Cystic vestibular schwannoma: classification, management, and facial nerve outcomes.
OBJECTIVE
Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system.


METHODS
Retrospective review.


METHODS
Tertiary care facility.


METHODS
Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients.


METHODS
Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach.


METHODS
Preoperative and postoperative (at least 1 yr) House-Brackmann facial nerve (HBFN) grade evaluation.


RESULTS
Favorable HBFN grades (I-III) were observed in 46 (81%) CVS patients, and unfavorable HBFN grades (IV-VI) were seen in 11 (19%) CVS patients. Comparison of tumor size and 1-year HBFN grades showed significant, moderate to strong, Pearson correlation (0.38). Comparison of long-term facial nerve outcomes with a sample of 57 matched SVS patients showed no significant difference (p = 0.74). When the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve, only subtotal resection could offer the CVS patients a normal facial nerve outcome.


CONCLUSIONS
In most CVS cases, complete resection should be foreseen. Central and thick-walled tumors can be removed in almost all cases. However, when peripheral thin-walled, adherent, cystic tumors are confronted and the cysts are medially or anteriorly located, we recommend subtotal resection, leaving portions of the cyst walls on neurovascular structures and on the facial nerve. This surgical strategy allows us to improve facial nerve outcomes and to reduce complications.
Piccirillo
Enrico
E
Gruppo Otologico, c/o Casa di Cura Piacenza spa, Piacenza, Italy. enricopiccirillo@libero.it
Wiet
Mark R
MR
Flanagan
Sean
S
Dispenza
Francesco
F
Giannuzzi
Annalisa
A
Mancini
Fernando
F
Sanna
Mario
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003390:Cranial Nerve Neoplasms / Q000145:classification* / Q000503:physiopathology / Q000601:surgery*; D003560:Cysts; D005155:Facial Nerve Diseases / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000145:classification* / Q000503:physiopathology / Q000601:surgery*; D013506:Otologic Surgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D016896:Treatment Outcome