title: The transspinous mini-open approach for resection of intradural spinal neoplasms: cadaveric feasibility study and report of 3 clinical cases.
abstract: OBJECTIVE
  Standard approaches to thoracic intradural tumors often involve a large incision and significant tissue destruction. Minimally invasive techniques have been applied successfully for a variety of surgical decompression procedures but have rarely been used for the removal of intradural thoracic tumors. Here, we demonstrate the feasibility and initial clinical experience with a new minimally invasive approach for resection of intradural tumors.
  
  
  METHODS
  Initially, 12 procedures were performed on six cadavers to determine the feasibility of the transspinous mini-open approach (using an expandable tubular retractor) and to compare this approach to a standard open approach. The body mass index (BMI) of all specimens was noted. Measurements were taken to compare the mini-open approach with the open approach in terms of the number of lamina accessed and the length of the incision. Subsequently, the transspinous mini-open approach was used to biopsy one clinical case of intradural, intramedullary tumor (glioblastoma multiforme) and to remove two intradural, extramedullary tumors (meningiomas) in two other patients.
  
  
  RESULTS
  The BMI of the cadavers ranged from 18 to 43. Regardless the BMI, up to three-level laminectomies could be performed in all the cadavers via a mini-open approach. In specimens with a BMI of <22, an additional half-level could be accessed. The incision length did not exceed 4.5 cm in all cadavers undergoing the mini-open approach. In the same cadavers, with the standard open approach, the incision length increased with increasing BMI from 8.0 to 15 cm. The three clinical cases were successfully performed through a mini-open transspinous approach without any complications. The mean operative time was 3½ hours (range = 3-4 hours), mean blood loss was 133 mL (range 100-150 mL), and the mean hospital stay was 5½ days (range = 4-7 days).
  
  
  CONCLUSIONS
  The mini-open approach allows complete dorsal access to the spinal canal, with less tissue disruption than with a standard open procedure. This is especially true in obese patients where the incision length may be 3 times smaller compared to a standard open approach. The mini-open transspinous resection of thoracic intradural tumors can be performed safely.
authors.affiliation: Department of Neurological Surgery, University of California, Los Angeles, California, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Lu
authors.forename: Sanjay S
authors.initials: SS
authors.lastname: Dhall
authors.forename: Praveen V
authors.initials: PV
authors.lastname: Mummaneni
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy / Q000379:methods; D015992:Body Mass Index; D005240:Feasibility Studies; D005260:Female; D005909:Glioblastoma / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology / Q000601:surgery; D008579:Meningioma / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D013117:Spinal Cord Compression / Q000473:pathology / Q000601:surgery; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000601:surgery*; D013525:Surgical Instruments; D013904:Thoracic Vertebrae / Q000601:surgery; D014741:Video Recording