Total En Bloc Spondylectomy for Solitary Metastatic Tumors of the Fourth Lumbar Spine in a Posterior-Only Approach

BACKGROUND: Total en bloc spondylectomy (TES) significantly decreases the rate of local recurrence and provides long-term survival in patients with malignant tumor of the spine. This procedure can be performed through a posterior-only approach. However, TES for lower lumbar spine through a posterior-only approach is technically challenging. METHODS: We retrospectively reviewed 9 patients with solitary metastatic tumors of the fourth lumbar spine who underwent TES in a posterior-only approach from June 2012 to December 2015. This series included 5 female and 4 male patients, with a mean age of 54.1 years. Endpoints included length of surgery, estimated blood loss, visual analogue scale for pain, instrumentation failure, perioperative complications, local control rate, and overall survival. RESULTS: All patients underwent TES and circumferential reconstruction of the involved level. Average operative time and estimated blood loss were 282 minutes and 2421 mL, respectively. The mean follow-up time was 41.2 months. We encountered nerve roots stretches in all patients during the surgeries. Three patients experienced acute lower-extremity neurologic dysfunction, but the symptoms were significantly alleviated in 4 weeks postoperatively and fully resolved within 6 months. Five patients showed no evidence of disease at the latest follow-up. Three patients died of metastasis and systemic failure. One patient developed new metastases and was alive with disease. Titanium mesh cage subsidence was observed in 3 patients, hut no implant failures or related clinical symptoms were found. CONCLUSIONS: TES for the fourth lumbar spine in a posterior-only approach is feasible. Although the surgery is challenging, long-term oncologic and neurologic outcomes are satisfying.