第5腰椎/仙椎高位腰椎椎間板ヘルニア転位例に対する経皮的内視鏡下椎弓間腔テクニック

Surgical Technique of Percutaneous Endoscopic Interlaminar Discectomy for Migrated Lumbar Disc Hernia at the L5/S Level

　背景：Interlaminar法による経皮的内視鏡下腰椎椎間板ヘルニア摘出術(percutaneous endoscopic lumbar discectomy)はL5/S高位に適応するが，転位例には可動性の高いカニューレ操作法の開発が必要とされていた．

　対象と方法：手術症例301例のうち，転位のない196例はinterlaminar法で手術した．下方転位42例と上方転位48例には部分椎弓切除術を追加した．L4/5からL5/Sまでの重度下方転位15例にはtransforaminal法とinterlaminar法を合併した．

　結果：術後成績のMacnab評価は満足90％(優163例，良108例)，不満足10％(可14例，不可16例)であった．転位別満足率は，転位なし94％，下方転位81％，上方転位83％，L4/5重度下方転位87％であった．

　まとめ：L5/S腰椎椎間板ヘルニア転位例には部分椎弓切除が有用である．

　Background：Percutaneous endoscopic discectomy by the interlaminar approach is indicated for lumbar disc herniation at the L5/S level, but a technique that allowed the cannula to move freely had to be developed to treat migrated hernias.

　Materials and Methods：The interlaminar method was used to 301 cases of lumbar disc herniation at the L5/S level.　They consisted of 196 non-migrated hernias, 42 down-migrated and 48 up-migrated hernias, which required supplementary partial laminotomy and bone resection with a high-speed drill or an original chisel, and 15 severely down-migrated hernias from L4/5 to L5/S, which were treated by a combination of both the interlaminar method and transforaminal method.

　Results：The outcome of 90% of the cases was rated satisfactory (“excellent” or “good”) according to Macnab's evaluation criteria.　Satisfactory ratings were recorded in 94% of the non-migrated cases, 81% of the down-migrated cases, 83% of the up-migrated cases and 87% of the severely down-migrated cases.

　Conclusions：The interlaminar method is safe and administered during the one-night stay, which is done under local anesthesia.　Bone resection is beneficial in migrated cases.