Laparoscopic common bile duct exploration four-task training model: construct validity

Background:

Training models in laparoscopic surgery allow the surgical team to practice procedures in a safe environment. We have proposed the use of a 4-task, low-cost inert model to practice critical steps of laparoscopic common bile duct exploration.

Methods:

The performance of 3 groups with different levels of expertise in laparoscopic surgery, novices (A), intermediates (B), and experts (C), was evaluated using a low-cost inert model in the following tasks: (1) intraoperative cholangiography catheter insertion, (2) transcystic exploration, (3) T-tube placement, and (4) choledochoscope management. Kruskal-Wallis and Mann-Whitney tests were used to identify differences among the groups.

Results:

A total of 14 individuals were evaluated: 5 novices (A), 5 intermediates (B), and 4 experts (C). The results involving intraoperative cholangiography catheter insertion were similar among the 3 groups. As for the other tasks, the expert had better results than the other 2, in which no significant differences occurred. The proposed model is able to discriminate among individuals with different levels of expertise, indicating that the abilities that the model evaluates are relevant in the surgeon''s performance in CBD exploration.

Conclusions:

Construct validity for tasks 2 and 3 was demonstrated. However, task 1 was no capable of distinguishing between groups, and task 4 was not statistically validated.     

Face, content and construct validity of a virtual reality simulator for robotic surgery (SEP Robot)

INTRODUCTION

This study aims to establish face, content and construct validation of the SEP Robot (SimSurgery, Oslo, Norway) in order to determine its value as a training tool.

SUBJECTS AND METHODS

The tasks used in the validation of this simulator were arrow manipulation and performing a surgeon''s knot. Thirty participants (18 novices, 12 experts) completed the procedures.

RESULTS

The simulator was able to differentiate between experts and novices in several respects. The novice group required more time to complete the tasks than the expert group, especially suturing. During the surgeon''s knot exercise, experts significantly outperformed novices in maximum tightening stretch, instruments dropped, maximum winding stretch and tool collisions in addition to total task time. A trend was found towards the use of less force by the more experienced participants.

CONCLUSIONS

The SEP robotic simulator has demonstrated face, content and construct validity as a virtual reality simulator for robotic surgery. With steady increase in adoption of robotic surgery world-wide, this simulator may prove to be a valuable adjunct to clinical mentorship.     

Construct Validity of an Inanimate Training Model for Laparoscopic Appendectomy

Background and Objective:

The use of training models in laparoscopic surgery allows the surgical team to practice procedures in a safe environment. The aim of this study was to determine the capability of an inanimate laparoscopic appendectomy model to discriminate between different levels of surgical experience (construct validity).

Methods:

The performance of 3 groups with different levels of expertise in laparoscopic surgery—experts (Group A), intermediates (Group B), and novices (Group C)—was evaluated. The groups were instructed of the task to perform in the model using a video tutorial. Procedures were recorded in a digital format for later analysis using the Global Operative Assessment of Laparoscopic Skills (GOALS) score; procedure time was registered. The data were analyzed using the analysis of variance test.

Results:

Twelve subjects were evaluated, 4 in each group, using the GOALS score and time required to finish the task. Higher scores were observed in the expert group, followed by the intermediate and novice groups, with statistically significant difference. Regarding procedure time, a significant difference was also found between the groups, with the experts having the shorter time. The proposed model is able to discriminate among individuals with different levels of expertise, indicating that the abilities that the model evaluates are relevant in the surgeon''s performance.

Conclusions:

Construct validity for the inanimate full-task laparoscopic appendectomy training model was demonstrated. Therefore, it is a useful tool in the development and evaluation of the resident in training.     

Development and validation of a virtual reality transrectal ultrasound guided prostatic biopsy simulator

Objective

We present the design, reliability, face, content and construct validity testing of a virtual reality simulator for transrectal ultrasound (TRUS), which allows doctors-in-training to perform multiple different biopsy schemes.

Methods

This biopsy system design uses a regular “end-firing” TRUS probe. Movements of the probe are tracked with a micro-magnetic sensor to dynamically slice through a phantom patient’s 3D prostate volume to provide real-time continuous TRUS views. 3D TRUS scans during prostate biopsy clinics were recorded. Intrinsic reliability was assessed by comparing the left side of the prostate to the right side of the prostate for each biopsy. A content and face validity questionnaire was administered to 26 doctors to assess the simulator. Construct validity was assessed by comparing notes from experts and novices with regards to the time taken and the accuracy of each biopsy.

Results

Imaging data from 50 patients were integrated into the simulator. The completed VR TRUS simulator uses real patient images, and is able to provide simulation for 50 cases, with a haptic interface that uses a standard TRUS probe and biopsy needle. Intrinsic reliability was successfully demonstrated by comparing results from the left and right sides of the prostate. Face and content validity respondents noted the realism of the simulator, and its appropriateness as a teaching model. The simulator was able to distinguish between experts and novices during construct validity testing.

Conclusions

A virtual reality TRUS simulator has successfully been created. It has promising face, content and construct validity results.     

Virtual reality uterine resectoscopic simulator: face and construct validation and comparative evaluation in an educational environment

Background and Objectives:

Recognizing that resectoscopic simulation may have an educational role, this pilot study was designed to evaluate the face validity and educational utility of a virtual reality uterine resectoscope training system.

Methods:

A pilot prospective comparative study of novice and expert hysteroscopists'' performance on a targeting exercise and myomectomy with the virtual loop electrode. At baseline, expert and novice resectoscopists each performed both exercises. Following instruction, novices practiced each exercise a total of 9 times with the 10th recorded as the training outcome. Results were compared both to baseline and to those of the experts. Data were analyzed with the paired t and Wilcoxon rank sum tests as appropriate.

Results:

At baseline, all experts touched 4 targets in a mean of 33 seconds with no perforations, compared to a mean of 2 for the 11 novices in a mean of 57 seconds (P=0.0034) with one perforation. In 3 minutes, the experts removed a mean of 97.3% of the virtual myoma, compared to 66.1% for the novices (P=0.0153). On the 10th “run,” novices touched a mean of 4 targets in a mean of 23 seconds, an improvement from baseline (P=0.0004) and improved to 89% on the myoma resection exercise (P=0.0515) 36.3% over baseline.

Conclusion:

Although this pilot study has a relatively small sample size and represents the results at one institution, it demonstrates that virtual reality resectoscopic systems have the potential to measure and improve the technical skills of novices before they operate on human patients.     

Validation of a new box trainer-related tracking device: the TrEndo

Background

There is an increasing demand for structured objective ex vivo training and assessment of laparoscopic psychomotor skills prior to implementation of these skills in practice. The aim of this study was to establish the internal validity of the TrEndo, a motion-tracking device, for implementation on a laparoscopic box trainer.

Methods

Face validity and content validity were addressed through a structured questionnaire. To assess construct validity, participants were divided into an expert group and a novice group and performed two basic laparoscopic tasks. The TrEndo recorded five motion analysis parameters (MAPs) and time.

Results

Participants demonstrated a high regard for face and content validity. All recorded MAPs differed significantly between experts and novices after performing a square knot. Overall, the TrEndo correctly assigned group membership in 84.7 and 95.7% of cases based on two laparoscopic tasks.

Conclusion

Face, content, and construct validities of the TrEndo were established. The TrEndo holds real potential as a (home) training device.     

Face,content and construct validation of the first virtual reality laparoscopic nephrectomy simulator

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To evaluate the face, content and construct validity, and to identify whether participants improved with practice, for the Procedicus MIST Nephrectomy? simulator (Mentice, Gothenburg, Sweden), which incorporates force feedback and can record numerous performance measures (metrics) during the simulation, and which is the first virtual reality simulator for laparoscopic nephrectomy.

SUBJECTS AND METHODS

Eight expert urological laparoscopic surgeons, 10 novices and 10 trainee urologists completed at least one simulated retroperitoneal radical nephrectomy. They completed a structured questionnaire to assess face and content validity; the performance of experts and novices were then compared to evaluate construct validity.

RESULTS

Face validity was established by the experts who all felt the simulator was a good training tool. Content validity was established by the experts who rated all aspects of the simulator as above average for realism. When performance metrics were analysed, experts completed the simulated nephrectomy significantly faster than novices, with fewer errors, less simulated haemorrhage and less tool travel, which established construct validity. After practice, both novices and trainees were able to perform the simulation faster, with fewer errors, less blood loss and less tool travel.

CONCLUSIONS

This study has established the face, content and construct validity for the Procedicus MIST Nephrectomy. The simulator can distinguish experts from novices and it has potential as a laparoscopic training tool for urology.     

Stereoscopic (3D) versus monoscopic (2D) laparoscopy: comparative study of performance using advanced HD optical systems in a surgical simulator model

Purpose

To compare task performances of novices and experts using advanced high-definition 3D versus 2D optical systems in a surgical simulator model.

Methods

Fifty medical students (novices in laparoscopy) were randomly assigned to perform five standardized tasks adopted from the Fundamentals of Laparoscopic Surgery (FLS) curriculum in either a 2D or 3D laparoscopy simulator system. In addition, eight experts performed the same tasks. Task performances were evaluated using a validated scoring system of the SAGES/FLS program. Participants were asked to rate 16 items in a questionnaire.

Results

Overall task performance of novices was significantly better using stereoscopic visualization. Superiority of performances in 3D reached a level of significance for tasks peg transfer and precision cutting. No significant differences were noted in performances of experts when using either 2D or 3D. Overall performances of experts compared to novices were better in both 2D and 3D. Scorings in the questionnaires showed a tendency toward lower scores in the group of novices using 3D.

Conclusions

Stereoscopic imaging significantly improves performance of laparoscopic phantom tasks of novices. The current study confirms earlier data based on a large number of participants and a standardized task and scoring system. Participants felt more confident and comfortable when using a 3D laparoscopic system. However, the question remains open whether these findings translate into faster and safer operations in a clinical setting.

     

An evidence-based virtual reality training program for novice laparoscopic surgeons

OBJECTIVE: To develop an evidence-based virtual reality laparoscopic training curriculum for novice laparoscopic surgeons to achieve a proficient level of skill prior to participating in live cases. SUMMARY BACKGROUND DATA: Technical skills for laparoscopic surgery must be acquired within a competency-based curriculum that begins in the surgical skills laboratory. Implementation of this program necessitates the definition of the validity, learning curves and proficiency criteria on the training tool. METHODS: The study recruited 40 surgeons, classified into experienced (performed >100 laparoscopic cholecystectomies) or novice groups (<10 laparoscopic cholecystectomies). Ten novices and 10 experienced surgeons were tested on basic tasks, and 11 novices and 9 experienced surgeons on a procedural module for dissection of Calot triangle. Performance of the 2 groups was assessed using time, error, and economy of movement parameters. RESULTS: All basic tasks demonstrated construct validity (Mann-Whitney U test, P < 0.05), and learning curves for novices plateaued at a median of 7 repetitions (Friedman's test, P < 0.05). Expert surgeons demonstrated a learning rate at a median of 2 repetitions (P < 0.05). Performance on the dissection module demonstrated significant differences between experts and novices (P < 0.002); learning curves for novice subjects plateaued at the fourth repetition (P < 0.05). Expert benchmark criteria were defined for validated parameters on each task. CONCLUSION: A competency-based training curriculum for novice laparoscopic surgeons has been defined. This can serve to ensure that junior trainees have acquired prerequisite levels of skill prior to entering the operating room, and put them directly into practice.     

The effect of video game "warm-up" on performance of laparoscopic surgery tasks

Background:

Performing laparoscopic procedures requires special training and has been documented as a significant source of surgical errors. “Warming up” before performing a task has been shown to enhance performance. This study investigates whether surgeons benefit from “warming up” using select video games immediately before performing laparoscopic partial tasks and clinical tasks.

Methods:

This study included 303 surgeons (249 men and 54 women). Participants were split into a control (n=180) and an experimental group (n=123). The experimental group played 3 previously validated video games for 6 minutes before task sessions. The Cobra Rope partial task and suturing exercises were performed immediately after the warm-up sessions.

Results:

Surgeons who played video games prior to the Cobra Rope drill were significantly faster on their first attempt and across all 10 trials. The experimental and control groups were significantly different in their total suturing scores (t=2.28, df=288, P<.05). The overall Top Gun score showed that the experimental group performed marginally better overall.

Conclusion:

This study demonstrates that subjects completing “warming-up” sessions with select video games prior to performing laparoscopic partial and clinical tasks (intracorporeal suturing) were faster and had fewer errors than participants not engaging in “warm-up.” More study is needed to determine whether this translates into superior procedural execution in the clinical setting.     

Analysis of hand motion differentiates expert and novice surgeons

Background

The number of operations performed by a surgeon may be an indicator of surgical skill. The hand motions made by a surgeon also reflect skill and level of expertise. We hypothesized that the hand motions of expert and novice surgeons differ significantly, regardless of whether they are familiar with specific tasks during an operation.

Methods

This study compared 11 expert surgeons, each of whom had performed >100 laparoscopic procedures, and 27 young surgeons, each of whom had performed <15 laparoscopic procedures. Each examinee performed a specific skill assessment task, in which instrument motion was monitored using magnetic tracking system. We analyzed the paths of the centers of gravity of the tips of the needle holders and the relative paths of the tips using two mathematical methods of detrended fluctuation analysis and unstable periodic orbit analysis.

Results

Detrended fluctuation analysis showed that the exponent in the function describing the initial scaling exponent (α₁) differed significantly for experts and novices, being close to 1.0 and 1.5, respectively (P < 0.01). This indicated that the expert group had a greater long-range coherence with an intrinsic sequence and smooth continuity among a series of motions. Likewise, unstable periodic orbit analysis showed that the second period of unstable orbit was significantly longer for experts in comparison with novices (P < 0.01). This demonstrates mathematically that the hands of experts are more stable when performing laparoscopic procedures.

Conclusions

Objective evaluation of hand motion during a simulated laparoscopic procedure showed a significant difference between experts and novices.     

Laparoscopic Approach for Metachronous Cecal and Sigmoid Volvulus

Background:

Metachronous colonic volvulus is a rare event that has never been approached laparoscopically.

Methods:

Here we discuss the case of a 63-year-old female with a metachronous sigmoid and cecal volvulus.

Results:

The patient underwent 2 separate successful laparoscopic resections.

Discussion and Conclusion:

The following is a discussion of the case and the laparoscopic technique, accompanied by a brief review of colonic volvulus. In experienced hands, laparoscopy is a safe approach for acute colonic volvulus.     

Laparoscopic Surgery Skills Evaluation: Analysis Based on Accelerometers

Background and Objective:

Technical skills assessment is considered an important part of surgical training. Subjective assessment is not appropriate for training feedback, and there is now increased demand for objective assessment of surgical performance. Economy of movement has been proposed as an excellent alternative for this purpose. The investigators describe a readily available method to evaluate surgical skills through motion analysis using accelerometers in Apple''s iPod Touch device.

Methods:

Two groups of individuals with different minimally invasive surgery skill levels (experts and novices) were evaluated. Each group was asked to perform a given task with an iPod Touch placed on the dominant-hand wrist. The Accelerometer Data Pro application makes it possible to obtain movement-related data detected by the accelerometers. Average acceleration and maximum acceleration for each axis (x, y, and z) were determined and compared.

Results:

The analysis of average acceleration and maximum acceleration showed statistically significant differences between groups on both the y (P = .04, P = .03) and z (P = .04, P = .04) axes. This demonstrates the ability to distinguish between experts and novices. The analysis of the x axis showed no significant differences between groups, which could be explained by the fact that the task involves few movements on this axis.

Conclusion:

Accelerometer-based motion analysis is a useful tool to evaluate laparoscopic skill development of surgeons and should be used in training programs. Validation of this device in an in vivo setting is a research goal of the investigators'' team.     

Motion analysis in the pediatric laparoscopic surgery (PLS) simulator: validation and potential use in teaching and assessing surgical skills

Background

Construct validity for the pediatric laparoscopic surgery (PLS) simulator has been established through a scoring system based on time and precision. We describe the development and initial validation of motion analysis to teach and assess skills related to pediatric minimal access surgery (MAS).

Methods

Participants were asked to perform a standardized intracorporeal suturing task. They were classified as novices, intermediates, and experts. Motion in the four degrees of freedom available during traditional MAS (PITCH, YAW, ROLL and SURGE) was assessed using range, velocity, and acceleration.

Results

Analysis of motion allowed discrimination between the 75 participants according to level of expertise. The most discriminating motion parameter was the acceleration in performing the ROLL (pronation/supination) with values of 30 ± 27 for novices, 15 ± 5 for intermediates, and 3.7 ± 3 for experts (p < 0.001).

Conclusions

Tracking and analyzing the motion of instruments within the PLS simulator allow discrimination between novices, intermediates, and experts, thus establishing construct validity. Further development may establish motion analysis as a useful “real time” modality to teach and assess MAS skills.     

Limitations of haptic feedback devices on construct validity of the LapSim® virtual reality simulator

Background

Surgeons performing laparoscopy need a high degree of psychomotor skills, which can be trained and assessed on virtual reality (VR) simulators. VR simulators simulate the surgical environment and assess psychomotor skills according to predefined parameters. This study aimed to validate a proficiency-based training setup that consisted of two tasks with predefined threshold values and handles with haptic feedback on the LapSim^® VR simulator. The two tasks have been found to have construct validity in previous studies using handles without haptic feedback.

Methods

The participants were divided into three groups: novices (0–50 laparoscopic procedures), intermediates (51–300 laparoscopic procedures), and experts (more than 300 procedures). It was assumed that psychomotor skills increase with experience. All participants conducted the tasks lifting and grasping and fine dissection 20 times each. Validity of the training setup was investigated by comparing the number of times each participant passed a predefined threshold level for a set of 19 parameters.

Results

Construct validity was established for one parameter; “misses on right side” on the lifting and grasping task, whereas the other 18 parameters did not show construct validity.

Conclusion

The setup employed in this study failed to establish construct validity for more than one parameter. This indicates that the simulation of haptic feedback influences the training performance on laparoscopic simulators and is an important part of validating a training setup. A haptic device should generate haptic sensations in a realistic manner, without introducing frictional forces that are not inherent to laparoscopy.     

Laparoscopic Hysterectomy and Prolapse: A Multiprocedural Concept

Background and Objectives:

Today, laparoscopic intrafascial hysterectomy and laparoscopic supracervical hysterectomy are well-accepted techniques. With our multimodal concept of laparoscopic hysterectomy for benign indications, preservation of the pelvic floor as well as reconstruction of pelvic floor structures and pre-existing prolapse situations can be achieved.

Methods:

The multimodal concept consists of 3 steps:

1. Intrafascial hysterectomy with preservation of existing structures
   1. Technique 1: Primary uterine artery ligation
   2. Technique 2: Classic intrafascial hysterectomy
2. A technique for the stable fixation of the vaginal or cervical stump
3. A new method of pectopexy to correct a pre-existing descensus situation

Results and Conclustion:

This well-balanced concept can be used by advanced endoscopic gynecologic surgeons as well as by novices in our field.     

SIMPLIFIED LAPAROSCOPIC CHOLECYSTECTOMY WITH TWO INCISIONS

Background

Laparoscopic cholecystectomy has traditionally been performed with four incisions to insert four trocars, in a simple, efficient and safe way.

Aim

To describe a simplified technique of laparoscopic cholecystectomy with two incisions, using basic conventional instrumental.

Technique

In one incision in the umbilicus are applied two trocars and in epigastrium one more. The use of two trocars on the same incision, working in "x" does not hinder the procedure and does not require special instruments.

Conclusion

Simplified laparoscopic cholecystectomy with two incisions is feasible and easy to perform, allowing to operate with ergonomy and safety, with good cosmetic result.     

Which skills really matter? proving face, content, and construct validity for a commercial robotic simulator

Background

A novel computer simulator is now commercially available for robotic surgery using the da Vinci^® System (Intuitive Surgical, Sunnyvale, CA). Initial investigations into its utility have been limited due to a lack of understanding of which of the many provided skills modules and metrics are useful for evaluation. In addition, construct validity testing has been done using medical students as a “novice” group—a clinically irrelevant cohort given the complexity of robotic surgery. This study systematically evaluated the simulator’s skills tasks and metrics and established face, content, and construct validity using a relevant novice group.

Methods

Expert surgeons deconstructed the task of performing robotic surgery into eight separate skills. The content of the 33 modules provided by the da Vinci Skills Simulator (Intuitive Surgical, Sunnyvale, CA) was then evaluated for these deconstructed skills and 8 of the 33 determined to be unique. These eight tasks were used for evaluating the performance of 46 surgeons and trainees on the simulator (25 novices, 8 intermediate, and 13 experts). Novice surgeons were general surgery and urology residents or practicing surgeons with clinical experience in open and laparoscopic surgery but limited exposure to robotics. Performance was measured using 85 metrics across all eight tasks.

Results

Face and content validity were confirmed using global rating scales. Of the 85 metrics provided by the simulator, 11 were found to be unique, and these were used for further analysis. Experts performed significantly better than novices in all eight tasks and for nearly every metric. Intermediates were inconsistently better than novices, with only four tasks showing a significant difference in performance. Intermediate and expert performance did not differ significantly.

Conclusion

This study systematically determined the important modules and metrics on the da Vinci Skills Simulator and used them to demonstrate face, content, and construct validity with clinically relevant novice, intermediate, and expert groups. These data will be used to develop proficiency-based training programs on the simulator and to investigate predictive validity.     

Simulation Training in Laparoscopy Using a Computerized Physical Reality Simulator

Objective:

To describe a new simulator, SurgicalSIM LTS, and summarize our preliminary experience with system.

Methods:

LTS was evaluated in 3 studies: (1) 124 participants from 3 Canadian universities: 13 students; 30 residents, fellows, attendings from surgery; 59 gynecologists; 22 urologists were classified based on laparoscopic experience as novice, intermediate, competent, or expert. All were tested on the LTS. Seventy-four were tested on the LTS and MISTELS (McGill Inanimate System for Training and Evaluation of Laparoscopic Skills). Participants completed a satisfaction questionnaire. (2) Twenty-five international gynecologists in-training at Kiel Gynaecologic Endoscopy Center, and 15 students from the center pretested on LTS underwent voluntary additional trials and posttesting. (3) Seventeen experienced laparoscopic surgeons from 3 specialties were recruited to perform on randomly assigned simulators involving 5 commercial, computer-based systems. The surgeons practiced repetitively for 1.5 days. Efficient, error-free performance was measured and proficiency score formulas were developed.

Results:

Study A: LTS showed a good correlation with level of experience (P=0.000) and MISTELS (0.79). Satisfaction: LTS vs MISTELS 79.9 vs 70.4 (P=0.012). Study B: Posttest scores were significantly better in all tasks for both groups, P<0.0001. Group mean scores with ≤5 trials were significantly better than with 2 or 3 trials (P<0.012, P<0.018). Study C: LTS had the highest effectiveness rating of the 5 simulators.

Conclusions:

A new computerized physical reality simulator can be used to assess/train laparoscopic technical skills.     

Aberrant Presentation of the Gallbladder During Laparoscopic Cholecystectomy

Background:

Aberrant gallbladder transposed to the left side is a rare congenital anomaly that has been seen in as many as 0.7% of the population. These gallbladders are situated under the left lobe of the liver between Segment III and IV and to the left of the falciform ligament. Many preoperative studies fail to identify the anomaly, causing confusion to the surgeon during laparoscopic resection. Selective use of intraoperative cholangiography and meticulous dissection can aid in safe resection.

Methods:

A 61-year-old female was admitted with ultra-sound confirmation of cholecystitis and subsequently taken to the operating room for a laparoscopic cholecystectomy.

Results:

Evaluation of the gallbladder under laparoscopic view revealed an inflamed left aberrant gallbladder. An intraoperative cholangiogram was obtained to delineate the biliary anatomy that showed the cystic duct entering the common hepatic duct on the right side.

Conclusion:

A left aberrant gallbladder is a rare presentation that requires awareness of biliary anatomy and selective use of intraoperative cholangiography to aid in the safe laparoscopic resection of the gallbladder.