(P 487) EN BLOC RESECTION FOR SPINAL TUMORS: A SINGLE CENTER EXPERIENCE OF 113 CONSECUTIVE CASES

Objective: This study aims to assess the clinical outcome of patients with spinal tumors who received en bloc resection and to provide theoretical basis for developing novel surgical technique in en bloc resection for spinal tumor.

Methods: We retrospectively reviewed the clinical and follow-up data of patients who received en bloc resection for spinal tumors in our center from Jan. 2007 to Dec. 2021. The surgical approach of en bloc resection for spinal tumors was determined according to the surgical classification for spinal tumors proposed by Boriani. The general condition, surgical treatment, peri- and post-operative complication, and survival of patients were retrospectively analyzed.

Results: 113 patients were enrolled in this study. There were 68 males and 45 females with an average age of 38.7±16.7 years. Primary malignant spinal tumors, primary aggressive spinal tumors and solitary metastatic spinal tumors were diagnosed in 55, 27 and 31 patients, respectively. All surgeries accomplished uneventfully except one patient died during surgery owing to the haemorrhagic shock caused by injury of major blood vessel. Mean operative time and volume of intra-operative haemorrhage was 517.6±267.4 min and 3802.7±3039.4 mL, respectively. R0 resection was achieved in 48 patients. Three patients died in peri-operative period. Peri-operative complications were identified in 44 patients (38.9%). 109 patients were followed up with a mean follow-up time of 39.4±35.2 months. 27 patients died during follow-up period and the mean post-operative overall survival (OS) was 115.4 (95% CI 97.9-133.0) months. In patients with primary malignant spinal tumors, the OS of patients who underwent R2 resection was significantly poorer than that of patients who underwent R0/R1 resection (P=0.024); while in patients with metastatic tumors, no difference of OS was observed in patients with different surgical margins (P=0.61). There were 29 recurrences, and the mean recurrence-free survival (RFS) was 105.8 (95% CI 87.5-124.1) months. In patients with primary malignant and aggressive spinal tumors, the RFS of patients underwent R2 resection was significantly lower than that of patients underwent R0/R1 resection (P=0.008, P=0.027); but in patients with metastatic spinal tumors, no significant difference of RFS was found in patients with different surgical margin (P=0.71).

Conclusion: Although en bloc resection for spinal tumors indicates complicated surgical procedure and high morbidity, it can significantly improve the OS of patients with primary malignant spinal tumors and the local control of primary malignant and aggressive spinal tumors. However, en bloc resection for spinal tumor showed no improvement in OS and local control in patients with solitary metastatic spinal tumor. It implies that further study should be focused on verifying whether metastatic tumor should be one of the indication of en bloc resections for spinal tumors or not.