Construct validity testing of a laparoscopic surgery simulator (Lap Mentor®)

Department of Surgery and Surgical Oncology, Charite Universitätsmedizin Berlin, Berlin, Germany.
Surgical Endoscopy (Impact Factor: 3.26). 07/2008; 22(6):1440-4. DOI: 10.1007/s00464-007-9625-x
Source: PubMed


Before surgical simulators can be implemented for assessment of surgical training, their construct validity should be assessed.
Nine novices (NOV), nine medical students (MS), and nine residents (RES) underwent a laparoscopic skills training on the virtual reality (VR) simulator Lap Mentor. Assessment of laparoscopic skill was based on parameters measured by the computer system before and after training.
Significant difference existed between RES and NOV at seven of nine tasks before training on the VR simulator. After the training in some tasks significant differences were observed between the experienced group (RES) and the nonexperienced groups (MS and NOV) or between medical groups (RES and MS) and nonmedical group (NOV).
Performance parameters of the Lap-Mentor can be used to distinguish between subjects with varying laparoscopic experience.

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    • "Lap-X (Epona Medical, Rotterdam, The Netherlands) [18] LAP Mentor (Simbionix USA, Cleveland, OH) [19], and LapVR (Immersion Medical, Gaithersburg, MD) [20] are examples of commercially available VR systems for laparoscopic surgery training. However, some of these systems lack realistic haptic feedback, are costly, or have not been validated for training of laparoscopic skills (e.g., Lap-X) [21] [22] [23] [24]. "
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    ABSTRACT: Introduction: The Fundamentals of Laparoscopic Surgery (FLS) trainer is currently the standard for training and evaluating basic laparoscopic skills. However, its manual scoring system is time-consuming and subjective. The Virtual Basic Laparoscopic Skill Trainer (VBLaST©) is the virtual version of the FLS trainer which allows automatic and real time assessment of skill performance, as well as force feedback. In this study, the VBLaST© pattern cutting (VBLaST-PC©) and ligating loop (VBLaST-LL©) tasks were evaluated as part of a validation study. We hypothesized that performance would be similar on the FLS and VBLaST© trainers, and that subjects with more experience would perform better than those with less experience on both trainers. Methods: Fifty-five subjects with varying surgical experience were recruited at the Learning Center during the 2013 SAGES annual meeting and were divided into two groups: experts (PGY 5, surgical fellows and surgical attendings) and novices (PGY 1-4). They were asked to perform the PC or the ligating loop task on the FLS and the VBLaST© trainers. Their performance scores for each trainer were calculated and compared. Results: There were no significant differences between the FLS and VBLaST© scores for either the PC or the ligating loop task. Experts' scores were significantly higher than the scores for novices on both trainers. Conclusion: This study showed that the subjects' performance on the VBLaST© trainer was similar to the FLS performance for both tasks. Both the VBLaST-PC© and the VBLaST-LL© tasks permitted discrimination between the novice and expert groups. Although concurrent and discriminant validity has been established, further studies to establish convergent and predictive validity are needed. Once validated as a training system for laparoscopic skills, the system is expected to overcome the current limitations of the FLS trainer.
    Full-text · Article · Aug 2014 · Surgical Endoscopy
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    • "Construct validity is essential to define the effectiveness of VRLS for training and certification because it demonstrates the ability of a simulator to discriminate between expert and novice surgeons. Several authors have proved construct validity by detecting statistically significant differences in performances measured between subjects with different levels of laparoscopic experience [8–14]. Although this is widely demonstrated for basic laparoscopic skills, there is little evidence for more complex procedures such as LRYGBP [15]. "
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    ABSTRACT: Construct validity of virtual laparoscopic simulators for basic laparoscopic skills has been proposed; however, it is not yet clear whether the simulators can identify the actual experience of surgeons in more complex procedures such as laparoscopic Roux-en-Y gastric bypass. This study tested the ability of the Lap Mentor simulator to recognize the experience in advanced laparoscopic procedures and to assess its role in the certification of bariatric surgeons. Twenty surgeons were divided into two groups according to their experience in laparoscopic and bariatric surgery. The general group included 10 general surgeons performing between 75 and 100 nonbariatric laparoscopic procedures. The bariatric group included 10 bariatric surgeons performing between 50 and 100 laparoscopic bariatric procedures. Participants were tested on the simulator in one basic task (task 1: eye-hand coordination) and in two tasks of the gastric bypass module (task 2: creation of the gastric pouch; task 3: gastrojejunal anastomosis). Comparing the groups, no significant differences were found in task 1. Analyzing the results from the gastric bypass module (bariatric vs. general), in task 2, significant differences (p < 0.05) were found in the median volume of the gastric pouch (21 vs. 48 cm(3)), in the percentage of fundus included in the pouch (8.4 vs. 29.4 %), in the complete dissection at the angle of His (10 vs. 3), and in safety parameters. In task 3, significant differences were found in the size and position of enterotomies. The Lap Mentor may be proposed as a certification tool for bariatric surgeons because it also recognizes their specific skills in the technical details of the procedure that affect long-term results. Furthermore, the possibility of analyzing the performance in detail can help define areas where the surgeon is lacking. These findings indicate a potential role of the Lap Mentor in tailoring the training to maximize improvement.
    Full-text · Article · Aug 2013 · Surgical Endoscopy
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    • "Furthermore, objective performance assessment (time taken, number of errors, and path length for each hand) is provided immediately, and without the need for monitored supervision [9]. Recent studies have provided validity evidence of these measures, with experienced performers tending to be faster, more accurate, and more efficient in their movement paths than their less experienced counterparts [2, 10–14]. "
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    ABSTRACT: It is recognised that one of the major difficulties in performing laparoscopic surgery is the translation of two-dimensional video image information to a three-dimensional working area. However, research has tended to ignore the gaze and eye-hand coordination strategies employed by laparoscopic surgeons as they attempt to overcome these perceptual constraints. This study sought to examine if measures related to tool movements, gaze strategy, and eye-hand coordination (the quiet eye) differentiate between experienced and novice operators performing a two-handed manoeuvres task on a virtual reality laparoscopic surgical simulator (LAP Mentor™). Twenty-five right-handed surgeons were categorised as being either experienced (having led more than 60 laparoscopic procedures) or novice (having performed fewer than 10 procedures) operators. The 10 experienced and 15 novice surgeons completed the "two-hand manoeuvres" task from the LAP Mentor basic skills learning environment while wearing a gaze registration system. Performance, movement, gaze, and eye-hand coordination parameters were recorded and compared between groups. The experienced surgeons completed the task significantly more quickly than the novices, used significantly fewer movements, and displayed shorter tool paths. Gaze analyses revealed that experienced surgeons spent significantly more time fixating the target locations than novices, who split their time between focusing on the targets and tracking the tools. A more detailed analysis of a difficult subcomponent of the task revealed that experienced operators used a significantly longer aiming fixation (the quiet eye period) to guide precision grasping movements and hence needed fewer grasp attempts. The findings of the study provide further support for the utility of examining strategic gaze behaviour and eye-hand coordination measures to help further our understanding of how experienced surgeons attempt to overcome the perceptual difficulties inherent in the laparoscopic environment.
    Full-text · Article · Feb 2011 · Surgical Endoscopy
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