Development and validation of an objective virtual reality tool for assessing technical aptitude among potential candidates for surgical training

BACKGROUND

Good technical skills are crucial for surgeons. Yet although surgical training programs strive to assess technical aptitude when selecting surgical residents, valid assessments of such aptitude are still lacking. Surgical simulators have been proposed as a potentially effective tool for this purpose. The current study aims to develop a technical aptitude test using a virtual reality surgical simulator, and to validate its use for the selection of surgical residents.

METHODS

The study had three phases. In Phase 1, we developed an initial version of the technical aptitude test using the Lap-X-VR laparoscopic simulator. In Phases 2 and 3 we refined the test and collected empirical data to evaluate four main sources of validity evidence (content, response process, internal structure, and relationships with other variables), and to evaluate the feasibility and acceptability of the test. Specifically, Phase 2 comprised a review of the test by 30 senior surgeons, and in Phase 3 a revised version of the test was administered to 152 interns to determine its psychometric properties.

RESULTS

Both the surgeons and interns rated the test as highly relevant for selecting surgical residents. Analyses of the data obtained from the trial administration of the test supported the appropriateness of the score calculation process and showed good psychometric properties, including reliability (α = 0.83) and task discrimination (mean discrimination = 0.5, SD = 0.1). The correlations between test scores and background variables revealed significant correlations with gender, surgical simulator experience, and video game experience (ps < 0.001). These variables, however, explained together only 10% of the variance in test scores.

CONCLUSIONS

We describe the systematic development of an innovative virtual reality test for assessing technical aptitude in candidates for surgical training, and present evidence for its validity, feasibility and acceptability. Further validation is required to support the application of the test for selection, as well as to discern the impact of gender, surgical simulator experience, and video game experience on the fairness of test results. However, the test appears to be a promising tool that may help training programs assess the suitability of candidates for surgical training.

A systematic review on classification and assessment of surgical skill levels for simulation-based training programs

BACKGROUND

Nowadays, advances in medical informatics have made minimally invasive surgery (MIS) procedures the preferred choice. However, there are several problems with the education programs in terms of surgical skill acquisition. For instance, defining and objectively measuring surgical skill levels is a challenging process. Accordingly, the aim of this study is to conduct a literature review for an investigation of the current approaches for classifying the surgical skill levels and for identifying the skill training tools and measurement methods.

MATERIALS AND METHODS

In this research, a search is conducted and a corpus is created. Exclusion and inclusion criteria are applied by limiting the number of articles based on surgical education, training approximations, hand movements, and endoscopic or laparoscopic operations. To satisfy these criteria, 57 articles are included in the corpus of this study.

RESULTS

Currently used surgical skill assessment approaches have been summarized. Results show that various classification approaches for the surgical skill level definitions are being used. Besides, many studies are conducted by omitting particularly important skill levels in between. Additionally, some inconsistencies are also identified across the skill level classification studies.

CONCLUSION

In order to improve the benefits of simulation-based training programs, a standardized interdisciplinary approach should be developed. For this reason, specific to each surgical procedure, the required skills should be identified. Additionally, appropriate measures for assessing these skills, which can be defined in simulation-based MIS training environments, should be refined. Finally, the skill levels gained during the developmental stages of these skills, with their threshold values referencing the identified measures, should be redefined in a standardized manner.

Retropubic trocar modified with a load cell to verify contact with pubic bone

BACKGROUND

Vital injuries during midurethral sling surgery are avoided by maintaining constant trocar contact with bone, and yet this is challenging for a teaching surgeon to monitor during this blind procedure. We modified a retropubic trocar with a load cell to distinguish on-bone and off-bone movement and tested it on a midurethral sling surgery 3-dimensional surgery simulator.

METHODS

Two experts and 3 novice surgeons performed retropubic trocar passage on the physical pelvic floor model using the modified trocar. Biofidelity was assessed comparing expert performance on a Thiel-embalmed cadaver and the physical model. The test-retest was assessed comparing performance on the physical pelvic model 2 weeks apart. The force variables were analyzed with paired and independent t tests. We performed post hoc analyses comparing the experts to novices on the physical model.

RESULTS

The root-mean-squared force was similar between the cadaver and model (24.3 vs 21.1 pounds, P = .62), suggesting biofidelity. Root-mean-squared force was also similar between the test and retest (14.0 vs 19.1 pounds, P =. 30). The expert surgeons exhibited a larger maximum force amplitude (51.2 vs 22.7 pounds, P = .03), shorter time to maximum force (2.7 vs 9.5 seconds, P = .03) and larger maximum rate of force development (171.5 vs 54.0 pounds/second, P = .01).

CONCLUSION

This study suggested high test-retest reliability and adequate biofidelity of the modified trocar used on our midurethral sling surgery 3-dimensional surgery simulator. This innovative trocar can be used both in simulation and in the operating room to help the novice surgeons stay on the bone and to help the attending surgeon monitor safe surgery.

Information, relative skill, and technology abandonment

We study the role of relative task-specific skill in explaining the heterogeneity in physicians' technology abandonment decisions in response to negative information shocks. We show that after an unexpected FDA safety warning on the use of minimally invasive hysterectomies, physicians alter their procedural mix towards open procedures and away from the minimally invasive procedures. This effect is less pronounced for physicians more skilled in performing minimally invasive procedures relative to open procedures, highlighting relative skill as an explanation for differential technology abandonment. Since physicians with higher relative skill are more likely to use minimally invasive procedures before the FDA safety communication, we find that the FDA intervention led to a substantial increase in practice variation across physicians with different relative skill levels. These findings are consistent with a theoretical model that predicts physicians' response to new information regarding the effectiveness of medical technology.

Distinguishing Intermediate and Novice Surgeons by Eye Movements

Surgical skill-level assessment is key to collecting the required feedback and adapting the educational programs accordingly. Currently, these assessments for the minimal invasive surgery programs are primarily based on subjective methods, and there is no consensus on skill level classifications. One of the most detailed of these classifications categorize skill levels as beginner, novice, intermediate, sub-expert, and expert. To properly integrate skill assessment into minimal invasive surgical education programs and provide skill-based training alternatives, it is necessary to classify the skill levels in as detailed a way as possible and identify the differences between all skill levels in an objective manner. Yet, despite the existence of very encouraging results in the literature, most of the studies have been conducted to better understand the differences between novice and expert surgical skill levels leaving out the other crucial skill levels between them. Additionally, there are very limited studies by considering the eye-movement behaviors of surgical residents. To this end, the present study attempted to distinguish novice- and intermediate-level surgical residents based on their eye movements. The eye-movement data was recorded from 23 volunteer surgical residents while they were performing four computer-based simulated surgical tasks under different hand conditions. The data was analyzed using logistic regression to estimate the skill levels of both groups. The best results of the estimation revealing a 91.3% recognition rate of predicting novice and intermediate surgical residents on one scenario were selected from four under the dominant hand condition. These results show that the eye-movements can be potentially used to identify surgeons with intermediate and novice skills. However, the results also indicate that the order in which the scenarios are provided, and the design of the scenario, the tasks, and their appropriateness with the skill levels of the participants are all critical factors to be considered in improving the estimation ratio, and hence require thorough assessment for future research.

The Effect of Training, Used-Hand, and Experience on Endoscopic Surgery Skills in an Educational Computer-Based Simulation Environment (ECE) for Endoneurosurgery Training

Today, virtual simulation environments create alternative hands-on practice opportunities for surgical training. In order to increase the potential benefits of such environments, it is critical to understand the factors that influence them. This study was conducted to determine the effects of training, used-hand, and experience, as well as the interactions between these variables, on endoscopic surgery skills in an educational computer-based surgical simulation environment. A 2-hour computer-based endoneurosurgery simulation training module was developed for this study. Thirty-one novice- and intermediate-level resident surgeons from the departments of neurosurgery and ear, nose, and throat participated in this experimental study. The results suggest that a 2-hour training during a 2-month period through computer-based simulation environment improves the surgical skills of the residents in both-hand tasks, which is necessary for endoscopic surgical procedures but not in dominant hand tasks. Based on the results of this study, it can be concluded that computer-based simulation environments potentially improve surgical skills; however, the scenarios for such training modules need to consider especially the bimanual coordination of hands and should be regularly adapted to the individual skill levels and progresses.

Are Left- and Right-Eye Pupil Sizes Always Equal?

Eye movements provide very critical information about the cognitive load and behaviors of human beings. Earlier studies report that under normal conditions, the left- and right-eye pupil sizes are equal. For this reason, most studies undertaking eye-movement analysis are conducted by only considering the pupil size of a single eye or taking the average size of both eye pupils. This study attempts to offer a better understanding concerning whether there are any differences between the left- and right-eye pupil sizes of the right-handed surgical residents while performing surgical tasks in a computer-based simulation environment under different conditions (left-hand, right-hand and both hands). According to the results, in many cases, the right-eye pupil sizes of the participants were larger than their left-eye pupil sizes while performing the tasks under right-hand and both hands conditions. However, no significant difference was found in relation to the tasks performed under left-hand condition in all scenarios. These results are very critical to shed further light on the cognitive load of the surgical residents by analyzing their left-eye and right-eye pupil sizes. Further research is required to investigate the effect of the difficulty level of each scenario, its appropriateness with the skill level of the participants, and handedness on the differences between the leftand right-eye pupil sizes.

Classification of Intermediate and Novice Surgeons' Skill Assessment Through Performance Metrics

Background. Endoscopic surgeries have become an alternative for open procedures whenever possible. For such types of operations, surgeons are required to gain several skills, whose development needs hands-on practice. Accordingly, gaining these skills today is a challenge for surgical education programs. Despite the development of several technology-enhanced training environments, there are still problems to better integrate these technologies into educational programs. For an appropriate integration, it is critical to assess the skill levels and adapt the training content according to the trainees' requirements. In the literature, there exist several methods for assessing these skill levels. However, there are still problems in practice for objective and repetitive assessment. Methods. The present study aims to estimate the skill levels of participants in surgical training programs in an objective manner by collecting experimental data from residents in an endoscopic surgical simulation environment and gathering performance metrics. Results. It is shown that, by comparing the results of a number of classification algorithms for the best accuracy estimation and feature set, the "novice" and "intermediate" skill levels can be estimated with an accuracy of 86%. Conclusions. The outcomes help surgical educators and instructional system designers to better assess the skill levels of the trainees and guide them accordingly. In addition, objective assessments as highlighted in this study can be beneficial when designing technology-enhanced adaptive learning environments.

Eye-Hand Coordination Patterns of Intermediate and Novice Surgeons in a Simulation-Based Endoscopic Surgery Training Environment

Endoscopic surgery procedures require specific skills, such as eye-hand coordination to be developed. Current education programs are facing with problems to provide appropriate skill improvement and assessment methods in this field. This study aims to propose objec-tive metrics for hand-movement skills and assess eye-hand coordination. An experimental study is conducted with 15 surgical residents to test the newly proposed measures. Two computer-based both-handed endoscopic surgery practice scenarios are developed in a simulation environment to gather the participants' eye-gaze data with the help of an eye tracker as well as the related hand movement data through haptic interfaces. Additionally, participants' eye-hand coordination skills are analyzed. The results indicate higher correla-tions in the intermediates' eye-hand movements compared to the novices. An increase in intermediates' visual concentration leads to smoother hand movements. Similarly, the novices' hand movements are shown to remain at a standstill. After the first round of practice, all participants' eye-hand coordination skills are improved on the specific task targeted in this study. According to these results, it can be concluded that the proposed metrics can potentially provide some additional insights about trainees' eye-hand coordi-nation skills and help instructional system designers to better address training requirements.

Technology-enhanced surgical education: attitudes and perceptions of the endoscopic surgery community in Turkey

The education programme of surgery has unique problems. In this study, first, a literature review is conducted to cover the studies found in the literature reporting on the problems of surgical education. Additionally, a survey study is conducted with 31 participants, who are either currently enrolled in endoscopic surgery education programmes in Turkey or are experts in the field. Supportively semistructured individual interviews are also conducted with five participants. These data are collected to better understand the instructional methods being used, their problems and the participants’ preferred methods to be used. Additionally, the participants’ attitudes are also investigated regarding the use of new technologies to enhance the current education programmes. The results indicate that, in Turkey, surgical education programmes are still mostly offered in traditional ways while other educational methods are used in an extremely limited manner. In general, the authors emphasise that more research needs to be conducted to better understand the characteristics of the medical students and develop standards for surgical education programmes, educational tools specific for related surgical domains and guidelines for the curriculum integration. The results of this study aimed to guide the instructional system designers for the endoscopic surgery education programmes.

Differential analysis of muscle fatigue induced elbow and wrist tremor in controlled laparoscopic manoeuvring

BACKGROUND

Fatigue induced hand tremor (FIT) is a primary limiting concern for the prolonged surgical intervention in minimally invasive surgery (MIS) and robot-assisted-minimally invasive surgery (RAMIS). A thorough analysis is necessary to understand the FIT characteristics in laparoscopic tool movement. The primary aim of this study is to perform a differential analysis of the elbow and wrist tremor due to muscle fatigue in laparoscopic manoeuvring.

METHODS

We have introduced a joint angle based tremor analysis method, which enables us to perform a differential study of FIT characteristics at the individual joint. Experimental data was acquired from a group of subjects during static and dynamic laparoscopic movement in an imitative RAMIS master manipulation scenario. A repetitive task was performed with a total span of 1 h for observing the effect of muscle fatigue. Along with the joint angle variation, surface electromyography (sEMG) signal was also studied in the analysis.

RESULTS

The wrist tremor is more predominant than tremor generated at the elbow, especially in highly fatigued condition. The high-frequency tremor (>4 Hz) is contributed by the wrist joint. Moreover, the variation of the wrist and elbow tremor ratio was found to be dependent upon the experience of the surgeons.

CONCLUSIONS

In this work, we have investigated the attribution of elbow and wrist joints in FIT during laparoscopic tool manipulation. The outcomes may be useful for the design of robot-assisted surgical manipulator, and can be used for quality assessment of surgical training as well.

Non-technical skills in minimally invasive surgery teams: a systematic review

BACKGROUND

Root cause analyses show that up to 70 % of adverse events are caused by human error. Strong non-technical skills (NTS) can prevent or reduce these errors, considerable numbers of which occur in the operating theatre. Minimally invasive surgery (MIS) requires manipulation of more complex equipment than open procedures, likely requiring a different set of NTS for each kind of team. The aims of this study were to identify the MIS teams' key NTS and investigate the effect of training and assessment of NTS on MIS teams.

METHODS

The databases of PubMed, Cochrane Library, Embase, PsycINFO, and Scopus were systematically searched according to Preferred Reporting Item for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles containing outcome measures related to MIS teams' key NTS, training, or assessment of NTS were included.

RESULTS

The search yielded 1984 articles, 11 of which were included. All were observational studies without blinding, and they differed in aims, types of evaluation, and outcomes. Only two studies evaluated patient outcomes other than operative time, and overall, the studies' quality of evidence was low. Different communication types were encountered in MIS compared to open surgery, mainly due to equipment- and patient-related challenges. Fixed teams improved teamwork and safety levels, while deficient planning and poor teamwork were found to obstruct workflow and increase errors. Training NTS mitigates these issues and improves staff attitudes towards NTS.

CONCLUSIONS

MIS teams' NTS are important for workflow and prevention of errors and can be enhanced by working in fixed teams. In the technological complex sphere of MIS, communication revolves around equipment- and patient-related topics, much more so than in open surgery. In all, only a few heterogeneous-design studies have examined this. In the future, the focus should shift to systematically identifying key NTS and developing effective, evidence-based team training programmes in MIS.

Minimally invasive preparation and design of a cantilevered, all-ceramic, resin-bonded, fixed partial denture in the esthetic zone: a case report and descriptive review

Resin-bonded, fixed partial dentures have the potential to offer a minimally invasive, fixed-prosthetic approach to tooth replacement in patients who may not be candidates for implant therapy. However, traditional preparation protocols often recommend extensive preparation designs on two abutment teeth, thereby potentially compromising the long-term health of the adjacent abutments and often resulting in unilateral debonding of one of the retainers in the long term. In light of advances in high-strength ceramic systems capable of being reliably bonded to tooth structure and offering improved esthetic outcomes, as well as clinical and case-series research demonstrating improved survivability of cantilevered resin-bonded fixed partial dentures, new preparation designs and methodologies can be advocated. The following case report demonstrates the clinical application of sonoabrasion, coupled with a dental operating microscope, to minimally prepare a single abutment for a cantilevered, all-ceramic resin-bonded fixed partial denture. Relevant historic and contemporary literature regarding double versus single-retainer resin-bonded fixed partial dentures are reviewed, as well as clinical conditions that are most favorable for such restorations to have an optimal long-term prognosis.

CLINICAL SIGNIFICANCE

If appropriate clinical conditions exist, a cantilevered, all-ceramic, resin-bonded, fixed partial denture may be the most conservative means of tooth replacement in a patient who is not a candidate for an endosseous implant.

Virtual reality simulator training of laparoscopic cholecystectomies - a systematic review

BACKGROUND AND AIMS

Simulators are widely used in occupations where practice in authentic environments would involve high human or economic risks. Surgical procedures can be simulated by increasingly complex and expensive techniques. This review gives an update on computer-based virtual reality (VR) simulators in training for laparoscopic cholecystectomies.

MATERIALS AND METHODS

From leading databases (Medline, Cochrane, Embase), randomised or controlled trials and the latest systematic reviews were systematically searched and reviewed. Twelve randomised trials involving simulators were identified and analysed, as well as four controlled studies. Furthermore, seven studies comparing black boxes and simulators were included.

RESULTS

The results indicated any kind of simulator training (black box, VR) to be beneficial at novice level. After VR training, novice surgeons seemed to be able to perform their first live cholecystectomies with fewer errors, and in one trial the positive effect remained during the first ten cholecystectomies. No clinical follow-up data were found. Optimal learning requires skills training to be conducted as part of a systematic training program. No data on the cost-benefit of simulators were found, the price of a VR simulator begins at EUR 60 000.

CONCLUSIONS

Theoretical background to learning and limited research data support the use of simulators in the early phases of surgical training. The cost of buying and using simulators is justified if the risk of injuries and complications to patients can be reduced. Developing surgical skills requires repeated training. In order to achieve optimal learning a validated training program is needed.

Is Learning in Low Immersive Environments Carried over to High Immersive Environments?

One of the more debated issues regarding training simulators is their validity for transfer of skills to sensory environments that differ from the simulator. In two experiments, the advantages of three-dimensional (3D) and collocated (Col) visual displays were evaluated in a realistic and complex visuomotor task. The two factors were evaluated independently, comparing Col-2D with dislocated-2D (experiment 1) and with Col-3D (experiment 2). As expected, in both cases the more immersive presentation condition facilitated better performance. Furthermore, improvement following training in the more immersive condition carried over to the following less immersive condition but there was no carry over in the opposing order of presentation. This is taken as an indication for the differential development of skills conditioned by the level of immersiveness of the training environment. This further suggests that learning of complex realistic tasks is not carried over from less immersive simulator to the complex sensory environment of reality, due to the large gap in sensory patterns.