Early experience with a patient-specific virtual surgical simulation for rehearsal of endoscopic skull-base surgery

Training in Endoscopic Endonasal Neurosurgical Procedures: A Systematic Review of Available Models

Background  Proficiency in endoscopic endonasal neurosurgery (EEN) requires a unique skill set and is associated with a steep learning curve. Endoscopic simulation models present an opportunity for trainees to enhance their surgical skills and anatomical knowledge in a risk-free environment. To date, four main categories of training modalities have been recorded: cadaveric, synthetic, animal, and virtual reality (VR) models. Objective  To analyze the features, advantages, and disadvantages of each EEN training model, describe the stages of simulation training, and propose future directions and an algorithm for EEN training. Methods  A comprehensive search was performed including studies published before August 2023. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed in the search and selection of studies included. Terms for searching title and abstract were ("simulation") AND ("endoscopic endonasal") AND ("neurosurgery"). Articles were screened for duplicates. Results  We identified 176 references, and 43 studies met the inclusion criteria. Twelve articles described cadaveric models, with 7 of them studying internal carotid artery injury management and 3 of them cerebrospinal leak management; 14 articles illustrated synthetic models, 1 article described animal models, and 16 articles outlined VR simulations. Conclusion  Cadaveric models provide realistic hands-on surgical training with acceptable cost and remain the gold standard method for training. Synthetic models are most effective for preoperative surgical planning and animal models are best suited for testing of hemostatic techniques. VR simulations may become the primary training tool for novices to acquire basic anatomical knowledge as their role in advanced surgical planning is evolving.

Does Total Turbinectomy Always Lead to Empty Nose Syndrome? A Computational Virtual Surgery Study

INTRODUCTION

Computational fluid dynamic (CFD) modeling has previously indicated that distorted nasal airflow patterns may contribute to empty nose syndrome (ENS); however, no data show that aggressive turbinate surgery always leads to ENS. We aim to use virtual surgery planning (VSP) to investigate how a total inferior turbinectomy affects airflow parameters compared with ENS patients.

METHODS

We retrospectively recruited six nasal obstruction patients who underwent turbinate reduction surgery. We virtually performed total inferior turbinectomy on these patients to compare CFD modeling results to patients' actual surgical outcomes and to that of a previously collected ENS patient cohort (n = 27).

RESULTS

Patients' actual surgery outcomes were excellent, with Nasal-Obstruction Symptom Evaluation (NOSE) score (pre: 72.5 ± 13.2 vs post-surgery: 10.8 ± 9.8, p < 0.001) and unilateral visual analog scale (VAS) scores of nasal obstruction (pre: 6 ± 2.56 vs post-surgery: 1.2 ± 1, p < 0.001) improved and was statistically significant. The virtual turbinectomy does not create the same distorted nasal airflow patterns as seen in ENS patients, with no statistically significant difference in nasal resistance as compared with post-actual surgery (virtual turbinectomy: 0.10 ± 0.03 Pa/mL*s; actual surgery: 0.12 ± 0.04 Pa/mL*s; ENS: 0.11 ± 0.04, p > 0.05) nor in regional wall shear force distribution, an important indicator of air/mucosa stimulation (inferior turbinate WSF%: virtual 47.3% ± 11.3% vs actual 51.5% ± 15.1%, p > 0.05); however, both are statistically significant higher than that of ENS patients (WSF: 32.2% ± 12.5%, p < 0.001), despite ENS cohort having wider inferior airway cross-sectional area (CSA) than actual surgeries.

CONCLUSION

Empty nose syndrome is likely a multifactorial disease process that cannot be solely attributed to aggressive turbinate reduction surgery.

LEVEL OF EVIDENCE

3 Laryngoscope, 135:562-569, 2025.

Extended Reality Applications in Otolaryngology Beyond the Operating Room: A Scoping Review

Objective: Extended reality (XR) has increasing usage in medicine, especially surgical fields, but the scope of applications is largely limited to intraoperative navigation. The aim of this scoping review is to evaluate all the available literature on how XR technologies have been applied to otolaryngology-head and neck surgery (OHNS) beyond the operating room for applications such as patient education and interdisciplinary communication. Review Methods: Using the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines, we systematically searched PubMed and Scopus. Studies were reviewed without temporal restriction. Inclusion criteria comprised English-language, peer-review papers or conference abstracts studying XR technologies for non-operative uses such as patient education, physician training, or interdisciplinary preoperative planning in the field of OHNS. Results: Database searching initially identified 1607 records. After filtering for duplicates, screening for relevance, and applying the inclusion criteria, 10 studies were ultimately included. This study identifies gaps in the existing literature and describes future applications and key areas of research. XR is a novel strategy for increasing patients' comprehension of their procedures and can facilitate improved communication and planning amongst a multidisciplinary surgical team during preoperative discussions. However, the existing literature is small in scale and has low statistical power for demonstrating clinical benefits. Conclusions: More robust studies are required to determine the true value of implementing XR. XR is a promising new technology with potential to advance education and patient care in OHNS. Ongoing research will continue to optimize the use of XR technology, ensuring safe and effective integration into clinical practice.

Developing a virtual Endoscopic Surgery Planning system to optimize surgical outcomes

Objective

Planning and predicting functional outcomes of endoscopic sinus surgeries (e.g., nasal airflow) based solely on visualizing Computerized Tomography (CT) or endoscopy poses a challenge to produce optimal clinical outcomes.

Study design

Technology development, retrospective case report.

Methods

A virtual surgery planning (VSP) tool is developed that can load any patient's CT data and allow surgeons to remove obstructive tissue using both visual and haptic feedback endoscopically. Pre-calculated airflow resistance, wall shear stress, pressure drop are displayed on the anatomy to identify potential sites of obstruction. After each virtual surgery, changes in nasal airflow can be computed, and the process is reiterated until an optimal result is reached.

Results

As proof-of-concept, a series of isolated or combined procedures were performed on CT of one patient, who had olfactory losses that may involve obstructions blocking the air/odor flow to the olfactory fossa (OF). For this patient, an isolated medial partial middle turbinectomy (PMT) demonstrated the best outcome, better than traditionally performed lateral PMT, while septal body reduction worsened air/odor flow to OF.

Conclusion

This proof of concept case report demonstrates the potential usefulness of VSP in preoperative planning based on objective benchmarks and could be a valuable tool for optimizing future surgical outcomes.

Development and Evaluation of a Mixed Reality Model for Training the Retrosigmoid Approach

BACKGROUND

The use of simulation has the potential to accelerate the learning curves and increase the efficiency of surgeons. However, there is currently a scarcity in models dedicated to skull base surgical approaches. Thus, the objective of this study was to develop a cost-effective mixed reality system consisting of an ultrarealistic physical model and augmented reality and evaluate its use in training surgeons on the retrosigmoid approach.

METHODS

The virtual models were developed from images of patients with vestibular schwannoma. The tumor was mirrored to allow bilateral approaches and the model has drawers for repositioning structures, allowing reuse of the material and cost reduction. Pre and posttest assessments were applied to 10 residents and young neurosurgeons, divided into control and test groups. Only the control group was exposed to the model. The difference in scores obtained by participants before and after exposure to the models was considered for analysis and participants in the control group answered self-satisfaction questionnaires.

RESULTS

The mean differences were 4.80 in the control group (95% credibility intervals=1.08-9.79) and 5.43 in the test group (95% credibility intervals=1.67-8.20). The average score of the self-satisfaction questionnaires was 24.0 (23-25).

CONCLUSIONS

The ultrarealistic model efficiently allowed retromastoid access to the cerebellopontine angle. A tendency toward greater gains in performance in the group exposed to the model was verified. Scores from the self-satisfaction questionnaires demonstrated that participants considered the model relevant for neurosurgical training and increased confidence among surgeons.

An update on simulation training in rhinology: a systematic review of evidence

BACKGROUND

Rhinological procedures demand a high degree of technical expertise and anatomical knowledge. Because of limited surgical opportunities, ethical considerations and the complexity of these procedures, simulation-based training has become increasingly important. This review aimed to evaluate the effectiveness of simulation models used in rhinology training.

METHODS

Searches were conducted on PubMed, Embase, Cochrane and Google Scholar for studies conducted between July 2012 and July 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis ('PRISMA') protocol defined a final list of articles. Each validated study was assigned a level of evidence and a level of recommendation based on the Oxford Centre of Evidence-Based Medicine classification.

RESULTS

Following exclusions, 42 articles were identified which encompassed six types of simulation models and 26 studies evaluated validity. The rhinological skills assessed included endoscopic sinus surgery (n = 28), skull base/cerebrospinal fluid leak repair (n = 14), management of epistaxis and/or sphenopalatine artery ligation (n = 8), and septoplasty and septorhinoplasty (n = 6). All studies reported the beneficial impact of their simulation models on trainee development.

CONCLUSION

Simulation training in rhinology is a valuable adjunct to traditional surgical education. Although evidence is of moderate quality, the findings highlight the importance of simulation-based training in rhinology training.

A Narrative Review on 3-Dimensional Visualization Techniques in Neurosurgical Education, Simulation, and Planning

BACKGROUND

High-fidelity visualization of anatomical organs is crucial for neurosurgical education, simulation, and planning. This becomes much more important for minimally invasive neurosurgical procedures. Realistic anatomical visualization can allow resident surgeons to learn visual cues and orient themselves with the complex 3-dimensional (3D) anatomy. Achieving full fidelity in 3D medical visualization is an active area of research; however, the prior reviews focus on the application area and lack the underlying technical principles. Accordingly, the present study attempts to bridge this gap by providing a narrative review of the techniques used for 3D visualization.

METHODS

We conducted a literature review on 3D medical visualization technology from 2018 to 2023 using the PubMed and Google Scholar search engines. The cross-referenced manuscripts were extensively studied to find literature that discusses technology relevant to 3D medical visualization. We also compiled and ran software applications that were accessible to us in order to better understand them.

RESULTS

We present the underlying fundamental technology used in 3D medical visualization in the context of neurosurgical education, simulation, and planning. Further, we discuss and categorize a few important applications based on the 3D visualization techniques they use.

CONCLUSIONS

The visualization of virtual human organs has not yet achieved a level of realism close to reality. This gap is largely due to the interdisciplinary nature of this research, population diversity, and validation complexities. With the advancements in computational resources and automation of 3D visualization pipelines, next-gen applications may offer enhanced medical 3D visualization fidelity.

Assessment of the viability of integrating virtual reality programs in practical tests for the Korean Radiological Technologists Licensing Examination: a survey study

PURPOSE

The objective of this study was to assess the feasibility of incorporating virtual reality/augmented reality (VR/AR) programs into practical tests administered as part of the Korean Radiological Technologists Licensing Examination (KRTLE). This evaluation is grounded in a comprehensive survey that targeted enrolled students in departments of radiology across the nation.

METHODS

In total, 682 students from radiology departments across the nation were participants in the survey. An online survey platform was used, and the questionnaire was structured into 5 distinct sections and 27 questions. A frequency analysis for each section of the survey was conducted using IBM SPSS ver. 27.0.

RESULTS

Direct or indirect exposure to VR/AR content was reported by 67.7% of all respondents. Furthermore, 55.4% of the respondents expressed that VR/AR could be integrated into their classes, which signified a widespread acknowledgment of VR among the students. With regards to the integration of a VR/AR or mixed reality program into the practical tests for purposes of the KRTLE, a substantial amount of the respondents (57.3%) exhibited a positive inclination and recommended its introduction.

CONCLUSION

The application of VR/AR programs within practical tests of the KRTLE will be used as an alternative for evaluating clinical examination procedures and validating job skills.

Training models and simulators for endoscopic transsphenoidal surgery: a systematic review

Endoscopic transsphenoidal surgery is a novel surgical technique requiring specific training. Different models and simulators have been recently suggested for it, but no systematic review is available. To provide a systematic and critical literature review and up-to-date description of the training models or simulators dedicated to endoscopic transsphenoidal surgery. A search was performed on PubMed and Scopus databases for articles published until February 2023; Google was also searched to document commercially available. For each model, the following features were recorded: training performed, tumor/arachnoid reproduction, assessment and validation, and cost. Of the 1199 retrieved articles, 101 were included in the final analysis. The described models can be subdivided into 5 major categories: (1) enhanced cadaveric heads; (2) animal models; (3) training artificial solutions, with increasing complexity (from "box-trainers" to multi-material, ct-based models); (4) training simulators, based on virtual or augmented reality; (5) Pre-operative planning models and simulators. Each available training model has specific advantages and limitations. Costs are high for cadaver-based solutions and vary significantly for the other solutions. Cheaper solutions seem useful only for the first stages of training. Most models do not provide a simulation of the sellar tumor, and a realistic simulation of the suprasellar arachnoid. Most artificial models do not provide a realistic and cost-efficient simulation of the most delicate and relatively common phase of surgery, i.e., tumor removal with arachnoid preservation; current research should optimize this to train future neurosurgical generations efficiently and safely.

Medical malpractice litigation involving otolaryngology residents and fellows: A case-based 30-year review

BACKGROUND

Errors, misdiagnoses, and complications can occur while trainees are involved in patient care. Analysis of such events could reveal areas for improvement by residency and fellowship programs.

AIM

To examine lawsuits tried at the state and federal level involving otolaryngology trainees.

METHODS

The LexisNexis database, an online legal research database containing state and federal case records from across the United States, was retrospectively reviewed for malpractice cases involving otolaryngology residents or fellows from January 1, 1990 to December 31, 2020. Case data collected: Plaintiff/trainee/defendant characteristics, allegations, medical outcomes, and legal outcomes.

RESULTS

Over the study period, 20 malpractice lawsuits involving otolaryngology trainees were identified. Plaintiffs raised numerous allegations including procedural error (n = 12, 25.5%), incorrect diagnosis and/or treatment (n = 8, 17.0%), and lack of knowledge of trainee involvement (n = 6, 12.8%). Nine cases (45%) had verdicts in favor of the plaintiff, whereas 5 cases (25%) had verdicts in favor of the defense. Six cases (30%) ended in a settlement. Awards to plaintiffs were heterogenous, with a median of $617,500 (range $32K-17M) for settled cases and verdicts favoring plaintiffs.

CONCLUSION

The findings enclosed herein represent the first published analysis of trainee involvement in otolaryngology malpractice cases held at the state/federal level. Otolaryngology trainees can be involved in lawsuits for both procedural and nonprocedural events. This study highlights the importance of education specifically in the domains of procedural errors, informed consent, proper diagnosis/management, and clear communication within patient care teams. Training programs should incorporate these study findings into effective simulation courses and didactic sessions. Educating trainees about common pitfalls holds the promise of decreasing healthcare systems costs, reducing trainee burnout, and, most importantly, benefiting patients.

[Development and evaluation of a simulator for endoscopic sinus surgery]

BACKGROUND

Endoscopic surgical procedures have been established as gold standard in sinus surgery. Challenges for surgical training have been addressed by the use of virtual reality (VR) simulators. To date, a number of simulators have been developed. However, previous studies regarding their training effects investigated only medically pretrained subjects or the time course of training outcomes has not been reported.

METHODS

A computer tomography (CT) dataset was segmented manually. A three-dimensional polygonal surface model was generated and textured using original photographic material. Interaction with the virtual environment was performed using a haptic input device. For the investigation of training outcomes with the simulator, the parameters duration and the number of errors were recorded. Ten subjects completed a training consisting of five runs on ten consecutive days.

RESULTS

Within the whole exercise period, four subjects reduced the duration of intervention by more than 60%. Four subjects reduced the number of errors by more than 60%. Eight out of 10 subjects showed an improvement with respect to both parameters. On median, the duration of the procedure was reduced by 46 seconds and the number of errors by 191. The statistical analysis between the two parameters showed a positive correlation.

CONCLUSION

Our data suggests that training on the FESS-simulator considerably improves the performance even in inexperienced subjects, both in terms of duration and accuracy of the procedure.

Simulation training in endoscopic skull base surgery: A scoping review

Objective

Proficiency in endoscopic endonasal skull base surgery requires both substantial baseline training and progressive lifelong learning. Endoscopic simulation models continue to evolve in an effort to optimize trainee education and preoperative preparation and improve surgical outcomes. The current scoping review systematically reviews all available literature and synthesizes the current paradigms of simulation models for endoscopic skull base surgery training and skill enhancement.

Methods

In accordance with Preferred Reporting Items for Systemic Review and Meta-Analyses guidelines, we systematically searched PubMed, Embase, CINAHL, and Cochrane databases. Studies were categorized according to the type of simulation models investigated.

Results

We identified 238 unique references, with 55 studies ultimately meeting inclusion criteria. Of these, 19 studies described cadaveric dissection models, 17 discussed three-dimensional (3D) printed models, 14 examined virtual surgical planning and augmented reality-based models, and five 5 articles described task trainers.

Conclusions

There are a wide variety of simulation models for endoscopic skull base surgery, including high-fidelity cadaveric, virtual reality, and 3D-printed models. These models are an asset for trainee development and preoperative surgical preparation.

Methods and Applications of 3D Patient-Specific Virtual Reconstructions in Surgery

3D modelling has been highlighted as one of the key digital technologies likely to impact surgical practice in the next decade. 3D virtual models are reconstructed using traditional 2D imaging data through either direct volume or indirect surface rendering. One of the principal benefits of 3D visualisation in surgery relates to improved anatomical understanding-particularly in cases involving highly variable complex structures or where precision is required.Workflows begin with imaging segmentation which is a key step in 3D reconstruction and is defined as the process of identifying and delineating structures of interest. Fully automated segmentation will be essential if 3D visualisation is to be feasibly incorporated into routine clinical workflows; however, most algorithmic solutions remain incomplete. 3D models must undergo a range of processing steps prior to visualisation, which typically include smoothing, decimation and colourization. Models used for illustrative purposes may undergo more advanced processing such as UV unwrapping, retopology and PBR texture mapping.Clinical applications are wide ranging and vary significantly between specialities. Beyond pure anatomical visualisation, 3D modelling offers new methods of interacting with imaging data; enabling patient-specific simulations/rehearsal, Computer-Aided Design (CAD) of custom implants/cutting guides and serves as the substrate for augmented reality (AR) enhanced navigation.3D may enable faster, safer surgery with reduced errors and complications, ultimately resulting in improved patient outcomes. However, the relative effectiveness of 3D visualisation remains poorly understood. Future research is needed to not only define the ideal application, specific user and optimal interface/platform for interacting with models but also identify means by which we can systematically evaluate the efficacy of 3D modelling in surgery.

Integration of Comprehensive Metrics into the PsT1 Neuroendoscopic Training System

OBJECTIVE

Metric-based surgical training can be used to quantify the level and progression of neurosurgical performance to optimize and monitor training progress. Here we applied innovative metrics to a physical neurosurgery trainer to explore whether these metrics differentiate between different levels of experience across different tasks.

METHODS

Twenty-four participants (9 experts, 15 novices) performed 4 tasks (dissection, spatial adaptation, depth adaptation, and the A-B-A task) using the PsT1 training system. Four performance metrics (collision, precision, dissected area, and time) and 6 kinematic metrics (dispersion, path length, depth perception, velocity, acceleration, and motion smoothness) were collected.

RESULTS

For all tasks, the execution time (t) of the experts was significantly lower than that of novices (P < 0.05). The experts performed significantly better in all but 2 of the other metrics, dispersion and sectional area, corresponding to the A-B-A task and dissection task, respectively, for which they showed a nonsignificant trend towards better performance (P = 0.052 and P = 0.076, respectively).

CONCLUSIONS

It is possible to differentiate between the skill levels of novices and experts according to parameters derived from the PsT1 platform, paving the way for the quantitative assessment of training progress using this system. During the current coronavirus disease 2019 pandemic, neurosurgical simulators that gather surgical performance metrics offer a solution to the educational needs of residents.

Fully automated preoperative segmentation of temporal bone structures from clinical CT scans

Middle- and inner-ear surgery is a vital treatment option in hearing loss, infections, and tumors of the lateral skull base. Segmentation of otologic structures from computed tomography (CT) has many potential applications for improving surgical planning but can be an arduous and time-consuming task. We propose an end-to-end solution for the automated segmentation of temporal bone CT using convolutional neural networks (CNN). Using 150 manually segmented CT scans, a comparison of 3 CNN models (AH-Net, U-Net, ResNet) was conducted to compare Dice coefficient, Hausdorff distance, and speed of segmentation of the inner ear, ossicles, facial nerve and sigmoid sinus. Using AH-Net, the Dice coefficient was 0.91 for the inner ear; 0.85 for the ossicles; 0.75 for the facial nerve; and 0.86 for the sigmoid sinus. The average Hausdorff distance was 0.25, 0.21, 0.24 and 0.45 mm, respectively. Blinded experts assessed the accuracy of both techniques, and there was no statistical difference between the ratings for the two methods (p = 0.93). Objective and subjective assessment confirm good correlation between automated segmentation of otologic structures and manual segmentation performed by a specialist. This end-to-end automated segmentation pipeline can help to advance the systematic application of augmented reality, simulation, and automation in otologic procedures.

Simulation of Pediatric Anterior Skull Base Anatomy Using a 3D Printed Model

OBJECTIVE

The pediatric skull base may present anatomic challenges to the skull base surgeon, including limited sphenoid pneumatization and a narrow nasal corridor. The rare nature of pediatric skull base pathology makes it difficult to gain experience with these anatomic challenges. The objective of this study was to create a 3-dimensionally (3D) printed model of the pediatric skull base and assess its potential as a training tool.

METHODS

Twenty-eight participants at various stages of training and practice were included in our study. They completed a pre- and postdissection questionnaire assessing challenges with endoscopic endonasal skeletonization of the carotid arteries and sella face using the 3D printed model.

RESULTS

The majority of participants had completed a skull base surgery fellowship (60.7%), were <5 years into practice (60.7%), and had <10 cases of pediatric skull base experience (82.1%). Anticipated challenges included limitation of maneuverability of instruments (71.4%), narrow nasal corridor and nonpneumatized bone (57.1%). On a scale of 0-10, 10 being very difficult, the average participant expected level of difficulty with visualization was 6.89 and expected level of difficulty with instrumentation was 7.3. On postdissection assessment, there was a nonstatistically significant change to 6.93 and 7.5, respectively. Participants endorsed on a scale of 0-10, 10 being very realistic, an overall model realism of 7.0 and haptic realism of 7.1.

CONCLUSIONS

A 3D printed model of the pediatric skull base may provide a realistic model to help participants gain experience with anatomic limitations characteristic of the pediatric anterior skull base.

Optimization of skull base exposure using navigation-integrated, virtual reality templates

In many skull base procedures, arriving at the optimal bone exposure is important. Whereas insufficient exposure can jeopardize the operation itself, over-doing the exposure might lead to complications. We developed a new technique, harnessing the strength of Virtual Reality (VR) technology in planning, rehearsal and navigation, to achieve the optimal skull base exposure for resection of tumors. VR models of patient-specific anatomy were used to rehearse the surgical exposure. From the altered models, the one with the ideal exposure was chosen, integrated with the navigation system in the operating suite, and used as a template to achieve the optimal exposure in surgery. The use of these VR templates is demonstrated in two cases involving skull base tumors. In both cases, over-zealous bone removal could have increased the risk of complications, and inadequate exposure would jeopardize the tumor resection. Navigation guided by the VR templates aided the creation of the "ideal" surgical exposure to reach the surgical goals. Complete resections were achieved and neither patient suffered any approach-related complications. In conclusion, virtual reality is a powerful tool to improve the safety and efficacy of neurosurgical procedures. With preoperatively-altered VR templates, the surgeon is no longer navigating just to find bearings, but to duplicate an opening designed to simultaneously provide sufficient exposure while limiting postoperative complications. Intuitively useful and successful in early application, there has been no identifiable disadvantages to date.

Robotics in Pediatric Otolaryngology-Head and Neck Surgery and Advanced Surgical Planning

Robotic surgery has been shown to be feasible and successful in several areas of pediatric head and neck surgery. However, adoption has been limited. Robotic surgery may be better integrated into practice with advanced preoperative surgical planning and the design of new robotic platforms with instrumentation specific for the application. With continued investigations, computer-aided surgical planning techniques including three-dimensional printing, virtual reality, multiobjective cost function for optimization of approach, mirror image overlay, and flexible robotic instruments may demonstrate value and utility over current practice.

Application of holographic augmented reality for external approaches to the frontal sinus

BACKGROUND

External approaches to the frontal sinus such as osteoplastic flaps are challenging because they require blind entry into the sinus, posing risks of injury to the brain or orbit. Intraoperative computed tomography (CT)-based navigation is the current standard for planning the approach, but still necessitates blind entry into the sinus. The aim of this work was to describe a novel technique for external approaches to the frontal sinus using a holographic augmented reality (AR) application.

METHODS

Our team developed an AR system to create a 3-dimensional (3D) hologram of key anatomical structures, based on CT scans images. Using Magic Leap AR goggles for visualization, the frontal sinus hologram was aligned to the surface anatomy in 6 fresh cadaveric heads' anatomic boundaries, and the boundaries of the frontal sinus were demarcated based on the margins of the fused image. Trephinations and osteoplastic flap approaches were performed. The specimens were re-scanned to assess the accuracy of the osteotomy with respect to the actual frontal sinus perimeter.

RESULTS

Registration and surgery were completed successfully in all specimens. Registration required an average of 2 minutes. The postprocedure CT showed a mean difference of 1.4 ± 4.1 mm between the contour of the osteotomy and the contour of the frontal sinus. One surgical complication (posterior table perforation) occurred (16%).

CONCLUSION

We describe proof of concept of a novel technique utilizing AR to enhance external approaches to the frontal sinus. Holographic AR-enhanced surgical navigation holds promise for enhanced visualization of target structures during surgical approaches to the sinuses.

The future of otology

BACKGROUND

The field of otology is increasingly at the forefront of innovation in science and medicine. The inner ear, one of the most challenging systems to study, has been rendered much more open to inquiry by recent developments in research methodology. Promising advances of potential clinical impact have occurred in recent years in biological fields such as auditory genetics, ototoxic chemoprevention and organ of Corti regeneration. The interface of the ear with digital technology to remediate hearing loss, or as a consumer device within an intelligent ecosystem of connected devices, is receiving enormous creative energy. Automation and artificial intelligence can enhance otological medical and surgical practice. Otology is poised to enter a new renaissance period, in which many previously untreatable ear diseases will yield to newly introduced therapies.

OBJECTIVE

This paper speculates on the direction otology will take in the coming decades.

CONCLUSION

Making predictions about the future of otology is a risky endeavour. If the predictions are found wanting, it will likely be because of unforeseen revolutionary methods.

A review of virtual reality simulators for neuroendoscopy

Neurosurgery is a challenging surgical specialty that demands many technical and cognitive skills. The traditional surgical training approach of having a trainee coached in the operating room by the faculty is time-consuming, costly, and involves patient risk factors. Simulation-based training methods are suitable to impart the surgical skills outside the operating room. Virtual simulators allow high-fidelity repeatable environment for surgical training. Neuroendoscopy, a minimally invasive neurosurgical technique, demands additional skills for limited maneuverability and eye-hand coordination. This study provides a review of the existing virtual reality simulators for training neuroendoscopic skills. Based on the screening, the virtual training methods developed for neuroendoscopy surgical skills were classified into endoscopic third ventriculostomy and endonasal transsphenoidal surgery trainers. The study revealed that a variety of virtual reality simulators have been developed by various institutions. Although virtual reality simulators are effective for procedure-based skills training, the simulators need to include anatomical variations and variety of cases for improved fidelity. The review reveals that there should be multi-centric prospective and retrospective cohort studies to establish concurrent and predictive validation for their incorporation in the surgical educational curriculum.

A review of simulation applications in temporal bone surgery

Background

Temporal bone surgery is a technically challenging and high-risk procedure in an anatomically complex area. Safe temporal bone surgery emphasizes a consummate anatomic understanding and technique development that requires the guidance of an experienced otologic surgeon and years of practice. Temporal bone simulation can augment otologic surgical training and enable rehearsal of surgical procedures.

Objectives

The purpose of this article is to provide an updated review of temporal bone simulation platforms and their uses.

Data Sources

PubMed literature search. Search terms included temporal bone, temporal bone simulation, virtual reality (VR), and presurgical planning and rehearsal.

Discussion

Various simulation platforms such as cadaveric bone, three-dimensional (3D) printed models, and VR simulation have been used for temporal bone surgery training. However, each simulation method has its drawbacks. There is a need to improve upon current simulation platforms to enhance surgical training and skills assessment, as well as a need to explore other clinically significant applications of simulation, such as preoperative planning and rehearsal, in otologic surgery.

Conclusions

There is no replacement for actual surgical experience, but high-fidelity temporal bone models such as those produced with 3D printing and computer simulation have emerged as promising tools in otolaryngologic surgery. Improvements in the fidelity of both 3D printed and VR simulators as well as integration of a standardized assessment format would allow for an expansion in the use of these simulation platforms in training and assessment.

Level of Evidence

5.

Optimal Timing of Entry-Level Otolaryngology Simulation

Objective

Appropriate timing of subspecialty simulation is critical to maximize learner benefit and guide resource utilization. We aimed to determine optimal timing of a simulation-based curriculum designed to teach entry-level procedural skills for otolaryngology residency.

Study Design

Simulation curriculum intervention tested among 3 comparison groups of varying clinical levels.

Setting

Academic otolaryngology training program and medical school.

Subjects and Methods

We developed a simulation-based technical skills curriculum incorporating the following task trainers: flexible laryngoscopy, peritonsillar abscess drainage, and myringotomy and tube insertion. Preclinical medical students (n = 40), subintern rotators (n = 35), and midyear interns (n = 8) completed the simulation-based curriculum. Pre- and postintervention knowledge/confidence and “level appropriateness” were rated on a 5-point Likert scale, and effect size was calculated.

Results

Overall self-reported knowledge/confidence levels improved in all 3 groups preintervention (1.05, 2.15, 3.17) to postintervention (2.79, 3.45, 4.38, respectively; all P < .01). Preclinical medical students uniformly reported very little to no familiarity with the procedures prior to the curriculum, while interns approached independence following the intervention. Large effect sizes were seen in all tasks for preclinical students (d = 3.13), subinterns (d = 1.46), and interns (d = 2.14). Five-point Likert scale measures of level appropriateness (1 = too challenging, 5 = too easy) for preclinical students, subinterns, and interns were 2.70 (95% CI, 2.56-2.84), 3.11 (95% CI, 2.97-3.25), and 3.75 (95% CI, 3.35-4.15), respectively.

Conclusion

Subinternship may represent the optimal timing for entry-level skills simulation training. The proposed curriculum shows utility for clinical levels ranging from medical students to postgraduate year 1 resident levels, with large effect sizes for all tested groups.

Validation of a rhinologic virtual surgical simulator for performing a Draf 3 endoscopic frontal sinusotomy

BACKGROUND

We recently introduced a patient-specific rhinologic virtual surgical environment (VSE) that has shown potential for surgical rehearsal of various skull base lesions. Our aim in this study was to validate the usefulness of the rhinology VSE in performing the Draf 3 procedure.

METHODS

An outside-in Draf 3 procedure was performed on 4 cadaver heads. Computed tomography (CT) scans were obtained before and after cadaver dissection (CD). Pre-dissection CT scans were used to construct a cadaver-specific VSE. A virtual Draf 3 dissection (VD) was performed using the same technique. Validation was conducted by comparing the final common frontal outflow tract. A subjective comparison of the post-dissection endoscopic findings (CD vs VD) and an objective measurement using the post-dissection CT scan for the CD and the reconstructed CT scan obtained from the data after the VD was performed.

RESULTS

Subjective overall resemblance of the 2 dissections (CD vs VD) assessed by the 4-point Likert scale (0-3) was 2.5 (median interquartile range [IQR], 0.25) for the 4 cadavers. The median difference for the anteroposterior dimension of the frontal neo-ostium (CD vs VD) assessed in the midsagittal view was 0.11 mm, whereas the median difference for the lateral dimension assessed in the coronal view was 2.71 mm. Thus, no statistical difference was observed.

CONCLUSION

VD showed nearly matching results with the actual cadaver dissection. With further validation, our rhinologic VSE may be used for presurgical planning and rehearsal before the actual Draf 3 procedure is performed in the operating room.

Virtual Reality Simulators for Endoscopic Sinus and Skull Base Surgery: The Present and Future

Endoscopic sinus and skull base surgeries are minimally invasive surgical techniques that reduce postoperative symptoms and complications and enhance patients’ quality of life. However, to ensure excellent surgical outcomes after such interventions, intimate familiarity with important landmarks and high-level endoscope manipulation skills are essential. Cadaver training is one possible option, but cadavers are expensive, scarce, and nonreusable and cadaver work requires specialized equipment and staff. In addition, it is difficult to mimic specific diseases using cadavers. Virtual reality simulators can create a computerized environment in which the patient’s anatomy is reproduced and interaction with endoscopic handling and realistic haptic feedback is possible. Moreover, they can be used to present scenarios that improve trainees’ skills and confidence. Therefore, virtual simulator training can be implemented at all levels of surgical education. This review introduces the current literature on virtual reality training for endoscopic sinus and skull base surgeons, and discusses the direction of future developments.