Application of intraoperative ABR during middle ear surgery to predict improvement in hearing

Abstract

Objective: The present study was aimed to develop an intraoperative hearing monitoring method for surgeons to evaluate hearing improvement in the operating room under general anesthesia. Method: Pure tone audiometry (PTA) and chirp auditory brainstem response (ABR) were evaluated for ears with normal hearing and conductive hearing loss before, immediately after, and 4 weeks after surgery. Result: Our result showed that for ears with normal hearing or conductive hearing loss, preoperative chirp ABR threshold measured in the operating room under general anesthesia was highly linear correlated to 1000 Hz pure tone threshold and PTA threshold measured in the sound-proof chamber. Most interestingly, postoperative chirp ABR measured in the operating room under general anesthesia was also highly correlated with PTA threshold 1 month after surgery, which indicated that intraoperative chirp ABR can predict hearing improvement immediately after surgery. Conclusion: Our findings demonstrate an effective intraoperative intervention to assess hearing improvement under general anesthesia in real time which might help avoid revision surgery. Keywords: Intraoperative auditory brainstem response, Middle ear surgery, Hearing