title: Transforaminal percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation: clinical outcome, prognostic factors, and technical consideration.
abstract: BACKGROUND
  Compared with lower lumbar disc herniations, upper lumbar disc herniations at L1-L2 and L2-L3 have specific characteristics that result in different surgical outcomes after conventional open discectomy. There are no published studies on the feasibility of percutaneous endoscopic lumbar discectomy for upper lumbar disc herniation. The purpose of this study was to assess the clinical outcome, prognostic factors and the technical pitfalls of PELD for upper lumbar disc herniation.
  
  
  METHODS
  Forty-five patients with a soft disc herniation at L1-L2 or L2-L3 underwent percutaneous endoscopic discectomy. Posterolateral transforaminal endoscopic laser-assisted disc removal was performed under local anesthesia. Clinical outcomes was assessed using the Prolo scale. The prognostic factors associated with outcome were then analyzed.
  
  
  RESULTS
  The mean follow-up was 38.8 months (range, 25-52 months). The outcome of the 45 patients was excellent in 21 (46.7%), good in 14 patients (31.1%), fair in six patients (13.3%), and poor in four patients (8.9%). Four patients with a poor outcome underwent further open surgery. Mean scores on a visual analog scale decreased from 8.38 to 2.36 (P < 0.0001). Age less than 45 years and a lateral disc herniation were independently associated with an excellent outcome (P < 0.05).
  
  
  CONCLUSIONS
  Patient selection and an anatomically modified surgical technique promote a more successful outcome after percutaneous endoscopic discectomy for upper lumbar disc herniation.
authors.affiliation: Department of Neurosurgery, Wooridul Spine Hospital, Daegu, 700-732, South Korea. ns-ay@hanmail.net
authors.forename: Yong
authors.initials: Y
authors.lastname: Ahn
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: June Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin Uk
authors.initials: JU
authors.lastname: Kim
authors.forename: Wei Chiang
authors.initials: WC
authors.lastname: Liu
mesh_terms: D000328:Adult; D000367:Age Factors; D017587:Diskectomy, Percutaneous / Q000295:instrumentation / Q000379:methods*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D017116:Low Back Pain / Q000209:etiology / Q000601:surgery; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D018579:Patient Selection; D011859:Radiography; D016896:Treatment Outcome