Postoperative Hearing Research Articles

Intraoperative Monitoring during Microvascular Decompression for Hemifacial Spasm

Brainstem auditory evoked potential(BAEP)and abnormal muscle response(AMR)monitoring are widely used during microvascular decompression(MVD)for hemifacial spasm(HFS). In BAEP monitoring, the intraoperative findings of wave V do not necessarily predict postoperative hearing function. However, if a warning sign as significant as wave V change appears, the surgeon must abort the operation or inject artificial cerebrospinal fluid into the VIII nerve. During MVD for HFS, BAEP monitoring must be performed to preserve hearing function. AMR monitoring is useful in identifying the offending vessels compressing the facial nerve and confirming the completion of decompression intraoperatively. During the operation of the offending vessels, AMR sometimes changes its onset latency and amplitude in real time. These findings allow surgeons to identify the offending vessels. Even if the AMRs remain after completion of decompression, a decrease in amplitude of more than 50% compared to baseline is predictive of postoperative loss of HFS in long-term outcomes. When the AMRs disappear after dural opening, the AMR monitoring should be continued because the AMRs sometimes reappear.

Auditory Brainstem Response: ABR

Intraoperative auditory brainstem response(ABR)monitoring has been established as a reliable method to evaluate cochlear function. Intraoperative ABR is mandatory in microvascular decompression for hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia. Cerebellopontine tumor with remaining effective hearing function also requires ABR monitoring during surgery to preserve hearing function. Prolonged latency and subsequent amplitude decrease in the ABR wave V predicts postoperative hearing impairment. Therefore, when alerted to an intraoperative ABR during surgery, the surgeon should release the cerebellar retraction stressing the cochlear nerve and wait for the abnormal ABR to recover.

Application of Belfast 15/30dB Rule of Thumb in Assessing Hearing Benefit in Middle Ear Reconstructive Surgery.

The objective of this study is to assess the concordance between Belfast 15/30dB rule of thumb and subjective hearing benefit in middle ear reconstruction surgery. A total of 105 cases of chronic otitis media (COM) (both mucosal and squamosal type) with conductive hearing loss and who underwent middle ear reconstructive surgery during the study period from January 2019 to January 2022 were included. All cases were followed up at 6week and at 3months of postoperative duration for subjective assessment of hearing with questionnaire and pure tone audiometry as per standard of care and correlated with Belfast 15/30dB rule of thumb. Concordance with Belfast rule of thumb was seen in 73.4% cases of both mucosal and squamosal type of COM. Belfast 15/30dB rule of thumb is a valuable and useful tool to predict hearing benefit following middle ear reconstructive surgery, but, it suffers from the disadvantages of all or none phenomenon and it does not grade the level of hearing improvement. The prediction of postoperative subjective hearing with this Belfast rule of thumb is more reliable in mucosal type of COM than in squamosal type of COM.

Application of an Intraoperative Auditory Brainstem Response Measurement System in Active Middle Ear Implant Revision Surgery.

To investigate the benefit of intraoperative auditory brainstem response (ABR) measurements in revision active middle ear implant surgery. Retrospective data analysis. Tertiary referral center with a large active middle ear implant program. Intraoperative ABR thresholds, audiogram, sound field thresholds, speech understanding in the Freiburger monosyllabic word test. Fourteen patients with active middle ear implant revision surgery. The application of the ABR measurement resulted in improved sound field thresholds and enhanced speech understanding. Analysis revealed a significant correlation of intraoperative gain in ABR threshold with the postoperative gain in sound field thresholds. ABR monitoring can be a useful tool to provide information intraoperatively about the coupling efficiency of the FMT. Especially in revision surgeries, this might help to improve postoperative hearing success.

A retrospective study on the outcomes of stapedotomy with vein graft interposition and vein graft surround techniques.

This study evaluated audiological outcomes of stapedotomy using two different techniques, vein graft interposition and vein graft surround, for sealing the stapes fenestra. A retrospective study of 130 patients who underwent stapedotomy for otosclerosis was performed. A total of 84 patients underwent the vein graft surround procedure and 46 underwent the vein graft interposition procedure. Post-operative hearing outcome was compared between them. A total of 55 of 130 patients had a post-operative air-bone gap of less than 10 dB. A total of 57 patients had an air-bone gap within 20 dB. The average air-bone gap was 13.16 dB at 3 months with a mean improvement of 22.06 dB (11.98 dB for vein graft interposition and 13.80 dB for vein graft surround; p = 0.79). There was no significant difference in hearing outcome between the two techniques. The vein graft interposition technique is preferred for large fenestra or stapedectomy cases and in cerebrospinal fluid gusher cases. The vein graft surround technique is easier to perform and preferred in small fenestra stapedotomy.

Stapes surgery for otosclerosis: Comparison of two techniques

Abstract BACKGROUND. Otosclerosis is a primary disease of the human otic capsule and stapes stage, being a frequent cause of conductive hearing loss in our country. The surgical treatment of choice is stapes surgery and prosthesis placement, performed in a conventional way, with a surgical microscope, for 30 years in our hospital. Recently, the option of performing stapes surgery endoscopically was introduced in our centre. OBJECTIVE. To evaluate the results in stapes surgery for otosclerosis between the conventional microscopic versus endoscopic procedure. MATERIAL AND METHODS. An observational, analytical and retrospective study on patients undergoing stapes surgery with microscopic and endoscopic technique was conducted. Data such as age, sex, state of origin, affected ear, as well as the technique used, duration of surgical intervention, hearing gain and postsurgical complications were taken. Data were taken from the records of patients admitted to the hospital. Descriptive statistics, Mann-Whitney U and Pearson’s Ji2, were used, considering a value of p≤ 0.05 as significant. RESULTS. No significant differences were found in surgical time or postoperative hearing between the two surgical techniques. The female sex was the most intervened. There was no significant difference between the post-surgical complications of both groups. CONCLUSION. Both procedures appear to be effective, with similar risks and postoperative results for the surgical treatment of otosclerosis.

889 Significance of Cortico-Bulbar Motor Evoked Potential (CoMEP) Monitoring in Vestibular Schwannoma Surgery for Prediction of Postoperative Facial Nerve Palsy

INTRODUCTION: Direct facial nerve stimulation during vestibular schwannoma surgery (VSS) allows preservation of the nerve in its continuity. However, prognostication of post- operative nerve function remains challinging. METHODS: In total, 51 patients (median age 52yrs; 19-84) with unilateral VS (median size 20mm;10-50) were included. Intraoperative neuromonitoring consisted of auditory evoked potentials (AEPs), direct facial nerve stimulation and CoMEPs. An anodal stimulation via subdermal corkscrew electrodes on position C3 or C4 and a cathode near Cz with a train of 6 pulses, each with a duration ono 500us, at a frequency of 5000 Hz and an interstimulus-interval of 2 ms was used. RESULTS: Complete resection was achieved in >90% of patients. Preoperative hearing was preserved in 78% (40/51) patients and postoperative serviceable hearing was preserved in 35% (18/49) patients and was closely related to preserved wave V of the AEPs. Additionally, MEPs were successfully monitored in every patient for the entire duration of the surgery. In 16% of the patients, more than 50% reduction of MEP baseline amplitude was recorded, correlating directly with moderate to severe postoperative facial palsy (House Brackman 3-5). No facial palsy without MEP amplitude reduction was observed. During 6 months FU, recovery of 1-2 HB Grades was observed in all cases. All patients with intraoperative MEP amplitude reduction had significant larger VS than patients without MEP amplitude reduction (27 vs 22 mm, p = 0.02) CONCLUSIONS: In addition to direct facial nerve stimulation, intraoperative CoMEP monitoring during VSS seems to be of high significance and value for intraoperative facial nerve preservation and prognosis estimation of postoperative short- and long-term facial palsy.

Quality-of-life outcomes with endoscopic and microscopic type I tympanoplasty—a prospective cohort study

PurposeEndoscopic type I tympanoplasty was originally introduced in the 1990s and the extensive spread of this practice can be easily observed. The conventional technique performed involves the repair of a tympanic membrane perforation and is defined as microscopic type I tympanoplasty. The aim of this study is the comparison of quality-of-life (QoL) outcomes with endoscopic to that with microscopic type I tympanoplasty.MethodsAll patients, or in the case of children with the aid of a parent, were asked to complete a novel QoL questionnaire drafted by our study group. The analysis was performed with descriptive statistics—mean, SD and relative frequency—and with a mixed model (generalized least squares fit). A two-sided p value of < 0.05 was regarded as statistically significant.ResultsA total of 83 patients completed the questionnaire, 38 in the endoscopic group and 45 in the microscopic group. Every question represented a different. A statistically significant result was found in favor of the endoscopic approach regarding average hospitalization rate (p = 0.003) and cosmetic outcomes (p = 0.015). No statistically significant difference was otherwise observed between the groups.ConclusionsBased on our prospective cohort study, the QoL outcomes of endoscopic type I tympanoplasty in terms of postoperative pain, headache, nausea, vomiting, dizziness, taste disorder and hearing were comparable to the microscopic type I tympanoplasty. In regard to cosmetics, an increase in desirable results was achieved in the endoscopic group, particularly the average hospitalization rate proved to be statistically significantly lower than in the microscopic group.

Surgical and audiological outcomes with a new transcutaneous bone conduction device with reduced transducer thickness in children

PurposeDue to smaller bone thickness, young children with conductive or mixed hearing loss or single-sided deafness were previously most commonly treated with a percutaneous osseointegrated bone-anchored hearing aid (BAHA) or an active middle-ear implant. While the BAHA increases the risk of implant infections, skin infection, overgrowth of the screw or involvement of the implant in head trauma, middle-ear implant surgery involves manipulation of the ossicles with possible risk of surgical trauma. These complications can be omitted with transcutaneous bone conduction implant systems like the MED-EL Bonebridge system. The purpose of this study was to analyze whether the second generation of the Bonebridge (BCI 602) that features a decreased implant thickness with a reduced surgical drilling depth can be implanted safely in young children with good postoperative hearing performance.MethodsIn this study, 14 patients under 12 years were implanted with the second generation of the Bonebridge. Preoperative workup comprised a CT scan, an MRI scan, pure tone audiometry, or alternatively a BERA (bone conduction, air conduction). Since children under 12 years often have a lower bone thickness, the CT was performed to determine the suitability of the temporal bone for optimal implant placement using the Otoplan software.ResultsAll patients (including three under the age of five) were successfully implanted and showed a good postoperative hearing performance.ConclusionWith adequate preoperative workup, this device can be safely implanted in children and even children under 5 years of age and allows for an extension of indication criteria toward younger children.

Residual low-frequency hearing after early device activation in cochlear implantation

PurposeThe cochlear implant (CI) is a standard treatment for patients with severe to profound hearing loss. In recent years, early device activation of the sound processor after 2–3 days following surgery has been established. The aim of this study is to evaluate the residual hearing of CI patients with substantial preoperative low-frequency hearing after early device activation over a period of 12 months.MethodsResults were compared between an early fitted group (EF) with device activation to less than 15 days after CI surgery and a control group (CG) with device activation after 3–6 weeks. In total, 57 patients were divided into EF group (n = 32), and CG (n = 25). Low-frequency residual hearing and speech recognition in quiet and in noise were compared over an observation period of 12 months.ResultsNo significant difference (p > 0.05) in the residual low-frequency hearing PTAlow between EF and CG was found, neither preoperatively (EF 33.2 dB HL/CG 35.0 dB HL), nor postoperatively (EF 46.8 dB HL/CG 46.2 dB HL). In both groups, postoperative residual hearing decreased compared to preoperative and remained stable within the first year after CI surgery. Furthermore, both groups showed no significant differences (p > 0.05) in speech recognition in quiet and in noise within the first year.ConclusionEarly device activation is feasible in CI patients with preoperative low-frequency residual hearing, without an additional effect on postoperative hearing preservation.

Real-time monitoring of middle ear prosthesis coupling

IntroductionIn reconstructive middle ear surgery, acoustic quality has received a high level of attention in recent years. Careful intraoperative selection and positioning of passive middle ear prostheses during tympanoplasty with ossiculoplasty is essential to ensure satisfactory sound transmission and postoperative hearing outcome. The reconstruction quality of the ossicular chain (OC) can be evaluated intraoperatively using a surgical assistance system which is based on a real-time monitoring system (RTM system) that acquires the transmission (middle ear transfer function (METF)) with electromagnetic excitation of the OC. In this experimental study, the METF with electromagnetic excitation of the (reconstructed) OC was compared to usual acoustic excitation and the benefit of the RTM system was investigated for the implantation of partial (PORP) and total (TORP) prostheses. MethodsLaser Doppler vibrometry (LDV) was used to measure the middle ear transfer function (METF) in 18 human temporal bones (TB). The RTM system uses electromagnetic excitation of the OC with a magnet placed on the umbo. Comparatively, measurements with the usual acoustical excitation, using an earphone in the external auditory canal, were performed. The measurements began with the intact OC, followed by real-time monitoring guided OC reconstruction with PORP and TORP. In addition, during the simulation of an intraoperative setting, the influence of the influence of opening (tympanomeatal flap lifted and pushed anteriorly) and closing (tympanomeatal flap folded back) the tympanic membrane on the measurements with the RTM system was determined. ResultsElectromagnetic and acoustic excitation of the intact and the reconstructed OC provided comparable METF. The application of the RTM system significantly improved the quality of the OC reconstruction. The METF increased by up to 10 dB over the entire frequency range during implantation of the PORP with positioning control by the RTM system. When using the TORP, the METF could be improved by up to 15 dB. The opening of the tympanomeatal flap did not affect the measurements with the RTM system at the reconstructed OC. ConclusionIn this TB study, we demonstrated that the quality of OC reconstruction (improved METF as a benchmark for improved transmission) could be significantly increased by means of a RTM system. Intraoperative studies should now be conducted to investigate to which quantitative extent the intraoperative reconstruction quality can be improved and whether or not this improvement also manifests in an increased (long-term) hearing outcome. This will enable conclusions to be drawn about the contribution of the intraoperative reconstruction quality to the (long-term) hearing outcome in the context of the conglomerate of various factors influencing the postoperative hearing outcome.

Overall outcome of Modified Radical Mastoidectomy (MRM)

Aims: To compare overall findings of our Modified Radical Mastoidectomy (MRM) practice with the available contemporary standards of international recognition. Design and Methodology: The cohort included the patients who underwent Modified Radical Mastoidectomy from 2013 to 2018 by the author, who were subjected to a retrospective study. The details obtained from clinic reports were preoperative and postoperative hearing (documented to the end of the fourth post op year), and findings that were documented intraoperatively and post operatively in successive clinic visits. The parameters analysed were hearing improvement, disease extension, anatomical variations, immediate and late post-operative complications. Result: There were no evidence of recurrence following the surgical intervention. Postoperative mean air-bone gap had reduced by 9.5dBHL, 5dBHL, 7.44dBHL, 4.9dBHL, 4.1dBHL, 3.75dBHL and 8.18dBHL at 0.125kHz, 0.250kHz, 0.5kHz, 1kHz, 2kHz, 4kHz and 8kHz respectively. Disease involvement was found in Attic, Antrum, Sinus tympani, facial recess, mesotympanum, oval window and posterior sinus, supra tubal recess, sinodural angle cells, sinus sub tympanum, external ear canal, in the descending order of occurrence. 36 audited patients achieved dry ears by the end of second year though some had at least one intermittent wet episode and 4 had continuous persistent wet ears. Intraoperative findings analysis showed 2.5% were observed with perilymph leak, 27.5% had erosion of malleus head by disease, 55% had erosion of incus, 90% intact suprastructure, 97.5% had intact stapes foot plate, 15% had significant dural overhang, 10% had exposed facial nerve, 10% had anterior sigmoid sinus and 2.5% had exposed dura. Immediate post intraoperative complications of 7.5% HB grade 1 facial nerve palsy, 42.5% taste alteration, 5% CSF leak, 25% complaining of disturbing head ache, 7.5% having exposed dura (iatrogenic), 7.5% had dressing removed due to risk of pressure necrosis of pinna or developing Facial nerve palsy and 2.5% (one) patient had the meatus migrating downward due to a connective tissue problem of skin. During post-operative period stitch abscess was noted among 5%, achieved self-cleaning dry ear in 15%, wax build up in the dry ear in 10%. However, over 50% patients had minimum of 1 episode of wet ear in this period. Meatal stenosis and keloid development was noted among 10% and, graft perforation among 20% and 2.5% (one) wound dehiscence. During post-operative period 7.5% developed BBPV and similar percentage had caloric effect during packing of the cavity while 22.5% developed caloric effect during suction of the cavity. Conclusions: The improvements in hearing when adjunct with Tympanoplasty in this audit keep up with recent compared studies. Further its ability to safely achieve a disease free ear is endorsed and complemented by the low complication rates.

Outcomes of canal wall down mastoidectomy in cholesteatoma: a 5-year experience

BackgroundCholesteatoma is an atticoantral disease that potentially causes life-threatening complications. Therefore, canal wall down mastoidectomy is a well-established technique to eradicate the disease, especially in extensive cholesteatoma.AimTo evaluate the status of dry ear and hearing outcome post-retrograde canal wall down mastoidectomy.MethodsA retrospective study of patients with cholesteatoma who underwent modified radical mastoidectomy (MRM), a form of canal wall down mastoidectomy between January 2014 and December 2018.ResultsFifty-seven patients were included with a mean age of 40 years. The majority of cases were adults, 86%, and 14% were children. Most of them complained of ear discharge (73.7%), followed by hearing loss (31.6%). Intraoperatively, cholesteatoma was primarily found in cases involving mastoid air cells, antrum, attic, and mesotympanum (47.4%). The presence of granulation tissue with cholesteatoma was noted in 57.9% of cases. Furthermore, 73.7 % of ossicular chain erosion cases involved erosion of all ossicles (47.6 %). In 26.3 % of cases, tegmen erosion was identified. Facial canal dehiscence accounted for 15.8% of MRM cases, sclerotic mastoid was noted for 10.5%, and lateral semicircular canal dehiscence involved 5.3%. Up to 3 months of follow-up post-MRM showed 70.2% had a dry ear. After 6 months, there were 15.8% complaints of ear discharge in the subsequent follow-up. In this study, 33 out of 57 patients underwent a postoperative hearing evaluation, and 21.2 % of patients showed an improvement in the air-bone gap.ConclusionCanal wall down mastoidectomy is a treatment of choice in extensive cholesteatoma to achieve a dry and safe ear with maintaining functional hearing outcomes.

Application of cochlear nerve action potential monitoring in the resection of vestibular schwannomas

Objective: To investigate the application of cochlear nerve action potential (CNAP) monitoring in the resection of vestibular schwannoma, especially evaluating its significance for hearing preservation. Methods: From April 2018 to December 2021, 54 patients with vestibular schwannoma who underwent resection via retrosigmoid approach were collected in Chinese PLA General Hospital. Before surgery, all patients had effective hearing (AAO-HNS grade C or above). Brainstem auditory evoked potential (BAEP) combined with CNAP monitoring was performed during surgery. The CNAP monitoring was combined with continuous monitoring and cochlear nerve mapping. And patients were divided into hearing preservation group and non-preserved group according to postoperative AAO-HNS grade. SPSS 23.0 software was used to analyze the differences of CNAP and BEAP parameters between the two groups. Results: A total of 54 patients completed intraoperative monitoring and data collection, including 25 males (46.3%) and 29 females (53.7%), aged 27-71 years with an average age of 46.2 years. The maximum tumor diameter were (18.1±5.9) mm (range 10-34 mm). All tumors were totally removed with preserved facial nerve function (House-Brackmann grade I-II). The hearing preservation rate of 54 patients was 51.9% (28/54). During surgery, the V wave extraction rate of BAEP waveform was 85.2% (46/54) before tumor resection, 71.4% (20/28) in the hearing preservation group after tumor resection, and disappeared in the hearing preservation group (0/26). CNAP waveform was elicited in 54 patients during operation. Differences were found in the distribution of CNAP waveforms after tumor resection. The waveforms of the hearing-preserving group were triphasic and biphasic, while those in the non-preserving group were low-level and positive. For hearing preservation group, the amplitude of N1 wave after tumor resection was significantly higher than that before tumor resection[14.45(7.54, 33.85)μV vs 9.13(4.88, 23.35)μV, P=0.022]; However, for the non-preserved group, the amplitude of N1 wave after tumor resection was significantly lower than that before tumor resection [3.07(1.96, 4.60)μV vs 6.55(4.54, 9.71)μV, P=0.007]; After tumor resection, the amplitude was significantly higher than that of the unreserved group [14.45(7.54, 33.85)μV vs 3.07(1.96, 4.60)μV, P<0.001]. Conclusions: BAEP combined with CNAP monitoring is conducive to intraoperative hearing protection, and the application of cochlear nerve mapping can prompt the surgeon to avoid nerve injury. The waveform and N1 amplitude of CNAP after tumor resection have a certain value in predicting postoperative hearing preservation status.

Primary ossiculoplasties provide better hearing results than revisions: a retrospective cohort study

PurposeTo evaluate the efficacy of ossicular chain reconstruction (OCR) in primary and revision surgeries, and to investigate the impact of the number of previous surgeries on hearing outcomes.MethodsRetrospective analysis of cases with OCR due to chronic otitis in a tertiary center between January 2018 and September 2021.ResultsAltogether, 147 cases of ossicle involvement were assessed. In 91.83% (n = 135) OCR was performed, 96.26% of them with titanium TORP/PORP (n = 130), two cases with autologous prosthesis and three with piston. Mean follow-up was 8.8 months. The ABG significantly improved in the total group (TORP/PORP) from a mean (SD) of 30.94 (15.55) to 19.76 (13.36) dB (p < 0.0001) with 60.86% success. The best results were achieved in primary OCR with PORP implantation without cholesteatoma (89.47%). Primary cases have a significantly higher success rate in contrary to revision surgeries (72.27%, vs. 52.00%, p = 0.032). The only relevant predictive factor proved to be the fact of revision (p = 0.029). A statistically significant correlation between the number of previous surgeries and hearing results could not be proved. There was no difference in hearing outcomes between patients with only one or more than one previous surgeries in the revision groups. Neither the presence of cholesteatoma, nor the type of OCR (TOPR/PORP) and the indication of revision had an impact on postoperative ABG.ConclusionsTitanium prostheses are effective in OCR both in primary and revision cases. It is not the number of previous surgeries, but the fact of revision that influences postoperative hearing results.

Longitudinal Electrocochleography as an Objective Measure of Serial Behavioral Audiometry in Electro-Acoustic Stimulation Patients.

Minimally traumatic surgical techniques and advances in cochlear implant (CI) electrode array designs have allowed acoustic hearing present in a CI candidate prior to surgery to be preserved postoperatively. As a result, these patients benefit from combined electric-acoustic stimulation (EAS) postoperatively. However, 30% to 40% of EAS CI users experience a partial loss of hearing up to 30 dB after surgery. This additional hearing loss is generally not severe enough to preclude use of acoustic amplification; however, it can still impact EAS benefits. The use of electrocochleography (ECoG) measures of peripheral hair cell and neural auditory function have shed insight into the pathophysiology of postimplant loss of residual acoustic hearing. The present study aims to assess the long-term stability of ECoG measures and to establish ECoG as an objective method of monitoring residual hearing over the course of EAS CI use. We hypothesize that repeated measures of ECoG should remain stable over time for EAS CI users with stable postoperative hearing preservation. We also hypothesize that changes in behavioral audiometry for EAS CI users with loss of residual hearing should also be reflected in changes in ECoG measures. A pool of 40 subjects implanted under hearing preservation protocol was included in the study. Subjects were seen at postoperative visits for behavioral audiometry and ECoG recordings. Test sessions occurred 0.5, 1, 3, 6, 12 months, and annually after 12 months postoperatively. Changes in pure-tone behavioral audiometric thresholds relative to baseline were used to classify subjects into two groups: one group with stable acoustic hearing and another group with loss of acoustic hearing. At each test session, ECoG amplitude growth functions for several low-frequency stimuli were obtained. The threshold, slope, and suprathreshold amplitude at a fixed stimulation level was obtained from each growth function at each time point. Longitudinal linear mixed effects models were used to study trends in ECoG thresholds, slopes, and amplitudes for subjects with stable hearing and subjects with hearing loss. Preoperative, behavioral audiometry indicated that subjects had an average low-frequency pure-tone average (125 to 500 Hz) of 40.88 ± 13.12 dB HL. Postoperatively, results showed that ECoG thresholds and amplitudes were stable in EAS CI users with preserved residual hearing. ECoG thresholds increased (worsened) while ECoG amplitudes decreased (worsened) for those with delayed hearing loss. The slope did not distinguish between EAS CI users with stable hearing and subjects with delayed loss of hearing. These results provide a new application of postoperative ECoG as an objective tool to monitor residual hearing and understand the pathophysiology of delayed hearing loss. While our measures were conducted with custom-designed in-house equipment, CI companies are also designing and implementing hardware and software adaptations to conduct ECoG recordings. Thus, postoperative ECoG recordings can potentially be integrated into clinical practice.

Radiological and audiological predictors of stapes destruction in adherent pars tensa.

Progressive adherent pars tensa occasionally induces ossicular erosion. Specifically, stapes discontinuity adversely affects postoperative hearing. However, this irretrievable sequela is challenging to prove preoperatively, partly because perimatrix inflammation on the pars tensa can obscure the visibility of the ossicles or the partial volume effect of computed tomography (CT) imaging can hamper detailed ossicular visualization. Therefore, there is no consensus regarding the ideal timing for switching from a wait-and-see approach to a surgical one. Herein, we aimed to explore the potential predictors of stapes superstructure destruction in adherent pars tensa. This retrospective cohort study enrolled consecutive patients who underwent primary tympanoplasty for adherent pars tensa categorized as grade IV on Sadé's grading scale between April 2016 and September 2021. The impact of features on otoscopy and CT and air-bone gap (ABG) on stapes superstructure destruction was assessed using uni- and multivariable logistic regression analyses. Sixty-four ears were included. Multivariate analysis revealed the presence of debris on the adherent pars tensa (odds ratio [OR] [95% confidence interval {CI}]): 4.799 [1.063-21.668], p = 0.0415), presence of soft-tissue density occupying the oval window (OR [95% CI]: 13.876 [3.084-62.437], p = 0.0006), and a ≥ 20-dB preoperative ABG at 3kHz (OR [95% CI]: 7.595 [1.596-36.132], p = 0.0108) as independent predictors for stapes superstructure destruction. High preoperative awareness of the possibility of destruction of the stapes superstructure would enable the surgeon to make a timely decision to provide surgical intervention before progression to severe stapes destruction, thereby maintaining long-term satisfactory hearing.

Endoscopic vs microscopic facial nerve decompression for traumatic facial nerve palsy: a randomized controlled trial.

To explore a minimally invasive trans-canal endoscopic facial nerve decompression for traumatic facial nerve palsy and compare it with microscopic facial nerve decompression. 35 and 38 patients underwent endoscopic and microscopic facial nerve decompression, respectively, for traumatic facial nerve palsy. Onset of symptoms, type of temporal bone fracture, day of surgical intervention following trauma, ossicular chain status and nature of insult to facial nerve were observed. Time period for recovery (House Brackmann grade ≤ 3), long term recovery rates, pre- and post-operative hearing status, surgical time and post-operative pain were compared between groups. Maximum patients in endoscopic and microscopic groups (77.1% and 76.3%, respectively) had acute onset of symptoms. 57.1% (20/35) had longitudinal, 17.1% (6/35) had transverse and 25.7% (9/35) had mixed fractures in endoscopic group. In the microscopic group, 57.9% (22/38) had longitudinal, 18.4% (7/38) had transverse and 23.7% (9/38) had mixed fractures. The mean (± S.D.) post-operative air-bone gap in endoscopic and microscopic group were 16.47 ± 4.5dB and 19.4 ± 5.2dB, respectively, which was statistically significant. The mean (± S.D.) time period for recovery of endoscopic and microscopic groups were 14.4 ± 5days and 22.5 ± 7days, respectively (p value < 0.05). The difference in post-operative pain between the two groups was also statistically significant. The difference in long term recovery rates was not statistically significant (p > 0.05). Endoscopic facial nerve decompression results in early recovery, less post-operative pain and better post-operative air-bone gap closure when compared to conventional microscopic technique.

Retrospective Study of 157 Patients with Otosclerosis to Evaluate Association Between Carhart Notch on the Preoperative Bone-Conduction Audiogram and Postoperative Hearing and Balance Evaluated by the Vestibular Disorders Activities of Daily Living Scale.

BACKGROUND A Carhart notch in the pure tone audiogram can be an indicator of stapes fixation in otosclerosis. This retrospective study of 157 patients with otosclerosis aimed to evaluate the association between the presence of a Carhart notch on the preoperative bone-conduction audiogram and postoperative hearing and balance evaluated by the Vestibular Disorders Activities of Daily Living scale. MATERIAL AND METHODS Patients with suspected otosclerosis based on medical history and audiometric tests were considered. The analysis included 157 consecutive patients who underwent surgery in the years 2016 to 2019, in whom the diagnosis of otosclerosis was confirmed during surgery. Carhart notch was defined as an impairment in the bone conduction threshold of ≥7.5 dB for 2000 Hz frequencies above the mean thresholds at higher and lower adjacent frequencies. The Vestibular Disorders Activities of Daily Living subjective scale was used in the preoperative period and 4 and 12 months after surgery. RESULTS The preoperative presence of Carhart notch and progressive sensorineural hearing loss were statistically significantly correlated with more common onset of tinnitus and then dizziness (P=0.006). Preoperative vertigo was observed in patients who had Carhart notch observed in the preoperative audiometric test. This vertigo more commonly coexisted with profound sensorineural hearing loss and minor or no improvement in average values of bone conduction after surgery (P=0.002). CONCLUSIONS Preoperative Carhart notch on audiogram and the severity of sensorineural hearing loss were associated with tinnitus and vertigo. However, preoperative Carhart notch was not associated with persistent postoperative tinnitus in patients with cochlear otosclerosis.

Vestibular Schwannoma Surgery with Endoscope-Assisted Retrolabyrinthine Approach under Modified Reinforced Continuous Intraoperative Monitoring for Hearing Preservation: Experience of 33 Cases in a Single Center.

Surgery for vestibular schwannoma includes various techniques such as the middle cranial fossa, suboccipital, translabyrinthine, and retrolabyrinthine approaches. The retrolabyrinthine approach does not impair the labyrinth and allows postoperative hearing preservation. Previously, we reported an endoscope-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring for preservation of hearing and facial nerve function. However, the hearing preservation rate was relatively low in patients with long-wave V latency in the auditory brainstem response or poor otoacoustic emission response under this approach. Thus, the hearing preservation rate in such patients remains to be improved. To overcome this limitation, we modified the previous approach. In 26 of the 33 consecutive cases (79%) over the last three years, preservation of hearing equivalent to that before surgery or improved hearing was achieved. Postoperative deafness was observed in only two of the 33 cases (6%). According to previous reports, the rate of hearing preservation using the retrolabyrinthine approach is approximately 30-50%. Therefore, we have achieved a higher hearing preservation rate than that previously reported using the endoscopy-assisted retrolabyrinthine approach under reinforced continuous intraoperative monitoring. These improvements in our department are considered to be helpful for hearing preservation.