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Background: In image-guided procedures, a high level of visual spatial ability may be an advantage for surgical trainees. We assessed the visual spatial ability of surgical trainees., Methods: Two hundred and thirty-nine surgical trainees and 61 controls were tested on visual spatial ability using 3 standardised tests, the Card Rotation, Cube Comparison and Map-Planning Tests., Results: Two hundred and twenty-one, 236 and 236 surgical trainees and 61 controls completed the Card Rotation test, Cube Comparison test and Map-Planning test, respectively. Two percent of surgical trainees performed statistically significantly worse than their peers on card rotation and map-planning test, > 1% on Cube Comparison test. Surgical trainees performed statistically significantly better than controls on all tests., Conclusions: Two percent of surgical trainees performed statistically significantly worse than their peers on visual spatial ability. The implication of this finding is unclear, further research is required that can look at the learning and educational portfolios of these trainees who perform poorly on visual spatial ability, and ascertain if they are struggling to learn skills for image-guided procedures.

Background: Technical limitations of minimally invasive surgery challenge both surgeons and camera assistants. Current research indicates that visual-spatial ability (VSA) has impact on learning of laparoscopic camera navigation (LCN). However, it remains unclear if complexity of LCN tasks influences the impact of VSA. The aim of this study was to examine the influence of VSA on LCN training within tasks of different complexity levels., Methods: The present study was conducted as a monocentric prospective trial. VSA was assessed with a cube comparison test before participants underwent LCN training. LCN training consisted of three tasks with increasing complexity. Each task was performed four times and performance was assessed each time. Correlations and multivariate regression analysis were used to assess the influence of VSA on LCN skills., Results: Seventy-one participants were included (35 males). Significant performance improvement and faster completion times were observed from the first to fourth trial of all three LCN training tasks. Significant positive correlations between VSA and performance on LCN task 3 were found (performance: r s  = 0.47; p < 0.001, time: r s  = -0.43; p < 0.001). Multivariate regression revealed that higher VSA resulted in greater reduction of time between the first trials of LCN training task 3 (B = -1.67, p = 0.031)., Conclusion: In the present study, all trainees improved LCN performance during the training. VSA seems to have impact on LCN performance and training progress particularly for complex LCN tasks. The relation of VSA and LCN performance was stronger for less experienced participants and in the beginning of the learning phase.

Background: The societies of thoracic surgery are working to incorporate simulation and competency-based assessment into specialty training. One challenge is the development of a simulation-based test, which can be used as an assessment tool. The study objective was to establish validity evidence for a virtual reality simulator test of a video-assisted thoracoscopic surgery (VATS) lobectomy of a right upper lobe., Methods: Participants with varying experience in VATS lobectomy were included. They were familiarized with a virtual reality simulator (LapSim ® ) and introduced to the steps of the procedure for a VATS right upper lobe lobectomy. The participants performed two VATS lobectomies on the simulator with a 5-min break between attempts. Nineteen pre-defined simulator metrics were recorded., Results: Fifty-three participants from nine different countries were included. High internal consistency was found for the metrics with Cronbach's alpha coefficient for standardized items of 0.91. Significant test-retest reliability was found for 15 of the metrics (p-values <0.05). Significant correlations between the metrics and the participants VATS lobectomy experience were identified for seven metrics (p-values <0.001), and 10 metrics showed significant differences between novices (0 VATS lobectomies performed) and experienced surgeons (>50 VATS lobectomies performed). A pass/fail level defined as approximately one standard deviation from the mean metric scores for experienced surgeons passed none of the novices (0 % false positives) and failed four of the experienced surgeons (29 % false negatives)., Conclusion: This study is the first to establish validity evidence for a VATS right upper lobe lobectomy virtual reality simulator test. Several simulator metrics demonstrated significant differences between novices and experienced surgeons and pass/fail criteria for the test were set with acceptable consequences. This test can be used as a first step in assessing thoracic surgery trainees' VATS lobectomy competency.

Background: This study was undertaken to introduce and establish the value of the Dundee Endoscopic Psychomotor Otolaryngology Surgery Trainer (DEPOST) as a customisable, objective real-time scoring system for trainee assessment. The construct validity of the system was assessed by comparing the performance of experienced otolaryngologists with that of otolaryngology trainees, junior doctors and medical students., Methods: Forty two subjects (13 Consultants, 8 senior trainees, 13 junior trainees and 8 junior doctors/medical students) completed a single test on DEPOST. The test involved using a 30° rigid endoscope and a probe with position sensor, to identify a series of lights in a complex 3-dimensional model. The system scored subjects for time, success rate, and economy of movement (distance travelled). An analysis of variance and correlation analysis were used for the data analysis, with statistical significance set at 0.05., Results: Increasing experience led to significantly improved performance with the DEPOST (p < 0.01). Senior trainees' results were significantly better than those of consultant otolaryngologists in success rate and time (p < 0.05 & p < 0.05). Consultants were the most efficient in their movement (p = 0.051) CONCLUSIONS: The system provides an accurate and customisable assessment of endoscopic skill in otolaryngologists. The DEPOST system has construct validity, with master surgeons and senior trainees completing the tasks more accurately without sacrificing execution time, success rate or efficiency of movement.

Background: Apart from animal testing and clinical trials, surgical research and laparoscopic training mainly rely on phantoms. The aim of this project was to design a phantom with realistic anatomy and haptic characteristics, modular design and easy reproducibility. The phantom was named open-source Heidelberg laparoscopic phantom (OpenHELP) and serves as an open-source platform., Methods: The phantom was based on an anonymized CT scan of a male patient. The anatomical structures were segmented to obtain digital three-dimensional models of the torso and the organs. The digital models were materialized via rapid prototyping. One flexible, using an elastic abdominal wall, and one rigid method, using a plastic shell, to simulate pneumoperitoneum were developed. Artificial organ production was carried out sequentially starting from raw gypsum models to silicone molds to final silicone casts. The reproduction accuracy was exemplarily evaluated for ten silicone rectum models by comparing the digital 3D surface of the original rectum with CT scan by calculating the root mean square error of surface variations. Haptic realism was also evaluated to find the most realistic silicone compositions on a visual analog scale (VAS, 0-10)., Results: The rigid and durable plastic torso and soft silicone organs of the abdominal cavity were successfully produced. A simulation of pneumoperitoneum could be created successfully by both methods. The reproduction accuracy of ten silicone rectum models showed an average root mean square error of 2.26 (0-11.48) mm. Haptic realism revealed an average value on a VAS of 7.25 (5.2-9.6) for the most realistic rectum., Conclusion: The OpenHELP phantom proved to be feasible and accurate. The phantom was consecutively applied frequently in the field of computer-assisted surgery at our institutions and is accessible as an open-source project at www.open-cas.org for the academic community.

Background: Computer-based surgical simulators capture a multitude of metrics based on different aspects of performance, such as speed, accuracy, and movement efficiency. However, without rigorous assessment, it may be unclear whether all, some, or none of these metrics actually reflect technical skill, which can compromise educational efforts on these simulators. We assessed the construct validity of individual performance metrics on the LapVR simulator (Immersion Medical, San Jose, CA, USA) and used these data to create task-specific summary metrics., Methods: Medical students with no prior laparoscopic experience (novices, N = 12), junior surgical residents with some laparoscopic experience (intermediates, N = 12), and experienced surgeons (experts, N = 11) all completed three repetitions of four LapVR simulator tasks. The tasks included three basic skills (peg transfer, cutting, clipping) and one procedural skill (adhesiolysis)., Results: We selected 36 individual metrics on the four tasks that assessed six different aspects of performance, including speed, motion path length, respect for tissue, accuracy, task-specific errors, and successful task completion. Four of seven individual metrics assessed for peg transfer, six of ten metrics for cutting, four of nine metrics for clipping, and three of ten metrics for adhesiolysis discriminated between experience levels. Time and motion path length were significant on all four tasks. We used the validated individual metrics to create summary equations for each task, which successfully distinguished between the different experience levels., Conclusion: Educators should maintain some skepticism when reviewing the plethora of metrics captured by computer-based simulators, as some but not all are valid. We showed the construct validity of a limited number of individual metrics and developed summary metrics for the LapVR. The summary metrics provide a succinct way of assessing skill with a single metric for each task, but require further validation.

Background and Aim: Navigation systems are promising tools for improving efficacy and safety in surgical endoscopy and other minimally invasive techniques. The aim of the current study is to investigate electromagnetic tracking (EMT) for navigated renal access in a porcine model., Methods: For our proof-of-principle study we modified a recently established porcine ex vivo model. Via a ureteral catheter which was placed into the desired puncture site, a small sensor was introduced and located by EMT. Then, a tracked needle was navigated into the collecting system in a "rendezvous" approach. A total of 90 renal tracts were obtained in six kidneys using EMT, with a maximum of three punctures allowed per intervention. For each puncture, number of attempts to success, final distance to probe, puncture time, and localization were assessed. We compared absolute and relative frequencies using the chi-square test and applied the Mann-Whitney U-test for continuous variables., Results: No major problems were encountered performing the experiment. Access to the collecting system was successfully obtained after a single puncture in 91% (82/90) and within a second attempt in the remaining 9% (8/90). Thus, a 100% success rate was reached after a maximum of two punctures. Location of the calyx did not have a significant effect on success rate (p = 0.637). After a learning phase of 30 punctures, higher success rate (96% versus 83%; p = 0.041) was accomplished within shorter puncture time (14 versus 17 s; p = 0.049) and with higher precision (1.7 versus 2.8 mm; p < 0.001)., Conclusions: With respect to other established techniques, use of EMT seems to decrease the number of attempts and procedural time remarkably. This might contribute to greater safety and efficacy when applied clinically. The presented approach appears to be promising, especially in difficult settings, provided that in vivo data support these initial results.

Background: Robotic laparoscopic surgery has revolutionized minimally invasive surgery for the treatment of abdominal pathologies. However, current training techniques rely on subjective evaluation. The authors sought to identify objective measures of robotic surgical performance by comparing novices and experts during three training tasks., Methods: Five novices (medical students) were trained in three tasks with the da Vinci Surgical System. Five experts trained in advanced laparoscopy also performed the three tasks. Time to task completion (TTC), total distance traveled (D), speed (S), curvature (kappa), and relative phase (Phi) were measured., Results: Before training, TTC, D, and kappa were significantly smaller for experts than for novices (p < 0.05), whereas S was significantly larger for experts than for novices before training (p < 0.05). Novices performed significantly better after training, as shown by smaller TTC, D, and kappa, and larger S. Novice performance after training approached expert performance., Conclusion: This study clearly demonstrated the ability of objective kinematic measures to distinguish between novice and expert performance and training effects in the performance of robotic surgical training tasks.

Background: A robotic virtual-reality (VR) simulator has been developed to improve robot-assisted training for laparoscopic surgery and to enhance surgical performance in laparoscopic skills. The simulated VR training environment provides an effective approach to evaluate and improve surgical performance. This study presents our findings of the VR training environment for robotic laparoscopy., Methods: Eight volunteers performed two inanimate tasks in both the VR and the actual training environment. The tasks were bimanual carrying (BC) and needle passing (NP). For the BC task, the volunteers simultaneously transferred two plastic pieces in opposite directions five times consecutively. The same volunteers passed a surgical needle through six pairs of holes in the NP task. Both tasks require significant bimanual coordination that mimics actual laparoscopic skills. Data analysis included time to task completion, speed and distance traveled of the instrument tip, as well as range of motion of the subject's wrist and elbow of the right arm. Electromyography of the right wrist flexor and extensor were also analyzed. Paired t-tests and Pearson's r were used to explore the differences and correlations between the two environments., Results: There were no significant differences between the actual and the simulated VR environment with respect to the BC task, while there were significant differences in almost all dependent parameters for the NP task. Moderate to high correlations for most dependent parameters were revealed for both tasks., Conclusions: Our data shows that the VR environment adequately simulated the BC task. The significant differences found for the NP task may be attributed to an oversimplification in the VR environment. However, they do point to the need for improvements in the complexity of our VR simulation. Further research work is needed to develop effective and reliable VR environments for robotic laparoscopic training.

Background: In the literature of skill acquisition and transfer of skills, it often is assumed that the rate of skill acquisition depends on what has been learned in a similar context (i.e., surgical simulators providing haptic feedback). This study aimed to analyze whether the addition of haptic feedback early in the training phase for image-guided surgical simulation improves performance., Methods: A randomized crossover study design was used, in which 38 surgical residents were randomized to begin a 2-h simulator training session with either haptic or nonhaptic training followed by crossover after 1 h. The graphic context was a virtual upper abdomen. The residents performed two diathermy tasks. Two validated tests were used to control for differences in visual-spatial ability: the BasIQ general cognitive ability test and Mental Rotation Test A (MRT-A)., Results: After 2 h of training, the group that had started with haptic feedback performed the two diathermy tasks significantly better (p < 0.05, unpaired t-test). Only the group that had started with haptic training significantly improved during the last 1-h session (p < 0.01, paired t-test)., Conclusion: The findings indicate that haptic feedback could be important in the early training phase of skill acquisition in image-guided surgical simulator training.