Surgical Outcomes of Sciatic Nerve Schwannomas: A Systematic Review and Individual Patient Data Meta-Analysis

Introduction: Sciatic nerve schwannomas are rare and commonly present as a painful palpable mass. Although surgical excision is preferred for management, no systematic investigations focused on the surgical outcomes of sciatic nerve schwannoma resection have been performed to date. The purpose of this study was to systemically review and describe the outcomes of sciatic nerve schwannoma excisions in the literature, which will aid surgeons in counseling patients.

Methods: Using the PubMed, Scopus, and Embase databases, we performed a literature search. After screening, data extraction was performed based on prespecified variables of interest, including demographics, symptoms, location/size of the schwannoma, type of surgery, neurologic/functional outcomes, intraoperative/postoperative complications, and length of follow-up. Level of evidence and study quality were assessed using the ROBINS-I (Risk Of Bias In Non-randomised Studies - of Interventions) and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) tools.

Results: Of 94 full-text articles identified, 21 studies (3 [14%] case series and 18 [86%] case reports) met inclusion criteria and were included in the review. Individual patient data was acquired from 28 patients. The average age of the patients was 45.4 ± 14.4 years. Most patients (19/21, 90%) reported pain as a presenting symptom. Other common presenting symptoms included swelling, numbness, and burning. Regarding outcomes of surgery, the majority of cases (19/28, 68%) reported no postoperative neurological/functional deficits, while 3/28 (11%) had postoperative deficits (including pain, sensory changes, and motor weakness) that did not resolve. Finally, 2/28 (7%) had surgical complications, including S1 nerve root injury and sciatic nerve damage.

Conclusion : Although sciatic nerve schwannomas are a rare cause of sciatica, they should be on the differential for persistent sciatic pain without radicular compression that does not respond to conservative treatment. Due to their long subclinical course and misleading clinical presentations, it can be difficult to diagnose sciatic nerve schwannomas. Surgical excision generally has a good prognosis and is successful in resolving symptoms with relatively low risk of permanent nerve damage. Overall, this methodologically rigorous and comprehensive study adds to the body of literature, and we anticipate it will aid in future research on the development of therapeutic algorithms for sciatic nerve schwannomas.