Spinal stability after resection of nerve sheath tumors.

BACKGROUND The aim of this paper was to present a generalizable group of patients who have undergone resection of spinal nerve sheath tumors and attempt to identify factors that may be predictive of the need for intraoperative fusion. METHODS We conducted a retrospective review of patients who underwent excision of spinal nerve sheath tumors performed by the senior author at the University of Miami/Jackson Memorial Medical Center. RESULTS Out of the 48 cases reviewed in this study, a total of 7 (14.6%) underwent fusion at the same time as decompression and tumor excision. Fusion was deemed necessary in these cases for a number of different reasons, including preexisting scoliosis, cervical instability, preexisting listhesis, and tumor size and/or aggressiveness warranting more extensive bony exposure. Cervical tumors in patients with NF-1 and total facetectomy being performed were both factors found to be predictive of the decision to perform intraoperative fusion with instrumentation (P values of 0.009 and <0.001, respectively). There were seven cases in which partial facetectomies were performed without fusion, none of which later developed instability. Finally, excision of malignant peripheral nerve sheath tumors was also associated with the decision to perform fusion (P=0.008). The average length of follow‑up was 2 years, 11 months (SEM 8 months). CONCLUSIONS Most patients can undergo resection of spinal nerve sheath tumors without fusion. Patients with pre‑existing deformity or instability, a history of NF-1 together with the tumor in the cervical region, malignant nerve sheath tumors, or those who undergo a total facet resection may require instrumented spinal fusion during tumor excision. We also observed that removal of one third or even half of a facet joint complex appears to be well tolerated with no instability seen on follow‑up.