腰部脊柱管狭窄症再手術症例の再手術原因と治療成績に関連する因子の検討

Reasons for Revision after Surgery for Lumbar Spinal Canal Stenosis and Factors Related to the Outcome

　腰部脊柱管狭窄症再手術症例114例の再手術原因と治療成績に関連する因子を検討した．初回もしくは前回術後の改善期間によって，早期再発(0～6カ月)，中期(6カ月～2年)，晩期(2年以降)の3群に分類した．症例は椎間孔部・孔外狭窄を原因とするものが全体の24.6％で最も多く，早期群の37.0％を占めていた．次いで再狭窄が多く，全体の20.2％で晩期群の主たる原因であった．再手術原因が椎間板ヘルニアによるものは他の原因と比較して治療成績が良好であったが，検討した他の因子と成績との間に関連はなかった．

　In this study the 114 cases in which revision surgery was performed in our institution for lumbar spinal canal stenosis between January 1998 and December 2007 were reviewed to identify the reasons for reoperation and factors associated with the outcome.　Foraminal stenosis and extraforaminal stenosis were the most common reasons for reoperation, and accounted for 24.6% of the cases.　It is important to make the differential diagnosis between intracanal lesion, foraminal stenosis and extraforaminal stenosis before primary surgery in order to prevent the need for revision.　Restenosis was the major reason for revision more than two years after the primary surgery.　Patients with disc herniation had a better outcome than patients in whom revision surgery was performed for other reasons.　None of the other factors examined were related to the clinical outcome.