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.

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.

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.

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.

Sudden Sensorineural Hearing and Vestibular Loss in a Case of Relapsing Polychondritis.

OBJECTIVES: To report a case of profound bilateral sensorineural hearing and vestibular loss from relapsing polychondritis and hearing outcomes after cochlear implantation. METHODS: Case report and literature review. RESULTS: A 43 year-old woman developed sudden loss of hearing and balance that progressed over several weeks to bilateral, profound hearing and vestibular loss. Steroid treatments were ineffective. She underwent vestibular physical therapy and left cochlear implantation. About 10 months after her initial presentation, she developed erythema, warmth, swelling, and pain of the left auricle sparing the lobule, flattening of the bridge of her nose, and right ankle swelling, warmth, and skin erythema. A biopsy of the left auricle revealed histopathologic findings consistent with relapsing polychondritis. She was treated with high dose prednisolone. The ear inflammation resolved, however, despite excellent auditory response to pure tone thresholds, the patient reported no improvement in speech perception after cochlear implantation. CONCLUSIONS: Relapsing polychondritis can present with rapidly progressive, profound loss of hearing and vestibular function. Hearing outcomes after cochlear implantation can include poor speech discrimination despite good pure tone detection thresholds.

Evaluation of the Video Ocular Counter-Roll (vOCR) as a New Clinical Test of Otolith Function in Peripheral Vestibulopathy.

Importance: Video-oculography (VOG) goggles have been integrated into the assessment of semicircular canal function in patients with vestibular disorders. However, a similar bedside VOG method for testing otolith function is lacking. Objective: To evaluate the use of VOG-based measurement of ocular counter-roll (vOCR) as a clinical test of otolith function. Design, Setting, and Participants: A case-control study was conducted to compare vOCR measurement among patients at various stages of unilateral loss of vestibular function with healthy controls. The receiver operating characteristic curve method was used to determine the diagnostic accuracy of the vOCR test in detecting loss of otolith function. Participants were recruited at a tertiary center including the Johns Hopkins outpatient clinic and Johns Hopkins Hospital, Baltimore, Maryland. Participants included 56 individuals with acute (≤4 weeks after surgery), subacute (4 weeks-6 months after surgery), and chronic (>6 months after surgery) unilateral vestibular loss as well as healthy controls. A simple bedside maneuver with en bloc, 30° lateral tilt of the head and trunk was used for vOCR measurement. The study was conducted from February 2, 2017, to March 10, 2019. Intervention: In each participant vOCR was measured during static tilts of the head and trunk en bloc. Main Outcomes and Measures: The vOCR measurements and diagnostic accuracy of vOCR in detecting patients with loss of vestibular function from healthy controls. Results: Of the 56 participants, 28 (50.0%) were men; mean (SD) age was 53.5 (11.4) years. The mean (SD) time of acute unilateral vestibular loss was 9 (7) days (range, 2-17 days) in the acute group, 61 (39) days (range, 28-172 days) in the subacute group, and 985 (1066) days (range 185-4200 days) in the chronic group. The vOCR test showed reduction on the side of vestibular loss, and the deficit was greater in patients with acute and subacute vestibular loss than in patients with chronic loss and healthy controls (acute vs chronic: -1.81°; 95% CI, -3.45° to -0.17°; acute vs control: -3.18°; 95% CI, -4.83° to -1.54°; subacute vs chronic: -0.63°; 95% CI, -2.28° to 1.01°; subacute vs control: -2.01°; 95% CI, -3.65° to -0.36°; acute vs subacute: -1.17°; 95% CI, -2.88° to 0.52°; and chronic vs control: -1.37°; 95% CI, -2.96° to 0.21°). The asymmetry in vOCR between the side of vestibular loss and healthy side was significantly higher in patients with acute vs chronic loss (0.28; 95% CI, 0.06-0.51). Overall, the performance of the vOCR test in discriminating between patients with vestibular loss and healthy controls was 0.83 (area under the receiver operating characteristic curve). The best vOCR threshold to detect vestibular loss at the 30° tilt was 4.5°, with a sensitivity of 80% (95% CI, 0.62%-0.88%) and specificity of 82% (95% CI, 0.57%-1.00%). Conclusions and Relevance: The findings of this case-control study suggest that the vOCR test can be performed with a simple bedside maneuver and may be used to detect or track loss of otolith function.

Characterization of patient head motion in otologic surgery: Implications for TEES.

PURPOSE: Middle ear disease is increasingly being managed via transcanal endoscopic ear surgery (TEES). A limitation of TEES is that it restricts the surgeon to single-handed dissection. One solution to this would be an endoscope holder to facilitate two-handed dissection. Current endoscope holders are stationary, and can cause potential damage from endoscope contact with the ossicles or ear canal if unintended head motion occurs from inadequate anesthetic. A dynamic device that could detect and react to patient motion would mitigate these concerns, but currently there is little formal characterization of the frequency, velocity and acceleration of unintended patient head motion during otologic procedures performed under general anesthesia. The present study aims to characterize intraoperative patient head motion kinematics during cases utilizing TEES. MATERIALS AND METHODS: This is a prospective study of adults undergoing otologic procedures performed with general anesthesia and without paralysis. Head motion was characterized using a nine-axis inertial measurement unit (IMU), (LPMS-B2, Life Performance Research) mounted to each patient's forehead for the procedure duration. RESULTS: Data was collected across 10 cases; 50% of patients were female and mean age was 50 ± 14 years. There was observed patient head motion in 40% of cases with maximum linear acceleration of 0.75 m/s2 and angular velocity of 12.50 degrees/s. CONCLUSIONS: Patient movement during otologic procedures was commonly observed, demonstrating the need for a dynamic holder to allow two-handed TEES. Results from this study are the first objective characterization of patient head motion kinematics during otologic procedures performed under general anesthesia.

Characterization of patient head motion in otologic surgery: Implications for TEES.

PURPOSE: Middle ear disease is increasingly being managed via transcanal endoscopic ear surgery (TEES). A limitation of TEES is that it restricts the surgeon to single-handed dissection. One solution to this would be an endoscope holder to facilitate two-handed dissection. Current endoscope holders are stationary, and can cause potential damage from endoscope contact with the ossicles or ear canal if unintended head motion occurs from inadequate anesthetic. A dynamic device that could detect and react to patient motion would mitigate these concerns, but currently there is little formal characterization of the frequency, velocity and acceleration of unintended patient head motion during otologic procedures performed under general anesthesia. The present study aims to characterize intraoperative patient head motion kinematics during cases utilizing TEES. MATERIALS AND METHODS: This is a prospective study of adults undergoing otologic procedures performed with general anesthesia and without paralysis. Head motion was characterized using a nine-axis inertial measurement unit (IMU), (LPMS-B2, Life Performance Research) mounted to each patient's forehead for the procedure duration. RESULTS: Data was collected across 10 cases; 50% of patients were female and mean age was 50 ± 14 years. There was observed patient head motion in 40% of cases with maximum linear acceleration of 0.75 m/s2 and angular velocity of 12.50 degrees/s. CONCLUSIONS: Patient movement during otologic procedures was commonly observed, demonstrating the need for a dynamic holder to allow two-handed TEES. Results from this study are the first objective characterization of patient head motion kinematics during otologic procedures performed under general anesthesia.

American Neurotology Society, American Otological Society, and American Academy of Otolaryngology - Head and Neck Foundation Guide to Enhance Otologic and Neurotologic Care During the COVID-19 Pandemic.

: This combined American Neurotology Society, American Otological Society, and American Academy of Otolaryngology - Head and Neck Surgery Foundation document aims to provide guidance during the coronavirus disease of 2019 (COVID-19) on 1) "priority" of care for otologic and neurotologic patients in the office and operating room, and 2) optimal utilization of personal protective equipment. Given the paucity of evidence to inform otologic and neurotologic best practices during COVID-19, the recommendations herein are based on relevant peer-reviewed articles, the Centers for Disease Control and Prevention COVID-19 guidelines, United States and international hospital policies, and expert opinion. The suggestions presented here are not meant to be definitive, and best practices will undoubtedly change with increasing knowledge and high-quality data related to COVID-19. Interpretation of this guidance document is dependent on local factors including prevalence of COVID-19 in the surgeons' local community. This is not intended to set a standard of care, and should not supersede the clinician's best judgement when managing specific clinical concerns and/or regional conditions.Access to otologic and neurotologic care during and after the COVID-19 pandemic is dependent upon adequate protection of physicians, audiologists, and ancillary support staff. Otolaryngologists and associated staff are at high risk for COVID-19 disease transmission based on close contact with mucosal surfaces of the upper aerodigestive tract during diagnostic evaluation and therapeutic procedures. While many otologic and neurotologic conditions are not imminently life threatening, they have a major impact on communication, daily functioning, and quality of life. In addition, progression of disease and delay in treatment can result in cranial nerve deficits, intracranial and life-threatening complications, and/or irreversible consequences. In this regard, many otologic and neurotologic conditions should rightfully be considered "urgent," and almost all require timely attention to permit optimal outcomes. It is reasonable to proceed with otologic and neurotologic clinic visits and operative cases based on input from expert opinion of otologic care providers, clinic/hospital administration, infection prevention and control specialists, and local and state public health leaders. Significant regional variations in COVID-19 prevalence exist; therefore, physicians working with local municipalities are best suited to make determinations on the appropriateness and timing of otologic and neurotologic care.

Histological characteristics of intra-temporal facial nerve paralysis in temporal bone malignancies.

OBJECTIVE: To describe the histopathologic findings and clinical presentation of intra-temporal facial nerve invasion in primary and metastatic malignancies of the human temporal bone (TB). MATERIALS AND METHODS: Retrospective analysis of all medical records of patients diagnosed with peripheral facial nerve palsy (PFnP) of a malignant origin was performed. Temporal bones underwent standard processing for histologic examination. Hematoxylin and eosin (H&E)-stained slides were examined by light microscopy. The histologic findings were compared to premortem clinical data. RESULTS: Eighteen TBs were identified in 16 patients. The male to female ratio was 9:7. The median (range) age of death was 56.5 years (27 months to 75 years). The median time interval from facial nerve injury to death was 5.5 months. There were 11 carcinomas and seven sarcomas identified. Primary TB malignancies were identified in seven TBs (39%), and the rest (11 TBs, 61%) were of metastatic origin. Complete facial nerve paralysis (House-Brackmann [HB] grade VI), was the most common clinical presentation affecting nine patients (10 TBs, 56%). Neural involvement was multifocal in nature (16 of 18 TBs, 89%). The most commonly involved cranial nerve (CN) VII segment was the meatal segment (13 TBs, 72%), followed by the labyrinthine, tympanic, and vertical segments (nine, eight, and six TBs, respectively). CONCLUSION: PFnP can be the result of local, regional, or distant malignancy, and is associated with poor survival. The facial nerve can serve as a route of tumor progression intracranially. Whereas every segment of CNV II can be violated by tumors, not all PFnP are related to direct tumor invasion. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:E358-E367, 2020.

Continuous vestibular implant stimulation partially restores eye-stabilizing reflexes.

BACKGROUNDBilateral loss of vestibular (inner ear inertial) sensation causes chronically blurred vision during head movement, postural instability, and increased fall risk. Individuals who fail to compensate despite rehabilitation therapy have no adequate treatment options. Analogous to hearing restoration via cochlear implants, prosthetic electrical stimulation of vestibular nerve branches to encode head motion has garnered interest as a potential treatment, but prior studies in humans have not included continuous long-term stimulation or 3D binocular vestibulo-ocular reflex (VOR) oculography, without which one cannot determine whether an implant selectively stimulates the implanted ear's 3 semicircular canals.METHODSWe report binocular 3D VOR responses of 4 human subjects with ototoxic bilateral vestibular loss unilaterally implanted with a Labyrinth Devices Multichannel Vestibular Implant System vestibular implant, which provides continuous, long-term, motion-modulated prosthetic stimulation via electrodes in 3 semicircular canals.RESULTSInitiation of prosthetic stimulation evoked nystagmus that decayed within 30 minutes. Stimulation targeting 1 canal produced 3D VOR responses approximately aligned with that canal's anatomic axis. Targeting multiple canals yielded responses aligned with a vector sum of individual responses. Over 350-812 days of continuous 24 h/d use, modulated electrical stimulation produced stable VOR responses that grew with stimulus intensity and aligned approximately with any specified 3D head rotation axis.CONCLUSIONThese results demonstrate that a vestibular implant can selectively, continuously, and chronically provide artificial sensory input to all 3 implanted semicircular canals in individuals disabled by bilateral vestibular loss, driving reflexive VOR eye movements that approximately align in 3D with the head motion axis encoded by the implant.TRIAL REGISTRATIONClinicalTrials.gov: NCT02725463.FUNDINGNIH/National Institute on Deafness and Other Communication Disorders: R01DC013536 and 2T32DC000023; Labyrinth Devices, LLC; and Med-El GmbH.

Pressure Transmission to the Inner Ear by Mastoid Palpation After Transmastoid Surgery for Superior Canal Dehiscence.

OBJECTIVE: To discuss an effect of transmastoid repair of superior semicircular canal dehiscence and its resolution using a mastoid titanium mesh plate. PATIENTS: A 53-year-old woman with a history of superior canal dehiscence syndrome (SCDS) and subsequent transmastoid repair experienced dizziness and a loud, drum-like sound in her repaired ear when touching the ear. Palpating the skin over the mastoid defect reproduced the symptoms and could be observed on binocular microscopy as tympanic membrane deformation synchronous with mastoid palpation. INTERVENTION (S): Surgery to place a titanium mesh cranioplasty plate over the mastoid cavity. MAIN OUTCOME MEASURE (S): Reduction in dizziness and auditory symptoms when palpating the mastoid. RESULTS: In follow-up 2 months after surgery, palpation of the left mastoid no longer results in vertigo or hearing a loud sound. Hearing and vestibular function remained unchanged. CONCLUSIONS: Despite resolution of SCDS symptoms after transmastoid plugging and resurfacing of the superior semicircular canal involving mastoidectomy, patients can be bothered by dizziness and vertigo when pressing on the mastoid soft tissue envelope. This acts like a balloon that, when compressed, changes middle ear pressure and moves the tympanic membrane and can even cause alternobaric vertigo. This can be avoided or resolved by rigidly reconstructing the defect in the mastoid bone.

Image-Guided Mastoidectomy with a Cooperatively Controlled ENT Microsurgery Robot.

Mastoidectomy is a common surgical procedure within otology. Despite being inherently well suited for implementation of robotic assistance, there are no commercially available robotic systems that have demonstrated utility in aiding with this procedure. This article describes a robotic technique for image-guided mastoidectomy with an experimental cooperatively controlled robotic system developed for use within otolaryngology-head and neck surgery. It has the ability to facilitate enhanced operative precision with dampening of tremor in simulated surgical tasks. Its kinematic design is such that the location of the attached surgical instrument is known with a high degree of fidelity at all times. This facilitates image registration and subsequent definition of virtual fixtures, which demarcate surgical workspace boundaries and prevent motion into undesired areas. In this preliminary feasibility study, we demonstrate the clinical utility of this system to facilitate performance of a cortical mastoidectomy by a novice surgeon in 5 identical temporal bone models with a mean time of 221 ± 35 seconds.

Perilymphatic Fistulas and Superior Semi-Circular Canal Dehiscence Syndrome.

Perilymphatic fistulas (PLF) and superior semi-circular canal dehiscence syndrome (SCDS) are 2 conditions that can present with sound and/or pressure-induced vertigo. PLF should be suspected in cases of trauma or surgery, while a spontaneous PLF is a diagnosis of exclusion. Research is ongoing to identify an ideal biomarker for perilymph. The diagnosis of SCDS continues to evolve with further research into vestibular-evoked myogenic potentials, electrocochleography, and higher resolution CT imaging. Treatment advances include the transmastoid approach, smaller middle fossa craniotomies, and usage of endoscopes. Temporal bone studies have furthered the understanding of pressure dynamics within the ear and how this relates to recommendations for repair versus alternative treatments such as round window plugging.

Applied Force during Piston Prosthesis Placement in a 3D-Printed Model: Freehand vs Robot-Assisted Techniques.

OBJECTIVES: To describe a 3D-printed middle ear model that quantifies the force applied to the modeled incus. To compare the forces applied during placement and crimping of a stapes prosthesis between the Robotic ENT Microsurgery System ( REMS) and the freehand technique in this model. STUDY DESIGN: Prospective feasibility study. SETTING: Robotics laboratory. SUBJECTS AND METHODS: A middle ear model was designed and 3D printed to facilitate placement and crimping of a piston prosthesis. The modeled incus was mounted to a 6-degree of freedom force sensor to measure forces/torques applied on the incus. Six participants-1 fellowship-trained neurotologist, 2 neurotology fellows, and 3 otolaryngology-head and neck surgery residents-placed and crimped a piston prosthesis in this model, 3 times freehand and 3 times REMS assisted. Maximum force applied to the incus was then calculated for prosthesis placement and crimping from force/torque sensor readings for each trial. Robotic and freehand outcomes were compared with a linear regression model. RESULTS: Mean maximum magnitude of force during prosthesis placement was 126.4 ± 73.6 mN and 105.0 ± 69.4 mN for the freehand and robotic techniques, respectively ( P = .404). For prosthesis crimping, the mean maximum magnitude of force was 469.3 ± 225.2 mN for the freehand technique and 272.7 ± 97.4 mN for the robotic technique ( P = .049). CONCLUSIONS: Preliminary data demonstrate that REMS-assisted stapes prosthesis placement and crimping are feasible with a significant reduction in maximum force applied to the incus during crimping with the REMS in comparison with freehand.