BACKGROUND: Facial nerve preservation surgery for large vestibular schwannomas 
is a novel strategy for maintaining normal nerve function by allowing residual 
tumor adherent to this nerve or root-entry zone.
OBJECTIVE: To report, in a retrospective study, outcomes for large Koos grade 3 
and 4 vestibular schwannomas.
METHODS: After surgical treatment for vestibular schwannomas in 52 patients 
(2004-2013), outcomes included extent of resection, postoperative hearing, and 
facial nerve function. Extent of resection defined as gross total, near total, 
or subtotal were 7 (39%), 3 (17%), and 8 (44%) in 18 patients after retrosigmoid 
approaches, respectively, and 10 (29.5%), 9 (26.5%), and 15 (44%) for 34 
patients after translabyrinthine approaches, respectively.
RESULTS: Hearing was preserved in 1 (20%) of 5 gross total, 0 of 2 near-total, 
and 1 (33%) of 3 subtotal resections. Good long-term facial nerve function 
(House-Brackmann grades of I and II) was achieved in 16 of 17 gross total (94%), 
11 of 12 near-total (92%), and 21 of 23 subtotal (91%) resections. Long-term 
tumor control was 100% for gross total, 92% for near-total, and 83% for subtotal 
resections. Postoperative radiation therapy was delivered to 9 subtotal 
resection patients and 1 near-total resection patient. Follow-up averaged 33 
months.
CONCLUSION: Our findings support facial nerve preservation surgery in becoming 
the new standard for acoustic neuroma treatment. Maximizing resection and close 
postoperative radiographic follow-up enable early identification of tumors that 
will progress to radiosurgical treatment. This sequential approach can lead to 
combined optimal facial nerve function and effective tumor control rates.