Skull base chordomas are rare, locally invasive tumors that remain a diagnostic and therapeutic challenge. We developed a machine-learning (ML) radiomics model to (i) distinguish chordoma from chondrosarcoma and skull base background, (ii) differentiate true postoperative residual tumor from treatment-related changes, and (iii) predict 2-year progression-free survival (PFS). In this retrospective, dual-center study, 61 patients underwent surgery between 1998 and 2023. Preoperative contrast-enhanced T1-weighted MRI images were pre-processed and segmented; data were augmented by 20%. ML models included nested cross-validated XGBoost and a 4-layer standard feedforward Multilayer Perceptron (MLP) (Python, Keras). The primary and secondary endpoints were diagnostic discrimination and residual-versus-treatment-related change classification; the exploratory endpoint was 2-year PFS prediction. XGBoost achieved diagnostic accuracy of 0.90 (95% CI: 0.84-0.96) in distinguishing chordoma from chondrosarcoma/skull base background, and residual-versus-change accuracy 0.91 (95% CI: 0.85-0.96). PFS prediction reached an accuracy of 0.87 (95% CI: 0.74-0.98). MLP showed comparable performance (diagnostic validation accuracy 0.89; residual classification 0.90; PFS 0.93). To our knowledge, this is the first dual-center MRI-based ML study to jointly address preoperative histologic discrimination, postoperative residual detection, and short-term PFS prediction in a small, heterogeneous cohort. These results support future clinical translation as a noninvasive decision-support tool for preoperative assessment, postoperative surveillance, and risk stratification.

HYPOTHESIS:The goal of this research is to gain deeper insight into the Eustachian tube mechanics using sheep cadaver to improve clinical management of ET diseases. BACKGROUND:Sheep are widely used to study the mechanics of the ET. However, the anatomic suitability of using sheep to study the human ET is poorly characterized. The aim of this study is to measure ET opening in cadaveric sheep specimens to understand its mechanics and compare the sheep ET anatomy to the human anatomy. METHODS:Five fresh-frozen sheep cadavers were used to study the ET mechanics. Using an in situ testing approach coupled with a µCT X-ray scanner, a muscle group was incrementally loaded. Results were compared with an unloaded human cadaver specimen to assess translatability. RESULTS:In all five sheep specimens, a gradual ET opening occurred upon loading the soft palate muscle group, but complete opening was not achieved. Comparison revealed significant structural differences between sheep and human cadaver anatomy, including ET orientation, relative position to surrounding bone structures, and muscle group angles. CONCLUSION:The developed method allowed to accurately track the ET opening in sheep. There were significant differences between human and sheep, which questions the suitability of using sheep to study the ET. As a result, future use of sheep to study the human ET has considerable limitations.

OBJECTIVES:Extra-cochlear electrodes (EEs) are a frequent complication in cochlear implant (CI) surgery, potentially leading to reduced speech-perception outcomes. Standard intraoperative tools such as contact impedances and electrically evoked compound action potentials often fail to detect these misplaced electrodes. Stimulation Current-Induced Non-Stimulating Electrode Voltages (SCINSEVs), or electrical field imaging (EFI) in the advanced bionics device, are presented here as a faster and more accurate intraoperative measure for identifying EE. Adopting this method clinically could reduce reliance on intraoperative or postoperative imaging and allow EE identification in the critical window of surgery, when immediate correction can occur. DESIGN:This prospective intraoperative study tested adult CI candidates or users undergoing new or revision surgery at a single institution. EFI measurements were recorded during electrode insertion, where the surgeon was asked to hold a randomly selected number of 1 to 6 electrodes outside of the cochlea before full insertion. Visual confirmation of the number of EE electrode positions was achieved with the surgical microscope. Recordings were taken simulating postoperative conditions (with EE surrounded by blood or fascia). Three expert reviewers blinded to surgical outcomes reviewed EFI data to identify the number of EEs. Agreement between reviewers and surgeons was analyzed using correlations, receiver operating characteristic plots, and sensitivity and specificity calculations. RESULTS:General linear models revealed significant effects of the number of EEs not inserted by the surgeon (0 to 6 EEs) and the reviewer (1 to 3) on the EE ranking error, and no effects of the surgery type (revision or first-time cochlear implantation), nor of the material used (blood or fascia). A correlation was observed between the number of not-inserted EEs and EEs ranked based on the EFIs (r = 0.63, p < 0.0001). For identification of the presence or absence of EEs based on visual inspection of SCINSEVs, an overall sensitivity of 95.9% and a specificity of 40.7% were achieved (97.9% and 65.7% with ±2 EE reviewer-surgeon agreement tolerance). CONCLUSIONS:SCINSEVs are a rapid, reliable tool for intraoperative EE detection. With high sensitivity and moderate specificity, they offer a non-radiative alternative to postoperative computerized tomography, with results available during the surgical procedure. Use of this tool may improve CI outcomes through immediate surgical correction. The authors recommend training of relevant clinical staff to record and interpret these measurements for use within clinical practice.

Eustachian tube (ET) dysfunction exists along a spectrum from obstructive to patulous phenotypes, yet no single gold-standard diagnostic test exists. This review examines current methods for assessing ET function alongside evolving therapeutic interventions. Clinical assessment and patient-reported outcome measures alone have limited diagnostic power. Objective tests, including tympanometry, advanced manometric techniques, and sonotubometry, each offer distinct strengths and limitations. Evidence shows that individual tests demonstrate variable sensitivity and specificity and perform best when combined. An integrated diagnostic approach that incorporates clinical history within a curated pathway of complementary objective measures is advocated to improve diagnostic accuracy and guide intervention selection.

OBJECTIVE:Surgical management of large vestibular schwannoma (VS; Koos grades III and IV) requires a balance between the maximum extent of resection and the best functional preservation. The primary objective of this study was to determine the volumetric threshold of the VS residual tumor at risk of progression after incomplete resection. The secondary objective was to identify other risk factors of regrowth after incomplete resection. METHODS:This retrospective study included patients who underwent incomplete resection of sporadic VS at a single center from January 2008 to December 2018. The inclusion criteria were: adult age, large single sporadic VS, incomplete resection, and follow-up of > 5 years. Quantitative 3D volumetry was assessed on pre- and postoperative contrast-enhanced T1-weighted MRI using semiautomated segmentation. The volumetric criteria for residual tumor were < 250 mm3 for near-total resection (NTR) and < 2 cm3 for subtotal resection (STR). Univariate and multivariate logistic regression analyses were performed to assess predictors of regrowth after incomplete resection. A residual volume cutoff for risk of regrowth was determined using the Youden index via area under the curve analysis. RESULTS:The cohort included 119 patients (60 female, median age 58 years) who were categorized into 3 subgroups based on the residual VS according to 3D volumetry: NTR, STR, and partial resection (PR). NTR achieved the best long-term tumor control. Kaplan-Meier progression-free survival rates at 2, 5, and 10 years were 98%, 97%, and 95% for the NTR group; 69%, 56%, and 56% for the STR group; and 20%, 0%, and 0% for the PR group, respectively (p < 0.0001). The cutoff residual volume at risk of growth was 200 mm3, with sensitivity of 95% (95% CI 74%-99%) and specificity of 77% (95% CI 68%-85%, p < 0.001). Moreover, good facial nerve outcomes (House-Brackmann grades I and II) were best achieved with PR (100%), followed by STR (96%) and NTR (90%). In the univariate analysis, the risk factors for regrowth of residual tumor were cystic morphology, residual volume, and residual location (internal auditory canal, cisternal segment, and brainstem combined). The multivariate model identified the volume and location of residual as risk factors (p < 0.0001). CONCLUSIONS:These findings suggest that limited NTR (< 250 mm3) offered an excellent compromise, with long-term tumor control comparable to that of radical resection while preserving superior functional preservation. The authors hope to stimulate discussion toward a unified volumetrically established classification of incomplete resections, allowing for cooperation in future multicenter studies.

Aims: Macroscopic "gross total resection" was the traditional goal for patients undergoing resection of vestibular schwannoma. There has been a shift toward "subtotal" resection in an attempt to mitigate the risk of cranial nerve injury, reserving radiotherapy and/or revision surgery for growing residual tumors. The decision for subtotal versus total resection may be made preoperatively. Additionally, "near-total" resection has been acknowledged as microscopic residual disease, the decision of which is often made intraoperatively when cranial nerve risk is encountered. In recent years, some centers have advocated for planned subtotal resection, citing overall lower risks of facial palsy; however, to date, no robust comparison of facial nerve outcomes has been performed. This study reviews a United Kingdom national, multicenter registry to explore the demographic and disease features of extent of resection and compare cranial nerve outcomes.

BACKGROUND AND OBJECTIVES:Surveillance studies offer sparse knowledge of predictors of future growth in sporadic vestibular schwannomas (VS).Our aim was identification of these risk factors. We propose a scoring system to estimate the risk of growth in sporadic vestibular schwannoma. METHODS:This retrospective study is based on the demographic and radiological data of 615 adult patients under the surveillance for single VS in our center. Univariate analysis, multivariate regression, and Kaplan-Meier analysis were used when appropriate. The regression coefficient-based "VS score" was calculated based on Cox proportional-hazards regression. RESULTS:During surveillance, 285 tumors (46%) remained stable, 314 tumors (51%) grew, and 16 tumors (3%) shrank. The significant risks factors for future growth identified both in univariate and multivariate analyses were younger age at onset, cystic morphology, larger tumor volume, and cisternal location (as per Hannover grade). The proportion of growing tumors was 40%, 75%, and 96% among the homogeneous VS, primary cystic, and VS transformed to cystic, respectively. Moreover, tumor growth during the 1st year was significant predictor of continuous growth. Our "VS score" includes variables such as age, sex, morphology, and Hannover grade. The score extends between -3 and 6 points. Kaplan-Meier, confusion matrix, and receiver operating characteristic analysis proved high accuracy of our scoring model. CONCLUSION:Our retrospective study revealed that younger age, cystic morphology, cisternal extent, larger volume, and growth during 1st year were strong predictors of future growth. Moreover, we propose a scoring system that accurately estimates the risks of future tumor growth.

The World Health Organization (WHO) estimate that by 2050 approximately 2 billion people worldwide will have a degree of hearing impairment, and more than 700,000,000 will require hearing rehabilitation. The presentation and aetiology of patients with hearing loss changes with age, and this can be a useful starting point for an assessment. Another important discriminator in the approach to patients with hearing loss is the timing of onset, which will differentiate those needing urgent management from the more routine. Hearing loss may be ‘conductive’, due to blockage of sound passage to the inner ear, which is often reversible, or ‘sensorineural’, due to damage to the inner ear or auditory nerve such as seen in age-associated hearing loss (also known as presbycusis), which is usually permanent. This article aims to provide a systematic framework for assessing these patients in primary care and a guide to indicate when referrals to secondary care are necessary.

Significance:The definitive treatment for pituitary adenoma is transsphenoidal surgical resection. Conventional white light imaging shows limited contrast between the adenoma and the pituitary gland, and only the tissue surface is visualized, leaving a pressing unmet need for improved intraoperative adenoma delineation to preserve pituitary function during surgery. Aim:To evaluate the potential of multispectral imaging to enhance visualization of adenoma during transsphenoidal resection. Approach:A multispectral camera based on a spectrally resolved detector array was coupled to a standard 4-mm rigid endoscope for in vivo imaging, such that the camera head could easily be switched with the standard of care camera head during surgery. Results:The multispectral imaging (MSI) endoscope was deployed during transsphenoidal surgery, and usable data were obtained from 12 patients. MSI was able to distinguish between an adenoma and a healthy pituitary based on the spectral angle with the reference spectrum of blood. Conclusions:The MSI endoscope holds the potential to differentiate adenoma tissue and healthy pituitary. With further development, MSI endoscopy could enable real-time label-free delineation of tumors during surgery, based on quantitative thresholds, which should contribute to improving the completeness of resection, while helping to preserve the pituitary gland, preventing serious life-changing complications.

BACKGROUND:Eustachian tube dysfunction (ETD) causes symptoms and signs of pressure dysregulation in the middle ear, and is associated with tympanic membrane retraction, otitis media with effusion, and chronic otitis media. Interventions aiming to improve symptoms can be non-surgical or surgical, including balloon dilatation of the Eustachian tube, also known as balloon eustachian tuboplasty (BET) for obstructive ETD. However, existing published evidence for the effectiveness and safety of BET remains unclear. OBJECTIVES:To evaluate the effects of balloon dilatation of the Eustachian tube in adults with obstructive Eustachian tube dysfunction. SEARCH METHODS:The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid M>DLINE; Ovid Embase; Web of Science; Clinicaltrials.gov; ICTRP and additional sources for published and unpublished trials. The final search was updated on 18th January 2024. There were no restrictions on language, publication date or study setting. SELECTION CRITERIA:Randomised controlled trials were included if they allocated adult participants with chronic obstructive ETD to treatment randomly and compared BET with non-surgical treatment, no treatment, or other surgical treatment. Studies with other designs were excluded. DATA COLLECTION AND ANALYSIS:At least two review authors independently selected trials using predetermined inclusion criteria, assessed the risk of bias, extracted data, and rated the certainty of evidence (CoE) according to GRADEpro. Statistical analyses were performed using a random-effects model and interpreted according to the most recent version of the Cochrane Handbook. Predefined primary outcomes were obstructive ETD symptoms, Eustachian tube function (objective or semi-objective tests), or serious adverse events. Secondary outcomes were hearing, tympanic membrane abnormalities, quality of life, and other adverse events. MAIN RESULTS:Nine trials were identified with 684 randomised participants across three comparisons: BET versus non-surgical treatment (five trials, 422 participants), BET versus no treatment (sham surgery; one trial, 17 participants), and BET versus other surgery (four trials, 275 participants). None of the studies were rated with an overall low risk of bias. Comparing BET to non-surgical treatment up to three months, there is low-certainty evidence showing that BET may reduce patient-reported ETD symptoms (change in ETDQ-7: mean difference (MD) -1.66 (95% CI -2.16 to -1.16; I2 = 63%; 4 RCTs, 362 participants)). There is very low-certainty evidence that BET may improve ETD as assessed by objective or semi-objective measures (improvement in tympanometry: RR 2.51 (95% CI 1.82 to 3.48; I2 = 0%; 3 RCTs, 369 participants). Between three and 12 months, the evidence is very uncertain whether BET reduces ETDQ-7: MD -0.55 (-1.31 to 0.21; 1 RCT, 24 participants). The evidence is very uncertain whether BET improves ETD as assessed by objective or semi-objective measures (improvement in tympanometry: RR 2.54 (95% CI 0.91 to 7.12)). Evidence was downgraded for risk of bias, imprecision, indirectness, or a combination of these. Comparing BET to no treatment (sham surgery trial) up to three months, there is very low-certainty evidence that BET improves ETD as assessed by patient-reported ETD symptoms (change in ETDQ-7: MD -0.54 (95% CI -2.55 to 1.47; 1 RCT, 17 participants)). Between three and 12 months, the evidence is very uncertain whether BET improves ETD as assessed by ETDQ-7 (MD 0.16 (95% CI -0.75 to 1.07; 1 RCT, 17 participants)). Evidence was downgraded for indirectness and twice for imprecision. Although there were no serious adverse events reported, these studies were underpowered to detect adverse events and were performed by highly trained and experienced investigators under strict study protocols. This could underestimate the true risk of adverse events by less experienced clinicians in everyday clinical practice. Evidence was rated as very low certainty, downgraded for risk of bias, imprecision, and indirectness. AUTHORS' CONCLUSIONS:BET may lead to a clinically meaningful improvement in ETD symptoms compared to non-surgical or no treatment (in the form of sham surgery) at up to three months. The effects of BET on ETD compared to non-surgical treatment are very uncertain beyond three months. However, the certainty of evidence ranged from low to very low, with the studies being underpowered to detect adverse events. The findings of this review should help to inform further BET research and guidelines. Future research should focus on longer-term outcomes and the incidence of adverse events or complications in real-world practice settings.

Knowledge of cerebellopontine angle (CPA) and temporal bone anatomy is critical in understanding the clinical features of vestibular schwannomas (VS) as well as the choice of surgical approach when considering resection. We describe relevant anatomy, concentrating on structures that are clinically important and how variations in these structures impact surgical management. This includes the changes in anatomy with VS growth due to compression of surrounding structures and their clinical relevance. There is a detailed description of the anatomy of translabyrinthine, middle fossa and retrosigmoid approaches, including both anatomical illustrations and relevant imaging to allow the reader to develop a full understanding and aid in selection of the most appropriate approach for individual tumors in their clinical practice.

OBJECTIVE:To examine the quality of information provided by artificial intelligence platforms ChatGPT-4 and Claude 2 surrounding the management of vestibular schwannomas. STUDY DESIGN:Cross-sectional. SETTING:Skull base surgeons were involved from different centers and countries. INTERVENTION:Thirty-six questions regarding vestibular schwannoma management were tested. Artificial intelligence responses were subsequently evaluated by 19 lateral skull base surgeons using the Quality Assessment of Medical Artificial Intelligence (QAMAI) questionnaire, assessing "Accuracy," "Clarity," "Relevance," "Completeness," "Sources," and "Usefulness." MAIN OUTCOME MEASURE:The scores of the answers from both chatbots were collected and analyzed using the Student t test. Analysis of responses grouped by stakeholders was performed with McNemar test. Stuart-Maxwell test was used to compare reading level among chatbots. Intraclass correlation coefficient was calculated. RESULTS:ChatGPT-4 demonstrated significantly improved quality over Claude 2 in 14 of 36 (38.9%) questions, whereas higher-quality scores for Claude 2 were only observed in 2 (5.6%) answers. Chatbots exhibited variation across the dimensions of "Accuracy," "Clarity," "Completeness," "Relevance," and "Usefulness," with ChatGPT-4 demonstrating a statistically significant superior performance. However, no statistically significant difference was found in the assessment of "Sources." Additionally, ChatGPT-4 provided information at a significant lower reading grade level. CONCLUSIONS:Artificial intelligence platforms failed to consistently provide accurate information surrounding the management of vestibular schwannoma, although ChatGPT-4 achieved significantly higher scores in most analyzed parameters. These findings demonstrate the potential for significant misinformation for patients seeking information through these platforms.