title: Clinical outcomes after microendoscopic discectomy for recurrent lumbar disc herniation.
abstract: METHODS
  Retrospective review of consecutive case series.
  
  
  OBJECTIVE
  To assess the safety and efficacy of the microendoscopic approach for treatment of recurrent lumbar disc herniation.
  
  
  BACKGROUND
  The standard surgical approach for the treatment of recurrent disc herniation uses an open technique with a wide exposure. Many would consider a minimally invasive approach such as microendoscopic discectomy (MED) to be contraindicated in the setting of recurrent disc herniation.
  
  
  METHODS
  Sixteen consecutive patients with recurrent lumbar disc herniation who failed conservative management underwent MED. Before surgery and at follow-up, patients completed the Oswestry Disability Index, SF-36, and assessment of leg pain using the Visual Analog Scale. Outcome was also assessed using modified McNab criteria.
  
  
  RESULTS
  No case required conversion to an open procedure. Mean operative time was 108 minutes, and mean estimated blood loss was 32 mL. The only surgical complications were 2 durotomies that were treated with dural sealant without sequelae. Mean hospital stay was 23 hours, and mean follow-up was 14.7 months. Approximately 80% of patients had good or excellent outcomes based on modified McNab criteria. The remaining 3 patients had fair outcomes, and no patient had a poor outcome. All standardized measures improved significantly, including mean Visual Analog Scale for leg pain (8.2 to 2.2, P<0.001), mean Oswestry Disability Index (59.3 to 26.7, P<0.001), SF-36 Physical Component Summary score (28.3 to 42.4, P<0.001), and SF-36 Mental Component Summary score (38.2 to 48.3, P<0.001). As of last follow-up no patient has showed recurrence of herniation or evidence of delayed instability.
  
  
  CONCLUSIONS
  MED is a safe and effective surgical approach for the treatment of recurrent lumbar disc herniation. Standardized measures of outcome show that MED for recurrent herniation produces improvement in pain, disability, and functional health that is at least comparable with outcomes reported for conventional open microdiscectomy.
authors.affiliation: Department of Neurological Surgery, University of Virginia, Charlottesville, VA 22908, USA. jss7f@virginia.edu
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.forename: Alfred T
authors.initials: AT
authors.lastname: Ogden
authors.forename: Stephen
authors.initials: S
authors.lastname: Shafizadeh
authors.forename: Richard G
authors.initials: RG
authors.lastname: Fessler
mesh_terms: D000328:Adult; D000368:Aged; D004185:Disability Evaluation; 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*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods; D017063:Outcome Assessment, Health Care; D010147:Pain Measurement; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D011859:Radiography; D012008:Recurrence; D012086:Reoperation; D012189:Retrospective Studies; D016896:Treatment Outcome