Adaptation of the fundamentals of laparoscopic surgery box for endoscopic simulation: performance evaluation of the first 100 participants.

BACKGROUND: The paucity of readily accessible, cost-effective models for the simulation, practice, and evaluation of endoscopic skills present an ongoing barrier for resident training. We have previously described a system for conversion of the Fundamentals of Laparoscopic Surgery box (FLS) for flexible endoscopic simulation. Six endoscopic tasks focusing on scope manipulation, and other clinically relevant endoscopic skills are performed within a 5-min time limit per task. This study describes our experience and validation results with the first 100 participants. METHODS: A total of 100 participants were evaluated on the simulator. Thirty individuals were classified as experts (having done over 200 endoscopic procedures), and 70 were classified as trainees (39 individuals reported having no prior endoscopy experience). Of the 100 participants, 55 individuals were retested on the simulator within a period of 4 months. These 55 individuals were also evaluated using the "Global Assessment of Gastrointestinal Endoscopic Skills" (GAGES). T-tests and Pearson correlations were used where appropriate, values less than 0.05 were considered significant. RESULTS: Experts completed all six tasks significantly faster than trainees. For the 55 participants who were retested on the simulator, all tasks demonstrated evidence of test-retest reliability for both experts and trainees who did not practice in between tests. Moderate correlations between lower completion times and higher GAGES scores were observed for all tasks except the clipping task. CONCLUSIONS: The results from the first 100 participants provide evidence for the simulator's validity. Based on task completion times, we found that experts perform significantly better than trainees. Additionally, preliminary data demonstrate evidence of test-retest reliability, as well as GAGES score correlation. Additional studies to determine and validate a scoring system for this simulator are ongoing.

Feasibility of adapting the fundamentals of laparoscopic surgery trainer box to endoscopic skills training tool.

BACKGROUND: The fundamentals of laparoscopic surgery (FLS) training box is a validated tool, already accessible to surgical trainees to hone their laparoscopic skills. We aim to investigate the feasibility of adapting the FLS box for the practice and assessment of endoscopic skills. This would allow for a highly available, reusable, low-cost, mechanical trainer. METHODS: The design and development process was based on a user-centered design, which is a combination of the design thinking method and cognitive task analysis. The process comprises four phases: empathy, cognitive, prototyping/adaptation, and end user testing. The underlying idea was to utilize as many of the existing components of FLS training to maintain simplicity and cost effectiveness while allowing for the practice of clinically relevant endoscopic skills. A sample size of 18 participants was calculated to be sufficient to detect performance differences between experts and trainees using a two tailed t test with alpha set at 0.05, standard deviation of 5.5, and a power of 80%. RESULTS: Adaptation to the FLS box included two fundamental attachments: a front panel with an insertion point for an endoscope and a shaft which provides additional support and limits movement of the scope. The panel also allows for mounting of retroflexion tasks. Six endoscopic tasks inspired by FLS were designed (two of which utilize existing FLS components). Pilot testing with 38 participants showed high user's satisfaction and demonstrated that the trainer was robust and reliable. Task performance times was able to discriminate between trainees and experts for all six tasks. CONCLUSIONS: A mechanical, reusable, low-cost adaptation of the FLS training box for endoscopic skills is feasible and has high user satisfaction. Preliminary testing shows that the simulator is able to discriminate between trainees and experts. Following further validation, this adaptation may act as a supplement to the FES program.

Evaluation of a porcine model of early aortic valve sclerosis.

BACKGROUND: Calcific aortic valve disease (CAVD) is associated with significant cardiovascular morbidity. While late-stage CAVD is well-described, early pathobiological processes are poorly understood due to the lack of animal models that faithfully replicate early human disease. Here we evaluated a hypercholesterolemic porcine model of early diet-induced aortic valve sclerosis. METHODS: Yorkshire swine were fed either a standard or high-fat/high-cholesterol diet for 2 or 5 months. Right coronary aortic valve leaflets were excised and analyzed (immuno)histochemically. RESULTS: Early human-like proteoglycan-rich onlays formed between the endothelial layer and elastic lamina in the fibrosa layer of valve leaflets, with accelerated formation associated with hypercholesterolemia (P<.05). Lipid deposition was more abundant in hypercholesterolemic swine (P<.001), but was present in a minority (28%) of onlays. No myofibroblasts, MAC387-positive macrophages, or fascin-positive dendritic cells were detected in 2-month onlays, with only scarce myofibroblasts present at 5 months. Cells that expressed osteochondral markers Sox9 and Msx2 were preferentially found in dense proteoglycan-rich onlays (P<.05) and with hypercholesterolemia (P<.05). Features of more advanced human CAVD, including calcification, were not observed in this necessarily short study. CONCLUSIONS: Early aortic valve sclerosis in hypercholesterolemic swine is characterized by the formation of proteoglycan-rich onlays in the fibrosa, which can occur prior to significant lipid accumulation, inflammatory cell infiltration, or myofibroblast activation. These characteristics mimic those of early human aortic valve disease, and thus the porcine model has utility for the study of early valve sclerosis.