Surgery after Surgery for Vestibular Schwannoma

Introduction: Management options of vestibular schwannoma (VS) include surgery, radiosurgery, and observation. Although benign in character, failure to remove it completely may result in a regrowth. Management of tumor recurrence after gross total resection (GTR) or progression after non-GTR is much more difficult to treat than initial VS and remains controversial as well as challenging, both for the surgeon and the patient.

Aim of the Study: The aim of the study was to evaluate the oncological and functional effectiveness of revision surgery for recurrent VS (rVS).

Materials and Methods: Twenty-nine consecutive patients operated for rVS were analyzed. Analyzed group included 16 women and 13 men with the mean age of 42.1 years old. Eleven of them were previously operated at our department and GTR using retrosigmoid approach (RSA) was initially performed. The mean time to recurrence in this group was 9.45 years.

Eighteen patients were referred from other centers with tumor progression after subtotal resection (RSA in all), including 4 patients with the additional radiosurgery treatment and 3 patients who have had multiple previous surgeries. The mean time for revision surgery was 5.1 years.

All patients presented with unilateral hearing loss (AAO–HNS class D) and with a different grade of facial nerve (FN) weakness [House–Brackmann (HB) grades: II–VI], including deep long-lasting FN paresis (HB grades: IV–VI) in 22 cases (75.86%). The size of recurrent tumor ranged from 6 to 51 mm (mean: 23.3 mm). Seven patients had neurofibromatosis type 2.

Results: GTR has been accomplished during revision surgery in all cases. Translabyrinthine approach (TLA) was the most common (14 small to medium tumors arising from IAC bottom) followed by RSA (12 large tumors as well as smaller ones located predominantly in CPA) and by the combination of TLA and RSA in 2 cases. Middle fossa approach was employed for 1 tumor progressing to the petrous apex.

In 15 patients, facial neurorrhaphy was performed, 11 of them had hemihypoglossal–facial neurorrhaphy (HHFN), of which 9 simultaneously with the revision surgery. In follow-up, 10 patients (34.48%) still had deep FN paresis (HB grades IV–VI). All patients after HHFN improved from HB grade VI to HB grade III, except for one who improved to grade IV. No subsequent tumor recurrence was noted during the mean follow-up of 3.46 years.

Conclusion: Complete tumor removal via tailored approaches together with modern FN reconstruction techniques yield durable oncological effect and may restore satisfactory FN function.