが診断に有効である．

・後外側方向からの椎間孔の顕微鏡的除圧術は，技術的にchallengingだが，いくつかのポイントを押さえることで成功に導くことができる．

・本疾患を正確に診断し，安易な固定に頼らず，症状を改善する技術に多くの脳神経外科医が習熟すれば，大きな社会的貢献となるであろう．

＊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：2028年2月まで）。

　Lumbar foraminal stenosis is a common problem; however, correct diagnosis and appropriate surgical treatment are difficult. This article describes the author's techniques for imaging diagnosis using thin-slice magnetic resonance imaging（MRI）and the microsurgical technique of foraminal decompression through the intermuscular approach.

　Thin-slice MRI consists of 1-mm thickness continuous images of the lumbar spine using a T2-weighted-image-based sequence. With multiplanar reconstruction in three planes, all nerve roots are carefully observed from the lateral recess to the extraforaminal area. This technique provides the correct diagnosis of subtle nerve root compression in the foramen.

　The outlet of the intervertebral foramen is exposed using Wiltse's intermuscular approach. To avoid disorientation, several surgical landmarks and two basic routes to reach the outlet of the foramen are established.

　The foramen is carefully unroofed by using an ultrasonic bone curette. For complete decompression of the nerve root and ganglion, the inferomedial aspect of the pedicle and its medial and lateral limits should be determined. In addition, the yellow ligament must be completely removed, and the intertransverse ligament lateral to the nerve root should be sufficiently decompressed.