Surgical Outcomes after Vestibular Schwannoma Surgery: Cystic Versus Solid Variants

Introduction: This study aims at comparing the surgical resection and facial nerve outcomes between cystic and solid variants of vestibular schwannoma (VS).Methods: All cases of VS surgically treated by an enlarged translabyrinthine approach over five years were included. Cases were divided into cystic and solid tumors based on the radiological evidence of presence or absence of a cystic component in the preoperative magnetic resonance imaging. 70 cases were included and divided in two groups: cystic tumors 31 patients and solid tumors 39 patients.Results: Tumors were significantly larger in the cystic group (p-value= 0.0002), together with higher incidence of brainstem compression. Complete tumor removal was done in 18 out of 31 cystic VS (58%) and in 30 out of 39 solid VS (77%) with no statistical significance between the two groups (p-value= 0.2). On postoperative radiological evaluation, residual tumor was detected in 14 out of 70 cases (20%). Of those 14 cases, six (19%) cases were in the cystic group and 8(21%) were in the solid group (p-value= 1). The immediate postoperative facial nerve results showed significantly better results in solid tumors (p-value= 0.006), but at the end of the follow-up period, there was no difference regarding facial nerve outcomes between the two groups.Conclusion: Cystic vestibular schwannoma is characterized by frequent facial nerve thinning over the surface of the tumor. Incomplete excision may be adopted in these cases to preserve facial nerve function.