Am I doing this right? Structured self-assessment during simulation training of mastoidectomy improves cadaver dissection performance: a prospective educational study.

PURPOSE: Temporal bone surgery requires excellent surgical skills and simulation-based training can aid novices' skills acquisition. However, simulation-based training is challenged by early stagnation of performance after few performances. Structured self-assessment during practice might enhance learning by inducing reflection and engagement in the learning task. In this study, structured self-assessment was introduced during virtual reality (VR) simulation of mastoidectomy to investigate the effects on subsequent performance during cadaveric dissection. METHODS: A prospective educational study with comparison with historical controls (reference cohort). At a temporal bone dissection course, eighteen participants performed structured self-assessment during 3 h of VR simulation mastoidectomy training before proceeding to cadaver dissection (intervention cohort). At a previous course, eighteen participants received identical VR simulation training but without the structured self-assessment (reference cohort). Final products from VR simulation and cadaveric dissection were recorded and assessed by two blinded raters using a 19-point modified Welling Scale. RESULTS: The intervention cohort completed fewer procedures (average 4.2) during VR simulation training than the reference cohort (average 5.7). Nevertheless, the intervention cohort achieved a significantly higher average performance score both in VR simulation (11.1 points, 95% CI [10.6-11.5]) and subsequent cadaveric dissection (11.8 points, 95% CI [10.7-12.8]) compared with the reference cohort, who scored 9.1 points (95% CI [8.7-9.5]) during VR simulation and 5.8 points (95% CI [4.8-6.8]) during cadaveric dissection. CONCLUSIONS: Structured self-assessment is a valuable learning support during self-directed VR simulation training of mastoidectomy and the positive effect on performance transfers to subsequent cadaveric dissection performance.

The cutting edge of customized surgery: 3D-printed models for patient-specific interventions in otology and auricular management-a systematic review.

PURPOSE: 3D-printing (three-dimensional printing) is an emerging technology with promising applications for patient-specific interventions. Nonetheless, knowledge on the clinical applicability of 3D-printing in otology and research on its use remains scattered. Understanding these new treatment options is a prerequisite for clinical implementation, which could improve patient outcomes. This review aims to explore current applications of 3D-printed patient-specific otologic interventions, including state of the evidence, strengths, limitations, and future possibilities. METHODS: Following the PRISMA statement, relevant studies were identified through Pubmed, EMBASE, the Cochrane Library, and Web of Science. Data on the manufacturing process and interventions were extracted by two reviewers. Study quality was assessed using Joanna Briggs Institute's critical appraisal tools. RESULTS: Screening yielded 590 studies; 63 were found eligible and included for analysis. 3D-printed models were used as guides, templates, implants, and devices. Outer ear interventions comprised 73% of the studies. Overall, optimistic sentiments on 3D-printed models were reported, including increased surgical precision/confidence, faster manufacturing/operation time, and reduced costs/complications. Nevertheless, study quality was low as most studies failed to use relevant objective outcomes, compare new interventions with conventional treatment, and sufficiently describe manufacturing. CONCLUSION: Several clinical interventions using patient-specific 3D-printing in otology are considered promising. However, it remains unclear whether these interventions actually improve patient outcomes due to lack of comparison with conventional methods and low levels of evidence. Further, the reproducibility of the 3D-printed interventions is compromised by insufficient reporting. Future efforts should focus on objective, comparative outcomes evaluated in large-scale studies.

Assessing competence in cochlear implant surgery using the newly developed Cochlear Implant Surgery Assessment Tool.

PURPOSE: To develop and gather validity evidence for a novel tool for assessment of cochlear implant (CI) surgery, including virtual reality CI surgery training. METHODS: Prospective study gathering validity evidence according to Messick's framework. Four experts developed the CI Surgery Assessment Tool (CISAT). A total of 35 true novices (medical students), trained novices (residents) and CI surgeons performed two CI-procedures each in the Visible Ear Simulator, which were rated by three blinded experts. Classical test theory and generalizability theory were used for reliability analysis. RESULTS: The CISAT significantly discriminated between the three groups (p < 0.001). The generalizability coefficient was 0.76 and most of the score variance (53.3%) was attributable to the participant and only 6.8% to the raters. When exploring a standard setting for CI surgery, the contrasting groups method suggested a pass/fail score of 36.0 points (out of 55), but since the trained novices performed above this, we propose using the mean CI surgeon performance score (45.3 points). CONCLUSION: Validity evidence for simulation-based assessment of CI performance supports the CISAT. Together with the standard setting, the CISAT might be used to monitor progress in competency-based training of CI surgery and to determine when the trainee can advance to further training.

Ultra-high-fidelity virtual reality mastoidectomy simulation training: a randomized, controlled trial.

PURPOSE: Ultra-high-fidelity (UHF) graphics in virtual reality (VR) simulation might improve surgical skill acquisition in temporal bone training. This study aims to compare UHF VR simulation training with conventional, screen-based VR simulation training (cVR) with respect to performance and cognitive load (CL). METHODS: In a randomized trial with a cross-over design, 24 students completed a total of four mastoidectomies in a VR temporal bone surgical simulator: two performances under UHF conditions using a digital microscope and two performances under conventional conditions using screen-based VR simulation. Performances were assessed by two blinded raters using an established assessment tool. In addition, CL was estimated as the relative change in secondary-task reaction time during simulation when compared with individual baseline measurements. Data were analyzed using linear mixed model analysis for repeated measurements. RESULTS: The mean final-product performance score was significantly lower in UHF VR simulation compared to cVR simulation [mean difference 1.0 points out of 17 points, 95% CI (0.2-1.7), p = 0.02]. The most important factor for performance during UHF simulation was the ability to achieve stereovision (mean difference = 3.4 points, p < 0.001). Under the UHF VR condition, CL was significantly higher than during cVR (28% vs. 18%, respectively, p < 0.001). CONCLUSION: UHF graphics in VR simulation training reduced performance and induced a higher CL in novices than conventional, screen-based VR simulation training. Consequently, UHF VR simulation training should be preceded by cVR training and might be better suited for the training of intermediates or experienced surgeons.

Performance metrics in mastoidectomy training: a systematic review.

OBJECTIVE: To investigate validity evidence, and strengths and limitations of performance metrics in mastoidectomy training. METHODS: A systematic review following the PRISMA guidelines. Studies reporting performance metrics in mastoidectomy/temporal bone surgery were included. Data on design, outcomes, and results were extracted by two reviewers. Validity evidence according to Messick's framework and level of evidence were assessed. RESULTS: The search yielded a total of 1085 studies from the years 1947-2018 and 35 studies were included for full data extraction after abstract and full-text screening. 33 different metrics on mastoidectomy performance were identified and ranked according to the number of reports. Most of the 33 metrics identified had some amount of validity evidence. The metrics with most validity evidence were related to drilling time, volume drilled per time, force applied near vital structures, and volume removed. CONCLUSIONS: This review provides an overview of current metrics of mastoidectomy performance, their validity, strengths and limitations, and identifies the gap in validity evidence of some metrics. Evidence-based metrics can be used for performance assessment in temporal bone surgery and for providing integrated and automated feedback in virtual reality simulation training. The use of such metrics in simulation-based mastoidectomy training can potentially address some of the limitations in current temporal bone skill assessment and ease assessment in repeated practice. However, at present, an automated feedback based on metrics in VR simulation does not have sufficient empirical basis and has not been generally accepted for use in training and certification. LEVEL OF EVIDENCE: 2a.

The effect of structured self-assessment in virtual reality simulation training of mastoidectomy.

PURPOSE: Virtual reality (VR) simulation surgical skills training is well established, but self-directed practice is often associated with a learning curve plateau. In this study, we investigate the effects of structured self-assessment as a means to improve performance in mastoidectomy training. METHODS: The study was a prospective, educational study. Two cohorts of novices (medical students) were recruited for practice of anatomical mastoidectomy in a training program with five distributed training blocks. Fifteen participants performed structured self-assessment after each procedure (intervention cohort). A reference cohort of another 14 participants served as controls. Performances were assessed by two blinded raters using a modified Welling Scale and simulator-recorded metrics. RESULTS: The self-assessment cohort performed superiorly to the reference cohort (mean difference of final product score 0.87 points, p = 0.001) and substantially reduced the number of repetitions needed. The self-assessment cohort also had more passing performances for the combined metrics-based score reflecting increased efficiency. Finally, the self-assessment cohort made fewer collisions compared with the reference cohort especially with the chorda tympani, the facial nerve, the incus, and the malleus. CONCLUSIONS: VR simulation training of surgical skills benefits from having learners perform structured self-assessment following each procedure as this increases performance, accelerates the learning curve thereby reducing time needed for training, and induces a safer performance with fewer collisions with critical structures. Structured self-assessment was in itself not sufficient to counter the learning curve plateau and for continued skills development additional supports for deliberate practice are needed.

Decentralized virtual reality mastoidectomy simulation training: a prospective, mixed-methods study.

PURPOSE: Virtual reality (VR) training of mastoidectomy is effective in surgical training-particularly if organized as distributed practice. However, centralization of practice facilities is a barrier to implementation of distributed simulation training. Decentralized training could be a potential solution. Here, we aim to assess the feasibility, use, and barriers to decentralized VR mastoidectomy training using a freeware, high-fidelity temporal bone simulator. METHODS: In a prospective, mixed-methods study, 20 otorhinolaryngology residents were given three months of local access to a VR mastoidectomy simulator. Additionally, trainees were provided a range of learning supports for directed, self-regulated learning. Questionnaire data were collected and focus group interviews conducted. The interviews were analyzed using thematic analysis and compared with quantitative findings. RESULTS: Participants trained 48.5 h combined and mainly towards the end of the trial. Most participants used between two and four different learning supports. Qualitative analysis revealed five main themes regarding implementation of decentralized simulation training: convenience, time for training, ease of use, evidence for training, and testing. CONCLUSIONS: Decentralized VR training using a freeware, high-fidelity mastoidectomy simulator is feasible but did not lead to a high training volume or truly distributed practice. Evidence for training was found motivational. Access to training, educational designs, and the role of testing are important for participant motivation and require further evaluation.

The effect of distributed virtual reality simulation training on cognitive load during subsequent dissection training.

BACKGROUND: Complex tasks such as surgical procedures can induce excessive cognitive load (CL), which can have a negative effect on learning, especially for novices. AIM: To investigate if repeated and distributed virtual reality (VR) simulation practice induces a lower CL and higher performance in subsequent cadaveric dissection training. METHODS: In a prospective, controlled cohort study, 37 residents in otorhinolaryngology received VR simulation training either as additional distributed practice prior to course participation (intervention) (9 participants) or as standard practice during the course (control) (28 participants). Cognitive load was estimated as the relative change in secondary-task reaction time during VR simulation and cadaveric procedures. RESULTS: Structured distributed VR simulation practice resulted in lower mean reaction times (32% vs. 47% for the intervention and control group, respectively, p < 0.01) as well as a superior final-product performance during subsequent cadaveric dissection training. CONCLUSIONS: Repeated and distributed VR simulation causes a lower CL to be induced when the learning situation is increased in complexity. A suggested mechanism is the formation of mental schemas and reduction of the intrinsic CL. This has potential implications for surgical skills training and suggests that structured, distributed training be systematically implemented in surgical training curricula.

European status on temporal bone training: a questionnaire study.

PURPOSE: In otorhinolaryngology training, introduction to temporal bone surgery through hands-on practice on cadaveric human temporal bones is the gold-standard training method before commencing supervised surgery. During the recent decades, the availability of such specimens and the necessary laboratory facilities for training seems to be decreasing. Alternatives to traditional training can consist of drilling artificial models made of plaster or plastic but also virtual reality (VR) simulation. Nevertheless, the integration and availability of these alternatives into specialist training programs remain unknown. METHODS: We conducted a questionnaire study mapping current status on temporal bone training and included responses from 113 departments from 23 countries throughout Europe. RESULTS: In general, temporal bone training during residency in ORL is organized as in-house training, or as participation in national or international temporal bone courses or some combination hereof. There are considerable differences in the availability of training facilities for temporal bone surgery and the number of drillings each ORL trainee can perform. Cadaveric dissection is still the most commonly used training modality. CONCLUSIONS: VR simulation and artificial models are reported to be used at many leading training departments already. Decreasing availability of cadavers, lower costs of VR simulation and artificial models, in addition to established evidence for a positive effect on the trainees' competency, were reported as the main reasons. Most remaining departments expect to implement VR simulation and artificial models for temporal bone training into their residency programs in the near future.

3D-printed temporal bone models for training: Does material transparency matter?

PURPOSE: To investigate the impact of 3D-printed temporal bone models with two different material transparencies on trainees' mastoidectomy performance. METHODS: Eleven ORL residents performed two anatomical mastoidectomies with posterior tympanotomy on two 3D-printed models with different transparency and VR simulation training. Participants where divided into two groups based on their experience. Within each group participants were randomized to start with the model printed in a completely opaque material or in a material featuring some degree of transparency. After drilling on 3D-printed models, the participants performed two similar mastoidectomies on human cadavers: one on the left side of one cadaver and one on the right side of another cadaver. After drilling 3D-printed models and cadavers, the final-product performances were evaluated by two experienced raters using the 26-item modified Welling Scale. Participants also evaluated the models using a questionnaire. RESULTS: Overall, the participants performed 25 % better on the 3D-printed models featuring transparency compared to the opaque models (18.6 points vs 14.9 points, mean difference = 3.7, 95 % CI 2.0-5.3, P < 0.001)). This difference in performance was independent of which material the participants had drilled first. In addition, the residents also subjectively rated the transparent model to be closer to cadaver dissection. The experienced group starting with the 3D-printed models scored 21.5 points (95 % CI 20.0-23.1), while the group starting with VR simulation training score 18.4 points (95 % CI 16.6-20.3). CONCLUSION: We propose that material used for 3D-printing temporal bone models should feature some degree of transparency, like natural bone, for trainees to learn and exploit key visual cues during drilling.

Cellular voids in the pathogenesis of otosclerosis.

BACKGROUND: Otosclerosis is a common ear disease that causes fixation of the stapes and conductive hearing impairment. However, the pathogenesis of otosclerosis is still unknown. Otosclerosis could be associated with the unique bony environment found in the otic capsule. Normal bone remodelling is almost completely absent around the inner ear after birth allowing degenerative changes and dead osteocytes to accumulate. High levels of inner ear anti resorptive osteoprotegerin (OPG) is most likely responsible for this capsular configuration. Studies have demonstrated how osteocyte lifespan variation creates occasional clusters of dead osteocytes, so-called cellular voids, at otosclerotic predilection sites in the human otic capsule. These cellular voids have been suggested as possible starting points of otosclerosis. AIM: To describe the cellular viability in otosclerotic lesions and compare it to that of cellular voids. MATERIALS AND METHODS: The study was based on unbiased stereological quantifications in undecalcified human temporal bones with otosclerosis. RESULTS: Osteocyte viability was found to vary within the otosclerotic lesions. Furthermore, the results presented here illustrate that inactive otosclerotic lesions consist of mainly dead interstitial bone, much like cellular voids. CONCLUSIONS AND SIGNIFICANCE: Focal degeneration in the otic capsule may play an important role in the pathogenesis of otosclerosis.

Learning Curves in Directed Self-Regulated Virtual Reality Training of Mastoidectomy and the Role of Repetition and Motivation.

BACKGROUND: Mastoidectomy is a complex procedure which can be trained on human cadaveric temporal bones or simulation models. The number of repetitions offered in most training curricula is considerably less than what is normally required for motor skills acquisition in crafts or sports. Directed, self-regulated virtual reality simulation training may provide unlimited repetitions but the effect on learning of extended but unsupervised training is unknown. This study recorded extended learning curves of novices in virtual reality simulation mastoidectomy training. METHODS: Six medical students used the visible ear temporal bone simulator at home for 100 repetitions. Virtual temporal bones were later assessed by 2 blinded experts on a 26-point modified Welling Scale. RESULTS: Four participants completed 100 procedures each and 2 participants completed 50 procedures. Learning curves and plots of time demonstrated great variation: one participant improved gradually during the first 50 procedures and sustained a high performance; another participant achieved only 16 points after 50 procedures; a third participant demonstrated mediocre performances between 10 and 15 points but only used about 5 minutes per procedure. The remaining 3 participants achieved high but fluctuating scores with very limited time use per procedure. Their score per time exceeds the performance of experienced otosurgeons and suggests the use of save/restore gaming strategies to inflate their performance. CONCLUSION: Deliberate learners may reach proficiency in virtual reality simulation of mastoidectomy after 50 repetitions. However, even 100 repetitions cannot guarantee proficiency if motivation fails. Creative "gaming" behavior must be considered and opposed by motivation, supervision, testing, and certification.

Are Video Recordings Reliable for Assessing Surgical Performance? A Prospective Reliability Study Using Generalizability Theory.

INTRODUCTION: Reliability is pivotal in surgical skills assessment. Video-based assessment can be used for objective assessment without physical presence of assessors. However, its reliability for surgical assessments remains largely unexplored. In this study, we evaluated the reliability of video-based versus physical assessments of novices' surgical performances on human cadavers and 3D-printed models-an emerging simulation modality. METHODS: Eighteen otorhinolaryngology residents performed 2 to 3 mastoidectomies on a 3D-printed model and 1 procedure on a human cadaver. Performances were rated by 3 experts evaluating the final surgical result using a well-known assessment tool. Performances were rated both hands-on/physically and by video recordings. Interrater reliability and intrarater reliability were explored using κ statistics and the optimal number of raters and performances required in either assessment modality was determined using generalizability theory. RESULTS: Interrater reliability was moderate with a mean κ score of 0.58 (range 0.53-0.62) for video-based assessment and 0.60 (range, 0.55-0.69) for physical assessment. Video-based and physical assessments were equally reliable (G coefficient 0.85 vs. 0.80 for 3D-printed models and 0.86 vs 0.87 for cadaver dissections). The interaction between rater and assessment modality contributed to 8.1% to 9.1% of the estimated variance. For the 3D-printed models, 2 raters evaluating 2 video-recorded performances or 3 raters physically assessing 2 performances yielded sufficient reliability for high-stakes assessment (G coefficient >0.8). CONCLUSIONS: Video-based and physical assessments were equally reliable. Some raters were affected by changing from physical to video-based assessment; consequently, assessment should be either physical or video based, not a combination.

3D-printing a cost-effective model for mastoidectomy training.

BACKGROUND: 3D-printed temporal bone models can potentially provide a cost-effective alternative to cadaver surgery that can be manufactured locally at the training department. The objective of this study was to create a cost-effective 3D-printed model suitable for mastoidectomy training using entry level and commercially available print technologies, enabling individuals, without prior experience on 3D-printing, to manufacture their own models for basic temporal bone training. METHODS: Expert technical professionals and an experienced otosurgeon identified the best material for replicating the temporal bone and created a cost-effective printing routine for the model using entry-level print technologies. Eleven participants at a temporal bone dissection course evaluated the model using a questionnaire. RESULTS: The 3D-printed temporal bone model was printed using a material extrusion 3D-printer with a heat resistant filament, reducing melting during drilling. After printing, a few simple post-processing steps were designed to replicate the dura, sigmoid sinus and facial nerve. Modifying the 3D-printer by installing a direct-drive and ruby nozzle resulted in more successful prints and less need for maintenance. Upon evaluation by otorhinolaryngology trainees, unanimous feedback was that the model provided a good introduction to the mastoidectomy procedure, and supplementing practice to cadaveric temporal bones. CONCLUSION: In-house production of a cost-effective 3D-printed model for temporal bone training is feasible and enables training institutions to manufacture their own models. Further, this work demonstrates the feasibility of creating new temporal bone models with anatomical variation to provide ample training opportunity.

3-D-Printed Models for Temporal Bone Training: A Validity Study.

OBJECTIVE: 3-D printing offers convenient and low-cost mastoidectomy training; nonetheless, training benefits using 3-D-printed temporal bones remain largely unexplored. In this study, we have collected validity evidence for a low-cost, 3-D-printed temporal bone for mastoidectomy training and established a credible pass/fail score for performance on the model. STUDY DESIGN: A prospective educational study gathering validity evidence using Messick's validity framework. SETTING: Seven Danish otorhinolaryngology training institutions. PARTICIPANTS: Eighteen otorhinolaryngology residents (novices) and 11 experienced otosurgeons (experts). INTERVENTION: Residents and experienced otosurgeons each performed two to three anatomical mastoidectomies on a low-cost, 3-D-printed temporal bone model produced in-house. After drilling, mastoidectomy performances were rated by three blinded experts using a 25-item modified Welling scale (WS). MAIN OUTCOME MEASURE: Validity evidence using Messick's framework including reliability assessment applying both classical test theory and Generalizability theory. RESULTS: Novices achieved a mean score of 13.9 points; experienced otosurgeons achieved 23.2 points. Using the contrasting groups method, we established a 21/25-point pass/fail level. The Generalizability coefficient was 0.91, and 75% of the score variance was attributable to participant performance, indicating a high level of assessment reliability. Subsequent D studies revealed that two raters rating one performance or one rater rating two performances were sufficiently reliable for high-stakes assessment. CONCLUSION: Validity evidence supports using a low-cost, 3-D-printed model for mastoidectomy training. The model can be printed in-house using consumer-grade 3-D printers and serves as an additional training tool in the temporal bone curriculum. For competency-based training, we established a cut-off score of 21 of 25 WS points using the contrasting groups method.

The Spatial Distribution of Cellular Voids in the Human Otic Capsule: An Unbiased Quantification of Osteocyte-Depleted Areas.

OBJECTIVE: This study aimed to describe the spatial distribution of osteocyte-depleted areas, so-called cellular voids, in the human otic capsule and compare it with that of otosclerosis. BACKGROUND: Systematic histological studies of the bony otic capsule have revealed an osteoprotegerin (OPG)-mediated inhibition of normal bone remodeling around the inner ear. The resulting accumulation of bony degeneration and dead osteocytes has been thoroughly documented, and the spatial distribution of dead osteocytes and matrix microcracks resembles that of the human ear disease otosclerosis. Clusters of dead osteocytes that may interfere with osteocyte connectivity and thereby the OPG signaling pathway have been described in human temporal bones. It is possible that these cellular voids create disruptions in the antiresorptive OPG signal that may give rise to local pathological remodeling. METHODS: Recently, a method of detecting cellular voids was developed. This study uses unbiased stereology to document the spatial distribution of cellular voids in bulk-stained undecalcified human temporal bone. RESULTS: Cellular voids accumulate around the inner ear and increase in number and size with age. Furthermore, cellular voids are more frequently found in the anterior and lateral regions of the otic capsule, which are known predilection sites of otosclerosis. CONCLUSION: This colocalization of cellular voids and otosclerosis suggests a causal relationship between focal degeneration and otosclerotic remodeling.

Cochlear implantation: Exploring the effects of 3D stereovision in a digital microscope for virtual reality simulation training - A randomized controlled trial.

In cochlear implantation (CI), excellent surgical technique is critical for hearing outcomes. Recent advances in temporal bone Virtual Reality (VR) training allow for specific training of CI and through introduction of new digital microscopes with ultra-high-fidelity (UHF) graphics. This study aims to investigate whether UHF increases performance in VR simulation training of CI electrode insertion compared with conventional, screen-based VR (cVR). METHODS: Twenty-four medical students completed a randomized, controlled trial of an educational intervention. They performed a total of eight CI electrode insertions each in blocks of four using either UHF-VR or cVR, in randomized order. CI electrode insertion performances were rated by two blinded expert raters using a structured assessment tool supported by validity evidence. RESULTS: Performance scores in cVR were higher than in the UHF-VR simulation although this was not significant (19.8 points, 95% CI [19.3-20.3] vs. 18.8 points, 95% CI [18.2-19.4]; P = 0.09). The decisive factor for performance was participants' ability to achieve stereovision (mean difference = 1.1 points, 95% CI [0.15-2.08], P = 0.02). DISCUSSION: No additional benefit was found from UHF-VR over cVR training of CI electrode insertion for novices. Consequently, standard cVR simulation should be used for novices' basic skills acquisition in CI surgery. Future studies should instead explore the effects of other improvements in CI surgery training and if the lacking benefit of UHF-VR also applies for more experienced learners. CONCLUSION: The increased graphical perception and the superior lifelikeness of UHF-VR does not improve early skills acquisition of CI insertion for novices.

Mastoidectomy Training: Is Anatomical Variation Needed? A Randomized, Controlled Trial on Performance and Skills Transfer From Virtual Reality to a Three-Dimensional Printed Model.

OBJECTIVE: Virtual reality (VR) simulation-based training effectively improves novices' mastoidectomy skills. Unfortunately, learning plateaus at an insufficient level and knowledge on optimizing mastoidectomy training to overcome this plateau is needed. In this study, we aim to investigate how training on anatomically different temporal bone cases affects learning, including the effect on retention and transfer of skills. STUDY DESIGN: Randomized controlled trial of an educational intervention. SETTING: The Simulation Center at Copenhagen Academy for Medical Education and Simulation. PARTICIPANTS: Twenty-four medical students from the University of Copenhagen. INTERVENTION: Participants were randomized to practice mastoidectomy on either 12 anatomically varying (intervention group) or 12 identical (control group) cases in a VR simulator. At the end of training and again ~ 3 weeks after training (retention), learners were tested on a new VR patient case and a three-dimensional printed model. MAIN OUTCOME MEASURE: Mastoidectomy performance evaluated by blinded expert raters using a 26-item modified Welling Scale. RESULTS: The intervention and control groups' performance results were comparable at the end of training. Likewise, retention and transfer performances were similar between groups. The overall mean score at the end of training corresponded to approximately 70% of the possible maximum score. CONCLUSIONS: Simulation-based training using anatomical variation was equivalent to training on a single case with respect to acquisition, retention, and transfer of mastoidectomy skills. This suggests that efforts to expose novices to variation during initial training are unnecessary as this variation has limited effect, and-conversely-that educators can expose novices to naturally different anatomical variations without worry of hindered learning.

Cochlear Implant Surgery: Virtual Reality Simulation Training and Transfer of Skills to Cadaver Dissection-A Randomized, Controlled Trial.

BACKGROUND: Cochlear implantation requires excellent surgical skills; virtual reality simulation training is an effective method for acquiring basic competency in temporal bone surgery before progression to cadaver dissection. However, cochlear implantation virtual reality simulation training remains largely unexplored and only one simulator currently supports the training of the cochlear implantation electrode insertion. Here, we aim to evaluate the effect of cochlear implantation virtual reality simulation training on subsequent cadaver dissection performance and self-directedness. METHODS: This was a randomized, controlled trial. Eighteen otolaryngology residents were randomized to either mastoidectomy including cochlear implantation virtual reality simulation training (intervention) or mastoidectomy virtual reality simulation training alone (controls) before cadaver cochlear implantation surgery. Surgical performance was evaluated by two blinded expert raters using a validated, structured assess- ment tool. The need for supervision (reflecting self-directedness) was assessed via post-dissection questionnaires. RESULTS: The intervention group achieved a mean score of 22.9 points of a maximum of 44 points, which was 5.4% higher than the control group's 21.8 points (P = .51). On average, the intervention group required assistance 1.3 times during cadaver drilling; this was 41% more frequent in the control group who received assistance 1.9 times (P = .21). CONCLUSION: Cochlear implantation virtual reality simulation training is feasible in the context of a cadaver dissection course. The addition of cochlear implantation virtual reality training to basic mastoidectomy virtual reality simulation training did not lead to a significant improvement of performance or self-directedness in this study. Our findings suggest that learning an advanced temporal bone procedure such as cochlear implantation surgery requires much more training than learning mastoidectomy.