腰椎後方内視鏡手術にみられる術後硬膜外血腫と術後閉鎖式ドレーンの設置不良との関連について

Association between Postoperative Epidural Hematomas and Improper Placement of Closed Wound Drains after Posterior Microendoscopic Lumbar Surgery

　目的：腰椎後方内視鏡下除圧術（MED法）の術後ドレーン設置位置を調査し，術後硬膜外血腫との関連を検討した．対象と方法：2004年以降の3年間に当科で行ったMED法による腰椎手術症例308例を調査し，ドレーン設置位置を同時期の従来法例170例と比較した．また術後硬膜外血腫による症状悪化とドレーンとの関連を検討した．結果：MED法ではドレーン設置不良例が従来法と比較して有意に多く，硬膜外血腫による症状悪化はドレーン設置不良例に有意に多く認めた．結語：ドレーン設置不良はMED法特有の問題であり，血腫による症状悪化を増加させる危険性がある．

　Objective：To assess the usefulness of closed wound suction drains in microendoscopic posterior lumbar decompressive surgery.　Methods：Between 2004 and 2006, 308 patients underwent microendoscopic lumbar surgery in our institution. Postoperative drain placement was evaluated by comparison with their placement in 170 patients who underwent conventional decompressive surgery during the same period, and the association between symptomatic epidural hematoma and drain placement was evaluated.　Results：Improper drain placement was found in a large number of cases after microendoscopic surgery, and improper drain placement had led to the formation of symptomatic epidural hematomas.　Conclusions：Meticulous and proper drain placement is needed to avoid postoperative neurological deterioration as a result of the formation of epidural hematomas after microendoscopic surgery.