title: A radiographic assessment of the ability of the extreme lateral interbody fusion procedure to indirectly decompress the neural elements.
abstract: METHODS
  Prospective nonrandomized clinical study on the decompressive effect of the extreme lateral interbody fusion (XLIF) procedure.
  
  
  OBJECTIVE
  This study evaluates the results of interbody distraction from a lateral retroperitoneal approach for the treatment of lumbar degenerative conditions inclusive of central and/or lateral stenosis.
  
  
  BACKGROUND
  Traditional treatment for symptomatic lumbar stenosis has been by direct posterior decompression (i.e., removal of ligamentum flavum, laminotomy/laminectomy, facetectomy, as needed). Stenotic symptoms may also be alleviated indirectly, through correction of intervertebral and foraminal height and correction of spinal alignment. Anterior-only spinal procedures rely on this indirect decompression when used in patients with radicular symptoms.
  
  
  METHODS
  Consecutive patients presenting with degenerative conditions that included concomitant lumbar stenosis were consented and treated via stand-alone XLIF. Pre- and postoperative radiographic measurements were made from plain lateral radiographs and sagittal and axial magnetic resonance imaging views by an independent radiologist using medical imaging software. Measurements included disc height, foraminal height, foraminal area, and canal diameter.
  
  
  RESULTS
  In all, 7 male and 14 female patients (mean age, 67.6 years; range, 40-83) underwent XLIF at 43 lumbar levels in an average operative time of 47 minutes and with an average 23 mL estimated blood loss per level. There were no intraoperative complications. Mean hospital stay was 29.5 hours. Transient postoperative psoas weakness occurred in 3 (14.3%) of the cases. Substantial dimensional improvement was evidenced in all radiographic parameters, with increases of 41.9% in average disc height, 13.5% in foraminal height, 24.7% in foraminal area, and 33.1% in central canal diameter. Two patients (9.5%) required a second procedure for additional posterior decompression and/or instrumentation.
  
  
  CONCLUSIONS
  The XLIF procedure provides the necessary decompression for the treatment of central and/orlateral stenosis in a minimally disruptive way, avoiding, in most cases, the need for the direct resection of posterior elements and associated morbidities. Indirect decompression may be limited in cases of congenital stenosis and/or locked facets. Its effect may also be reduced by postoperative subsidence and/or loss of correction.
authors.affiliation: Instituto de Patologia de Coluna, São Paulo, Brazil. leonardo@luizpimenta.com.br
authors.forename: Leonardo
authors.initials: L
authors.lastname: Oliveira
authors.forename: Luis
authors.initials: L
authors.lastname: Marchi
authors.forename: Etevaldo
authors.initials: E
authors.lastname: Coutinho
authors.forename: Luiz
authors.initials: L
authors.lastname: Pimenta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome