Additional Benefits of Facial Nerve Monitoring during Otologic Surgery

Abstract

Objective This study assesses the role of facial nerve monitoring (FNM) for intraoperative decision making during otologic surgery and possible benefits beyond protecting facial nerve integrity. Study Design This prospective study examines intraoperative FNM data and structured interviews collected during 52 otologic procedures. Setting Tertiary referral center. Subjects and Methods Subjects include adults and children undergoing middle ear or mastoid surgery. Data include intraoperative neuromonitoring activity and structured interviews conducted with the operating surgeon immediately following surgery. Results Facial nerve stimulation was used to confirm the position of the nerve in 42 of 52 surgical procedures. In 26.9% of cases, the patient became “light” and moved under anesthesia, which was predicted by neuromonitoring 71.4% of the time. Through structured interviews, the operating surgeons reported the following. (1) The facial nerve took an unexpected anatomic course in 7.8% of patients and was difficult to identify in 39.2%. (2) The nerve was at increased risk of injury in 66.7% of cases due to chronic disease or previous surgery. (3) Among these high-risk cases, the monitor helped reduce the risk of nerve damage 100% of the time. (4) Neuromonitoring allowed the surgeon to operate faster 86.5% of the time, and (5) FNM allowed the resident to perform more of the operation 68.9% of the time. No patients experienced postoperative facial weakness. Conclusions Beyond potentially protecting facial nerve integrity, this study identified additional benefits of FNM, including warning of patient movement during anesthesia, confirming facial nerve anatomic location, reducing operative time, and enhancing resident surgical experience.

Immediate Facial Nerve Palsy Secondary to Otological Surgery: A Systematic Review and Narrative Synthesis

“…A facial nerve monitor can be used intraoperatively to assess and confirm the position of the FN and can reduce the risk of further injury (20). Of the middle ear and mastoid procedures, only Linder et al (14) reported using a monitor.…”

Accessing the stapedius muscle via novel surgical retrofacial approach during cochlear implantation surgery: Intraoperative results on feasibility and safety

“…From the surgical point of view, the role of the FN monitoring device appears quite crucial. In fact, besides providing continuous feedback to the otologic surgeons on the anatomic course of the FN reducing potential nerve damage [ 31 ], it offered them a validation tool to verify the successful access to the SM belly visually. The availability of the 3D reconstruction of the individual patient anatomy during the surgery session and the possibility to dynamically visualize different orientations of the SM is important.…”

Optimizing Location of Subdermal Recording Electrodes for Intraoperative Facial Nerve Monitoring

“…Although some correctly suggest that reliance on IOFNM alone is no substitute for a solid understanding of surgical anatomy, the potential benefits for nerve identification and injury avoidance are well established, even in routine otologic surgery. [1][2][3] In addition to risk reduction, IOFNM with stimulation has been shown, particularly in posterior fossa surgery, to allow for improved prediction of postoperative facial function. [4][5][6][7][8] This can be accomplished either by determining the lowest current necessary to generate a compound muscle action potential (CMAP) [9][10][11] or the amplitudes of the CMAPs themselves.…”