title: Comparative assessment of different percutaneous endoscopic interlaminar lumbar discectomy (PEID) techniques.
abstract: BACKGROUND
  Percutaneous endoscopic lumbar discectomy is a common surgical treatment for lumbar disc herniation, and percutaneous endoscopic interlaminar lumbar discectomy (PEID) is commonly used for direct decompression of L5-S1. Like microdiscectomy, recurrence of herniation after endoscopic discectomy is an important problem. In this study, we aimed to decrease the recurrence after PEID using a new surgical technique.
  
  
  OBJECTIVE
  We propose a new surgical technique for reducing the recurrence after PEID for lumbar disc herniation. The new technique uses annular sealing after fragmentectomy. We compared clinical results and recurrent lumbar disc herniation (had radiculopathy and confirmed by MRI) between patients who underwent surgery with and without annular sealing during PEID.
  
  
  METHODS
  Retrospective cohort study of patients undergoing PEID.
  
  
  METHODS
  A total of 224 patients with radiculopathy due to L5-S1 disc herniation who were treated by PEID with (91 patients) or without annular sealing (133) were included in this study. We compared the demographic characteristics (age, sex, height, weight, BMI, smoking status, and occupation), clinical results, and recurrence rates between the 2 groups. We classified recurrence according to time period (early recurrence ≤ 6 months, late recurrence > 6 months).
  
  
  RESULTS
  The study groups were demographically similar, and substantial improvement in clinical results was noted. There were 5 recurrences (5.5%) (2 early, 3 late recurrences) in the group with annular sealing, and 18 (13.5%) (13 early, 5 late recurrences) in the group without annular sealing. Early recurrence rates were significantly higher in the group without sealing (2 vs. 13, P = 0.029). Increasing age was associated with overall recurrence (P = 0.004) and late recurrence (P = 0.008), while operative technique correlated with early recurrence (P = 0.026).
  
  
  CONCLUSIONS
  First, this study incorporates a retrospective design. Second, the operations were performed by 2 surgeons. Additionally, this is relatively a short-term follow-up study (mean 19.5 ± 5.0 months).
  
  
  CONCLUSIONS
  Though a learning curve is needed in order to become familiar with PEID, recurrence after PEID was associated with advanced age, and PEID with annular sealing resulted in lower early recurrence rates than without annular sealing. Thus, PEID with annular sealing may be a useful technique for reducing early recurrence.
authors.affiliation: Department of Neurosurgery, Hurisarang Spine Hospital, Daejeon, South Korea.
authors.forename: Hyeun Sun
authors.initials: HS
authors.lastname: Kim
authors.forename: Jeong Yoon
authors.initials: JY
authors.lastname: Park
mesh_terms: D000328:Adult; D017587:Diskectomy, Percutaneous / Q000379:methods*; D004724:Endoscopy / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055502:Secondary Prevention; D016896:Treatment Outcome