腰椎手術におけるドレーン留置の効果―術翌日MRIの比較

Does Closed Wound Drainage Really Prevent Epidural Hematoma after Lumbar Surgery? Investigation Upon Postoperative Magnetic Resonance Images

　一定期間に施行した腰椎手術(Love法と開窓術)に対して閉鎖式ドレーンを留置するかどうかを術者別に予め決めておき2群に分けた．非留置群(n＝13)と留置群(n＝18)の間で年齢，性比，止血機能に差はなく，両群とも術後経過は良好であった．全例に施行した術翌日MRIで無症候性血腫を認めたのは非留置群の54％で，留置群の17％より多かった．ただしこの差は開窓術における差であり，Love法では両群とも無症候性血腫を認めず，Love法に限ってはドレーンを非留置としても問題はないと思われた．

　In order to determine whether subfascial suction drains prevent epidural hematomas, 31 patients who underwent open lumbar discectomy or one-level decompression laminectomy were prospectively randomized with respect to each surgeon.　The drain group (n＝18) and the no-drain group (n＝13) were comparable in regard to age, sex ratio, and preoperative coagulation indices.　All patients underwent MRI the day after surgery and were evaluated for the presence of an epidural hematoma on axial T2-weighted images.　All patients in both groups showed significant neurological improvement following surgery and there were no events suggestive of an epidural hematoma, such as intolerable pain or muscle weakness in the lower extremities.　Although evidence of an asymptomatic epidural hematoma on the MRI scans was observed in a higher proportion of the patients in the drain group than in the no-drain group (54% vs. 17%), none of the patients who underwent open discectomy in either group were found to have evidence of a hematoma on their MRI scans.　The results of the study suggested that suction drains are not required after open lumbar discectomy.