Manchester Series of Vestibular Schwannomas Excised Following Irradiation

Problem: Vestibular schwannomas (VSs) are treated conservatively, surgically, or by irradiation. There is increasing interest in the outcome of patients who are not controlled by irradiation and therefore require salvage surgery.

Method: A retrospective analysis was conducted on VS cases from the senior authors VS database of more than 1000 cases. Outcomes were analyzed, with particular focus on facial nerve function, technical difficulty, and percentage of tumor removal.

Result: Ten patients underwent salvage surgery for VSs because of exacerbation of symptoms and/or growth. The age range of these patients was 20–78 years. Their preoperative tumor sizes ranged from 1.5 to >4 cm, and time to surgery ranged from 5 months to 11 years. All had nonserviceable hearing, hence a translabyrinthine approach was used. Preoperative facial nerve function was grade I in 7 of 10 patients, II in 1, and VI in 2. Postoperative facial nerve function was grade I in 4 of 10 patients, III in 1, IV in 1, V in 1, and VI in 3. Two patients had facial hypoglossal anastomosis. In 9 of the 10 patients, >90% of tumor removal was achieved. Two patients were found to have heterotopic ossification of the VS center or capsule.

Conclusion: This work confirms that irradiation does increase the difficulty of excision of VSs by making the tumor firmer and more fibrous, which increases the risk to the facial nerve. Despite this, most of the tumor can be removed with the risk of incomplete excision considered less severe than the risk to the facial nerve. Heterotopic ossification is extremely rare and has not been previously described in this group.