後方経路腰椎椎体間固定術後椎体間感染の診断とサルベージ手術についての検討

Assessment of the Diagnosis of Intervertebral Infection after Posterior Lumbar Interbody Fusion and Treatment by Salvage Surgery

　対象と方法：当科で経験した後方経路腰椎椎体間固定術後の椎体間感染15例を調査した．

　結果：血液データ上の白血球数，C反応性蛋白と体温の再上昇が認められた時点で感染発症の疑いが強まるが，椎体間感染は術後1カ月以内のMRIT1矢状断像での椎体低信号域により早期診断が可能である．

　まとめ：椎体間感染が判明した場合は，可及的早期の後方からのケージ抜去，再固定がサルベージ手術として推奨される．椎体間感染の診断が遅れた場合には，大血管周囲の瘢痕癒着形成による血管損傷のリスクが高まるので，側方アプローチによる腰椎椎体間固定術を選択する方法が望ましい．

　Method：This was a retrospective study of 15 cases of intervertebral infection as a postoperative complication of posterior lumbar intervertebral fusion.

　Outcome：Intervertebral infection was suspected when unexpected increases in WBC count, serum CRP level, and body temperature were observed in the postoperative period.

　Conclusion：An early definitive diagnosis was made when low signal intensity changes were seen in the vertebral body and endplate on T1 sagittal MRI scans.　Early cage removal and fixation with an autograft by the posterior approach is recommended as salvage surgery in cases of early intervertebral infection.　Lumbar intervertebral fusion via the lateral approach is recommended in cases of late intervertebral infection, because the risk of vascular injury is increased by adhesion of the tissues around the blood vessels.