title: Unsuccessful percutaneous endoscopic lumbar discectomy: a single-center experience of 10,228 cases.
abstract: BACKGROUND
  Percutaneous endoscopic lumbar discectomy (PELD) has remarkably evolved with successful results. Although PELD has gained popularity for the treatment of herniated disc (HD), the risk of surgical failure may be a major obstacle to performing PELD. We analyzed unsuccessful cases requiring reoperation.
  
  
  OBJECTIVE
  To find common causes of surgical failure and elucidate the limitations of the conventional PELD technique.
  
  
  METHODS
  A retrospective review was performed on all patients who had undergone PELD between January 2001 and December 2012. Unsuccessful PELD was defined as a case requiring reoperation within 6 weeks after primary surgery. Chart review was done, and preoperative, intraoperative, and postoperative radiographic reviews were performed. All unsuccessful PELD cases were classified according to the type of HD, location of herniation, extruded disc migration, working channel position, and intraoperative and postoperative findings.
  
  
  RESULTS
  In 12 years, 10,228 patients had undergone PELD; 436 (4.3%) cases were unsuccessful. The causes were incomplete removal of HDs in 283 patients (2.8%), recurrence in 78 (0.8%), persistent pain even after complete HD removal in 41 (0.4%), and approach-related pain in 21 (0.2%). Incomplete removal of the HD was caused by inappropriate positioning (95 cases; 33.6%) of the working channel and occurred in central HDs (91 cases; 32.2%), migrated HDs (70 cases; 24.7%), and axillary type HDs (63 cases; 22.3%).
  
  
  CONCLUSIONS
  Proper surgical indications and good working channel position are important for successful PELD. PELD techniques should be specifically designed to remove the disc fragments in various types of HD.
authors.affiliation: *Department of Neurosurgery, The Leon Wiltse Memorial Hospital, Anyang, Korea; ‡Department of Neurosurgery, Wooridul Spine Hospital, Seoul, Korea; §Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University, Seoul, Korea; ¶Department of Orthopeadics, Wooridul Spine Hospital, Seoul, Korea; ‖Department of Clinical Research, Wooridul Spine Hospital, Seoul, Korea.
authors.forename: Kyung-Chul
authors.initials: KC
authors.lastname: Choi
authors.forename: June-Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Jin-Sung
authors.initials: JS
authors.lastname: Kim
authors.forename: Luigi Andrew
authors.initials: LA
authors.lastname: Sabal
authors.forename: Sol
authors.initials: S
authors.lastname: Lee
authors.forename: Ho
authors.initials: H
authors.lastname: Kim
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000328:Adult; D017587:Diskectomy, Percutaneous / Q000379:methods*; D004724:Endoscopy; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000473:pathology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000601:surgery; D011184:Postoperative Period; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome