Combined application and evaluation of two types of auditory monitoring in acoustic neuroma surgery / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To explore the significance of intraoperative auditory monitoring(IAMA) in surgery of acoustic neuroma and to compare the value of auditory brainstem response(ABR) and cochlear nerve action potential(CNAP) in auditory monitoring.METHODS Retrospective analysis of 12 cases of acoustic neuroma from January 2016 to December 2016 was performed.All patients have a practical hearing(AAO-HNS,grade class a,b),the ABR waveform can be elicited,wave v differentiation,All tumors were removed via posterior sigmoid sinus approach.RESULTS ABR waveform of all patients were prolonged with different degrees of change(0.68±0.41) ms compared with the preoperative data.Amplitude of CNAP diverse in different individuals,with an average prolong compared to the data before operation(0.25±0.16) ms.In all 12 cases,8 (66.7％) patients remained usable hearing after the operation,4 cases(33.3％) failed to have a usable hearing.Among these 4 patients,3 showed disappearance of wave v,1 patient showed wave v latency prolong in the ABR,meanwhile,2 patients showed P1 dissapear,2 patients showed P1 latency prolong in CNAP.The intraoperative auditory monitoring could play a role in preventing the hearing damage in the procedure.Drilling,noise,surgical nerve stretch or thermal injury may cause the hearing damage.A 5 minutes pause could get some degree of regain,with the amplitude rise again.CONCLUSION A combination use of the ABR and CNAP monitoring has a certain significance in surgery of acoustic neuroma.ABR waveform is stable and reliable,but costs longer time;CNAP stack quickly and improve monitoring sensitivity,but waveform varies.Vibration and noise caused by drilling,nerve stretch during operation and heat damage can be monitored timely.Combined use of ABR and CNAP monitoring can enhance the auditory preservation rate during acoustic neuroma surgery.