Temporal Bone Research Articles

Open- and closed-type congenital cholesteatomas of the middle ear: computed tomography differentiation and correlation with surgical staging.

To investigate the differences in computed tomography (CT) features between closed-type congenital cholesteatoma (CCC) and open-type congenital cholesteatoma (OCC) of the middle ear and to evaluate the usefulness of preoperative CT examination for staging workup of congenital cholesteatoma (CC) in correlation with the surgical findings. We retrospectively reviewed the preoperative CT scans of the temporal bone obtained from 80 patients with surgically confirmed CC of the middle ear. All patients had a solitary lesion, except for one patient with two lesions, resulting in 81 CCs, which formed the basis of this study. We compared the CT features between CCCs and OCCs, focusing on their morphological characteristics, such as size, shape, location, and bone change. Based on the Potsic classification, the stage of CCs was determined at CT and surgery, and the results were compared between CCCs and OCCs. Of the 81 CCs, surgery revealed 43 CCCs and 38 OCCs. On CT scans, CCC was frequently seen as a small (median: 3.15 mm), round to oval (65.1%) mass, most commonly located in the anterosuperior quadrant (74.4%) of the middle ear with less frequent ossicular erosion (14.0%). In contrast, OCC was frequently seen as a large (median: 6.70 mm), irregular (94.7%) mass, most commonly located in the posterosuperior quadrant (68.4%) of the middle ear with frequent ossicular erosion (55.3%). The size, shape, location, and presence of ossicular erosion were significantly different between the two types. Overall, the CT and surgical stages of CCs demonstrated good agreement (kappa value: 0.77) and the CT and surgical stages of OCCs were statistically significantly higher than those of CCCs (P < 0.001 in both). CT is useful for preoperative determination of the types and staging of CC of the middle ear. Preoperative differentiation between CCC and OCC is important to avoid reoperation and prevent an extensive surgery. By providing valuable information on the morphology and extent of the lesions, CT is useful for not only the accurate preoperative determination of the type of CCs but also the accurate prediction of staging of the lesion, which should be important to preparing optimal treatment plans.

Neurologic symptoms due to cholesteatoma in a cat with lysis of the temporal and occipital bone demonstrated by computed tomography and magnetic resonance imaging

AbstractA 7‐year‐old cat was presented with vestibular signs. The cat had a history of a presumed aural polyp that had been removed via ventral bulla osteotomy 4 years prior to presentation, followed by bacterial otitis externa and media that had been treated medically and healed within 8 weeks. At representation, computed‐tomographic imaging and video‐otoscopy showed obstruction of the right tympanic bulla by a heterogeneous mass, severe lysis of the surrounding bones, and pale, friable material within the horizonal external ear canal, extruding from the middle ear. The bacterial culture was negative. Histopathologic examinations supported the diagnosis of cholesteatoma. Due to the rapid progression of the disease, the cat was humanely euthanased 2 months later. Before euthanasia, magnetic resonance imaging documented the worsening of the disease, with an increased size of the expansile lesion and progressive changes in the adjacent structures. Furthermore, additional signs of otitis interna were visible.

Rhabdomyosarcoma of the Middle Ear Case Report

Background: Rhabdomyosarcoma (RMS) is a highly malignant soft tissue tumor derived from primitive embryonal mesenchymal tissue that differentiates into striated skeletal muscle. Despite the improved outcome based on the EFS and OS using the three different treatment modalities-chemotherapy, radiotherapy and surgical treatment, the survival of patients depends on their IRS groups—pathological and surgical. On the other hand in the last thirty years a great improvement of the five-year overall survival (OS) of children with RMS have been observed based on the results of large multinational collaborative trials and successive studies dedicated to children, though prognosis is variable and dependent on several factors including histologic variant, primary sites of the tumor, extent of disease (disease resectability), and molecular-level characteristics. Case presentation: We present a clinical case of a five-year-old male with initial complains of left side peripheral facial nerve palsy and secondary cervical and retroauricular lymphadenomegaly. After an exam, surgery of the temporal bone, CT and MRI embryonal type of rhabdomyosarcoma was diagnosed, and adjuvant chemotherapy was initiated in combination with concomitant local radiotherapy. Results: The results show that in these areas surgery itself is insufficient for RMS treatment(usually it is limited to taking a biopsy only). The combination of chemotherapy and local control with radiotherapy achieved a good result in our patient. Conclusions: Middle ear Embryonal Rhabdomyosarcoma is a common solid tumor, which could mimic middle ear inflammation or mastoid inflammation in patients. The multimodal approach seemed to be the ideal management of RMS. It involves a combination of chemotherapy and local control with surgery and/or radiotherapy.

Arcuate eminence distance to temporal bone outer table in the middle fossa repair of superior canal dehiscence.

To investigate the influence of arcuate eminence's distance to temporal bone outer table (AE-OT) on surgical outcomes following the middle fossa repair of superior canal dehiscence (SCD). We conducted a cohort study of consecutive repairs at a center between 2011 and 2022. AE-OT was measured on temporal bone CT imaging. Surgical outcomes were assessed with established metrics including Symptom Resolution Score (SRS), rate of Overall Symptom Improvement (OSI), and change in low-frequency air-bone gap (ΔLF-ABG) from pre- to post-surgery. Multivariable regression models assessing surgical outcomes were constructed with AE-OT as the primary predictor. Models adjusted for patient demographics, medical and surgical history, and follow-up duration. A total of 402 repairs were included. Mean AE-OT was 27.1mm (SD 2.1, range 20.8-33.9). Every mm increase in AE-OT was independently associated with a 14% reduction in odds of OSI (aOR 0.86, 95% C.I. [0.75, 0.98]) and a 4-point decrease in SRS (adj. β - 4.0 [- 6.9, - 1.1]) among frank dehiscences. AE-OT was also not associated with operative duration and ΔLF-ABG among both frank dehiscences and near dehiscences. Longer AE-OT predicted poorer symptomatic response but similar operative duration and audiometric improvementamong frank SCDcases.

Somatic genetic alterations of oncogenes and tumor suppressor genes in cholesteatoma

Background Cholesteatoma is a proliferative disease that affects the tympanic cavity and temporal bone. Despite many studies and various theories, the etiopathogenesis of cholesteatoma has not been fully elucidated. Features such as invasion, migration, uncontrolled proliferation, and lack of differentiation are observed in both cholesteatoma and neoplasia. Aims/Objectives The aim of this study is to investigate somatic genetic alterations in known proto-oncogenes and tumor suppressor genes in cholesteatoma. Material and Methods 60 different known proto-oncogenes and tumor suppressor genes were comparatively analyzed in cholesteatoma and peripheric blood samples from 15 middle ear cholesteatoma patients using next-generation sequencing. Results JAK3 c.2164G > A, TP53 c.284delC, and KRAS c.377A > T alterations were observed in cholesteatoma tissue but not in normal tissue. In addition, 12 different germline variants were also identified in 8 patients. Conclusions and Significance In this study, the presence of changes in cancer-related genes in cholesteatoma was determined and these changes were discussed in terms of possible clinical applications. We hope that the genetic alterations that emerged in this study, will be beneficial in guiding future research in this field.

Granulocyte colony-stimulating factor promotes regeneration of severed facial nerve in rats

Background and aimThe administration of growth and neurotrophic factors has been attempted experimentally as a new therapeutic strategy for severe facial paralysis. Granulocyte colony-stimulating factor (G-CSF) has an effect on the treatment of central nervous system injuries, such as cerebral infarction and spinal cord injury. This study aimed at examining the effects of G-CSF on facial nerve regeneration in rats.MethodsThe left facial nerve of rats was either partially resected (resection group) or severed and sutured (suture group) at the main trunk outside the temporal bone. In each surgical group, saline or G-CSF was administered via the gelatin hydrogel drug delivery system. The suture group was further divided into two subgroups for the late administration of G-CSF (2 weeks after surgical treatment) or immediate administration of G-CSF after surgical treatment. Recovery of the facial nerve was assessed by the evaluation of facial movements (after 12 weeks), complex muscle action potential amplitude measurements (after 2, 4, 8, and 12 weeks), electroneurography values (after 12 weeks), and histological evaluation (comparison of myelinated axon diameters among the groups).ResultsRecovery of the function and morphology of damaged nerves was faster in the suture groups than in the resection group. In the suture groups, recovery was faster for G-CSF-treated rats than for saline-treated rats. Furthermore, recovery was faster in the group that received G-CSF immediately after surgical treatment than in the group that received G-CSF 2 weeks later. However, the group that received G-CSF 2 weeks later also showed faster recovery than did the control group.ConclusionG-CSF effectively promoted nerve regeneration during facial nerve paralysis. Thus, G-CSF may be a potential treatment strategy for injured facial nerves as it has been safely administered in clinical treatments for hematological diseases.

Tbx1 haploinsufficiency leads to local skull deformity, paraflocculus and flocculus dysplasia, and motor-learning deficit in 22q11.2 deletion syndrome

Neurodevelopmental disorders are thought to arise from intrinsic brain abnormalities. Alternatively, they may arise from disrupted crosstalk among tissues. Here we show the local reduction of two vestibulo-cerebellar lobules, the paraflocculus and flocculus, in mouse models and humans with 22q11.2 deletion syndrome (22q11DS). In mice, this paraflocculus/flocculus dysplasia is associated with haploinsufficiency of the Tbx1 gene. Tbx1 haploinsufficiency also leads to impaired cerebellar synaptic plasticity and motor learning. However, neural cell compositions and neurogenesis are not altered in the dysplastic paraflocculus/flocculus. Interestingly, 22q11DS and Tbx1+/– mice have malformations of the subarcuate fossa, a part of the petrous temporal bone, which encapsulates the paraflocculus/flocculus. Single-nuclei RNA sequencing reveals that Tbx1 haploinsufficiency leads to precocious differentiation of chondrocytes to osteoblasts in the petrous temporal bone autonomous to paraflocculus/flocculus cell populations. These findings suggest a previously unrecognized pathogenic structure/function relation in 22q11DS in which local skeletal deformity and cerebellar dysplasia result in behavioral deficiencies.

Long-Term Outcomes of Temporal Bone Aneurysmal Bone Cysts: Ambispective Study With Systematic Review and Pooled Analysis.

To analyse the clinical, radiological, and surgical management of temporal bone aneurysmal bone cysts (ABCs) and identify factors affecting outcomes. Ambispective study. A single tertiary care institution. This study reviewed 6 cases of temporal bone ABCs treated between 2017 and 2024. Patient demographics, clinical presentation, imaging characteristics, surgical details, and outcomes were collected. A systematic review of the literature was conducted, adhering to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, to compare institutional cases with published data. Statistical analyses were performed to identify predictors of treatment success and recurrence. The cohort had a mean age of 27.5 years. Presenting symptoms included scalp swelling, aural fullness, tinnitus, and hearing impairment. Imaging showed expansile lesions with fluid-fluid levels and bone erosion. All patients underwent gross total excision, with a mean intraoperative blood loss of 230.6 ml. One patient experienced temporary grade III facial palsy, which resolved within 3 months. No recurrences were observed during a mean follow-up of 35 months. A pooled analysis of 45 cases from the literature revealed that swelling in the temporal region was the most common presenting feature, and gross total resection was the most frequently employed treatment. Recurrences were rare and typically associated with subtotal resections or advanced-stage tumors. Surgical excision, particularly gross total resection, is the treatment of choice for temporal bone ABCs, with a low recurrence rate. Stage and extent of resection are critical factors in predicting outcomes. This study enhances understanding of the diagnostic and therapeutic approaches for this rare condition.

Surgical Anatomy of the Retrosigmoid Approach with Endoscopic-Assisted Reverse Anterior Petrosectomy: Optimizing Meckel's Cave Access from the Posterior Fossa

Abstract Objectives We investigated the extent of access to Meckel's cave (MC) and the middle cranial fossa (MCF) protecting the internal carotid artery (ICA) using the retrosigmoid approach with endoscopic-assisted reverse anterior petrosectomy (EA-RAP). Methods Five specimens were dissected using the limited and extended EA-RAP. Based on the bone removal of the internal acoustic meatus (IAM) and subarcuate fossa, exposure of the MC and ICA were statistically compared. Results The limited and extended EA-RAP allowed access to the medial and anterior MC (4 mm posterior to the first genu of the cavernous ICA, and 20 mm posterior to foramen rotundum [FR]). The access to the lateral MC varied with distance of 12 and 8 mm medial to the foramen ovale for the limited and extended EA-RAP, respectively.In the extended EA-RAP, the exposure of the ICA was gained by drilling with the 0-degree endoscope (3 mm) versus 45-degree endoscope (9 mm). The working distances from the midpoint of the IAM to the most medial point of the exposed ICA was 24 mm. The most lateral point of the exposed ICA varied between 0- and 45-degree endoscopes with a distance of 21 and 13 mm, respectively. Conclusion A coronal plane from the posterior genu of the cavernous ICA and a sagittal plane to the common crus of the semicircular canals can define the area of MCF accessed by the EA-RAP. Drilling of the temporal bone should be carefully customized according to the patient and can be aided by endoscopic assistance for direct visualization to minimize the risk of injuries to ICA.

Otosclerosis and the evolution of stapes surgery: A historical and otopathological study.

To explore the historical evolution of surgical techniques for otosclerosis treatment, viewed through the lens of human temporal bone pathology to aid in understanding the disease and refining surgical interventions. A review of historical literature on otosclerosis, surgical techniques, and otopathological findings was conducted. Eight temporal bone specimens from the Paparella Otopathology & Pathogenesis Laboratory, University of Minnesota, and one from the University of California, Los Angeles, were analyzed. We selected two temporal bones from donors who underwent four different types of surgical procedures for otosclerosis: stapes mobilization, fenestration, stapedectomy, and stapedotomy. One successful and one complication case was selected for each procedure. Histopathological analysis was performed to assess the outcomes and complications associated with each technique. The study chronicles the progression of otosclerosis surgery from the stapes mobilization to modern stapedectomy and stapedotomy techniques. Initial procedures, like stapes mobilization and fenestration, yielded limited and temporary results with significant complications. The introduction of stapedectomy marked a significant improvement, with better long-term outcomes. Histopathological analysis revealed insights into the causes of surgical failures and complications. Otosclerosis surgery has evolved significantly, driven by advances in otopathology and surgical technology. While earlier techniques offered limited success, modern procedures like stapedectomy and stapedotomy provide improved outcomes and fewer complications. Ongoing research promises further advancements in the field, improving patient care and surgical efficacy. NA.

Imaging and clinical significance of tubular cell in lateral facial recess

Objective:To observe the position and morphology of tubular cell in lateral facial recess by CT scanning and surgical finding, and its clinical significance. Methods:Thirty patients（32 ears） with cholesteatoma and/or adhesive otitis media requiring radical mastoidectomy and tympanoplasty were included in this study. To observe the morphology of the tubular cell in the lateral facial recess cavity through temporal bone HRCT and surgery, and to analyze its relationship with the facial nerve. Results:Tubular cell were found in 59.4%（19/32） ears by temporal bone HRCT and through surgeon. The length ranged from 1.5-6.5 mm, with median length of 2.5 mm. All of them opened in the facial recess, ran on the posterior wall of the facial recess, and even reached the bottom of the inferior tympanic cavity or the level of the inferior wall of the external auditory canal（sagittal view and surgical findings）. Probing from the inside out, the tubular cell located between the second genu of the facial nerve and the chorda tympani, which was a part of the lateral wall of the facial nerve（facial crest）. When the tubular cell is occupied by granulation tissue, it is easy to be regarded as the facial nerve. Fully drilling out the tubular cell is helpful to cut down the facial nerve crest. In the study, the follow-up and/or postoperative no facial paralysis happens during the operation and in the follow up. Conclusion:Preoperative temporal bone HRCT can clearly show the tubular cell in the lateral facial recess cavity. Comprehensive and accurate identification of these structures is helpful to fully cut down the facial nerve crest and remove the hidden lesions in the posterior tympanic cavity.

A lightweight multi-scale multi-angle dynamic interactive Transformer-CNN fusion model for 3D medical image segmentation

Combining Convolutional Neural Network(CNN) and Transformer has become one of the mainstream methods for three-dimensional (3D) medical image segmentation. However, the complexity and diversity of target forms in 3D medical images require models to capture complex feature information for segmentation, resulting in an excessive number of parameters which are not conducive to training and deployment. Therefore, we have developed a lightweight 3D multi-target semantic segmentation model. In order to enhance contextual texture connections and reinforce the expression of detailed feature information, we designed a multi-scale and multi-angle feature interaction module to enhance feature representation by interacting multi-scale features from different perspectives. To address the issue of attention collapse in Transformers, leading to the neglect of other detailed feature learning, we utilized local features as dynamic parameters to interact with global features, dynamically grouping and learning critical features from global features, thereby enhancing the model's ability to learn detailed features. While ensuring the segmentation capability of the model, we aimed to keep the model lightweight, resulting in a total of 9.63M parameters. Extensive experiments were conducted on public datasets ACDC and Brats2018, as well as a private dataset, Temporal Bone CT. The results indicate that our proposed model is more competitive compared to the latest techniques in 3D medical image segmentation.

Cochlear nerve visualization in Normal anatomy and inner ear malformations.

This study aimed to qualitatively evaluate the variations in nerve bundles between patients with normal anatomy and those with inner-ear anomalies. Magnetic resonance imaging (MRI) scans of the temporal bones of candidates for cochlear implants (CIs) enrolled at a tertiary center were retrospectively reviewed from the clinical database. The 3.0-Tesla MRI scans were analyzed using a three-dimensional slicer to visualize the nerve bundles in the internal auditory canal. A total of 49 ears were analyzed. Twenty ears exhibited normal inner ear anatomy, whereas 29 ears had various inner-ear malformations. The cochlear nerve (CN) was visible on all 20 scans with normal inner-ear anatomy. In addition, the CN was visualized in 18 scans with inner ear malformations. Furthermore, the CN was identified in six of the eight scans with IP type I, whereas in two scans, the CN and vestibular nerve were unclear. Three scans with a common cavity showed only two nerve bundles. The findings of this study show that the CN can be visualized in most inner-ear anatomical types. Even in severely malformed inner ears, the common nerve bundle that represents the cochlear and vestibular nerves can be visualized. The MRI is highly recommended for CN assessment before CI surgery. Level IV.

Estimating Cognitive Workload Using Task-Related Pupillary Responses in Simulated Drilling in Cochlear Implantation.

Training of temporal bone drilling requires more than mastering technical skills with the drill. Skills such as visual imagery, bimanual dexterity, and stress management need to be mastered along with precise knowledge of anatomy. In otorhinolaryngology, these psychomotor skills underlie performance in the drilling of the temporal bone for access to the inner ear in cochlear implant surgery. However, little is known about how psychomotor skills and workload management impact the practitioners' continuous and overall performance. To understand how the practitioner's workload and performance unfolds over time, we examine task-evoked pupillary responses (TEPR) of 22 medical students who performed transmastoid-posterior tympanotomy (TMPT) and removal of the bony overhang of the round window niche in a 3D-printed model of the temporal bone. We investigate how students' TEPR metrics (Average Pupil Size [APS], Index of Pupil Activity [IPA], and Low/High Index of Pupillary Activity [LHIPA]) and time spent in drilling phases correspond to the performance in key drilling phases. All TEPR measures revealed significant differences between key drilling phases that corresponded to the anticipated workload. Enlarging the facial recess lasted significantly longer than other phases. IPA captured significant increase of workload in thinning of the posterior canal wall, while APS revealed increased workload during the drilling of the bony overhang. Our findings contribute to the contemporary competency-based medical residency programs where objective and continuous monitoring of participants' progress allows to track progress in expertise acquisition. Laryngoscope, 134:5087-5095, 2024.

Diagnosis and management of external auditory canal cholesteatoma (EAC)

Introduction: Cholesteatoma is a lesion formed from keratinized stratified squamous epithelium that occurs in the temporal bone and is often found in the middle ear. Cholesteatoma of the ear canal, commonly referred to as External Auditory Canal Cholesteatoma (EAC), involves the invasion of squamous epithelial tissue into the bone of the external auditory canal, which is locally aggressive and erodes the bone. Other terms introduced by experts include keratoma, squamous epitheliosis, cholesteatosis, epidermoid cholesteatoma, epidermoid cyst, and epidermosis. Management of external auditory canal cholesteatoma can be either conservative or surgical. Conservative treatment is indicated when the cholesteatoma and bone erosion are limited to the external auditory canal. Surgical intervention is required when there is extension to the middle ear or mastoid, the presence of complications or potential complications, persistent otorrhea not responsive to conservative therapy, or significant hearing loss. Case Report: We report a case of a 21-year-old woman with External Auditory Canal Cholesteatoma (EAC). Conclusion: The definitive diagnosis of cholesteatoma is made through histopathological examination revealing benign keratinized squamous cells. Extirpationf of granulation tissue and cholesteatoma via a transcanal approach was performed, involving the removal of debris and keratin through surgery. The pathological tissue was scraped until normal skin margins were achieved. Eroded bone was cleaned, and granulation tissue was removed until healthy tissue was identified to facilitate healing.

Reflections of an Otorhinolaryngologist Based on Genetics Concepts

Otorhinolaryngology is rich in a large number of hypothetical approaches related to anatomical and functional concepts as well as in theories concerning the etiopathogenesis and physiopathology of various diseases. The function of the paranasal sinuses, the pneumatization of the temporal bone and the factors that predispose to the appearance and evolution of otitis media, mainly. Following the path of the nonconformists and with the aim of presenting new concepts based on the principle that Genetics as the universal science capable of explaining everything related to life in the animal and plant kingdoms, we present our concepts. This paper is composed of a compendium of 3 articles created by the author with the aim of presenting a new theory of the etiopathogenesis and physiopathology of otitis media, taking as its main element the genetic factors as the only elements capable of explaining its appearance, development and evolution, mainly its transition to chronicity. In addition, the current paper includes reflections related to the “Auditory System” and the elements that influence individual constitutional characteristics that could help to understand the enormous variety in auditory quality, including gifted ears. Criteria related to the controversial, mysterious and still unresolved “Havana neurosensory syndrome” are also included with the intention of contributing to solving a health problem.

Endolymphatic sac and duct as an anatomical repair to achieve complete exposure of the internal auditory canal through the retrosigmoid approach: Anatomical study.

The retrosigmoid approach (RSA) is used in a wide variety of pathologies in the cerebellopontine angle (CPA), especially according to the findings, it can preserve hearing function during the resection of vestibular schwannomas (VS). Complete exposure of the fundus of the internal auditory canal (IAC) could jeopardize the integrity of the otic capsule and subsequently cause profound hearing loss and chronic disabling vertigo. Great variability has been described in labyrinthine structures and to date there is no clear data on the distances of these structures to safely expose the IAC fundus. ObjectiveEstablish reference values of the endolymphatic sac and duct to achieve safe and complete exposure of the IAC through the RSA. MethodologyThis is a cross-sectional descriptive study where complete dissection of the endolymphatic sac and duct (ELSD) was performed on 20 preserved human temporal bones, measuring the distances of nine anatomical structures underlying or closely related to the ELSD. ResultsWhen evaluating the variability between the structures, the distance between the ELSD to the acoustic pore (AP) had little variability and remained constant in all specimens. The distance between the AP and the common cross (CC) presented in our study had the lowest coefficient of variation. The distance that had the greatest variability was the measurement of the jugular foramen (JF) both by retrosigmoid and translabyrinthine approaches (RSA-TLA). The rest of the variables remained stable. ConclusionsThe ELSD is a safe anatomical technique for dissection and exposure of the IAC during RSA in VS surgeries. In our study, the structures evaluated present little variability with the exception of the distances between the ELSD and the JF, which in some cases the JF exceeds the lower limit of the ELSD and IAC.

Vestibular electrode position stability over time.

In vestibular implants (VI), the electrode position is thought to be important for optimal neural activation. The objective of this study was to evaluate the stability of the vestibular electrode position over time. Seven patients implanted with a VI were followed for one year. When possible, the fenestrations of the semicircular canals were kept very small (approximately 0.8mm) to stabilize the electrode lead. Additionally, the electrodes were fixed at their fenestration sites using bone cement. A temporal bone CT scan was performed intraoperatively, and one week and one year postoperatively. In one patient reliable analysis of the intraoperative CT scan was not possible due to a technical error. A displacement of the vestibular electrodes of more than 0.5mm was considered significant. Fourteen out of 18 electrodes did not show a significant displacement between the intraoperative scan and the first postoperative scan. In the remaining four electrodes, a displacement of ≥ 0.5mm occurred (mean 0.54mm, range 0.50-0.58mm). These four electrodes were found in the two first implanted patients. In both cases, the intraoperative CT scan had a slice thickness of 0.5mm and showed severe scattering. This might imply that the measured displacement was (partially) related to a higher measurement error. None of the vestibular electrodes migrated outside of the ampulla. No displacement was observed in any of the vestibular electrodes between the first postoperative scan and the one-year follow-up scan. The current surgical technique seems to securely stabilize the vestibular VI electrodes over time.

Next-generation Robotics in Otology: The HEARO Procedure.

In a world that is globalizing and centered on rapid communication, hearing impairment is one of the most common disabilities. The most effective and successful neural prosthesis in humans for treating the dysfunction of a sensory organ is cochlear implantation. The minimally invasive placement of the array in the cochlea should warrant the rehabilitation of profound hearing loss over all frequencies. Some key factors for structure and hearing preservation consist of minimal invasive drilling in the temporal bone and tailored inner ear access. Next-generation Robotically Assisted Cochlear Implantation Surgery (RACIS) focuses on robotic inner ear access. The purpose of this cadaveric preclinical study was to assess the viability and precision of a novel technology (the HEARO method) for RACIS, or more particularly, personalized robotic inner ear access. The external auditory canal, chorda tympani, ossicles, facial nerve, and other pertinent anatomical components were all 3-dimensional (3D)-reconstructed by the surgeon. The mean intended distance and drilling trajectory to the chorda tympani and facial nerve were, respectively, 0.44±0.13 and 0.35±0.27mm. With a mean insertion percentage of 94%, the surgeon was able to complete the HEARO method in 9 out of 10 procedures. There was no evidence of a collision or damage to vital structures. Future iterations of RACIS will prioritize haptic feedback, automated segmentation and trajectory, robotic insertion with adjustable speed, and imaging mobile cone beam computed tomography.

The Impact of Preoperative Facial Nerve Weakness and Facial Nerve Outcomes in the Management of Patients With Parotid Metastases of Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinomas (cSCC) metastasizing to the parotid gland can cause facial nerve (FN) dysfunction secondary to direct invasion, perineural spread, or surgical ablation. This study aims to characterize the prevalence of preoperative FN involvement in metastatic cSCC to the parotid and identify risk factors resulting in FN sacrifice. Patients with parotid metastases from cSCC, treated surgically with parotidectomy with curative intent were identified through a retrospective cohort analysis of a prospectively maintained Sydney Head and Neck database from 1992 to 2021. Of 408 patients identified, 39 (10%) were found to have preoperative FN weakness, of which 41% underwent concurrent temporal bone resection compared to 9.1% for the overall cohort. All patients with preoperative FN weakness underwent FN sacrifice. FN sacrifice occurred in n = 145 (36%), of which 88 (61%) required sacrifice of a trunk or division. The 5-year disease free survival and disease specific survival was worse for patients requiring sacrifice of the FN trunk compared to no sacrifice, however there was no difference in survival for patients requiring sacrifice of the FN division or branch. We found those with > 23.5 mm parotid deposits had an odds ratio of 9.9 for FN sacrifice (95% CI 3.0-32.8, p < 0.001). Preoperative FN weakness was present in 10% of patients and 36% had some part of the FN sacrificed. There was no significant difference in outcomes for patients with and without preoperative FN weakness. Patients who undergo sacrifice of the FN trunk have worse survival compared to those not requiring FN sacrifice, however similar outcomes were observed in those requiring lessor degrees of FN sacrifice. The likelihood FN sacrifice rises with increasing parotid deposit size.