Functional nerve root tumors have worse resection rates: Outcome predictors for gross total resection in non-syndromic spinal schwannomas.

Introduction: Spinal schwannomas are common benign tumors arising from Schwann cells that can result in significant neurological deficits. The standard treatment for these tumors is complete surgical resection. This study aims to investigate the differences in the surgical variables and clinical outcomes based on the anatomical location of the tumors.

Methods: We retrospectively reviewed medical records from patients who underwent surgical resection for non-syndromic spinal schwannomas at Johns Hopkins Medical Institutes between 2009 and 2023. The patients were stratified into two cohorts based on the tumors' location: those with schwannomas at the functional nerve roots of C5-T1 or L2-S1 (FNRT group) and those with schwannomas at other spinal levels (non-FNRT group).

Results: A total of 116 patients were included [Mean (SD) age, 51.87 (16.96); 50.9 % females] with 54 (47.7 %) in the FNRT group. The predominant symptoms were pain (89.4 %), sensory deficits (47.2 %), and weakness (37.3 %), with no significant differences between FNRT and non-FNRT groups. Gross total resection (GTR) was achieved in 85.4 % of patients with a significantly lower GTR rate in the FNRT group (76.7 %) compared to non-FNRT cases (93.4 %) (p = 0.016). The FNRT group had significantly higher intraoperative blood loss, longer operative duration, and extended hospital stay than the non-FNRT group (p < 0.001). The mean follow-up duration was 39.74 (+-171.65) months, with the FNRT group having a longer duration (52.63 (+-244.40) compared to the non-FNRT group 27.69 (+-36.90), p = 0.013). Postoperative pain relief was reported in 78 patients, with a higher rate in the FNRT group (65.7 %) compared to non-FNRT (59.0 %) (p < 0.001). Recovery rates from motor and sensory deficits were 67.1 % and 44.1 %, respectively, with higher recovery rates observed in the non-FNRT group compared to the FNRT group. Tumor recurrence was seen in 16 (13.0 %) patients, with no significant difference between both groups. Apart from location, preoperative biopsy (p = 0.003, OR 0.13 95 %CI [0.035-0.482]) and extradural extension (p = 0.006 OR 0.21 95 %CI[0.066-0.649]) were significant negative prognostic variables for GTR.

Conclusion: Complete surgical resection of spinal schwannomas is associated with favorable clinical outcomes and manageable risks. Tumor location plays a critical role in determining the extent of surgical resection, intraoperative blood loss, surgical duration, length of hospital stay, and clinical outcomes.