title: Transtubular microsurgical approach to treating extraforaminal lumbar disc herniations.
abstract: OBJECTIVE
  Approaches to treating extraforaminal lumbar disc herniations can be challenging due to the unique anatomy and the need to prevent spinal instability. Numerous approaches, including conventional midline, paramedian, minimally invasive, and full endoscopic approaches, have been described. The purposes of this study were to point out the outcome and clinical advantages of a transtubular microsurgical approach and to describe and illustrate this technique.
  
  
  METHODS
  Between 2009 and 2012, a series of 51 patients underwent a minimally invasive dilative transtubular microsurgical approach for the treatment of extraforaminal lumbar disc herniations. All patients were clinically evaluated using the visual analog scale (VAS) and Oswestry Disability Index preoperatively and 6 months postoperatively.
  
  
  RESULTS
  Both pain scores and functional status showed significant improvement after surgery (p < 0.001): radicular pain decreased from VAS score of 7.9 to one of 1.3, lower back pain from VAS score of 2.4 to 1.4, and the Oswestry Disability Index from 42.0 to 12.3. Subgroup analyses revealed no differences in outcome regarding obesity or timing of surgery (early vs late intervention). Highly significant was the correlation between preoperative radicular pain activity and timing of surgical intervention (p < 0.001).
  
  
  CONCLUSIONS
  The dilative transtubular microsurgical approach combines the advantages of the conventional open muscle-splitting approach and the endoscopic approach. The technique is easy to use with a steep learning curve. Less muscle trauma and the absence of bony resection prevent facet pain and instability, thereby contributing to a rapid recovery. Patients in this series improved excellently in the short-term follow-up.
authors.affiliation: Department of Neurosurgery, Heinrich-Heine-University, Düsseldorf, Germany. eicker.s@mac.com
authors.forename: Sven O
authors.initials: SO
authors.lastname: Eicker
authors.forename: Sascha
authors.initials: S
authors.lastname: Rhee
authors.forename: Hans-Jakob
authors.initials: HJ
authors.lastname: Steiger
authors.forename: Jörg
authors.initials: J
authors.lastname: Herdmann
authors.forename: Frank W
authors.initials: FW
authors.lastname: Floeth
mesh_terms: D000328:Adult; D000368:Aged; D017587:Diskectomy, Percutaneous / Q000379:methods*; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D059032:Learning Curve; D008279:Magnetic Resonance Imaging; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D010147:Pain Measurement; D012189:Retrospective Studies; D016896:Treatment Outcome