Steven Andersen
MD, PhD
Otology
Publication Types:
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.
Keywords: 3D-printing; Additive manufacturing; Ear surgery; Otology; Patient-specific.74
Cochlear implantation: Exploring the effects of 3D stereovision in a digital microscope for virtual reality simulation training - A randomized controlled trial
Background: 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.
Keywords: Cochlear implantation; Simulation-based surgical training; Virtual reality simulation.
Automated calculation of cochlear implant electrode insertion parameters in clinical cone-beam CT
Hypothesis: Automated processing of postoperative clinical cone-beam CT (CBCT) of cochlear implant (CI) patients can be used to accurately determine electrode contacts and integrated with an atlas-based mapping of cochlear microstructures to calculate modiolar distance, angular insertion distance, and scalar location of electrode contacts.
Background: Hearing outcomes after CI surgery are dependent on electrode placement. CBCT is increasingly used for in-office temporal bone imaging and might be routinely used for pre- and post-surgical evaluation.
Methods: Thirty-six matched pairs of pre- and postimplant CBCT scans were obtained. These were registered with an atlas to model cochlear microstructures in each dataset. Electrode contact center points were automatically determined using thresholding and electrode insertion parameters were calculated. Automated localization and calculation were compared with manual segmentation of contact center points as well as manufacturer specifications.
Results: Automated electrode contact detection aligned with manufacturer specifications of spacing and our algorithms worked for both distantly- and closely spaced arrays. The average difference between the manual and the automated selection was 0.15 mm, corresponding to a 1.875 voxel difference in each plane at the scan resolution. For each case, we determined modiolar distance, angular insertion depth, and scalar location. These calculations also resulted in similar insertion values using manual and automated contact points as well as aligning with electrode properties.
Conclusion: Automated processing of implanted high-resolution CBCT images can provide the clinician with key information on electrode placement. This is one step toward routine use of clinical CBCT after CI surgery to inform and guide postoperative treatment.
Patient-specific virtual temporal bone simulation based on clinical cone-beam computed tomography
Objectives: Patient-specific surgical simulation allows presurgical planning through three-dimensional (3D) visualization and virtual rehearsal. Virtual reality simulation for otologic surgery can be based on high-resolution cone-beam computed tomography (CBCT). This study aimed to evaluate clinicians’ experience with patient-specific simulation of mastoid surgery.
Methods: Prospective, multi-institutional study. Preoperative temporal bone CBCT scans of patients undergoing cochlear implantation (CI) were retrospectively obtained. Automated processing and segmentation routines were used. Otologic surgeons performed a complete mastoidectomy with facial recess approach on the patient-specific virtual cases in the institution’s temporal bone simulator. Participants completed surveys regarding the perceived accuracy and utility of the simulation.
Results: Twenty-two clinical CBCTs were obtained. Four attending otologic surgeons and 5 otolaryngology trainees enrolled in the study. The mean number of simulations completed by each participant was 16.5 (range 3-22). “Overall experience” and “usefulness for presurgical planning” were rated as “good,” “very good,” or “excellent” in 84.6% and 71.6% of the simulations, respectively. In 10.7% of simulations, the surgeon reported to have gained a significantly greater understanding of the patient’s anatomy compared to standard imaging. Participants were able to better appreciate subtle anatomic findings after using the simulator for 60.4% of cases. Variable CBCT acquisition quality was the most reported limitation.
Conclusion: Patient-specific simulation using preoperative CBCT is feasible and may provide valuable insights prior to otologic surgery. Establishing a CBCT acquisition protocol that allows for consistent segmentation will be essential for reliable surgical simulation.
Current status of handheld otoscopy training: a systematic review
Objective: Otoscopy is a frequently performed procedure and competency in this skill is important across many specialties. We aim to systematically review current medical educational evidence for training of handheld otoscopy skills.
Methods: Following the PRISMA guideline, studies reporting on training and/or assessment of handheld otoscopy were identified searching the following databases: PubMed, Embase, OVID, the Cochrane Library, PloS Medicine, Directory of Open Access Journal (DOAJ), and Web of Science. Two reviewers extracted data on study design, training intervention, educational outcomes, and results. Quality of educational evidence was assessed along with classification according to Kirkpatrick’s model of educational outcomes.
Results: The searches yielded a total of 6064 studies with a final inclusion of 33 studies for the qualitative synthesis. Handheld otoscopy training could be divided into workshops, physical simulators, web-based training/e-learning, and smartphone-enabled otoscopy. Workshops were the most commonly described educational intervention and typically consisted of lectures, hands-on demonstrations, and training on peers. Almost all studies reported a favorable effect on either learner attitude, knowledge, or skills. The educational quality of the studies was reasonable but the educational outcomes were mostly evaluated on the lower Kirkpatrick levels with only a single study determining the effects of training on actual change in the learner behavior.
Conclusion: Overall, it seems that any systematic approach to training of handheld otoscopy is beneficial in training regardless of learner level, but the heterogeneity of the studies makes comparisons between studies difficult and the relative effect sizes of the interventions could not be determined.
Current evidence for simulation-based training and assessment of myringotomy and ventilation tube insertion: A systematic review
Objective: Myringotomy and ventilation tube insertion (MT) is a key procedure in otorhinolaryngology and can be trained using simulation models. We aimed to systematically review the literature on models for simulation-based training and assessment of MT and supporting educational evidence.
Databases reviewed: PubMed, Embase, Cochrane Library, Web of Science, Directory of Open Access Journals.
Methods: Inclusion criteria were MT training and/or skills assessment using all types of training modalities and learners. Studies were divided into 1) descriptive and 2) educational interventional/observational in the analysis. For descriptive studies, we provide an overview of available models including materials and cost. Educational studies were appraised using Kirkpatrick’s level of educational outcomes, Messick’s framework of validity, and a structured quality assessment tool.
Results: Forty-six studies were included consisting of 21 descriptive studies and 25 educational studies. Thirty-one unique physical and three virtual reality simulation models were identified. The studies report moderate to high realism of the different simulators and trainees and educators perceive them beneficial in training MT skills. Overall, simulation-based training is found to reduce procedure time and errors, and increase performance as measured using different assessment tools. None of the studies used a contemporary validity framework and the current educational evidence is limited.
Conclusion: Numerous simulation models and assessment tools have been described in the literature but educational evidence and systematic implementation into training curricula is scarce. There is especially a need to establish the effect of simulation-based training of MT in transfer to the operating room and on patient outcomes.
Content validity evidence for a simulation-based test of handheld otoscopy skills
Purpose: At graduation from medical school, competency in otoscopy is often insufficient. Simulation-based training can be used to improve technical skills, but the suitability of the training model and assessment must be supported by validity evidence. The purpose of this study was to collect content validity evidence for a simulation-based test of handheld otoscopy skills.
Methods: First, a three-round Delphi study was conducted with a panel of nine clinical teachers in otorhinolaryngology (ORL) to determine the content requirements in our educational context. Next, the authenticity of relevant cases in a commercially available technology-enhanced simulator (Earsi, VR Magic, Germany) was evaluated by specialists in ORL. Finally, an integrated course was developed for the simulator based on these results.
Results: The Delphi study resulted in nine essential diagnoses of normal variations and pathologies that all junior doctors should be able to diagnose with a handheld otoscope. Twelve out of 15 tested simulator cases were correctly recognized by at least one ORL specialist. Fifteen cases from the simulator case library matched the essential diagnoses determined by the Delphi study and were integrated into the course.
Conclusion: Content validity evidence for a simulation-based test of handheld otoscopy skills was collected. This informed a simulation-based course that can be used for undergraduate training. The course needs to be further investigated in relation to other aspects of validity and for future self-directed training.
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.
Cochlear Implant Surgery: Learning Curve in Virtual Reality Simulation Training and Transfer of Skills to a 3D-printed Temporal Bone—a prospective Trial.
Objective: Mastering Cochlear Implant (CI) surgery requires repeated practice, preferably initiated in a safe – i.e. simulated – environment. Mastoidectomy Virtual Reality (VR) simulation-based training (SBT) is effective, but SBT of CI surgery largely uninvestigated. The learning curve is imperative for understanding surgical skills acquisition and developing competency-based training. Here, we explore learning curves in VR SBT of CI surgery and transfer of skills to a 3D-printed model.
Methods: Prospective, single-arm trial. Twenty-four novice medical students completed a pre-training CI inserting test on a commercially available pre-drilled 3D-printed temporal bone. A training program of 18 VR simulation CI procedures was completed in the Visual Ear Simulator over four sessions. Finally, a post-training test similar to the pre-training test was completed. Two blinded experts rated performances using the validated Cochlear Implant Surgery Assessment Tool (CISAT). Performance scores were analyzed using linear mixed models.
Results: Learning curves were highly individual with primary performance improvement initially, and small but steady improvements throughout the 18 procedures. CI VR simulation performance improved 33% (p < 0.001). Insertion performance on a 3D-printed temporal bone improved 21% (p < 0.001), demonstrating skills transfer.
Discussion: VR SBT of CI surgery improves novices’ performance. It is useful for introducing the procedure and acquiring basic skills. CI surgery training should pivot on objective performance assessment for reaching pre-defined competency before cadaver – or real-life surgery. Simulation-based training provides a structured and safe learning environment for initial training.
Conclusion: CI surgery skills improve from VR SBT, which can be used to learn the fundamentals of CI surgery.
Effects on cognitive load of tutoring in virtual reality simulation training
Aims: According to the guidance hypothesis, tutoring during technical skills training can result in tutoring over-reliance, reflected in a negative effect on performance when tutoring is discontinued. In this study, we wanted to explore if similar effects would be found for cognitive load.
Methods: Two cohorts of novice medical students were recruited for distributed virtual simulation training (five practice blocks of three procedures): 16 participants received intermittent simulator-integrated tutoring and 14 participants served as a reference cohort and did not receive simulator-integrated tutoring. Cognitive load during simulation was estimated using secondary task reaction time. Linear mixed models were used to account for repeated measurements.
Results: Overall, the tutored cohort had a significantly higher cognitive load than the reference cohort (mean difference = 7 %, p=0.006). Simulator-integrated tutoring did seem to lower cognitive load when active but also caused the tutored cohort to have a substantially higher cognitive load in subsequent performances where it was turned off (mean difference = 7 %, respectively, p<<0.001).
Conclusions: Concurrent feedback by simulator-integrated tutoring causes tutoring over-reliance and modifies cognitive load. This suggests that tutoring, in addition to degrading motor skills learning also affects the cognitive processes involved.
Development and validation of an assessment tool for technical skills in handheld otoscopy
OBJECTIVE: Handheld otoscopy requires both technical and diagnostic skills, and is often reported to be insufficient after medical training. We aimed to develop and gather validity evidence for an assessment tool for handheld otoscopy using contemporary medical educational standards.
STUDY DESIGN: Educational study.
SETTING: University/teaching hospital.
SUBJECTS AND METHODS: A structured Delphi methodology was used to develop the assessment tool: nine key opinion leaders (otologists) in undergraduate training of otoscopy iteratively achieved consensus on the content. Next, validity evidence was gathered by the video-taped assessment of two handheld otoscopy performances of 15 medical students (novices) and 11 specialists in otorhinolaryngology using two raters. Standard setting (pass/fail criteria) was explored using the contrasting groups and Angoff methods.
RESULTS: The developed Copenhagen Assessment Tool of Handheld Otoscopy Skills (CATHOS) consists 10 items rated using a 5-point Likert scale with descriptive anchors. Validity evidence was collected and structured according to Messick’s framework: for example the CATHOS had excellent discriminative validity (mean difference in performance between novices and experts 20.4 out of 50 points, p<0.001); and high internal consistency (Cronbach’s alpha=0.94). Finally, a pass/fail score was established at 30 points for medical students and 42 points for specialists in ORL.
CONCLUSION: We have developed and gathered validity evidence for an assessment tool of technical skills of handheld otoscopy and set standards of performance. Standardized assessment allows for individualized learning to the level of proficiency and could be implemented in under- and postgraduate handheld otoscopy training curricula, and is also useful in evaluating training interventions.
Understanding the effects of structured self-assessment in directed, self-regulated simulation-based training of mastoidectomy: a mixed methods study
OBJECTIVE: Self-directed training represents a challenge in simulation-based training as low cognitive effort can occur when learners overrate their own level of performance. This study aims to explore the mechanisms underlying the positive effects of a structured self-assessment intervention during simulation-based training of mastoidectomy.
METHODS: A prospective, educational cohort study of a novice training program consisting of directed, self-regulated learning with distributed practice (5×3 procedures) in a virtual reality temporal bone simulator. The intervention consisted of structured self-assessment after each procedure using a rating form supported by small videos. Semi-structured telephone interviews upon completion of training were conducted with 13 out of 15 participants. Interviews were analysed using directed content analysis and triangulated with quantitative data on secondary task reaction time for cognitive load estimation and participants’ self-assessment scores.
RESULTS: Six major themes were identified in the interviews: goal-directed behaviour, use of learning supports for scaffolding of the training, cognitive engagement, motivation from self-assessment, self-assessment bias, and feedback on self-assessment (validation). Participants seemed to self-regulate their learning by forming individual sub-goals and strategies within the overall goal of the procedure. They scaffolded their learning through the available learning supports. Finally, structured self-assessment was reported to increase the participants’ cognitive engagement, which was further supported by a quantitative increase in cognitive load.
CONCLUSIONS: Structured self-assessment in simulation-based surgical training of mastoidectomy seems to promote cognitive engagement and motivation in the learning task and to facilitate self-regulated learning.
Expert sampling of VR simulator metrics for automated assessment of mastoidectomy performance.
OBJECTIVE: Often the assessment of mastoidectomy performance requires time-consuming manual rating. Virtual reality (VR) simulators offer potentially useful automated assessment and feedback but should be supported by validity evidence. We aimed to investigate simulator metrics for automated assessment based on the expert performance approach, comparison with an established assessment tool, and the consequences of standard setting.
METHODS: The performances of 11 experienced otosurgeons and 37 otorhinolaryngology residents. Participants performed three mastoidectomies in the Visible Ear Simulator. Nine residents contributed additional data on repeated practice in the simulator. One hundred and twenty-nine different performance metrics were collected by the simulator and final-product files were saved. These final products were analyzed using a modified Welling Scale by two blinded raters.
RESULTS: Seventeen metrics could discriminate between resident and experienced surgeons’ performances. These metrics mainly expressed various aspects of efficiency: Experts demonstrated more goal-directed behavior and less hesitancy, used less time, and selected large and sharp burrs more often. The combined metrics-based score (MBS) demonstrated significant discriminative ability between experienced surgeons and residents with a mean difference of 16.4% (95% confidence interval [12.6-20.2], P << 0.001). A pass/fail score of 83.6% was established. The MBS correlated poorly with the final-product score but excellently with the final-product score per time.
CONCLUSION: The MBS mainly reflected efficiency components of the mastoidectomy procedure, and although it could have some uses in self-directed training, it fails to measure and encourage safe routines. Supplemental approaches and feedback are therefore required in VR simulation training of mastoidectomy.
Otologic Skills Training
This article presents a summary of the current simulation training for otologic skills. There is a wide variety of educational approaches, assessment tools, and simulators in use, including simple low-cost task trainers to complex computer-based virtual reality systems. A systematic approach to otologic skills training using adult learning theory concepts, such as repeated and distributed practice, self-directed learning, and mastery learning, is necessary for these educational interventions to be effective. Future directions include development of measures of performance to assess efficacy of simulation training interventions and, for complex procedures, improvement in fidelity based on educational goals.
Mapping the plateau of novices in virtual reality simulation training of mastoidectomy
OBJECTIVES/HYPOTHESIS: To explore why novices’ performance plateau in directed, self-regulated virtual reality (VR) simulation training and how performance can be improved.
STUDY DESIGN: Prospective study.
METHODS: Data on the performances of 40 novices who had completed repeated, directed, self-regulated VR simulation training of mastoidectomy were included. Data were analyzed to identify key areas of difficulty as well as the procedures terminated without using all the time allowed.
RESULTS: Novices had difficulty in avoiding drilling holes in the outer anatomical boundaries of the mastoidectomy and frequently made injuries to vital structures such as the lateral semicircular canal, the ossicles, and the facial nerve. The simulator-integrated tutor function improved performance on many of these items, but overreliance on tutoring was observed. Novices also demonstrated poor self-assessment skills and often did not make use of the allowed time, lacking knowledge on when to stop or how to excel.
CONCLUSION: Directed, self-regulated VR simulation training of mastoidectomy needs a strong instructional design with specific process goals to support deliberate practice because cognitive effort is needed for novices to improve beyond an initial plateau.
Virtual reality simulation training of mastoidectomy - studies on novice performance
Virtual reality (VR) simulation-based training is increasingly used in surgical technical skills training including in temporal bone surgery. The potential of VR simulation in enabling high-quality surgical training is great and VR simulation allows high-stakes and complex procedures such as mastoidectomy to be trained repeatedly, independent of patients and surgical tutors, outside traditional learning environments such as the OR or the temporal bone lab, and with fewer of the constraints of traditional training. This thesis aims to increase the evidence-base of VR simulation training of mastoidectomy and, by studying the final-product performances of novices, investigates the transfer of skills to the current gold-standard training modality of cadaveric dissection, the effect of different practice conditions and simulator-integrated tutoring on performance and retention of skills, and the role of directed, self-regulated learning. Technical skills in mastoidectomy were transferable from the VR simulation environment to cadaveric dissection with significant improvement in performance after directed, self-regulated training in the VR temporal bone simulator. Distributed practice led to a better learning outcome and more consolidated skills than massed practice and also resulted in a more consistent performance after three months of non-practice. Simulator-integrated tutoring accelerated the initial learning curve but also caused over-reliance on tutoring, which resulted in a drop in performance when the simulator-integrated tutor-function was discontinued. The learning curves were highly individual but often plateaued early and at an inadequate level, which related to issues concerning both the procedure and the VR simulator, over-reliance on the tutor function and poor self-assessment skills. Future simulator-integrated automated assessment could potentially resolve some of these issues and provide trainees with both feedback during the procedure and immediate assessment following each procedure. Standard setting by establishing a proficiency level that can be used for mastery learning with deliberate practice could also further sophisticate directed, self-regulated learning in VR simulation-based training. VR simulation-based training should be embedded in a systematic and competency-based training curriculum for high-quality surgical skills training, ultimately leading to improved safety and patient care.
The effect of self-directed virtual reality simulation on dissection training performance in mastoidectomy
OBJECTIVES/HYPOTHESIS: To establish the effect of self-directed virtual reality (VR) simulation training on cadaveric dissection training performance in mastoidectomy and the transferability of skills acquired in VR simulation training to the cadaveric dissection training setting.
STUDY DESIGN: Prospective study.
METHODS: Two cohorts of 20 novice otorhinolaryngology residents received either self-directed VR simulation training before cadaveric dissection training or vice versa. Cadaveric and VR simulation performances were assessed using final-product analysis with three blinded expert raters.
RESULTS: The group receiving VR simulation training before cadaveric dissection had a mean final-product score of 14.9 (95 % confidence interval [CI] [12.9-16.9]) compared with 9.8 (95% CI [8.4-11.1]) in the group not receiving VR simulation training before cadaveric dissection. This 52% increase in performance was statistically significantly (P < 0.0001). A single dissection mastoidectomy did not increase VR simulation performance (P = 0.22).
CONCLUSIONS: Two hours of self-directed VR simulation training was effective in increasing cadaveric dissection mastoidectomy performance and suggests that mastoidectomy skills are transferable from VR simulation to the traditional dissection setting. Virtual reality simulation training can therefore be employed to optimize training, and can spare the use of donated material and instructional resources for more advanced training after basic competencies have been acquired in the VR simulation environment.
LEVEL OF EVIDENCE: NA.
The effect of implementing cognitive load theory-based design principles in virtual reality simulation training of surgical skills: a randomized controlled trial
BACKGROUND: Cognitive overload can inhibit learning, and cognitive load theory-based instructional design principles can be used to optimize learning situations. This study aims to investigate the effect of implementing cognitive load theory-based design principles in virtual reality simulation training of mastoidectomy.
METHODS: Eighteen novice medical students received 1 h of self-directed virtual reality simulation training of the mastoidectomy procedure randomized for standard instructions (control) or cognitive load theory-based instructions with a worked example followed by a problem completion exercise (intervention). Participants then completed two post-training virtual procedures for assessment and comparison. Cognitive load during the post-training procedures was estimated by reaction time testing on an integrated secondary task. Final-product analysis by two blinded expert raters was used to assess the virtual mastoidectomy performances.
RESULTS: Participants in the intervention group had a significantly increased cognitive load during the post-training procedures compared with the control group (52 vs. 41 %, p = 0.02). This was also reflected in the final-product performance: the intervention group had a significantly lower final-product score than the control group (13.0 vs. 15.4, p < 0.005).
CONCLUSIONS: Initial instruction using worked examples followed by a problem completion exercise did not reduce the cognitive load or improve the performance of the following procedures in novices. Increased cognitive load when part tasks needed to be integrated in the post-training procedures could be a possible explanation for this. Other instructional designs and methods are needed to lower the cognitive load and improve the performance in virtual reality surgical simulation training of novices.
Retention of Mastoidectomy Skills After Virtual Reality Simulation Training
IMPORTANCE: The ultimate goal of surgical training is consolidated skills with a consistently high performance. However, surgical skills are heterogeneously retained and depend on a variety of factors, including the task, cognitive demands, and organization of practice. Virtual reality (VR) simulation is increasingly being used in surgical skills training, including temporal bone surgery, but there is a gap in knowledge on the retention of mastoidectomy skills after VR simulation training.
OBJECTIVES: To determine the retention of mastoidectomy skills after VR simulation training with distributed and massed practice and to investigate participants’ cognitive load during retention procedures.
DESIGN, SETTING, AND PARTICIPANTS: A prospective 3-month follow-up study of a VR simulation trial was conducted from February 6 to September 19, 2014, at an academic teaching hospital among 36 medical students: 19 from a cohort trained with distributed practice and 17 from a cohort trained with massed practice.
INTERVENTIONS: Participants performed 2 virtual mastoidectomies in a VR simulator a mean of 3.2 months (range, 2.4-5.0 months) after completing initial training with 12 repeated procedures. Practice blocks were spaced apart in time (distributed), or all procedures were performed in 1 day (massed).
MAIN OUTCOMES AND MEASURES: Performance of the virtual mastoidectomy as assessed by 2 masked senior otologists using a modified Welling scale, as well as cognitive load as estimated by reaction time to perform a secondary task.
RESULTS: Among 36 participants, mastoidectomy final-product skills were largely retained at 3 months (mean change in score, 0.1 points; P = .89) regardless of practice schedule, but the group trained with massed practice took more time to complete the task. The performance of the massed practice group increased significantly from the first to the second retention procedure (mean change, 1.8 points; P = .001), reflecting that skills were less consolidated. For both groups, increases in reaction times in the secondary task (distributed practice group: mean pretraining relative reaction time, 1.42 [95% CI, 1.37-1.47]; mean end of training relative reaction time, 1.24 [95% CI, 1.16-1.32]; and mean retention relative reaction time, 1.36 [95% CI, 1.30-1.42]; massed practice group: mean pretraining relative reaction time, 1.34 [95% CI, 1.28-1.40]; mean end of training relative reaction time, 1.31 [95% CI, 1.21-1.42]; and mean retention relative reaction time, 1.39 [95% CI, 1.31-1.46]) indicated that cognitive load during the virtual procedures had returned to the pretraining level.
CONCLUSIONS AND RELEVANCE: Mastoidectomy skills acquired under time-distributed practice conditions were retained better than skills acquired under massed practice conditions. Complex psychomotor skills should be regularly reinforced to consolidate both motor and cognitive aspects. Virtual reality simulation training provides the opportunity for such repeated training and should be integrated into training curricula.
OBJECTIVE: To evaluate the short-term stability of postoperative hearing results after tympanoplasty.
STUDY DESIGN: Prospective database study.
SETTING: Tertiary referral center.
PATIENTS: 1,367 cases of tympanoplasty I-IV were registered in the OTOKIR database between February 2004 and November 2013.
INTERVENTION: The authors included the 553 cases attending postoperative follow-ups at both 3 and 12 months.
MAIN OUTCOME MEASURE: Analysis of the changes in pure-tone average of air conduction (AC), air-bone gap, and speech reception threshold and Word Recognition Score between follow-ups were performed.
RESULTS: The overall mean change between follow-ups was 0.7, 0.5, and 0.3 dB for the AC, air-bone gap, and speech reception threshold, respectively. A majority of cases (87.7%) had a change in AC of 10 dB or less, and only 7.6% of the tympanoplasty type I cases had a decrease in AC of more than 10 dB. Of the 1,367 cases registered, 47.5% of cases were lost to follow-up at 12 months.
CONCLUSION: The changes in hearing results after tympanoplasty are minimal during 3 to 12 months after surgery. This suggests that 3-month results are as valid for reporting as 12-month results. In addition, a possible bias that compromises the validity of reported results is introduced at 12 months because half of the cases are lost to follow-up. Including results from 3-month postoperative follow-up when reporting on tympanoplasty could reduce bias in reporting and enable more centers to contribute valid results.
CONCLUSION: Current guidelines recommend reporting short-term results of > 12 months after treatment of conductive hearing loss. This study suggests that short-term hearing results after stapedotomy recorded at the 3-month follow-up are without loss of vital information compared with data from the currently recommended > 12-month follow-up. The use of 3-month data in reporting outcome could reduce the bias inherent to the loss to follow-up at 12 months.
OBJECTIVE: To investigate the stability of short-term postoperative hearing after stapedotomy for otosclerosis.
METHODS: This was a prospective database study; 371 cases with otosclerosis were registered in the database between August 2004 and June 2013. We included the 166 primary cases and 37 revision cases that had attended both follow-ups.
RESULTS: The mean changes in postoperative hearing thresholds between the 3-month and 12-month follow-up in both primary and revision cases were minimal and clinically insignificant. In all, 3-5% of primary cases and 14-16% of revision cases experienced a change of ≥ 10 dB for the worse of one or more parameters between follow-ups. Results were also stable when considering a range of traditional success criteria. Other complications following surgery were infrequent and typically resolved long term.
OBJECTIVE: To present a prospective ear surgery database and investigate the graft take-rate and prognostic factors for graft take-rate in tympanoplasty using the database.
STUDY DESIGN: Prospective database study.
SETTING: Tertiary referral center.
PATIENTS: A total of 1606 cases undergoing tympanoplasty types I to IV were registered in the database in the period from February 2004 to November 2013.
INTERVENTION: A total of 837 cases underwent myringoplasty/tympanoplasty type I.
MAIN OUTCOME MEASURE: Graft take-rate and prognostic factors (age, discharge at time of surgery, tuba function, technique, graft material, and revision surgery) for tympanoplasty type I were studied. A comparison with the graft take-rates for tympanoplasty types II to IV and/or cholesteatoma was made.
RESULTS: A user-friendly ear surgery database with fast data entry and direct import of audiometric data was developed. The graft take-rate was found to be 93.0% at 2 to 6 months and 86.6% at more than 12 months. Except for a discharging ear at the time of surgery, no significant differences using χ² test of association were found when comparing graft take-rates for different prognostic factors or more advanced tympanoplasty with or without cholesteatoma. A long-term graft take-rate overestimation of 6% was found if cases with defaulted follow-up because of early reperforation were not included.
CONCLUSION: A prospective database can be used to study prognostic factors and reduce bias in reporting the graft take-rate. Prospective databases are needed for high-quality longitudinal studies but require a continuous and daily effort of involved surgeons and therefore need to be convenient and fast to use.