The use of an expandable cage for corpectomy reconstruction of vertebral body tumors through a posterior extracavitary approach: a multicenter consecutive case series of prospectively followed patients.

BACKGROUND CONTEXT: Posterior decompressions in the form of laminectomies for vertebral body tumors have poor outcomes. Surgical management typically requires anterior decompression and reconstruction; however, these procedures can be associated with significant morbidity and mortality.
PURPOSE: To evaluate the feasibility of anterior spinal column reconstruction using an expandable cage through a posterior approach. STUDY DESIGN/
SETTING: Multicenter consecutive case series of 21 prospectively followed patients. PATIENT SAMPLE: Twenty-one patients with vertebral body tumors treated with anterior and posterior resection and reconstruction from a single posterior approach were followed prospectively. OUTCOME MEASURES: Pre- and postoperative neurologic status, number of levels instrumented and fused, length of surgery, length of stay after surgery, and complications related directly or indirectly to surgery were analyzed. In addition, pre- and postoperative radiographs, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans were evaluated for involvement of the vertebral body and associated posterior elements. Particular attention was paid to the presence of either unilateral or bilateral pedicle and/or middle column involvement.
METHODS: Patients were placed in a prone position on a rotating radiolucent table. Corpectomy was performed from an extracavitary approach, and anterior column reconstruction was completed with an expandable cage. The posterior tension band and spinal fusion was completed with segmental pedicle screw fixation and performed through the same posterior exposure. No patient required a separate anterior procedure.
RESULTS: Patients' average age was 60.3 years (range, 17-78); there were 12 women and 9 men. Eighteen underwent single-level corpectomies (11 thoracic and 7 lumbar), and 3 underwent two-level corpectomies (T4-T5, T11-T12, and T12-L1). Average estimated blood loss (EBL) and length of surgery per level were 1,360 cc (range, 200-2,500) and 5.3 hours (range, 2.7-8.6), respectively. Average postoperative stay was 4.7 days. Nine patients had at least one partial motor grade improvement. One patient had postoperative left lower extremity weakness after surgical decompression and reconstruction secondary to iatrogenic nerve root traction but remained ambulatory. No chest tubes or postoperative bracing was required. At the most recent follow-up, six patients were alive at an average of 16.1 months (range, 3-33). For the 15 patients who died, the average life span after surgery was 6.8 months (range, 1-16). In addition to the iatrogenic nerve root injury, one cage required repositioning on postoperative Day 2 and one cage demonstrated radiographic evidence of settling but did not require surgical intervention; there were no deep venous thromboses (DVTs), pneumothoraces, pneumonias, ileus, or other complications, with a total complication rate of 14.3%.
CONCLUSIONS: This is the largest study that specifically examines the use of an expandable cage through a posterior extracavitary approach for reconstruction after vertebral body tumor resection. The use of an expandable cage combined with an extracavitary approach is feasible and allows the surgeon to address both the anterior and posterior columns through a single incision. Although technically challenging, both one- and two-level corpectomies in the thoracic and/or lumbar spine can be performed with this technique. Furthermore, insertion of the expandable cage in the collapsed position and then expansion in situ after implantation allowed for all lumbar reconstructions to be completed without sacrificing any of the lumbar nerve roots. Our 14.3% complication rate is similar to those reported in anterior-alone and circumferential spinal procedures.