Over the past 50 years, the focus of acoustic neuroma surgery has shifted from low mortality and tumor resection to retention of neurological function. Hearing preservation is another point in addition to facial nerve function preservation. Hearing preservation rates overall ranged from 2% to 93% in recent studies. Characteristics such as approach, pre-operative neurological function, tumor size, nerve of origin and fundal fluid of the internal auditory canal have been reported as possible influencing factors. This review provides a summary of recent studies and describes the prognostic factors that predict hearing preservation.

Humans ; SARS-CoV-2 ; COVID-19

Objective: To evaluate the application of combination use of microscope and endoscope in cerebral pontine angle (CPA) surgery. Methods: A total of 72 patients undergone lateral skull base surgeries via endoscope under microscopic control from January 2006 to January 2015 was reviewed respectively. The patients including 35 males and 37 females were composed of 22 cases of vestibular swannnomas, 45 cases of cranial neuropathy and 5 cases of CPA chelesteatoma. Twenty cases of vestibular swannnomas, 15 cases of cranial neuropathy and 2 cases of CPA chelesteatoma undergone the surgery via retrosigmoid approach, while other cases undergone the surgery via retrolabyrinthine approach. Surgical procedures were accomplished under the control of microscope and different angular endoscope with imaging fusion. The surgical results were evaluated according to subjective and objective criteria, and all patients were followed up for 15 years. Results: The symptoms was disappeared in the cranial neuropathy patients, without facial paralysis, complication of other nerves or hearing loss. Twenty-two patients with vestibular schwannomas got total tumor removal without facial palsy or neurological deficits; useful hearing was preserved in 16 of 22 patients (72.7%), and no tumor recurrence was found during 1-5 years follow-up. There was also no facial palsy or other complications in 5 cases of CPA chelesteatoma, which gained completely surgical removal; useful hearing was preserved in 3 of 5 cases of these patients and no recurrence was occurred during 1-1.5 years follow-up. Conclusions A combination use of endoscope and microscope could combine advantages and avoid disadvantages of two techniques. It can provide better exposure with minimal invasion in CPA surgery, and is especially applicable in surgery for cranial neuropathy, vestibular schwannoma and CPA cholesteatoma, which should be performed through retrosigmoid approach and retrolabyrinthine approach.