Analysis of Hearing Outcomes following Middle Fossa Approach for Vestibular Schwannoma
Authors List
Barber, Lucy, Auckland Hospital, New Zealand
Sillars, Hamish, Auckland Hospital, New Zealand
Objectives: The middle fossa approach (MFA) is one of the commonly used techniques to excise intracanalicular vestibular schwannomas with a goal to preserve hearing function. We will determine our ‘Hearing Preservation Rate’ (HPR) following this surgery. However, we believe HPR may bear little relationship to the patient’s view of success. We aim present our results in a more accurate way that could aid in pre-operative counselling for our patients.
Method: A retrospective case review was performed identifying 65 patients from August 1999 to February 2018 that underwent MFA removal of a vestibular schwannoma by a single surgeon. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. Hearing was widely considered to be successfully ‘preserved’ with post-operative pure tone audiometry (PTA) less than 50 dB and speech discrimination (SD) greater than 50% (class A or B). We then conducted our own analysis looking at three groups: retained binaural hearing, retained PTA within 5 dB (although not binaural pre-operatively), and those that are likely to benefit from amplification (speech discrimination >90%).
Results: 61 patients had pre-operative A or B class hearing, with 32 retaining this level of hearing after surgery (HPR 53%). 39% of patients with pre-operative binaural hearing retained binaural hearing. 28% of patients who did not have binaural hearing pre-operatively retained PTA within 5 dB. The total percentage all patients who retained binaural hearing or who would likely benefit from amplification was 46%.
Conclusion: Hearing preservation rate may not accurately represent true hearing benefit for our patients. Analysis of our post-operative hearing results reveal that we can be confident that at least 46% of patients have benefited from the surgery with regard to their hearing outcomes. This will aid in pre-operative counselling of patients in the future.
Barber, Lucy, Auckland Hospital, New Zealand
Sillars, Hamish, Auckland Hospital, New Zealand
Objectives: The middle fossa approach (MFA) is one of the commonly used techniques to excise intracanalicular vestibular schwannomas with a goal to preserve hearing function. We will determine our ‘Hearing Preservation Rate’ (HPR) following this surgery. However, we believe HPR may bear little relationship to the patient’s view of success. We aim present our results in a more accurate way that could aid in pre-operative counselling for our patients.
Method: A retrospective case review was performed identifying 65 patients from August 1999 to February 2018 that underwent MFA removal of a vestibular schwannoma by a single surgeon. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. Hearing was widely considered to be successfully ‘preserved’ with post-operative pure tone audiometry (PTA) less than 50 dB and speech discrimination (SD) greater than 50% (class A or B). We then conducted our own analysis looking at three groups: retained binaural hearing, retained PTA within 5 dB (although not binaural pre-operatively), and those that are likely to benefit from amplification (speech discrimination >90%).
Results: 61 patients had pre-operative A or B class hearing, with 32 retaining this level of hearing after surgery (HPR 53%). 39% of patients with pre-operative binaural hearing retained binaural hearing. 28% of patients who did not have binaural hearing pre-operatively retained PTA within 5 dB. The total percentage all patients who retained binaural hearing or who would likely benefit from amplification was 46%.
Conclusion: Hearing preservation rate may not accurately represent true hearing benefit for our patients. Analysis of our post-operative hearing results reveal that we can be confident that at least 46% of patients have benefited from the surgery with regard to their hearing outcomes. This will aid in pre-operative counselling of patients in the future.
