title: Posterior-only approach for lumbar vertebral column resection and expandable cage reconstruction for spinal metastases.
abstract: OBJECTIVE
  The increasing incidence of spinal metastasis, a result of improved systemic therapies for cancer, has spurred a search for an alternative method for the surgical treatment of lumbar metastases. The authors report a single-stage posterior-only approach for resecting any pathological lumbar vertebral segment and reconstructing with a medium to large expandable cage while preserving all neurological structures.
  
  
  METHODS
  The authors conducted a retrospective consecutive case review of 11 patients (5 women, 6 men) with spinal metastases treated at 1 institution with single-stage posterior-only vertebral column resection and reconstruction with an expandable cage and pedicle screw fixation. For all patients, the indications for operative intervention were spinal cord compression, cauda equina compression, and/or spinal instability. Neurological status was classified according to the American Spinal Injury Association impairment scale, and functional outcomes were analyzed by using a visual analog scale for pain.
  
  
  RESULTS
  For all patients, a circumferential vertebral column resection was achieved, and full decompression was performed with a posterior-only approach. Each cage was augmented by posterior pedicle screw fixation extending 2 levels above and below the resected level. No patient required a separate anterior procedure. Average estimated blood loss and duration of each surgery were 1618 ml (range 900-4000 ml) and 6.6 hours (range 4.5-9 hours), respectively. The mean follow-up time was 14 months (range 10-24 months). The median survival time after surgery was 17.7 months. Delayed hardware failure occurred for 1 patient. Preoperatively, 2 patients had intractable pain with intact lower-extremity strength and 8 patients had severe intractable pain, lower-extremity paresis, and were unable to walk; 4 of whom regained the ability to walk after surgery. Two patients who were paraplegic before decompression recovered substantial function but remained wheelchair bound, and 2 patients remained paraparetic after the surgery. No patients had lasting intraoperative neuromonitoring changes, and none died. Complications included 2 reoperations, 1 delayed hardware failure (cage subsidence that did not require revision), and 3 incidental durotomies (none of which required reoperation). No postoperative pneumonia, ileus, or deep venous thrombosis developed in any patient.
  
  
  CONCLUSIONS
  A posterior-only approach for vertebral segment resection with preservation of spinal nerve roots is a viable technique that can be used throughout the entire lumbar spine. Extensive mobilization of the nerve roots is of utmost importance and allows for insertion and expansion of medium-sized, in situ expandable cages in the midline. This approach, although technically challenging, might reduce the morbidity associated with an anterior approach.
authors.affiliation: Division of Neurosurgery, City of Hope National Medical Center, Duarte, California 91010, USA.
authors.forename: Rahul
authors.initials: R
authors.lastname: Jandial
authors.forename: Brandon
authors.initials: B
authors.lastname: Kelly
authors.forename: Mike Yue
authors.initials: MY
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D001863:Bone Screws / Q000009:adverse effects; D002420:Cauda Equina / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D010523:Peripheral Nervous System Diseases / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013117:Spinal Cord Compression / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D013125:Spinal Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult