Traumatic Events Preceding the Development of Superior Canal Dehiscence Syndrome.

OBJECTIVE: To describe the features of antecedent head trauma in patients with superior canal dehiscence syndrome (SCDS). STUDY DESIGN: Cross-sectional survey. SETTING: Tertiary referral center. METHODS: An online survey was sent to 450 adult patients who underwent surgical repair for SCDS patients asking questions about the nature of internal or external traumatic events preceding symptoms. RESULTS: One-hundred and thirty-six patients (avg. age, 51.9 years, 62.8% female) completed the survey, of which 61 (44.9%) described either preceding external head trauma (n = 35, 26%), preceding internal pressure event (n = 33, 25%), or both (8, 6%). Of those endorsing external trauma, 22 (63%) described a singular event (head hit by object (n = 8); head hit ground (n = 5); motor vehicle accident (n = 4); assault (n = 2); other (n = 3). One-third experienced loss of consciousness because of the trauma. For those describing internal pressure events (n = 33), the most common events were heavy physical exertion (9, 27%); pressure changes while flying (6, 18%); coughing, nose blowing with illness (5, 15%); childbirth (5, 15%); and self contained underwater breathing apparatus diving events (3, 9%). The interval between trauma and onset of symptoms averaged 5.6 years (SD, 10.7 years). One-third (n = 19) described onset of symptoms immediately after the external trauma or internal pressure event. Symptoms began on the side ipsilateral to the trauma in 91%. Sound- and pressure-induced vertigo/oscillopsia developed more commonly after external trauma versus internal pressure events (68% and 61% vs 44% and 32%, respectively). CONCLUSION: Trauma or internal pressure-related events precede SCDS symptoms in nearly half of cases, with roughly half of preceding events being external.

Patient-Reported Outcomes After Vestibular Implantation for Bilateral Vestibular Hypofunction.

Importance: Standard-of-care treatment proves inadequate for many patients with bilateral vestibular hypofunction (BVH). Vestibular implantation is an emerging alternative. Objective: To examine patient-reported outcomes from prosthetic vestibular stimulation. Design, Setting, and Participants: The Multichannel Vestibular Implant (MVI) Early Feasibility Study is an ongoing prospective, nonrandomized, single-group, single-center cohort study conducted at Johns Hopkins Hospital that has been active since 2016 in which participants serve as their own controls. The study includes adults with severe or profound adult-onset BVH for at least 1 year and inadequate compensation despite standard-of-care treatment. As of March 2023, 12 candidates completed the eligibility screening process. Intervention: The MVI system electrically stimulates semicircular canal branches of the vestibular nerve to convey head rotation. Main Outcomes and Measures: Patient-reported outcome instruments assessing dizziness (Dizziness Handicap Inventory [DHI]) and vestibular-related disability (Vestibular Disorders-Activities of Daily Living [VADL]). Health-related quality of life (HRQOL) assessed using the Short Form-36 Utility (SF36U) and Health Utilities Index Mark 3 (HUI3), from which quality-adjusted life-years were computed. Results: Ten individuals (5 female [50%]; mean [SD] age, 58.5 [5.0] years; range, 51-66 years) underwent unilateral implantation. A control group of 10 trial applicants (5 female [50%]; mean [SD] age, 55.1 [8.5] years; range, 42-73 years) completed 6-month follow-up surveys after the initial application. After 0.5 years of continuous MVI use, a pooled mean (95% CI) of within-participant changes showed improvements in dizziness (DHI, -36; 95% CI, -55 to -18), vestibular disability (VADL, -1.7; 95% CI, -2.6 to -0.7), and HRQOL by SF36U (0.12; 95% CI, 0.07-0.17) but not HUI3 (0.02; 95% CI, -0.22 to 0.27). Improvements exceeded minimally important differences in the direction of benefit (exceeding 18, 0.65, and 0.03, respectively, for DHI, VADL, and SF36U). The control group reported no mean change in dizziness (DHI, -4; 95% CI, -10 to 2), vestibular disability (VADL, 0.1; 95% CI, -0.9 to 1.1) or HRQOL per SF36U (0; 95% CI, -0.06 to 0.05) but an increase in HRQOL per HUI3 (0.10; 95% CI, 0.04-0.16). Lifetime HRQOL gain for MVI users was estimated to be 1.7 quality-adjusted life-years (95% CI, 0.6-2.8) using SF36U and 1.4 (95% CI, -1.2 to 4.0) using HUI3. Conclusions and Relevance: This cohort study found that vestibular implant recipients report vestibular symptom improvements not reported by a control group. These patient-reported benefits support the use of vestibular implantation as a treatment for bilateral vestibular hypofunction.

The association of hearing loss with frailty among community-dwelling older adults: findings from the National Health and Aging Trends Study.

BACKGROUND: The identification of modifiable risk factors is crucial for the prevention and/or reversal of frailty, which is associated with significant morbidity and mortality. Hearing loss affects two-thirds of older adults in the United States (U.S.) and is associated with physical and cognitive decline which may increase frailty risk. We investigated the association of hearing loss and hearing aid use with frailty and pre-frailty in a nationally representative sample of older adults in the U.S. METHODS: Cross-sectional analysis of the National Health and Aging Trends Study (2021 round). The better-hearing ear pure-tone average (BPTA) at speech-frequencies (0.5-4 kHz) was modeled continuously (per 10 dB) and categorically (no ≤ 25 dB, mild 26-40 dB, moderate or greater > 40 dB hearing loss). Hearing aid use was self-reported. The physical frailty phenotype (frail, pre-frail, robust) was determined based on Fried criteria: unintentional weight loss, exhaustion, low physical activity, weakness, slow walking speed. We used multinomial multivariable regression adjusted for sociodemographic and health characteristics (odds ratios [95% Confidence Intervals]). RESULTS: Among 2,361 participants (mean age = 81 years, 56% female, 19% Black), 860 (36%) had mild and 864 (37%) had moderate or greater hearing loss. Worse hearing was associated with greater odds of being frail versus robust (OR = 1.20 [1.05-1.38] per 10 dB difference). Categorically, moderate or greater hearing loss was associated with greater odds of being frail (OR = 1.84 [1.01-3.08]) and pre-frail (OR = 1.46 [1.01-2.10]) versus robust. Among 1,724 participants with hearing loss, compared to hearing aid users (N = 522), nonusers had greater odds of being frail (OR = 2.54 [1.54-4.18]) and pre-frail (OR = 1.51 [1.05-2.17]) versus robust, and frail versus pre-frail (OR = 1.68 [1.04-2.72]). CONCLUSIONS: In a nationally representative sample of older adults in the U.S., using gold-standard hearing measures and a validated frailty phenotype, hearing loss and lack of hearing aid use was cross-sectionally associated with frailty and pre-frailty. Future longitudinal studies are needed to establish if hearing loss is a risk factor for frailty, which may have significant clinical importance.

Detection and Quantification of Calcitonin Gene-Related Peptide (CGRP) in Human Plasma Using a Modified Enzyme-Linked Immunosorbent Assay.

Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide that plays a putative role in the pathophysiology of migraine headaches and may be a candidate for biomarker status. CGRP is released from neuronal fibers upon activation and induces sterile neurogenic inflammation and arterial vasodilation in the vasculature that receives trigeminal efferent innervation. The presence of CGRP in the peripheral vasculature has spurred investigations to detect and quantify this neuropeptide in human plasma using proteomic assays, such as the enzyme-linked immunosorbent assay (ELISA). However, its half-life of 6.9 min and the variability in technical details of assay protocols, which are often not fully described, have yielded inconsistent CGRP ELISA data in the literature. Here, a modified ELISA protocol for the purification and quantification of CGRP in human plasma is presented. The procedural steps involve sample collection and preparation, extraction using a polar sorbent as a means of purification, additional steps to block non-specific binding, and quantification via ELISA. Further, the protocol has been validated with spike and recovery and linearity of dilution experiments. This validated protocol can theoretically be used to quantify CGRP concentrations in the plasma of individuals not only with migraine, but also with other diseases in which CGRP may play a role.

Cochlear Aqueduct Morphology in Superior Canal Dehiscence Syndrome.

The cochlear aqueduct (CA) connects the scala tympani to the subarachnoid space and is thought to assist in pressure regulation of perilymph in normal ears, however, its role and variation in inner ear pathology, such as in superior canal dehiscence syndrome (SCDS), is unknown. This retrospective radiographic investigation compared CA measurements and classification, as measured on flat-panel computerized tomography, among three groups of ears: controls, n = 64; anatomic superior canal dehiscence without symptoms (SCD), n = 28; and SCDS, n = 64. We found that in a multinomial logistic regression adjusted for age, sex, and BMI, an increase in CA length by 1 mm was associated with a lower odds for being in the SCDS group vs. control (Odds ratio 0.760 p = 0.005). Hierarchical clustering of continuous CA measures revealed a cluster with small CAs and a cluster with large CAs. Another multinomial logistic regression adjusted for the aforementioned clinical covariates showed an odds ratio of 2.97 for SCDS in the small CA cluster as compared to the large (p = 0.004). Further, no significant association was observed between SCDS symptomatology-vestibular and/or auditory symptoms-and CA structure in SCDS ears. The findings of this study lend support to the hypothesis that SCDS has a congenital etiology.

Vestibular Implantation Can Work Even After More Than 20 Years of Bilateral Vestibular Hypofunction.

OBJECTIVE: To determine whether prosthetic stimulation delivered via a vestibular implant can elicit artificial sensation of head movement despite long (23-yr) duration adult-onset ototoxic bilateral vestibular hypofunction (BVH). STUDY DESIGN: Case report. SETTING: Tertiary care center as part of a first-in-human clinical trial. PATIENTS: One. INTERVENTIONS: Unilateral vestibular implantation with an investigational multichannel vestibular implant in a 55-year-old man with a well-documented 23-year history of aminoglycoside-induced BVH. MAIN OUTCOME MEASURES: Electrically evoked vestibulo-ocular reflexes (eeVOR). RESULTS: Vestibular implant stimulation can drive stimulus-aligned eeVOR and elicit a vestibular percept 23 years after the onset of bilateral vestibulopathy. Prosthetic stimulation targeting individual semicircular canals elicited eye movements that approximately aligned with each targeted canal's axis. The magnitude of the eeVOR response increased with increasing stimulus current amplitude. Response alignment and magnitude were similar to those observed for implant recipients who underwent vestibular implantation less than 10 years after BVH onset. Responses were approximately stable for 18 months of continuous device use (24 h/d except during sleep). CONCLUSIONS: Vestibular implantation and prosthetic electrical stimulation of semicircular canal afferent nerves can drive canal-specific eye movement responses more than 20 years after the onset of ototoxic vestibular hypofunction.

Otolith Membrane Herniation, not Semicircular Canal Duct Dilation, Is Associated with Decreased Caloric Responses in Ménière's Disease.

Ménière's disease (MD) is a debilitating disorder with unclear pathophysiology whose diagnosis often relies on clinical judgment rather than objective testing. To complicate matters further, a dissociation has emerged between two vestibular function tests commonly used in patients with MD to examine the same end-organ (the semicircular canals): the caloric test and video head impulse testing (vHIT). Caloric responses are often abnormal, while vHIT results remain normal. Explaining this dissociation could reveal novel insights into MD pathophysiology. Here, we conduct a histopathological study using temporal bone specimens (N = 58, 21 MD-affected ears and 37 age-matched controls) and their clinical testing data to examine current hypotheses aimed at this dissociation. We find otolith membrane herniation into the horizontal semicircular canal in 69% of MD ears, with 90% of these ears demonstrating a diminished caloric response. No ears with a normal response had this herniation. Moreover, we evaluated the semicircular canals for endolymphatic hydrops, which had been hypothesized to contribute to the dissociation, and found no evidence of duct dilation/hydrops. We did, however, note a potentially novel morphologic finding-smaller bony labyrinth cross-sectional diameters/areas in some MD ear canals compared to controls, suggesting relative size of the membranous duct to the bony canal rather than absolute size may be of importance. Taken together, this study refines hypotheses on the vestibular test dissociation in MD, holding diagnostic implications and expanding our understanding of the mechanisms underlying this enigmatic disease.

Augmented Reality in Otology/Neurotology: A Scoping Review with Implications for Practice and Education.

OBJECTIVE: To determine how augmented reality (AR) has been applied to the field of otology/neurotology, examine trends and gaps in research, and provide an assessment of the future potential of this technology within surgical practice and education. DATA SOURCES: PubMed, EMBASE, and Cochrane Library were assessed from their inceptions through October 2022. A manual bibliography search was also conducted. REVIEW METHODS: A scoping review was conducted and reported according to PRISMA-ScR guidelines. Data from studies describing the application of AR to the field of otology/neurotology were evaluated, according to a priori inclusion/exclusion criteria. Exclusion criteria included non-English language articles, abstracts, letters/commentaries, conference papers, and review articles. RESULTS: Eighteen articles covering a diverse range of AR platforms were included. Publication dates spanned from 2007 to 2022 and the rate of publication increased over this time. Six of 18 studies were case series in human patients although the remaining were proof of concepts in cadaveric/artificial/animal models. The most common application of AR was for surgical navigation (14 of 18 studies). Computed tomography was the most common source of input data. Few studies noted potential applications to surgical training. CONCLUSION: Interest in the application of AR to otology/neurotology is growing based on the number of recent publications that use a broad range of hardware, software, and AR platforms. Large gaps in research such as the need for submillimeter registration error must be addressed prior to adoption in the operating room and for educational purposes. LEVEL OF EVIDENCE: N/A Laryngoscope, 133:1786-1795, 2023.

Combined Arterial and Venous Phase Computed Tomographic Imaging of the Skull Base in Pulsatile Tinnitus.

OBJECTIVE: To describe the demographic, clinical, and radiologic findings in a consecutive series of patients presenting with a chief complaint of pulsatile tinnitus (PT). STUDY DESIGN: Retrospective review of 157 patients undergoing a combined arterial/venous phase computed tomographic (CT) imaging study. SETTING: Tertiary referral center. PATIENTS: Adult patients referred to neurotology faculty for evaluation of PT between 2016 and 2020. INTERVENTIONS: Triple phase high-resolution arteriography/venography/temporal bone CT. MAIN OUTCOME MEASURES: Prevalence of osseous, venous, and/or arterial pathology, clinicodemographic characteristics. RESULTS: One hundred fifty-seven adults (mean age, 52 years; 79.6% female) were evaluated. A history of migraine headaches was common (19.7%). The average body mass index was 30.0 (standard deviation, 6.8), and 17.2% of subjects had a diagnosis of obstructive sleep apnea. Idiopathic intracranial hypertension was diagnosed by elevated opening pressure on lumbar puncture in 13.4%. Comorbid depression and anxiety were common (25.5% and 26.1%, respectively). Overall, abnormalities were found in 79.0% of scans, with bilateral transverse sinus stenosis (TSS) seen in 38.9% and unilateral TSS found in 20.4%. Fifteen subjects (9.6%) had evidence of osseous etiologies, including superior canal dehiscence or thinning in 8.9% and sigmoid sinus dehiscence in one subject. There were 3 dural arteriovenous fistulae identified. Unilateral PT was ipsilateral to the side of TSS in 84.4% of subjects with unilateral TSS. CONCLUSION: In a large consecutive series of patients with PT referred for CT venography/arteriography, transverse sinus stenosis was the most common finding at 59%. Venous etiologies for PT should be suspected when patients are referred to neurotologists for evaluation.

Predictive Factors for Concurrent Tegmen Dehiscence in Superior Canal Dehiscence Syndrome.

OBJECTIVES: To describe factors predictive of tegmen dehiscence in subjects with superior semicircular canal dehiscence syndrome (SCDS). STUDY DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Subjects with SCDS who underwent middle fossa craniotomy (MFC) for plugging/resurfacing. MAIN OUTCOME MEASURES: Operative and radiographic findings of tegmen dehiscences, preoperative low frequency air-bone gaps (LF-ABGs), ocular vestibular evoked myogenic potential (oVEMP) amplitudes, size of superior semicircular canal dehiscence (SCD), and history of obesity or obstructive sleep apnea (OSA). RESULTS: One hundred thirty six patients (avg. age, 50.6 yr, 55.1% female) underwent MFC for repair of SCDS. Tegmen dehiscences were commonly found intraoperatively (tegmen tympani dehiscence [TTD] in 19.9% [11% with dural contact of ossicles], tegmen mastoideum dehiscence [TMD] in 28.7%). There were no differences in preoperative LF-ABGs and preoperative oVEMP amplitudes with respect to tegmen status. The sensitivity and specificity of computed tomography (CT) for predicting an intraoperatively confirmed TTD was 85 and 74%, respectively, and 44 and 79% for TMD. History of obesity and OSA did not differ between those with and without tegmen dehiscences. The presence of contralateral SCD and increasing cross-sectional area of SCD were both significantly associated with concurrent tegmen defects. CONCLUSIONS: Obesity, OSA, preoperative oVEMP, and LF-ABG do not differ between those with SCD alone and those with SCD and concurrent tegmen dehiscences. Likewise, CT scans have relatively low sensitivity for identifying tegmen dehiscences. The presence of concurrent tegmen defects is more common in subjects with larger SCD cross-sectional areas and contralateral SCD.

2D Measurements of the Angle of the Vestibular Aqueduct Using CT Imaging.

Recently, Bächinger et al. developed a software that measures the angle between the vestibular aqueduct proximal to the vestibule and the distal vestibular aqueduct on computed tomography (CT) scans and found differences in the vestibular aqueduct angle between the hypoplastic and degenerative categories of Meniere's disease (MD). Hypoplastic radiological findings were associated with the development of bilateral MD and hypoplastic changes were not found outside of fetal temporal bones and individuals with MD. The purpose of this study is to examine how the software developed by Bächinger et al. performs when applied to a large dataset of adult patients with varied otologic diagnoses. Adult patients who underwent high resolution flat panel CT scans without intravenous contrast (n = 301) were retrospectively reviewed. Measurements of the angle of the vestibular aqueduct were made using the previously developed software tool. The tool could be applied to measure the vestibular aqueduct angle in most CT scans of the temporal bones (n = 572 ears, 95%). While the majority of ears fell within the normal range of <120 degrees (n = 462, 80%), fourteen ears (2.3%) in 13 patients were found to have vestibular aqueduct angles that meet criteria for hypoplastic MD (>140 degrees). Only one of the 13 patients had a diagnosis of MD and not in the ear in the hypoplastic category. An inconsistent pattern of other otologic diagnoses were found among the 13 individuals meeting criteria for hypoplastic MD. Although prior reports indicate the software has prognostic value in individuals with MD, these results suggest that the software may have lower positive predictive value when applied to a large population of individuals with varied otologic diagnoses.

Three dimensional printing of a low-cost middle-ear training model for surgical management of otosclerosis.

BACKGROUND: Surgical management of otosclerosis is technically challenging with studies demonstrating that outcomes are commensurate with surgical experience. Moreover, experts apply less force on the ossicular chain during prosthesis placement than their novice counterparts. Given the predicted decreasing patient pool and the rising cost of human temporal bone specimens it has become more challenging for trainees to receive adequate intraoperative or laboratory-based experience in this procedure. As such, there is a need for a low-cost training model for the procedure. Here we describe such a model. METHODS: A surgical model of the middle ear was designed using computer aided design (CAD) software. The model consists of four components, the superior three dimensional (3D)-printed component representing the external auditory canal, a 90° torsion spring representing the incus, a 3D-printed base with a stapedotomy underlying the torsion spring, and a 3D-printed phone holder to facilitate video-recording of trials and subsequent calculation of the force applied on the modeled incus. Force applied on the incus is calculated based on Hooke's Law from post-trial computer-vision analysis of recorded video following experimental determination of the spring constant of the modeled incus. RESULTS: The described model was manufactured with a total cost of $56.50. The spring constant was experimentally determined to be 97.0 mN mm/deg, resulting in an ability to detect force applied to the modeled incus across a range of 1.2 to 5200 mN. CONCLUSIONS: We have created a low-cost middle-ear training model with measurable objective performance outcomes. The range of detectable force exceeds expected values for the task.Level of Evidence: IV.

A Cohort Study Comparing Importance of Clinical Factors in Determining Diagnosis and Treatment for Superior Semicircular Canal Dehiscence Syndrome.

OBJECTIVE: To determine which clinical factors have the strongest impact on determining diagnosis and decision for surgical repair for superior semicircular canal dehiscence syndrome (SCDS). PATIENTS: A total of 81 patients presented with a suspicion for SCDS between October 2017 and October 2018. 38 patients ultimately were diagnosed with SCDS, and 28 chose surgical repair. METHODS: Clinical factors of subjective patient symptoms (autophony, sensitivity to loud sounds, vertigo induced by loud sounds, dizziness, hearing their own heartbeats or other visceral organs) and audiogram findings (low frequency conductive hearing loss [CHL], bone-conduction hyperacusis, low cVEMP threshold [<80 db nHL], increased oVEMP [>17 µV] amplitudes) were analyzed with logistic regression to identify factors that predicted those who would ultimately be diagnosed with SCDS and those who would have surgical repair. Preoperative high-resolution CT imaging was performed on all patients. RESULTS: Significant predictors of presence of SCDS from logistic regression included low frequency CHL and increased oVEMP amplitude (p = 0.002 [OR 40, 95%CI 3.8-413], p = 0.001 [OR 93, 95%CI 6.8-1267], respectively). These were also significant predictors of individuals who chose to have surgical repair (p = 0.004 [OR 47, 95%CI 3.5-620], p = 0.001 [OR 126, 95%CI 8.2-1941], respectively). Area under the receiver operating characteristic curve (ROC curve) for these two variables are 93% for diagnosing SCDS and 94% for predicting choice for surgical repair. CONCLUSIONS: Low frequency CHL and increased oVEMP amplitude are the strongest predictive factors for making a diagnosis of SCDS and for choosing surgical repair.

Volumetric Accuracy Analysis of Virtual Safety Barriers for Cooperative-Control Robotic Mastoidectomy.

HYPOTHESIS: Virtual fixtures can be enforced in cooperative-control robotic mastoidectomies with submillimeter accuracy. BACKGROUND: Otologic procedures are well-suited for robotic assistance due to consistent osseous landmarks. We have previously demonstrated the feasibility of cooperative-control robots (CCRs) for mastoidectomy. CCRs manipulate instruments simultaneously with the surgeon, allowing the surgeon to control instruments with robotic augmentation of motion. CCRs can also enforce virtual fixtures, which are safety barriers that prevent motion into undesired locations. Previous studies have validated the ability of CCRs to allow a novice surgeon to safely complete a cortical mastoidectomy. This study provides objective accuracy data for CCR-imposed safety barriers in cortical mastoidectomies. METHODS: Temporal bone phantoms were registered to a CCR using preoperative computed tomography (CT) imaging. Virtual fixtures were created using 3D Slicer, with 2D planes placed along the external auditory canal, tegmen, and sigmoid, converging on the antrum. Five mastoidectomies were performed by a novice surgeon, moving the drill to the limit of the barriers. Postoperative CT scans were obtained, and Dice coefficients and Hausdorff distances were calculated. RESULTS: The average modified Hausdorff distance between drilled bone and the preplanned volume was 0.351 ±â€Š0.093 mm. Compared with the preplanned volume of 0.947 cm3, the mean volume of bone removed was 1.045 cm3 (difference of 0.0982 cm3 or 10.36%), with an average Dice coefficient of 0.741 (range, 0.665-0.802). CONCLUSIONS: CCR virtual fixtures can be enforced with a high degree of accuracy. Future studies will focus on improving accuracy and developing 3D fixtures around relevant surgical anatomy.

Hearing Outcomes for an Underwater Endoscopic Technique for Transmastoid Repair of Superior Semicircular Canal Dehiscence.

OBJECTIVES: To compare hearing outcomes between traditional microsurgical transmastoid repairs and underwater, endoscopic transmastoid repairs of superior semicircular canal dehiscence syndrome (SCDS). METHODS: A retrospective review of 14 patients undergoing transmastoid repair of SCDS between 2013 and 2017. Preoperative, immediate (7-10 d) postoperative, and long-term (>6 wk) postoperative speech discrimination scores, pure-tone averages, as well as pure-tone air conduction and bone conduction thresholds were obtained at 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz. Hearing threshold changes were all calculated as preoperative thresholds subtracted from postoperative threshold at each frequency. Wilcoxon rank-sum tests were conducted to assess changes in postoperative hearing thresholds at both the immediate and long-term postoperative period between those undergoing the traditional transmastoid technique and the underwater, endoscopic transmastoid technique. RESULTS: Our results demonstrate patients who underwent underwater transmastoid repairs had significantly less increase in their high-frequency bone conduction thresholds at both time periods, indicating less sensorineural hearing loss, compared to the traditional microscopic repair (p = 0.02 [effect size, r = 0.4], p = 0.006 [r = 0.6]). At long-term follow-up, there was also significantly improved pure-tone averages in the patients in the underwater repair cohort compared to the traditional group (p = 0.004 [r = 0.6]). There were no differences in air-bone gaps at any frequency or any time period between the two cohorts. CONCLUSIONS: Preliminary findings show that the underwater endoscopic technique may prevent sensorineural hearing loss during transmastoid repair of SCDS.