Outcomes after total en bloc spondylectomy at a mean follow-up of 11 years

Abstract

<p>OBJECTIVE: Total en bloc spondylectomy (TES) of spinal tumors results in a large vertebral defect. Despite reconstruction and fusion, there is the potential concern for long-term mechanical stability. This retrospective cohort study investigated the long-term outcome of TES and reconstruction. METHODS: Twenty-three patients (mean age 40.0 ± 15.3 years) underwent TES for either primary spinal tumors or solitary metastasis and reconstruction with instrumented posterior spinal fusion and anterior fusion with titanium mesh cages at the authors' institution from November 2001 to April 2022. The mean follow-up was 11.5 ± 4.9 years. Primary diagnoses included giant cell tumors (n = 13), primary sarcomas (n = 3), hemangiopericytomas (n = 2), solitary metastases (n = 2), aneurysmal bone cyst (n = 1), hemangioma (n = 1), and chordoma (n = 1). Tumors were located in the lumbar (n = 10) or thoracic (n = 13) spine. Fifteen patients had 1 vertebral level resected, 2 patients had 2, 4 patients had 3, 1 patient had 4, and 1 patient had 5 levels resected. The mean operative duration was 751.7 ± 212.6 minutes, and the mean intraoperative blood loss was 2864.3 ± 2124.8 ml. The mean length of resected tumor was 51.6 ± 23.3 mm. Investigated outcomes were instrumentation failure, revision, and postoperative complications. RESULTS: Twelve patients required revision surgery, 8 of whom had instrumentation failure with rod fracture. The mean time to instrumentation failure was 7.6 ± 3.9 years. Instrumentation failure with rod fracture was associated with longer operation time (p = 0.031), more blood loss (p = 0.002), and a longer length of resected tumor (p = 0.035). No significant association was identified between instrumentation failure and radiological bony union, which was demonstrated in 73.9% of patients. The overall revision-free survivals were 67.0% and 48.8% at 5 and 10 years postoperatively, respectively. The 5- and 10-year instrumentation failure-free survivals were 85.2% and 65.7%, respectively. Local recurrence of the pathology occurred in 3 patients (13.0%), with a mean time to local recurrence of 3.4 ± 4.4 years. Kaplan-Meier analysis showed that 91.3% and 84.3% of the patients would be free from local recurrence at 5 and 10 years postoperatively, respectively. CONCLUSIONS: Although local recurrence was uncommon after TES, revision surgery, particularly for instrumentation failure, emerged as a common late complication following TES. Long resection length and long complicated operations increase the likelihood of future instrumentation failure. Radiological bony union does not guarantee long-term success of the construct.</p>