Different Surgical Approaches for Spinal Schwannoma: A Single Surgeon's Experience with 49 Consecutive Cases

Abstract

Objective: Comparing different surgical approaches for spinal schwannoma, the safety and efficacy of the minimally invasive surgery (MIS) approach were demonstrated, and a suitable indication for each surgical approach was analyzed.

Methods: This study comprised 49 consecutive patients with intradural extramedullary schwannoma who underwent surgical resection: 31 patients via MIS approach (MIS group; 6 patients via a muscle-splitting approach using a tubular retractor and 25 patients via unilateral hemilaminectomy preserving the contralateral paraspinal muscle) and 18 patients via total laminectomy (TL group). Medical records including perioperative data and radiologic data were reviewed.

Results: On initial magnetic resonance imaging, the mean maximal sagittal diameter of the tumor was 23.9 mm in the MIS group and 26.9 mm in the TL group, and the mean maximal axial diameter was 16.1 mm in the MIS group and 22.8 mm in the TL group (P = 0.452 and P = 0.011, respectively). The foraminal extension of tumor was identified in 8 patients in the MIS group and 9 patients in the TL group (P = 0.081). The tumor location was the lumbar spine in 20 patients in the MIS group and the cervicothoracic spine in 17 patients in the TL group (P = 0.001). Intraoperatively, all tumors in the MIS group could be totally resected with reduced operative time and blood loss. During the follow-up period of 38.2 months in the MIS group and 51.2 months in the TL group, the clinical improvement was not different between the surgical approaches (P = 0.332).

Conclusions: Safe and complete resection of intradural extramedullary schwannoma was obtained through the MIS approach. Regardless of sagittal extension of the tumor, a schwannoma with an axial diameter of 16 mm located in the lumbar spine can be effectively treated with the MIS approach, including foraminal extension.

Keywords: Hemilaminectomy; Minimally invasive surgery; Spinal schwannoma; Tubular retractor.