Virtual reality simulators for temporal bone dissection: overcoming limitations of previous models
Article information
Abstract
Temporal bone dissection is a critical skill for otolaryngology trainees: however, it is challenging to master due to the complex anatomy and limited exposure to cadaveric specimens. The aim of this review was to develop and evaluate a novel virtual reality (VR) simulator for temporal bone dissection, addressing the limitations of previous simulators reported in the literature. A comprehensive literature search was conducted in the PubMed, Embase, and Cochrane Library databases from inception to September 2022. The search was limited to studies that evaluated the effectiveness of VR simulators for temporal bone dissection. The quality of the included studies was assessed using the Cochrane Risk of Bias Tool. The results showed that VR simulators can significantly improve temporal bone dissection skills, including anatomical knowledge, instrument handling, and surgical performance. Compared to traditional training methods, VR simulation was associated with faster learning curves, better retention of skills, and greater confidence among trainees. However, some limitations of current VR models were identified, including the lack of haptic feedback, limited realism, and short duration of practice. VR simulators are a valuable adjunct to traditional methods for temporal bone dissection training. The recently developed VR simulator addressed the limitations of previous simulators and demonstrated its potential to enhance the training of clinicians in temporal bone dissection. Future directions for research include further validation of the simulator and exploration of its potential for use in clinical settings.
INTRODUCTION
Temporal bone dissection is a crucial skill for otolaryngologists and neurosurgeons; however, the traditional method of learning this technique through cadaveric dissection has limitations, including the cost and availability of specimens. The temporal bone has unique compartments, different types of pneumatization of mastoid air cells, facial nerve, dura matter, sigmoid sinus, and many more. Thus dissecting the cadaveric temporal bone allows us to recognize its unique anatomical characteristics. In otology, the temporal bone must be surgically drilled to expose the structures, and preservation of the facial nerve is of utmost importance. Micromotor drilling needs the best coordination of surgical skills as with driving a car including eye, hand, and foot movements. Overall, it is a challenging task for all surgeons.
However, dissecting temporal bone from a cadaver can lead to the transmission of highly infectious diseases, such as hepatitis B and C viruses, Mycobacterium tuberculosis infection, and prion infection [1]. In some countries, there is a shortage of cadavers, and the high costs make its use financially difficult for students’ dissection and surgeons’. Additionally, a temporal bone laboratory should have a microscope, drills, burrs, a suction machine, water connections, and bone-storing sections. Because of these difficulties using cadaveric bone, this is a limited training resource. To resolve these problems, artificial temporal bones from polymer materials or computer-based surgical simulators with a combination of haptic devices are used to create virtual background imaging to perform actual surgery where every medical student, resident, and doctor can increase their surgical abilities [2,3].
Virtual reality (VR) simulators offer an alternative approach to training in temporal bone dissection, allowing for a safe and repeatable environment for learners to develop their skills. In recent years, there has been a growing interest in the development and evaluation of VR simulators for temporal bone dissection. VR educational studies have shown several advantages. Participants in VR temporal bone dissection agreed that VR training is useful for improving confidence, technical skills, fine motor movement, navigation of the instruments, and understanding of anatomy. Combining case rehearsals with VR allows more case familiarization and safety [4,5]
The benefits of VR in temporal bone dissection compared to traditional methods are numerous. One of the main advantages is the increased safety for the patient, as learners can practice in a risk-free environment without damaging delicate anatomical structures. Additionally, VR allows for greater accessibility, as learners can train remotely without requiring access to cadavers or specialized equipment. Furthermore, VR can enhance the learning experience by providing learners with immediate feedback, allowing them to track their progress and identify areas for improvement. Lastly, VR is a cost-effective solution, as it eliminates the need for costly cadavers and equipment. Overall, VR has the potential to revolutionize the way in which temporal bone dissection is taught, making it more accessible, safer, and more efficient.
The aim of this review paper was to provide a comprehensive overview of the effectiveness of VR simulators in temporal bone dissection, by synchronizing the findings of 26 previous studies. In addition, we wish to support our suggestion that the new VR simulator is an effective and valuable tool for medical education, outperforming traditional book-based learning.
METHODS
Study Selection for Systemic Review of Virtual Reality Temporal Bone Dissection
The randomized controlled trials we analyzed were focused on the effects of VR on temporal bone dissection and were collected from the PubMed, Web of Science, and Embase databases. The search strategy consisted of the following terms and synonyms: “virtual reality,” “temporal bone dissection,” and “simulation.” All of the databases were searched from the year 2000 to December 2022. Papers from these databases were screened based on their titles, abstracts, and results. Articles were selected using exclusion and inclusion criteria. Studies were excluded if they were notes, letters, books, animal studies, review articles, case-control studies, cohort studies, case reports, and controlled trials, available only as the abstract, written in languages other than English, and were on non-otology and nonmedical fields. We only analyzed studies that included otology anatomy and discussed surgery evaluated via VR simulators between surgeons, residents, and medical students. The papers must have evaluated VR training on otology via questionnaires and performance. A VR questionnaire was used to independently extract data using the Cochrane data collection form. We used the participants’ data to extract the study design, participants’ characteristics, participants’ numbers, methods of evaluation, and questionnaire evaluation methods. Outcome data included questionnaire tools and statistical methods used. Data included non-randomized trials assessed for their risk of bias using the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I).
Data Analysis
Extracted data was performed using Cochrane RevMan 5.3. Statistical heterogeneity was performed using the I2 test with a random-effects model that could not be explained by characteristics.
In a meta-analysis, statistics were used with mean values and standard deviation. Standardized mean differences were calculated for the data of VR outcome changes. All of the data questionnaires were evaluated with a 5-point Likert scale. The p-values and confidence intervals (CIs) were used, and the p-value was set at 0.05. A forest plot was used when studies had the same outcome as in the questionnaire. The risk ratio was analyzed for the number of participants and tasks performed.
RESULTS
Study Selection
In total 751 articles were searched from three databases and reviewed. All of these articles were analyzed by title and abstract, 717 articles were excluded due to duplication, and the exclusion criteria. The remaining 34 articles were reviewed using the full text. Eight articles were excluded due to comparisons between three-dimensional (3D) and VR (n=3), unavailability of the full text (n=3), and the questionnaire being incomplete (n=2) (Fig. 1). The selected 26 articles (Table 1 [4-29]) were published from 2004 to 2022 and evaluated using a 5-point Likert scale; the discussed temporal bone dissection using a VR simulator. The participants had or did not have previous experience in temporal bone dissection, and included surgeons, trainers, trainees, and medical students. Cadaver temporal bones and patient-specific temporal bone scans were used in a VR environment, and each participant performed selected tasks according to the article. VR usefulness in training and clinical fields was evaluated by a questionnaire and evaluation in each article.
Flowchart of study selection for systematic review and meta-analysis. 3D, three-dimensional; VR, virtual reality.
Characteristics and results of included studies of outcome and limitations on temporal bone VR simulators among the participants (n=26)
The use of VR simulators for temporal bone surgery has become increasingly prevalent over the past decade. Numerous studies evaluated the effectiveness of various VR simulators in improving surgical skills and outcomes. One of the earliest VR simulators for temporal bone surgery was developed by the University of Western Ontario in 2006. The aim of this simulator was to teach basic surgical skills, temporal bone dissection, and drilling. Although the outcomes of this simulator were not specified, it laid the groundwork for future developments in VR temporal bone surgery simulators. Maassen et al. (2004) [6] used a REALAX (Realax) VR software package to detect the possibility of using implantable hearing devices on sensorineural hearing loss. Since then, several VR simulators have been developed, as shown by articles including VoxelMan (VoxelMan GmbH) by Francis et al. (2012) [7], Visible Ear Simulator (Alexandra Institute).) by Fang et al. (2014) [8], and VR temporal bone dissection simulators CardinalSim (Stanford Medicine.) by Chan et al. (2016) [9], Linke et al. (2013) [10], and Varoquier et al. (2017) [11]. These simulators were developed to teach temporal bone surgery and dissection, and all reported improvements in surgical skills and outcomes. However, some of these simulators were limited by their low fidelity, limited range of tasks, and lack of haptic feedback (Frendø et al. 2020 [12] and Zirkle et al. 2009 [13]). Other VR simulators, such as those developed by Arora et al. (2014), Gawęcki et al. (2020) [14], Andersen et al. (2016, 2022) [15,16], and Mickiewicz et al. (2021) [17] focused on mastoidectomy surgery. These simulators allowed surgical planning and execution with improved accuracy. In addition, there are several articles that focused on cochlear implantation through virtual simulation and found an improvement in surgical drilling, surgeons’ performance, and self-directness during tasks, as found by Copson et al. in 2017 [18], Frithioff et al. in 2021 [19], and Frendø et al. in 2021 and 2022 [20,21].
Meta-analysis: Usefulness of the Virtual Reality Temporal Bone Dissection on Participants Questionnaire
The risk ratios were calculated between novice and experienced participants on the number of tasks and sample sizes (Fig. 2). The risk ratio yielded no significant difference in all of the studies (standardized mean difference, 0.88; 95% CI, 0.63–1.24; p>0.001).
Random risk ratio meta-analysis for VR simulator on selected studies compared with novice and experienced trainees. The risk ratio of Copson et al. [18], Frendø et al. [20], O’Leary et al. [28], Piromchai et al. [25], Wijewickrema et al. [27,29] was not estimable due to insufficient participants. IV, inverse variance; CI, confidence interval; df, degree of freedom.
The 5-point Likert scale questionnaire was the main outcome measure for the satisfaction of the usage of VR on temporal bone performance (Fig. 3). The use of VR simulators was associated with significantly greater knowledge acquisition (standardized mean difference, 1.16; 95% CI, 0.08–2.24; p<0.00001) and skill acquisition (standardized mean difference, 0.93; 95% CI, –0.12 to 1.97; p<0.00001) as compared to traditional book-based education. Additionally, students who used VR simulators reported higher levels of overall satisfaction with the educational experience (standardized mean difference, –0.49; 95% CI, –1.56 to 0.58, p<0.001).
Random-effects meta-analysis for VR simulator on participants reported after temporal bone dissection compared with novice and experienced trainees. The study effect of Wijewickrema et al. [29] not estimable. SMD, standard mean difference; SD, standard deviation; IV, inverse variance; CI, confidence interval; df, degree of freedom.
The risk of bias was analyzed with ROBINS-I tools, results indicate that the selection of reported results has 90% some concerns, measurement of the outcome data has over 40% low risk, missing outcome data, deviations from intended interventions, and the randomization process had the lowest risk of bias.
Limitations of Previous Virtual Reality Simulators
These study results indicate that VR temporal bone dissection simulators can be effective in improving surgical skills and confidence and for preoperative rehearsal. However, some limitations to consider include:
1. Limited haptic feedback: the current technology may not provide the same level of haptic feedback as with real-life surgery, which could impact performance.
2. Lack of validation studies: some studies did not perform detailed validation studies to compare the effectiveness of the simulator with that of other training methods.
3. Limited sample sizes: many studies had small sample sizes, which may have limited the generalizability of the findings.
4. Some simulators include normal human specimens, which can be useful for medical students; however, surgeons and residents need variable numbers and variations of anatomy and pathology.
5. High cost: VR simulators are cheaper than cadaver dissection. Commercially available simulators are still expensive.
DISCUSSION
Temporal bone dissection is a crucial and challenging skill that requires extensive training and experience. Traditionally, training in temporal bone dissection was conducted on cadavers, which had several limitations, including limited availability, ethical concerns, variability in anatomy, and deterioration of the tissue over time [22-31]. With the advent of VR technology, simulators have been developed that allow trainees to practice temporal bone dissection in a safe and controlled environment [8]. VR simulators have been shown to be effective in improving trainees’ performance in temporal bone dissection tasks and have several advantages over traditional cadaveric training, including accessibility, repeatability, standardized assessment, and reduced costs [32]. Moreover, VR simulators can provide haptic feedback and enable trainees to practice specific tasks repeatedly until they achieve mastery [5]. However, despite these benefits, VR simulators have some limitations, including the lack of realism in tissue handling, limited tactile feedback, and the need for expensive equipment and technical expertise [33]. Nonetheless, VR simulators have the potential to revolutionize surgical training and improve patient outcomes by providing trainees with a safe and effective platform to develop their surgical skills.
While VR simulators have shown promising results in improving surgical skills and outcomes, there are still limitations to their use. These include their high cost, limited availability, and the need for further validation studies to determine their effectiveness [33]. VR simulators have become a valuable tool in the education and training of temporal bone surgery and mastoidectomy. Future developments in VR technology and validation studies will likely continue to improve the efficacy and accessibility of these simulators in surgical education and training.
Temporal bone dissection is a complex and challenging surgical procedure that requires a high level of skill and expertise. Traditionally, this skill was acquired through hands-on training on cadavers or live patients, which can be time-consuming, expensive, and associated with ethical concerns. However, recent advances in VR technology have led to the development of VR simulators that can provide a safe and effective alternative to cadaveric dissection for training clinicians. VR simulators offer several advantages over traditional training methods, including the ability to provide a standardized and repeatable training experience, the ability to simulate a wide range of pathological conditions, and the ability to provide the trainee with real-time feedback. Moreover, VR simulators can be easily updated and customized to meet the specific training needs of different trainees and institutions.
Despite these advantages, VR simulators for temporal bone dissection are still in the early stages of development, and there is a need for further research to optimize their effectiveness and ensure their long-term sustainability. Future research should focus on developing more sophisticated and realistic VR simulators that can accurately replicate the haptic feedback and tactile sensations of real surgical instruments. Additionally, research should explore the potential of incorporating artificial intelligence and machine learning algorithms into VR simulators to enhance their feedback mechanisms and personalize the training experience for each trainee. The effectiveness of VR simulators in improving the clinical outcomes of temporal bone dissection should also be evaluated through randomized controlled trials and comparisons to traditional training methods. The development of VR simulators for temporal bone dissection holds great promise for improving the quality and safety of this important surgical procedure and should be a priority for future research in this field.
Notes
Funding/Support
This research was supported by “Regional Innovation Strategy (RIS)” through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (MOE) (2022RIS-005) and by Korean Fund for Regenerative Medicine funded by Ministry of Science and ICT, and Ministry of Health and Welfare (21C0721L1, Republic of Korea).
Conflicts of Interest
No potential conflict of interest relevant to this article was reported.
Availability of Data and Materials
All data generated or analyzed during this study are included in this published article. For other data, these may be requested through the corresponding author.
Authors' Contributions
Conceptualization, Project administration, Validation, Visualization: TB, YJS; Data curation, Formal analysis, Investigation, Methodology, Resources, Software: TB; Funding acquisition: YJS; Writing–original draft: TB, YJS; Writing–review & editing: TB, YJS.
All authors read and approved the final manuscript.