BackgroundThe BONEBRIDGE bone conduction implant (BB-BCI) (MED-EL GmbH, Innsbruck, Austria) is an active transcutaneous system indicated for patients with conductive or mixed hearing loss, or single-sided deafness. It was first launched in 2012 as the BCI 601, with a second-generation implant (BCI 602) released in 2019. The BCI 602 features a thinner implantable portion, which expanded selection criteria to include patients who previously could not receive the implant. The middle fossa surgical approach offers a viable alternative for patients with mastoid anatomy which precludes implantation in the traditional transmastoid position, including patients with sclerotic mastoids, mastoid cavities, and histories of recurrent mastoiditis.MethodsAn institutional review was conducted of patients who underwent unilateral BB-BCI implantation with either implant generation via the middle fossa approach between April 2013 and March 2025. Preoperative air conduction (AC) and bone conduction (BC) pure-tone averages (PTAs) measured at 0.5–3.0 kHz, postoperative aided thresholds, and speech perception scores (CNC words and AzBio sentences) at an average of 6.5 months post-implantation were recorded. Surgical outcomes and complications were also reviewed.ResultsSeventy-two patients were included in the review (30 male, 42 female; mean age at implantation 43.9 years; 48 with conductive hearing loss, 24 with mixed hearing loss; 39 implanted on the right side). For the BCI 601 group (n =44), AC and BC PTAs were 64.3 ± 14.7 dB (mean ± standard deviation) and 24.1 ± 12.6 dB, respectively; for the BCI 602 group (n = 28), they were 64.5 ± 14.8 dB and 23.4 ± 13.2 dB, respectively. The mean ABG was 41.1 dB across the cohort. Mean functional gain was 38.7 ± 15.0 dB, with no significant difference between groups (601: 38.5 ± 15.0 dB; 602: 39.1 ± 15.2 dB; p = 0.85). Speech perception improved for all patients postoperatively. No intraoperative complications or revision surgeries were reported.ConclusionThe middle fossa approach for BONEBRIDGE implantation demonstrates favorable audiological benefit and an excellent safety profile. This study reports on a 12-year institutional experience using the middle fossa technique, comparing audiological and surgical outcomes between the first- and second-generation implants. No statistically significant difference was observed between device generations, supporting the ongoing use of this technique for appropriately selected patients.

OBJECTIVE:To develop and externally validate a deep learning segmentation network capable of automatically segmenting the inner ear in preoperative clinical computed tomography (CT) scans across various resolutions and protocols. METHODS:A deep learning-based segmentation network was developed using 100 cadaveric specimens that were scanned with synchrotron-radiation phase contrast imaging (SR-PCI) and various clinical CT scanners. Different acquisitions, protocols, and augmentations were used to create a total of 4,784 paired SR-PCI and clinical three-dimensional datasets used for deep learning training and model development. Performance and accuracy of the network were assessed on a separate unseen dataset and externally validated against manual segmentations from seven individual domain experts (otologists and radiologists), the mean expert performance, and a simultaneous truth and performance level (STAPLE) consensus segmentation. RESULTS:The network pipeline significantly outperformed each individual expert segmentation, the average of the expert segmentations, and the STAPLE consensus segmentation. Compared to the SR-PCI ground truth data, the network achieved a Dice similarity coefficient of 0.922, a maximum absolute Hausdorff distance of 0.329 mm, and an average Hausdorff distance of 0.006 mm on cone-beam CT and helical CT with resolutions as low as 625 μm. CONCLUSION:This is the first automated segmentation algorithm for the inner ear that has been shown to outperform segmentations from domain experts, establishing a new clinical gold standard. LEVEL OF EVIDENCE:N/A.

Clinical imaging is routinely used pre-operatively for cochlear implantation, yet lacks the resolution and contrast necessary to visualize the fine intracochlear structures critical for individualized intervention. To address this limitation, an ensemble deep learning model was developed to automatically segment cochlear micro-anatomy from standard clinical scans. The model was trained and validated using an independent internal dataset comprised of paired synchrotron and clinical scans of the same cochleae across various acquisition protocols. Performance was evaluated quantitatively on an unseen internal test dataset and a multi-institutional external test dataset. The deep learning model achieves accurate segmentation of the scala tympani (ST) and scala vestibuli (SV) across all tested modalities, with a mean Dice similarity coefficient of 0.895 ± 0.024 and 0.891 ± 0.029, a max Hausdorff distance of 0.396 ± 0.100 mm and 0.444 ± 0.280 mm, and an average Hausdorff distance of 0.008 ± 0.003 mm and 0.008 ± 0.003 mm, respectively. The model achieves performance metrics superior to previously published scalar models and demonstrates strong viability on the multi-institutional external dataset. Furthermore, anatomical measurements on the automatic segmentations closely match those obtained from high-resolution ground truth segmentations, measured using scalar volume and lateral ST length, confirming reliable estimation of clinically relevant metrics. By bridging the gap between high-resolution imaging and routine clinical imaging, this work could provide a practical solution for patient-specific cochlear implant surgical planning through electrode selection and post-operative assessment through image fusion, advancing the goals of atraumatic insertions and more effective hearing restoration. Micuda et al. develops and validates an ensemble deep learning model that segments cochlear micro-anatomy using paired synchrotron and routine clinical scans. The model accurately delineates the scala tympani and scala vestibuli across imaging configurations, outperforming prior methods and preserving clinically relevant measurements. Imaging used before cochlear implant surgery often does not have enough detail to visualize the small structures inside the cochlea that are important for surgical planning and patient outcomes. To address this limitation, a deep learning model was developed to automatically extract the small anatomical structures from routine clinical scans. The model was developed using paired high-resolution and clinical scans of cadaveric cochleae. It was subsequently evaluated quantitatively on a cadaveric dataset, assessed for clinical plausibility on an international external patient dataset, and compared against previously published models. The model achieved high accuracy on both objective and cochlear-specific metrics across all imaging configurations, closely matched the high-resolution reference images, and outperformed similar models reported in the literature. This deep learning model has the potential to be used in clinical practice to improve surgical planning for cochlear implantation, support patient-specific implant selection, and aid in the assessment of the implant position after surgery.

Importance Robotic-assisted cochlear implantation has the potential to reduce surgical variability, enhance insertion precision, and minimize intracochlear trauma; however, real-world clinical evidence remains limited. Objective To evaluate the safety, accuracy, and early hearing outcomes of robot-assisted cochlear implant (CI) electrode array insertion using the OTODRIVE ® system. Design Retrospective cohort study. Setting A tertiary academic CI center. Participants Adult patients who underwent robot-assisted cochlear implantation between the dates of February 2025 and August 2025. Intervention or Exposures Robot-assisted electrode array insertion with preoperative planning using the OTOPLAN software. Main Outcome Measures Intraoperative safety outcomes; audiologic performance, including unaided and aided pure-tone averages (PTAs) and AzBio sentence scores; and imaging-based electrode insertion accuracy, including angular insertion depth (AID) and electrode contact insertion on postoperative cone-beam computed tomography. Results The review identified 39 patients, mean age of 59.5 ± 19.2 years, with 59% male participants. The most common etiology of hearing loss (HL) was idiopathic sudden sensorineural HL. Mean total surgical time was 122.2 ± 49.4 minutes. No intraoperative complications or robotic-related adverse events occurred. Audiologic outcomes demonstrated significant improvement, with a mean preoperative unaided PTA of 92.4 ± 16.7 dB HL, improving to a postoperative aided PTA of 31.6 ± 6.3 dB HL. Mean AzBio sentence recognition scores increased from 18.1% preoperatively to 75.7% postoperatively, representing a 57.6% absolute improvement. Mean cochlear duct length was 34.6 ± 1.6 mm, and the planned versus achieved AIDs were 582.7° ± 35.2° and 569.0° ± 38.9°, respectively. Full insertion was achieved in 89.7% of implanted ears, with no tip fold-overs or electrode malposition identified. Conclusions Robot-assisted cochlear implantation using the OTODRIVE ® system was safely integrated into clinical practice in this cohort, with reproducible electrode insertion and early postoperative audiologic outcomes. Relevance These findings support the feasibility and safety of integrating robotic systems into routine CI surgery.

Clinical imaging is routinely used for cochlear implant surgical planning yet lacks the resolution and contrast necessary to visualize the fine intracochlear structures critical for individualized intervention. To address this limitation, an ensemble deep learning model was developed to automatically segment cochlear micro-anatomy from standard clinical scans. The model was trained and validated using an independent internal dataset comprised of paired synchrotron and clinical scans of the same cochlea across various acquisition protocols. Performance was evaluated quantitatively on an unseen internal test dataset and a multi-institutional external test dataset. The deep learning model achieved accurate segmentation of intracochlear anatomy across all tested modalities, outperformed all previously published models, and demonstrated strong viability on the multi-institutional external dataset. Furthermore, anatomical measurements on the automatic segmentations closely matched those obtained from high-resolution ground truth segmentations, confirming reliable estimation of clinically relevant metrics. By bridging the gap between high-resolution imaging and routine clinical imaging, this work provides a practical solution for patient-specific cochlear implant surgical planning and postoperative assessment, advancing the goals of atraumatic insertions and more effective hearing restoration.

Objective. Preoperative imaging is vital for cochlear implant surgeries, aiding diagnosis, and surgical planning. This study evaluated global practices and the value of preoperative imaging through an international survey. Methods. A cross-sectional survey was conducted among international cochlear implantation experts using a 112-item questionnaire. The study explored imaging modalities, anatomical targets, evaluated parameters, and different imaging approaches' perceived value and risks. Participants were recruited from a global consortium of otolaryngology, otology, neurotology, and cochlear implant surgery professionals. Results. Thirty-nine practitioners from 36 centers in 16 countries completed the survey (95.1% response rate). All used computed tomography (CT) and magnetic resonance imaging (MRI) for preoperative evaluation; MRI was deemed more valuable for diagnosis and candidacy assessment, while CT was preferred for surgical planning. Nearly half utilized additional imaging modalities, with functional MRI being the most common (20.5%). Additionally, 79.5% of respondents reported using image-based surgical planning software. Discussion. Results show a universal reliance on CT and MRI for cochlear implant evaluations, with MRI aiding diagnosis and CT focusing on surgical planning. Advanced imaging techniques may emerge in specific clinical cases. Implications for practice. Modern imaging practices and their potential changes can enhance protocol development and improve preoperative evaluations, ultimately boosting patient safety and outcomes in cochlear implantation.

Natural variations in cochlear anatomy have substantial implications for both clinical care and research in the fields of otology, neurotology, and audiology. While precise anatomic characterization is essential for a multitude of applications, comprehensive reference dimensions of both osseous and membranous cochlear structure obtained from a large and morphologically heterogeneous sample set do not currently exist. In this study, one hundred healthy human cadaveric temporal bone samples, without historical or visible pathology, underwent high-resolution three-dimensional synchrotron radiation phase-contrast imaging (SR-PCI) to develop a morphometric compendium of the human cochlea. Measurements of both bone and soft tissue in the cochlea were obtained, including basal turn diameter and width, cochlear height, and cochlear length along multiple anatomic paths (lateral wall, basilar membrane, and modiolar wall). The hook region, scalar geometry (diameter, area, tilt, width, and volume), and round window dimensions were also comprehensively characterized. Normative tonotopic frequency distributions of the basilar membrane and spiral ganglion were derived using cochlear length measurements and Greenwood's frequency-position function. These anatomic benchmarks establish invaluable reference data which may be used for anatomically informed, precision medicine approaches, including patient-specific surgical planning, intracochlear pharmaceutical delivery optimization, the development of automated image analysis algorithms, and the investigation of cochlear structure-function relationships in pathological conditions.

Finite element (FE) modeling is a powerful computational tool used to simulate complex systems. In recent years, a considerable number of publications have reported the use of the FE method to study the cochlea and cochlear implants (CIs). However, large variability exists in the development of cochlear FE models. To present a systematic review of FE macromechanical modeling of the cochlea, identifying the techniques used and associated limitations across existing studies. A literature search was conducted through PubMed, Scopus, and IEEE-Xplore databases of studies using FE modeling to study the cochlea and CIs. Studies published between January 1, 1985, and February 15, 2025, were assessed using the Covidence systematic review platform ( www.covidence.org ). A total of 1209 publications were found through the initial database search. After screening and full-text review, 77 studies met the inclusion criteria. Two primary modeling strategies were identified: simplified uncoiled model or realistic coiled model, including either two chambers or three chambers by incorporating the scala media and Reissner’s membrane. Substantial variation was observed in material assumptions, particularly regarding basilar membrane stiffness. Validation was inconsistent; most studies compared model outputs with established experimental data such as Greenwood’s frequency–place function, while some used computational comparisons or limited clinical data. FE cochlear models provide valuable insight into cochlear mechanics yet remain constrained by simplified geometries, non-standardized material parameters, and insufficient experimental validation. Future work should integrate imaging and functional data and establish standardized modeling, material properties, and validation frameworks to improve physiological and clinical relevance.

The human inner ear (IE) is a complex structure whose morphological variability underpins both normal function and the manifestation of otologic pathologies. Previous studies aiming to describe the structural variability of the IE have been limited by low-resolution imaging and small sample numbers. This study utilized the largest number of cadaveric high-resolution micro-computed tomography (CT) images to date to characterize the bony morphology of the healthy human IE. Fifty-four cadaveric temporal bone specimens underwent micro-CT imaging. Images were semi-automatically segmented and converted to three-dimensional surface mesh models for morphological measurement and analysis. Statistical shape models (SSMs) were created for the IE, cochlea, and vestibular system, as well as for sex- and side-based subgroups. Normative ranges for linear and volumetric dimensions of the IE were determined, and mean values were consistent with those previously reported. Significant sex-based differences and strong univariate linear relationships were identified for many dimensions and volumes. SSMs highlighted the semicircular canals, cochlear basal turn, and hook regions as key contributors to morphological variability across the total sample set. Sex-specific SSMs revealed distinct variation patterns: females exhibited greater vestibular variability, while males showed cochlear basal turn/hook region variability. Multivariate models were developed for the prediction of IE volumes from dimensions obtainable from clinical quality scans, with high accuracy. The morphological variability of the healthy IE was described in extensive detail and depicted in three dimensions. These findings may be used to inform the assessment of IE malformations, analysis of drug delivery strategies to the IE, and otologic implant design optimization.

BackgroundDespite its location near infection-prone areas, the human inner ear demonstrates remarkable resilience. This suggests that there are inherent instruments deterring the invasion and spread of pathogens into the inner ear. Here, we combined high-resolution light microscopy, super-resolution immunohistochemistry (SR-SIM) and synchrotron phase contrast imaging (SR-PCI) to identify the protection and barrier systems in the various parts of the human inner ear, focusing on the lateral wall, spiral ganglion, and endolymphatic sac.Materials and methodsLight microscopy was conducted on mid-modiolar, semi-thin sections, after direct glutaraldehyde/osmium tetroxide fixation. The tonotopic locations were estimated using SR-PCI and 3D reconstruction in cadaveric specimens. The sections were analyzed for leucocyte and macrophage activity, and the results were correlated with immunohistochemistry using confocal microscopy and SR-SIM.ResultsLight microscopy revealed unprecedented preservation of cell anatomy and several macrophage-like cells that were localized in the cochlea. Immunohistochemistry demonstrated IBA1 cells frequently co-expressing MHC II in the spiral ganglion, nerve fibers, lateral wall, spiral limbus, and tympanic covering layer at all cochlear turns as well as in the endolymphatic sac. RNAscope assays revealed extensive expression of fractalkine gene transcripts in type I spiral ganglion cells. CD4 and CD8 cells occasionally surrounded blood vessels in the modiolus and lateral wall. TMEM119 and P2Y12 were not expressed, indicating that the cells labeled with IBA1 were not microglia. The round window niche, compact basilar membrane, and secondary spiral lamina may form protective shields in the cochlear base.DiscussionThe results suggest that the human cochlea is surveilled by dwelling and circulating immune cells. Resident and blood-borne macrophages may initiate protective immune responses via chemokine signaling in the lateral wall, spiral lamina, and spiral ganglion at different frequency locations. Synchrotron imaging revealed intriguing protective barriers in the base of the cochlea. The role of the endolymphatic sac in human inner ear innate and adaptive immunity is discussed.

OBJECTIVE(S):Recently directed methods of inner ear drug delivery underscore the necessity for understanding critical anatomical dimensions. This study examines anatomical measurements of the human middle and inner ear relevant for inner ear drug delivery studied with three different imaging modalities. METHODS:Post-mortem human temporal bones were analyzed using human temporal bone histopathology (N = 24), micro computerized tomography (μCT; N = 4), and synchrotron radiation phase-contrast imaging (SR-PCI; N = 7). Nine measurements involving the oval and round windows were performed when relevant anatomical structures were visualized for subsequent age-controlled analysis, and comparisons were made between imaging methods. RESULTS:Combined human temporal bone histopathology showed the mean distance to the saccule from the center of the stapes footplate (FP) was 2.07 ± 0.357 mm and the minimum distance was 1.23 mm. The mean distance from the round window membrane (RWM) to the osseous spiral lamina (OSL) was 1.75 ± 0.199 mm and the minimum distance was 1.43 mm. Instruments inserted up to 1 mm past the center of the FP are unlikely to cause saccular damage, provided there are no endolymphatic hydrops. Similarly, instruments inserted up to 1 mm through the RWM in the trajectory toward the OSL are unlikely to cause OSL damage. CONCLUSION:The combined analyses of inner-ear dimensions of age-controlled groups and imaging modalities demonstrate critical dimensions of importance to consider when inserting delivery vehicles into the human cochlea. LEVEL OF EVIDENCE:N/A Laryngoscope, 134:2879-2888, 2024.

Introduction: Otosclerosis is a bone disorder affecting the labyrinthine capsule that leads to conductive and occasionally sensorineural hearing loss. The etiology of otosclerosis remains unknown; factors such as infection, hormones, inflammation, genetics, and autoimmunity have been discussed. Treatment consists primarily of surgical stapes replacement and cochlear implantation. High-resolution computed tomography is routinely used to visualize bone pathology. In the present study, we used synchrotron radiation phase-contrast imaging (SR-PCI) to examine otosclerosis plaques in a temporal bone for the first time. The primary aim was to study their three-dimensional (3D) outline, vascular interrelationships, and connections to the middle ear. Methods: A donated ear from a patient with otosclerosis who had undergone partial stapedectomy with the insertion of a stapes wire prosthesis was investigated using SR-PCI and compared with a control ear. Otosclerotic lesions were 3D rendered using the composite with shading technique. Scalar opacity and color mapping were adjusted to display volume properties with the removal of bones to enhance surfaces. Vascular bone channels were segmented, and the communications between lesions and the middle ear were established. Results: Fenestral, cochlear, meatal, and vestibular lesions were outlined three-dimensionally. Vascular bone channels were found to be frequently connected to the middle ear mucosa, perilabyrinthine air spaces, and facial nerve vessels. Round window lesions partly embedded the cochlear aqueduct which was pathologically narrowed, while the inferior cochlear vein was significantly dilated in its proximal part. Conclusion: Otosclerotic/otospongiotic lesions were imaged for the first time using SR-PCI and 3D rendering. The presence of shunts and abnormal vascular connections to the labyrinth appeared to result in hyper-vascularization, overloading the venous system, and leading to sensorineural hearing loss. We speculate about possible local treatments to alleviate the impact of such critical lesions on the labyrinthine microcirculation.

In cochlear implantation (CI) surgery, there are a wide variety of intraoperative tests available. However, no clear guide exists on which tests must be performed as the minimum intraoperative testing battery. Toward this end, we studied the usage patterns, recommendations, and attitudes of practitioners toward intraoperative testing. This study is a multicentric international survey of tertiary referral CI centers. A survey was developed and administered to a group of CI practitioners (n = 34) including otologists, audiologists and biomedical engineers. Thirty six participants were invited to participate in this study based on a their scientific outputs to the literature on the intraoperative testing in CI field and based on their high load of CI surgeries. Thirty four, from 15 countries have accepted the invitation to participate. The participants were asked to indicate the usage trends, perceived value, influence on decision making and duration of each intraoperative test. They were also asked to indicate which tests they believe should be included in a minimum test battery for routine cases. Thirty-two (94

Traditional approaches to the human cochlear nerve have been impeded by its bony encasement deep inside the skull base. We present an innovative, minimally invasive, therapeutic pathway for direct access to the nerve to deliver novel regenerative therapies. Neuroanatomical studies on 10 cadaveric human temporal bones were undertaken to identify a potentially safe therapeutic pathway to the cochlear nerve. Simulations based on three-dimensional delineation of anatomical structures obtained from synchrotron phase-contrast imaging were analyzed. This enabled the identification of an approach to the nerve in the fundus of the internal auditory meatus by trephining the medial modiolar wall of the cochlea via the round window for a median depth of 1.48 mm (range 1.21-1.91 mm). The anatomical access was validated on 9 additional human temporal bones using radio-opaque markers and contrast injection with micro-computed tomography surveillance. We thus created an effective conduit for the delivery of therapeutic agents to the cochlear nerve.

OBJECTIVES:To use synchrotron radiation phase-contrast imaging (SR-PCI) to visualize and measure the morphology of the entire cochlear scala tympani (ST) and assess cochlear implant (CI) electrode trajectories. METHODS:SR-PCI images were used to obtain geometric measurements of the cochlear scalar diameter and area at 5-degree increments in 35 unimplanted and three implanted fixed human cadaveric cochleae. RESULTS:The cross-sectional diameter and area of the cochlea were found to decrease from the base to the apex. This study represents a wide variability in cochlear morphology and suggests that even in the smallest cochlea, the ST can accommodate a 0.4 mm diameter electrode up to 720°. Additionally, all lateral wall array trajectories were within the anatomically accommodating insertion zone. CONCLUSION:This is the first study to use SR-PCI to visualize and quantify the entire ST morphology, from the round window to the apical tip, and assess the post-operative trajectory of electrodes. These high-resolution anatomical measurements can be used to inform the angular insertion depth that can be accommodated in CI patients, accounting for anatomical variability. LEVEL OF EVIDENCE:N/A. Laryngoscope, 134:2889-2897, 2024.

Background: The BONEBRIDGE® (Med-El GmbH) is a bone-conduction device comprising an external audio processor and an internal Bone Conduction-Floating Mass Transducer (BC-FMT) surgically anchored to the temporal bone. Due to the implant's size, its placement may be challenging in certain anatomies, necessitating thorough surgical planning. Manual planning methods are laborious, time-intensive, and prone to errors. This study aimed to develop and validate an automated algorithm for determining skull thickness, aiding in the surgical planning of the BONEBRIDGE and other devices requiring similar bone thickness estimations. Materials and methods: Twelve cadaveric temporal bones underwent clinical computed tomography (CT). A custom Python algorithm was developed to automatically segment bone from soft tissue, generate 3D models, and perform ray-tracing to estimate bone thickness. Two thickness colormaps were generated for each sample: the cortical thickness to the first air cell and the total thickness down to the dura. The algorithm was validated against expert manual measurements to achieve consensus interpretation. Results: The algorithm estimated bone-to-air thicknesses (mean = 4.7 mm, 95% Confidence Interval [CI] of 4.3–5.0 mm) that closely matched the expert measurements (mean = 4.7 mm, CI of 4.4–5.0 mm), with a mean absolute difference (MAD) of 0.3 mm. Similarly, the algorithm's estimations to the dura (6.0 mm, CI of 5.4–6.5 mm) were comparable to the expert markings (5.9 mm, CI of 5.4–6.5 mm), with a MAD of 0.3 mm. Conclusions: The first automated algorithm to calculate skull thickness to both the air cells and dura in the temporal bone was developed. Colormaps were optimized to aid with the surgical planning of BONEBRIDGE implantation, however the tool can be generalized to aid in the surgical planning of any bone thickness application. The tool was published as a freely available extension to the open-source 3D Slicer software program (www.slicer.org).

BackgroundThere still exists controversy about whether the healthy human middle ear mucosa is sterile or if it may harbor a diverse microbiome. Considering the delicacy of the human round window membrane (RWM), different mechanisms may exist for avoiding inner ear pathogen invasion causing sensorineural deafness. We re-analyzed archival human RWMs using light and transmission electron microscopy after decalcification to determine if bacteria are present in clinically normal human middle ears. We also searched for the presence of inborn immune defensive mechanisms within the round window niche (RWN), as previously reported in non-human primate ears.Materials and methodsFive round window niches, removed and directly fixed at transcochlear petroclival meningioma surgery, were re-investigated after ethical permission using light and transmission electron microscopy. The morphology of the RWM, including its bony attachment and pseudomembrane outline, was analyzed. Moreover, 64 human temporal bones were investigated using synchrotron phase-contrast imaging (SR-PCI) aiming to identify potentially “hidden” spaces, including the RWN potentially harboring infectious material.ResultsHistologic evidence of free-living bacteria and biofilm was found in 40% of RWNs in seemingly “healthy” middle ears. The RWM in these ears was pathologically changed with repealed epithelial and intercellular junctional integrity. Putative membranous defense machinery consisted of a lymphatic drainage system together with free phagocytic cells seemingly serving to protect the inner ear from alleged pathogens. Synchrotron analyses showed that a pseudomembrane was present in the human round window niche (RWN) in 80% of the specimens, of which 20% were complete. In 3%, the RWN contained dense tissue or serous fluid plugs partly obstructing the RWN. Infralabyrinthic clefts and tympanomeningeal fissures (Hyrtl’s fissure) were occasionally enclosed by delicate membranes near the round window. These may represent predilection sites for “hidden” infections potentially endangering inner ear function, particularly in connection with round window surgery.ConclusionConsidering the fragility of the normal human RWM, we speculate that occult colonies of biofilm may be a factor in surgeries involving the RWM, sensorineural hearing loss, and hearing preservation/fibrosis following cochlear implantation, and more controversially in hidden perilymph leaks causing sudden deafness and labyrinthine pathology.

OBJECTIVES:A wide variety of intraoperative tests are available in cochlear implantation. However, no consensus exists on which tests constitute the minimum necessary battery. We assembled an international panel of clinical experts to develop, refine, and vote upon a set of core consensus statements. DESIGN:A literature review was used to identify intraoperative tests currently used in the field and draft a set of provisional statements. For statement evaluation and refinement, we used a modified Delphi consensus panel structure. Multiple interactive rounds of voting, evaluation, and feedback were conducted to achieve convergence. RESULTS:Twenty-nine provisional statements were included in the original draft. In the first voting round, consensus was reached on 15 statements. Of the 14 statements that did not reach consensus, 12 were revised based on feedback provided by the expert practitioners, and 2 were eliminated. In the second voting round, 10 of the 12 revised statements reached a consensus. The two statements which did not achieve consensus were further revised and subjected to a third voting round. However, both statements failed to achieve consensus in the third round. In addition, during the final revision, one more statement was decided to be deleted due to overlap with another modified statement. CONCLUSIONS:A final core set of 24 consensus statements was generated, covering wide areas of intraoperative testing during CI surgery. These statements may provide utility as evidence-based guidelines to improve quality and achieve uniformity of surgical practice.