title: Image-guided navigation and video-assisted thoracoscopic spine surgery: the second generation.
abstract: OBJECTIVE
  Video-assisted thoracoscopic surgery (VATS) has evolved for treatment of a variety of spinal disorders. Early incorporation with image-guided surgery (IGS) was challenged due to reproducibility and adaptability, limiting the procedure's acceptance. In the present study, the authors report their experience with second-generation IGS and VATS technologies for anterior thoracic minimally invasive spinal (MIS) procedures.
  
  
  METHODS
  The surgical procedure is described in detail including operating room set-up, patient positioning (a lateral decubitus position), placement of the spinal reference frame and portal, radiographic localization, registration, surgical instruments, and the image-guided thoracoscopic discectomy.
  
  
  RESULTS
  Combined IGS and VATS procedures were successfully performed and assisted in anatomical localization in 14 patients. The mean patient age was 59 years (range 32-73 years). Disc herniation pathology represented the most common indication for surgery (n = 8 patients); intrathoracic spinal tumors were present in 4 patients and the remaining patients had infection and ossification of the posterior longitudinal ligament. All patients required chest tube drainage postoperatively, and all but 1 patient had drainage discontinued the following day. The only complication was a seroma that was presumed to be due to steroid therapy for postoperative weakness. At the final follow-up, 11 of the patients were improved neurologically, 2 patients had baseline neurological status, and the 1 patient with postoperative weakness was able to ambulate, albeit with an assistive device. The evolution of thoracoscopic surgical procedures occurring over 20 years is presented, including their limitations. The combination of VATS and IGS technologies is discussed including their safety and the importance of 3D imaging. In cases of large open thoracotomy procedures, surgeries require difficult, extensive, and invasive access through the chest cavity; using a MIS procedure can potentially eliminate many of the complications and morbidities associated with large open procedures. The authors report their experience with thoracic spinal surgeries that involved MIS procedures and the new technologies.
  
  
  CONCLUSIONS
  The most significant advance in IGS procedures has resulted from intraoperative CT scanning and automatic registration with the IGS workstation. Image guidance can be used in conjunction with VATS techniques for thoracic discectomy, spinal tumors, infection, and ossification of the posterior longitudinal ligament. The authors' initial experience has revealed this technique to be useful and potentially applicable to other MIS procedures.
authors.affiliation: Departments of Neurosurgery and.
authors.forename: J Patrick
authors.initials: JP
authors.lastname: Johnson
authors.forename: Doniel
authors.initials: D
authors.lastname: Drazin
authors.forename: Wesley A
authors.initials: WA
authors.lastname: King
authors.forename: Terrence T
authors.initials: TT
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D013131:Spine / Q000473:pathology / Q000601:surgery*; D025321:Surgery, Computer-Assisted / Q000379:methods; D020775:Thoracic Surgery, Video-Assisted / Q000379:methods; D016896:Treatment Outcome