Assessment of construct validity of a virtual reality laparoscopy simulator

BACKGROUND: The aim of this study was to assess whether virtual reality (VR) can discriminate between the skills of novices and intermediate-level laparoscopic surgical trainees (construct validity), and whether the simulator assessment correlates with an expert's evaluation of performance. METHODS: Three hundred and seven (307) participants of the 19th-22nd Davos International Gastrointestinal Surgery Workshops performed the clip-and-cut task on the Xitact LS 500 VR simulator (Xitact S.A., Morges, Switzerland). According to their previous experience in laparoscopic surgery, participants were assigned to the basic course (BC) or the intermediate course (IC). Objective performance parameters recorded by the simulator were compared to the standardized assessment by the course instructors during laparoscopic pelvitrainer and conventional surgery exercises. RESULTS: IC participants performed significantly better on the VR simulator than BC participants for the task completion time as well as the economy of movement of the right instrument, not the left instrument. Participants with maximum scores in the pelvitrainer cholecystectomy task performed the VR trial significantly faster, compared to those who scored less. In the conventional surgery task, a significant difference between those who scored the maximum and those who scored less was found not only for task completion time, but also for economy of movement of the right instrument. CONCLUSIONS: VR simulation provides a valid assessment of psychomotor skills and some basic aspects of spatial skills in laparoscopic surgery. Furthermore, VR allows discrimination between trainees with different levels of experience in laparoscopic surgery establishing construct validity for the Xitact LS 500 clip-and-cut task. Virtual reality may become the gold standard to assess and monitor surgical skills in laparoscopic surgery.     

Face-, expert,and referent validity of the Xitact LS500 laparoscopy simulator

Background: This study was undertaken to establish face-, expert, and referent validity of the Xitact LS500; a virtual reality laparoscopic cholecystectomy simulator. Methods: A four-page, 20-item structured questionnaire was presented to 120 surgeons attending a surgical convention. Participants received an instructed hands-on "tour" on the Xitact simulator. Data were analyzed according to the level of experience of the surgeon, resulting in an "expert group opinion" of 87 surgeons and a "referent group opinion" of 33 surgeons. Results: The majority of respondents believe Xitact has the potential to become a useful tool in teaching (93.1%) and measuring performance assessment (79.3%) in laparoscopic cholecystectomy. Expert- and referent-group opinion does not differ significantly on any of the presented statements. The opinion regarding the realism of the virtual laparoscopic cholecystectomy environment is favorable among both groups, although it is considered not yet perfect. The "haptic feedback" sensation of the Xitact is a parameter that needs further development. Conclusions: Both expert- and referent surgeons value Xitact to be an important and useful tool in the laparoscopic teaching setting. Further studies need to be performed to establish the construct validity of the simulator (e.g., to what extent is the simulator logically encompassed into a theoretical framework of acquiring skills, needed for the laparoscopic cholecystectomy) to measure shortening of learning curves on the laparoscopic cholecystectomy procedure, and ultimately to justify its use in the surgical curriculum.     

Construct validity

Background: This study was undertaken to establish construct validity of the Xitact LS500, a virtual reality laparoscopic cholecystectomy simulator. The primary research statement is: The clip-and-cut task on the Xitact LS500 virtual reality laparoscopic cholecystectomy simulator mimics the surgical procedure of the clipping and cutting of the cystic duct and artery during the laparoscopic cholecystectomy adequately. Methods: According to the level of experience of the surgeon, an expert group opinion was formed resulting from 37 surgeons having performed over 100 laparoscopic cholecystectomies, and a novice group opinion was formed resulting of 37 surgeons having no experience at all with performing laparoscopic cholecystectomy. Participants received an instructed hands-on tour on the Xitact simulator and performed three formal simulation runs. Results: The novice group is younger and more surgeons are female. Performance scores in the expert group are significantly higher on the second (p value 0.011) and third (p value 0.005) run, compared to the novices scores. Experts are significantly faster on completion of all three runs. There is an increase in score over runs in both groups, which is statistically significant in the expert group. Less than one-third of surgeons in either group are able to correctly predict their performance score as generated by Xitact. Both experts and novices feel it is useful to train with Xitact LS500 in the surgical curriculum. Conclusions: Three hypotheses, formulated to operationalize the primary research statement, could be answered affirmatively. Although further validation studies are needed, the Xitact LS500 simulator seems to be able to discriminate between expert and novice surgeons in this research setting, and thus the construct for this setting is considered to be valid.     

The learning curve on the Xitact LS 500 laparoscopy simulator: profiles of performance

Background: This study assesses the acquisition of skill and the learning curve associated with the performance of the clip-and-cut task on the Xitact LS 500 virtual reality (VR) simulator in laparoscopic cholecystectomy.Methods: A group of 33 residents and interns with no previous laparoscopic experience participated in the study. All participants received a 1-h familiarization tour on the simulator. Thirty participants completed a full course of 30 simulation runs over 3 days (10 runs per day). The outcome parameters were a previously validated sum-score and time to complete performance. Results: Group demographics were similar. Of the participants who completed the full study, 16.7% appeared to have such a high level of innate psychomotor abilities that they were considered proficient in the task immediately after the initial familiarization tour. Most participants (63.3%) had a moderate level of innate abilities, and their performance improved through repetitive VR training. In our study, 20% of the participants had such a low level of innate abilities that they were unable to achieve an acceptable performance in our minimal-access surgery (MAS) simulation.Conclusions: Learning curves cannot be assessed by examining the repetitive training of only one person. There seem to be four different performance profiles, reflecting the fact that some people are more adept than others to be trained by MAS procedural VR simulation. For participants receptive to training—63.3% in this study—proficiency in the task occurs after ~25 simulative runs.     

Correlation between psychometric test scores and learning tying of surgical reef knots

We have investigated the correlation between the scores attained on a computerised psychometric test, measuring psychomotor aptitude and learning tying of a surgical reef knot. Fifteen surgical trainees performed a test of psychomotor aptitude (ADTRACK 2) from the MICROPAT testing system. They then performed a simple test of their ability to tie a surgical reef knot and were assessed by a panel of experts prior to embarking on a standardised course of instruction and practice session. The knot-tying test was repeated at the end of the day and the differences in average scores recorded. There was a significant correlation between the means of the differences in knot tying scores and ADTRACK 2 scores (r = -0.533, P < 0.05). Psychomotor abilities appear to be determinants of trainees' initial proficiency in learning to tie a surgical reef knot.     

The Eindhoven laparoscopic cholecystectomy training course—improving operating room performance using virtual reality training: results from the first E.A.E.S. accredited virtual reality trainings curriculum

Background: This study was undertaken to investigate operating room performance of surgical residents, after participating in the Eindhoven virtual reality laparoscopic cholecystectomy training course. This course is the first formal surgical resident trainings course, using a variety of complementary virtual reality (VR) skills training simulation in order to prepare surgical residents for their first laparoscopic cholecystectomy. The course was granted EAES certification. Methods: The four-day course is based on multimedia and multimodality approach. A variety of increasingly difficult simulation training sessions, next to intimate focus-group “knowledge sessions” are included. Both basic and procedural VR simulation is featured, using MIST-VR and the Xitacts' LapChol simulation software. The operating room performance of twelve surgical residents who participated in the course and twelve case-control counterparts were compared. The case-control grup was matched for clinical number laparoscopic cholecystectomy performance (maximum of 4 procedures). Two observers analyzed a randomly mixed videotape, featuring the part of the “clip-and-cut” procedure of the laparoscopic cholecystectomy, and were blinded for participants' group status. Structured questionnaires including multiple observation scales were used to assess performance. Results: Residents of both the experimental and control group did not differ in demographic parameters, except for number of laparoscopic cholecystectomies in favor of the control group (p-value 0.008). Both observers judge the experimental group to perform significantly better (p-value 0.004 and 0.013). Experimental group residents valued their course highly in terms of their laparoscopic surgical skills improvement and the use of VR simulators in the surgical curiculum. Conclusions: The Eindhoven Virtual Reality laparoscopic cholecyctectomy training course improves surgical skill in the operating room above the level of residents trained by a variety of other training methods.     

The intercollegiate Basic Surgical Skills Course

Objective: This study was undertaken to establish residents progress in minimal access surgery (MAS) after attending the Intercollegiate Basic Surgical Skills Course (BSSC) by means of the Xitact LS500 laparoscopy simulator assessment program. Methods: Twenty-five surgical residents attended the BSSC in Leiden and Eindhoven, The Netherlands. Before and after the course, participants performed three runs on the Xitact LS500, featuring a standardized laparoscopic cholecystectomy clip-and-cut task. A control group of 25 interns not attending the course also performed two sessions of three runs. Parameters of interest were score and time for completion of task. Results: No significant differences were found within the resident group for the parameters time and score when comparing outcomes pre- and post-BSSC. No significant differences were found comparing time and score between residents and interns on each of the six runs, except for time in run 2. Over six runs, both residents and interns became significantly faster. Conclusions: The Xitact LS500 cholecystectomy simulator did not detect significant improvement in MAS performance among a group of surgical residents attending the BSSC.     

Randomized clinical trial of virtual reality simulation for laparoscopic skills training

BACKGROUND: This study examined the impact of virtual reality (VR) surgical simulation on improvement of psychomotor skills relevant to the performance of laparoscopic cholecystectomy. METHODS: Sixteen surgical trainees performed a laparoscopic cholecystectomy on patients in the operating room (OR). The participants were then randomized to receive VR training (ten repetitions of all six tasks on the Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR)) or no training. Subsequently, all subjects performed a further laparoscopic cholecystectomy in the OR. Both operative procedures were recorded on videotape, and assessed by two independent and blinded observers using predefined objective criteria. Time to complete the procedure, error score and economy of movement score were assessed during the laparoscopic procedure in the OR. RESULTS: No differences in baseline variables were found between the two groups. Surgeons who received VR training performed laparoscopic cholecystectomy significantly faster than the control group (P=0.021). Furthermore, those who had VR training showed significantly greater improvement in error (P=0.003) and economy of movement (P=0.003) scores. CONCLUSION: Surgeons who received VR simulator training showed significantly greater improvement in performance in the OR than those in the control group. VR surgical simulation is therefore a valid tool for training of laparoscopic psychomotor skills and could be incorporated into surgical training programmes.     

Can skills assessment on a virtual reality trainer predict a surgical trainee’s talent in laparoscopic surgery?

Background A number of studies have investigated several aspects of feasibility and validity of performance assessments with virtual reality surgical simulators. However, the validity of performance assessments is limited by the reliability of such measurements, and some issues of reliability still need to be addressed. This study aimed to evaluate the hypothesis that test subjects show logarithmic performance curves on repetitive trials for a component task of laparoscopic cholecystectomy on a virtual reality simulator, and that interindividual differences in performance after considerable training are significant. According to kinesiologic theory, logarithmic performance curves are expected and an individual’s learning capacity for a specific task can be extrapolated, allowing quantification of a person’s innate ability to develop task-specific skills. Methods In this study, 20 medical students at the University of Basel Medical School performed five trials of a standardized task on the LS 500 virtual reality simulator for laparoscopic surgery. Task completion time, number of errors, economy of instrument movements, and maximum speed of instrument movements were measured. Results The hypothesis was confirmed by the fact that the performance curves for some of the simulator measurements were very close to logarithmic curves, and there were significant interindividual differences in performance at the end of the repetitive trials. Conclusions Assessment of perceptual motor skills and the innate ability of an individual with no prior experience in laparoscopic surgery to develop such skills using the LS 500 VR surgical simulator is feasible and reliable.     

The performance of master surgeons on standard aptitude testing

BACKGROUND: Identification of the desired psychomotor abilities of optimal surgical performance, if possible, would be useful in the selection of surgical trainees. The aim of this study was to determine the level of these abilities among endoscopic consultant surgeons held in high regard by their peers. METHODS: Twenty endoscopic consultant "master" surgeons were tested on three aptitude tests: the Gibson Spiral Maze Test (error score measures eye-hand coordination), the Crawford Small Parts Dexterity Test (execution time indicates manual dexterity), and the Space Relations Test (correct scores reflect visuo-spatial ability). Their performance was compared with that of 20 medical students and the reference norm as provided by the tests' manuals. RESULTS: The median scores of master surgeons fell in the 20th, 24th, and 30th percentiles, whereas the scores of medical students fell in the 50th, 20th, and 65th percentile of norm reference for the Gibson Spiral Maze, Crawford Small Parts Dexterity, and Space Relations tests, respectively. The master surgeons enacted significantly fewer errors (Gibson Spiral Maze), had similar execution times (Crawford Small Parts Dexterity), and lower visuo-spatial scores (Space Relations) than medical students. CONCLUSION: The level of eye-hand coordination and manual dexterity of master surgeons was found to be higher than that of the average norm including medical students, while their visuo-spatial ability was lower.     

Construct validation of the ProMIS simulator using a novel laparoscopic suturing task

Background The use of simulation for minimally invasive surgery (MIS) skills training has many advantages over current traditional methods. One advantage of simulation is that it enables an objective assessment of technical performance. The purpose of this study was to determine whether the ProMIS augmented reality simulator could objectively distinguish between levels of performance skills on a complex laparoscopic suturing task. Methods Ten subjects — five laparoscopic experts and five laparoscopic novices — were assessed for baseline perceptual, visio-spatial, and psychomotor abilities using validated tests. After three trials of a novel laparoscopic suturing task were performed on the simulator, measures for time, smoothness of movement, and path distance were analyzed for each trial. Accuracy and errors were evaluated separately by two blinded reviewers to an interrater reliability of >0.8. Comparisons of mean performance measures were made between the two groups using a Mann-Whitney U test. Internal consistency of ProMIS measures was assessed with coefficient α. Results The psychomotor performance of the experts was superior at baseline assessment (p < 0.001). On the laparoscopic suturing task, the experts performed significantly better than the novices across all three trials (p < 0.001). They performed the tasks between three and four times faster (p < 0.0001), had three times shorter instrument path length (p < 0.0001), and had four times greater smoothness of instrument movement (p < 0.009). Experts also showed greater consistency in their performance, as demonstrated by SDs across all measures, which were four times smaller than the novice group. Observed internal consistency of ProMIS measures was high (α = 0.95, p < 0.00001). Conclusions Preliminary results of construct validation efforts of the ProMIS simulator show that it can distinguish between experts and novices and has promising psychometric properties. The attractive feature of ProMIS is that a wide variety of MIS tasks can be used to train and assess technical skills.     

Chirurgisches Training am Simulator

Learning of laparoscopic operative skills is often complex and time consuming resulting in a learning curve especially for novices in surgery. Virtual reality (VR) simulation was developed as an alternative to conventional training, such as active assistance and conventional laparoscopic training with artificially perfused organs (Pop-Trainer). VR simulation enables a wide range of repeatable laparoscopic techniques in variable virtual scenarios. For abdominal surgery four different simulation systems (MIST-VR®, LapSim®, Simsurgery®, Lap-Mentor®) are currently available and the modules allow simulation of abstract exercises to more advanced laparoscopic procedures, such as laparoscopic sigmoid resection. The effect of VR training on laparoscopic performance and its impact on non-technical skills was evaluated using the simulator LapSim® after a constructive validity study. Novices benefited most from VR training and performance in the operating room improved significantly after VR training. Good spatial perception and positive stress coping strategies also enhanced laparoscopic performance. VR simulation provides a tool to shift the laparoscopic learning curve outside the operating room and thus contributes to patient safety. It would be worthwhile to include VR training in the surgical curriculum. For economic reasons regional training centers seem to be an effective way to realize a broad implementation of VR simulation in surgical training. Application and development of VR simulators should be professionally promoted just as flight simulators in aviation.     

Evaluation of resident laparoscopic performance using global operative assessment of laparoscopic skills

BACKGROUND: The Global Operative Assessment of Laparoscopic Skills (GOALS), developed by Vassiliou and colleagues, has construct validity in the assessment of surgical residents' laparoscopic skills in dissection of the gallbladder from the liver bed. We hypothesized that GOALS would have construct validity for the entire laparoscopic cholecystectomy procedure and also for laparoscopic appendectomy. METHODS: Using GOALS, attending surgeons evaluated PGY1 through PGY5 surgical resident performance during laparoscopic cholecystectomy (LC, n = 51) and laparoscopic appendectomy (LA, n = 43). Scores for five domains (depth perception, bimanual dexterity, efficiency, tissue handling, and autonomy) were recorded on a Web-based operative report generator at the conclusion of all cases. Domain scores were recorded using a 5-point Likert scale. Difficulty of the case was similarly rated on a 5-point scale. For analysis, residents were divided into two groups: novice (PGY1 to 3) and experienced (PGY4 to 5). Biostatistical analysis was performed using a two-sample t-test. Paired t-test was used to compare mean scores of residents who performed both LA and LC. RESULTS: For both LC and LA, the experienced group scored higher than novices did in all five domains. The differences were significant in all domains. Using the mean of the scores from all 5 domains for both LC and LA, the experienced residents scored significantly better than novices did (LC 3.93 versus 2.76, p < 0.001) (LA 4.22 versus 2.75, p < 0.001). No significant differences were noted in difficulty of the cases (p = 0.060 for LC and p = 0.19 for LA). CONCLUSIONS: This study provides additional evidence in support of GOALS as an assessment tool for objectively measuring technical skills in laparoscopic surgery.     

Proficiency-based virtual reality training significantly reduces the error rate for residents during their first 10 laparoscopic cholecystectomies

BACKGROUND: Virtual reality (VR) training has been shown previously to improve intraoperative performance during part of a laparoscopic cholecystectomy. The aim of this study was to assess the effect of proficiency-based VR training on the outcome of the first 10 entire cholecystectomies performed by novices. METHODS: Thirteen laparoscopically inexperienced residents were randomized to either (1) VR training until a predefined expert level of performance was reached, or (2) the control group. Videotapes of each resident's first 10 procedures were reviewed independently in a blinded fashion and scored for predefined errors. RESULTS: The VR-trained group consistently made significantly fewer errors (P = .0037). On the other hand, residents in the control group made, on average, 3 times as many errors and used 58% longer surgical time. CONCLUSIONS: The results of this study show that training on the VR simulator to a level of proficiency significantly improves intraoperative performance during a resident's first 10 laparoscopic cholecystectomies.     

Motion analysis

BACKGROUND: The ability to make an objective evaluation of a surgeon's operative ability remains an elusive goal. In this study, we used motion analysis as a measure of dexterity in the performance of a simulated operation. METHODS: Fifteen surgeons performed a total of 45 laboratory-based laparoscopic cholecystectomies on a cadaveric porcine liver model. Subjects were assigned to one of three groups according to their level of experience in human laparoscopic cholecystectomy. Electromagnetic tracking devices were used to analyze the surgeon's hand movements as they performed the procedure. Movement data (time, distance, number of movements, and speed of movement) were then compared. RESULTS: Analysis of variance (ANOVA) movement scores across the three groups showed significantly better performance among the experienced laparoscopic surgeons than the novices. Learning curves across repetitions of procedures were plotted. Novices made more improvement than experts. CONCLUSIONS: Motion analysis provides useful data for the assessment of laparoscopic dexterity, and the porcine liver model is a valid simulation of the real procedure.     

Simulation-based training for thoracoscopic lobectomy: a randomized controlled trial

Background

Video-assisted thoracic surgery is gradually replacing conventional open thoracotomy as the method of choice for the treatment of early-stage non-small cell lung cancers, and thoracic surgical trainees must learn and master this technique. Simulation-based training could help trainees overcome the first part of the learning curve, but no virtual-reality simulators for thoracoscopy are commercially available. This study aimed to investigate whether training on a laparoscopic simulator enables trainees to perform a thoracoscopic lobectomy.

Methods

Twenty-eight surgical residents were randomized to either virtual-reality training on a nephrectomy module or traditional black-box simulator training. After a retention period they performed a thoracoscopic lobectomy on a porcine model and their performance was scored using a previously validated assessment tool.

Results

The groups did not differ in age or gender. All participants were able to complete the lobectomy. The performance of the black-box group was significantly faster during the test scenario than the virtual-reality group: 26.6 min (SD 6.7 min) versus 32.7 min (SD 7.5 min). No difference existed between the two groups when comparing bleeding and anatomical and non-anatomical errors.

Conclusion

Simulation-based training and targeted instructions enabled the trainees to perform a simulated thoracoscopic lobectomy. Traditional black-box training was more effective than virtual-reality laparoscopy training. Thus, a dedicated simulator for thoracoscopy should be available before establishing systematic virtual-reality training programs for trainees in thoracic surgery.     

Construct Validity of Fresh Frozen Human Cadaver as a Training Model in Minimal Access Surgery

Background:

The construct validity of fresh human cadaver as a training tool has not been established previously. The aims of this study were to investigate the construct validity of fresh frozen human cadaver as a method of training in minimal access surgery and determine if novices can be rapidly trained using this model to a safe level of performance.

Methods:

Junior surgical trainees, novices (<3 laparoscopic procedure performed) in laparoscopic surgery, performed 10 repetitions of a set of structured laparoscopic tasks on fresh frozen cadavers. Expert laparoscopists (>100 laparoscopic procedures) performed 3 repetitions of identical tasks. Performances were scored using a validated, objective Global Operative Assessment of Laparoscopic Skills scale. Scores for 3 consecutive repetitions were compared between experts and novices to determine construct validity. Furthermore, to determine if the novices reached a safe level, a trimmed mean of the experts score was used to define a benchmark.Mann-Whitney U test was used for construct validity analysis and 1-sample t test to compare performances of the novice group with the benchmark safe score.

Results:

Ten novices and 2 experts were recruited. Four out of 5 tasks (nondominant to dominant hand transfer; simulated appendicectomy; intracorporeal and extracorporeal knot tying) showed construct validity. Novices’ scores became comparable to benchmark scores between the eighth and tenth repetition.

Conclusion:

Minimal access surgical training using fresh frozen human cadavers appears to have construct validity. The laparoscopic skills of novices can be accelerated through to a safe level within 8 to 10 repetitions.     

Correlating motor performance with surgical error in laparoscopic cholecystectomy

Background Analysis of motor performance in minimally invasive surgery (MIS) is a new field with applications in surgical training, surgical simulators, and robotics. Force/torque and derivatives of tool tip position (velocity, acceleration, and jerk) are examples of measures of motor performance (MMPs). Few studies have measured MMPs or have correlated MMPs with surgical performance during MIS on humans. The objectives of this study were to determine the feasibility of a novel multimodal system to quantify MMPs in laparoscopic cholecystectomy and to attempt to correlate MMPs with the magnitude of error as a measure of surgical performance. Methods Novice and expert surgeons performed laparoscopic cholecystectomies in two groups of three patients each. MMPs were obtained using a combination of optical and electromagnetic tool tip tracking and a force/torque sensor on a modified Maryland dissector. Error scores for laparoscopic cholecystectomy were calculated using a previously validated system. Novice and expert measurements were compared, and correlations were made between error scores and MMPs. Results Error scores were similar between novices and experts. Novice surgeons had a significantly greater mean velocity (566 ± 83 vs 85 ± 32 mm/s, p = 0.006) and acceleration (2,600 ± 760 vs 440 ± 174 mm/s², p = 0.050) compared to expert surgeons. Force (16.5 ± 4.6 vs 18.3 ± 6.0 N, p = 0.829), position (121 ± 25 vs 135 ± 72 mm, p = 0.863), and jerk (19,600 ± 7,410 vs 2,430 ± 367 mm/s³, p = 0.138) were similar between groups. A positive correlation was found in novice surgeons between error score and jerk (Pearson correlation, 0.999; p = 0.035). Conclusions It is feasible to quantify MMPs in laparoscopic cholecystectomy. Novice and expert surgeons can be differentiated by MMPs; moreover, there may be a positive correlation between jerk and error score in novice surgeons.     

The Impact of Self-Belief on Laparoscopic Performance of Novices and Experienced Surgeons

BACKGROUND: In many professions, nontechnical aspects such as motivation or coping with stress are known to influence performance, success, and outcome. These qualities are assessed and trained in novices for quality and safety reasons. This study explored the impact of self-belief of surgeons on laparoscopic performance using a virtual reality simulator (LapSim((R))). METHODS: Eighteen inexperienced surgical residents (with less than ten laparoscopic procedures performed) and 22 advanced residents (with more than 50 laparoscopic procedures performed) filled out a ten-item questionnaire used for the assessment of the individual sense of general self-efficacy (GSE). Afterward the participants were asked to perform three defined tasks on the LapSim, each at two different levels of difficulty. The tasks consisted of coordination, dissection, and application of clips. To assess laparoscopic performance, the total time to complete the tasks, economy of motion, and damage parameters were analyzed and correlated with the GSE score by means of Bravis-Pearson correlation analysis. RESULTS: In novices, high GSE scores correlated with more errors and poor economy of motion, while in advanced residents, laparoscopic performance was independent of the level of assessed self-efficacy. CONCLUSION: In a small sample, high self-belief does not predict success. In novices it negatively correlates with laparoscopic skills, while in advanced residents it is independent of laparoscopic performance. Thus, training aspects seem to be of greater importance for laparoscopic skills. Nevertheless, nontechnical aspects like self-belief, motivation, stress-coping strategies, judgment, decision-making, and leadership should be included in the surgical curriculum.     

PicSOr: An objective test of perceptual skill that predicts laparoscopic technical skill in three initial studies of laparoscopopic performance

Background: Laparoscopic surgery requires surgeons to infer the shape of 3-D structures, such as the internal organs of patients, from 2-D displays on a video monitor. Recent evidence indicates that the issue is not resolved by the use of contemporary 3-D camera systems. It is therefore crucial to find ways of measuring differences in aptitude for recovering 3-D structure from 2-D images, and assessing its impact on performance. Our aim was to test empirically for a relationship between laparoscopic ability and the perceptual skill of recovering information about 3-D structures from 2-D monitor displays. Methods: Participants in three studies completed a simulated laparoscopic cutting task as well as the Pictorial Surface Orientation (PicSOr)³ Test. In studies 1 (n = 48) and 2 (n = 32) both groups were laparoscopic novices, and in study 3 (n = 34) 18 of the participants were experienced laparoscopic surgeons. Findings: All three studies showed that PicSOr consistently predicted the laparoscopic performance of participants on the laparoscopic cutting task (study 1, r = 0.5, p < 0.0003; study 2, r = 0.5, p < 0.004; and study 3, r = 0.42, p = 0.017). Furthermore, it was also a significant predictor of laparoscopic surgeons performance (r = 0.54, p = 0.047). Interpretations: This is the first objective perceptual psychometric test to reliably predict laparoscopic technical skills. PicSOr provides a tool for assessing which trainees have the potential to learn minimal access surgery.