下位腰椎の脊椎腫瘍に対する腫瘍脊椎骨全摘術―後方－前方合併アプローチ

Total En Bloc Spondylectomy for Vertebral Tumors of the Lower Lumbar Spine. A Combined Posterior-Anterior Approach

　下位腰椎の周囲には腹大動脈，下大静脈，左右総腸骨動静脈などの大血管群や腰仙骨神経叢が存在するため，同部位の脊椎腫瘍を腫瘍学的に切除するのは難しい．下位腰椎に発生した脊椎腫瘍に対して後方→前方合併アプローチによる腫瘍脊椎骨全摘術を施行した10例を検討した．後方→前方の2段階アプローチ，丁寧な神経根，大血管のはく離操作などを行うことで下位腰椎高位の椎体外に伸展した脊椎腫瘍に対しても，安全に腫瘍脊椎骨全摘術を行うことが可能であった．

　Total en bloc spondylectomy at the lower lumbar level is technically challenging because of the anatomy of the iliac wing, major vessels, and nerves of the lumbosacral plexus.　We describe a procedure for total en bloc spondylectomy of the lower lumbar spine by a combined posterior - anterior approach.　Step1：Posterior approach.　The lumbar nerves are dissected from the vertebral body to their conjunction.　The posterior halves of the cranio-caudal adjacent discs of the tumor vertebra are excised.　Step2：Anterior approach.　The segmental vessels on both sides are ligated and sectioned.　The major vessels and the psoas muscles are retracted.　The anterior halves of the discs adjacent to vertebra containing the tumor are excised.　The tumor vertebral body is removed en bloc.　A vertebral spacer is inserted to between the adjacent vertebrae.　Total en bloc spondylectomy for a spinal tumor of L4 and/or 5 with preservation of the lumbar nerves is safely achieved by this combined posterior-anterior approach.