Acoustic neuromas after failed radiation therapy: challenges of surgical salvage.
OBJECTIVE
As stereotactic radiation has emerged as a treatment option for acoustic neuromas, cases that require surgical salvage after unsuccessful radiation have emerged. We present a comparison of the technical challenges faced by the surgeons in the treatment of irradiated versus nonirradiated acoustic neuromas.


METHODS
Matched case-control series.


METHODS
We identified nine patients with acoustic neuromas that required surgical resection after radiation therapy. Cases were performed with suboccipital and translabyrinthine approaches. Nine nonirradiated case-control subjects matched for age, sex, tumor size, and surgical approach were identified for purposes of general comparison. Operative findings and outcomes were compared for the two groups.


RESULTS
Surgical removal was found to be significantly more difficult after radiation therapy because of increased fibrosis and adhesion to adjacent nervous structures, particularly at the porus acousticus. Excessive scarring hindered identification of the facial nerve and added uncertainty as to the completeness of tumor removal. Decompression of the internal auditory canal (IAC) dura and resection of neoplasm in the IAC before cerebellopontine angle dissection was required for facial nerve identification. Operative time was significantly longer for irradiated cases, and facial nerve outcomes tended to be poorer, particularly when facial nerve dysfunction prompted the salvage procedure.


CONCLUSIONS
Surgical salvage of acoustic neuromas after radiation therapy is feasible, but it presents technical challenges beyond that associated with primary surgical therapy. Poorer outcomes of postoperative cranial nerve status were caused primarily by anatomic changes at the nerve/tumor interface. As surgical experience with the irradiated acoustic neuroma grows, operative observations should be incorporated into the counsel provided to patients with acoustic neuromas as they weigh different management options.
Limb
Charles J
CJ
Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, MD 21287, USA. climb@jhmi.edu
Long
Donlin M
DM
Niparko
John K
JK
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D006801:Humans; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery*; D013517:Otorhinolaryngologic Surgical Procedures / Q000379:methods; D016634:Radiosurgery; D016879:Salvage Therapy; D017211:Treatment Failure