title: Minimally invasive extracavitary approach for thoracic discectomy and interbody fusion: 1-year clinical and radiographic outcomes in 13 patients compared with a cohort of traditional anterior transthoracic approaches.
abstract: OBJECTIVE
  Open transthoracic approaches, considered the standard in treating thoracic disc herniation (TDH), are associated with significant comorbidities. The authors describe a minimally invasive lateral extracavitary tubular approach for discectomy and fusion (MIECTDF) to treat TDH.
  
  
  METHODS
  In 13 patients (5 men, 8 women; mean age 51.8 years) with myelopathy and 15 noncalcified TDHs, the authors achieved a far-lateral trajectory by dilating percutaneously to a 20-mm working portal docked at the transverse process-facet junction, which then provided a corridor for a near-total discectomy, bilateral laminotomies, and interbody arthrodesis requiring minimal cord retraction. A cohort of 11 demographically comparable patients treated via transthoracic approaches was used as control.
  
  
  RESULTS
  Preoperative Frankel grades were B in 1 patient, C in 4, D in 5, and E in 3, whereas at mean of 10 months, 11 had Grade E function and 2 had Grade D function. Mean surgical metrics were operating room time 93.75 minutes, blood loss 33 ml, and hospital stay 3.1 days. Complications included 4 transient paresthesias, 1 CSF leak, 1 abdominal wall weakness, and 3 nonwound infections. One-year follow-up MR imaging revealed full decompression in all cases and no cage migration. Mean visual analog scales scores preoperative, at 6 weeks, 3 months, and 1 year were 5.6, 4.5, 3.2, and 1.2, respectively. No differences existed in preoperative clinical and radiographic profile of the study and control groups. Compared with controls, the MIECTDF group achieved superior scores in all metrics (p < 0.01) except for equivalent 1-year neurological outcomes.
  
  
  CONCLUSIONS
  Compared with transthoracic procedures, MIECTDF effectively decompressed the spinal canal, yielding identical 1-year radiographic and clinical outcomes to those seen in controls, while producing superior clinical scores in the interim. Thus, MIECTDF is the authors' treatment of choice for TDH.
authors.affiliation: Department of Neurological Surgery, University of California, Los Angeles, California, USA. lkhoo@laspineclinic.com
authors.forename: Larry T
authors.initials: LT
authors.lastname: Khoo
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Smith
authors.forename: Farbod
authors.initials: F
authors.lastname: Asgarzadie
authors.forename: Yorgios
authors.initials: Y
authors.lastname: Barlas
authors.forename: Sean S
authors.initials: SS
authors.lastname: Armin
authors.forename: Vartan
authors.initials: V
authors.lastname: Tashjian
authors.forename: Baron
authors.initials: B
authors.lastname: Zarate
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017586:Diskectomy / Q000379:methods*; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D011859:Radiography; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods*; D013525:Surgical Instruments; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D055815:Young Adult