title: Percutaneous endoscopic lumbar herniectomy for high-grade down-migrated L4-L5 disc through an L5-S1 interlaminar approach: a technical note.
abstract: BACKGROUND
  L4-L5 disc herniations can be treated with percutaneous endoscopic lumbar discectomy (PELD) using a transforaminal posterolateral approach. Although PELD has some distinct advantages over conventional open discectomy, inadequate decompression is a major cause of failure of the procedure, especially with high-grade migrations. The objective of this technical note is to present a new surgical approach for treating high-grade, down-migrated, L4-L5 disc herniations through an L5-S1 interlaminar endoscopic approach.
  
  
  METHODS
  This technical report presents 4 consecutive patients with high-grade, down-migrated, L4-L5 disc herniations, who were treated with PELD through an L5-S1 interlaminar approach under local anesthesia and conscious sedation. All patients were evaluated clinically using both the visual analogue scale (VAS) for back and leg pain and the Oswestry disability index (ODI) and radiologically using MR imaging postoperatively.
  
  
  RESULTS
  All 4 patients experienced improvement in their preoperative symptoms and signs immediately postoperatively. The mean VAS scores for back and leg pain improved from 3.75 to 1.75 and from 8.5 to 0.75, respectively. The mean ODI score improved from 65% to 3%. Postoperative MR imaging also depicted L5 root decompression. There were no complications during the procedure.
  
  
  CONCLUSIONS
  This technical note presents a new technique for treating high-grade, down-migrated, L4-L5 disc herniations with PELD using an L5-S1 interlaminar approach.
authors.affiliation: Department of Neurosurgery, Wooridul Spine Hospital, Seoul, South Korea.
authors.forename: G
authors.initials: G
authors.lastname: Choi
authors.forename: N
authors.initials: N
authors.lastname: Prada
authors.forename: H N
authors.initials: HN
authors.lastname: Modi
authors.forename: N B
authors.initials: NB
authors.lastname: Vasavada
authors.forename: J-S
authors.initials: JS
authors.lastname: Kim
authors.forename: S-H
authors.initials: SH
authors.lastname: Lee
mesh_terms: D017587:Diskectomy, Percutaneous / Q000295:instrumentation / Q000379:methods*; D004724:Endoscopy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011859:Radiography