title: Early outcomes and safety of the minimally invasive, lateral retroperitoneal transpsoas approach for adult degenerative scoliosis.
abstract: OBJECTIVE
  The object of this study was to evaluate an alternative surgical approach to degenerative thoracolumbar deformity in adults. The authors present their early experience with the minimally invasive, lateral retroperitoneal transpsoas approach for placing interbody grafts and providing anterior column support for adult degenerative deformity.
  
  
  METHODS
  The authors retrospectively reviewed a prospectively acquired database of all patients with adult thoracolumbar degenerative deformity treated with the minimally invasive, lateral retroperitoneal transpsoas approach at our institution. All patient data were recorded including demographics, preoperative evaluation, procedure used, postoperative follow-up, operative time, blood loss, length of hospital stay, and complications. The Oswestry Disability Index and visual analog scale (for pain) were also administered pre- and postoperatively as early outcome measures. All patients were scheduled for follow-up postoperatively at weeks 2, 6, 12, and 24, and at 1 year.
  
  
  RESULTS
  The authors identified 25 patients with adult degenerative deformity who were treated using the minimally invasive, lateral retroperitoneal transpsoas approach. All patients underwent discectomy and lateral interbody graft placement for anterior column support and interbody fusion. The mean total blood loss was 53 ml per level. The average length of stay in the hospital was 6.2 days. Mean follow-up was 11 months (range 3-20 months). A mean improvement of 5.7 points on visual analog scale scores and 23.7% on the Oswestry Disability Index was observed. Perioperative complications include 1 patient with rhabdomyolysis requiring temporary hemodialysis, 1 patient with subsidence, and 1 patient with hardware failure. Three patients (12%) experienced transient postoperative anterior thigh numbness, ipsilateral to the side of approach. In this series, 20 patients (80%) were identified who had more than 6 months of follow-up and radiographic evidence of fusion. The minimally invasive, lateral retroperitoneal transpsoas approach, without the use of osteotomies, did not correct the sagittal balance in approximately one-third of the patients.
  
  
  CONCLUSIONS
  Degenerative scoliosis of the adult spine is secondary to asymmetrical degeneration of the discs. Surgical decompression and correction of the deformity can be performed from an anterior, posterior, or combined approach. These procedures are often associated with long operative times and a high incidence of complications. The authors' experience with the minimally invasive, lateral retroperitoneal transpsoas approach for placement of a large interbody graft for anterior column support, restoration of disc height, arthrodesis, and realignment is a feasible alternative to these procedures.
authors.affiliation: Department of Neurological Surgery, University of South Florida, Tampa, Florida, USA. edakwar@health.usf.edu
authors.forename: Elias
authors.initials: E
authors.lastname: Dakwar
authors.forename: Rafael F
authors.initials: RF
authors.lastname: Cardona
authors.forename: Donald A
authors.initials: DA
authors.lastname: Smith
authors.forename: Juan S
authors.initials: JS
authors.lastname: Uribe
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001174:Arthrodesis / Q000379:methods; D016025:Bone Transplantation / Q000379:methods; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D019637:Orthopedic Procedures / Q000379:methods*; D016658:Psoas Muscles; D011859:Radiography; D012187:Retroperitoneal Space; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods; D013904:Thoracic Vertebrae / Q000601:surgery; D016896:Treatment Outcome