title: Minimally invasive removal of thoracic and lumbar spinal tumors using a nonexpandable tubular retractor.
abstract: OBJECTIVE
  Resection of spinal tumors traditionally requires bilateral subperiosteal muscle stripping, extensive laminectomy, and, in cases of foraminal extension, partial or radical facetectomy. Fusion is often warranted in cases of facetectomy to prevent deformity, pain, and neurological deterioration. Recent reports have demonstrated safety and efficacy of mini-open removal of these tumors using expandable tubular retractors. The authors report their experience with the minimally invasive removal of extradural foraminal and intradural-extramedullary tumors using the nonexpandable tubular retractor.
  
  
  METHODS
  A retrospective chart review of consecutive patients who underwent minimally invasive resection of spinal tumors at Notre Dame Hospital was performed.
  
  
  RESULTS
  Between December 2005 and March 2012, 13 patients underwent minimally invasive removal of spinal tumors at Notre Dame Hospital, Montreal. There were 6 men and 7 women with a mean age of 55 years (range 20-80 years). There were 2 lumbar and 2 thoracic intradural-extramedullary tumors and 7 thoracic and 2 lumbar extradural foraminal tumors. Gross-total resection was achieved in 12 patients. Subtotal resection (90%) was attained in 1 patient because the tumor capsule was adherent to the diaphragm. The average duration of surgery was 189 minutes (range 75-540 minutes), and the average blood loss was 219 ml (range 25-500 ml). There were no major procedure-related complications. Pathological analysis revealed benign schwannoma in 8 patients and meningioma, metastasis, plasmacytoma, osteoid osteoma, and hemangiopericytoma in 1 patient each. The average equivalent dose of postoperative narcotics after surgery was 66.3 mg of morphine. The average length of hospitalization was 66 hours (range 24-144 hours). All working patients returned to normal activities within 4 weeks. The average MRI and clinical follow-up were 13 and 21 months, respectively (range 2-68 months). At last follow-up, 92% of patients had improvement or resolution of pain with a visual analog scale score that improved from 7.8 to 1.2. All patients with neurological impairment improved. The American Spinal Injury Association grade improved in all but 1 patient.
  
  
  CONCLUSIONS
  Intradural-extramedullary and extradural tumors can be completely and safely resected through a minimally invasive approach using the nonexpandable tubular retractor. This approach may be associated with even less tissue destruction than mini-open techniques, translating into a quicker functional recovery. In cases of foraminal tumors, by eliminating the need for facetectomy, this minimally invasive approach may decrease the incidence of postoperative deformity and eliminate the need for adjunctive fusion surgery.
authors.affiliation: Department of Surgery, Section of Neurosurgery, Centre Hospitalier de l'Université de Montréal, Hôpital Notre-Dame, Montréal, Quebec, Canada.
authors.forename: Andre
authors.initials: A
authors.lastname: Nzokou
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Weil
authors.forename: Daniel
authors.initials: D
authors.lastname: Shedid
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult