A novel ex vivo porcine simulator for transanal endoscopic operation training

National bowel screening programs have led to an increase in early rectal cancer and complex rectal polyp detection by using the transanal endoscopic operation (TEO). Our aim is to develop an ex vivo porcine simulator for TEO training. A video of the prototype is provided (Video 1, available online at www.giejournal.org). Porcine rectal tissue was injected with a “polyp mix” in order to simulate a rectal lesion. This was attached to a TEO device, as demonstrated in Figure 1. A simulated, partial-thickness transanal endoscopic procedure was performed by using the apparatus. The simulator re-created TEO in a realistic manner. The rectal lesion was removed with standard TEO techniques. The model also can be used to practice TEO suturing. This video demonstrates a unique way of simulating TEO that is reproducible and economically viable. The next stage is to validate this model for use in TEO skills training

The WIMAT colonoscopy suitcase model: a novel porcine polypectomy trainer

Aim Simulation allows the acquisition of complex skills within a safe environment. Endoscopic polypectomy has a long learning curve. Our novel polypectomy simulator may be a useful adjunct for training. The aim of this study was to assess its content validity. Method The Welsh Institute for Minimal Access Therapy (WIMAT) endoscopy suitcase was designed to simulate colonic polypectomy. Participants from regional and national courses were recruited into the study. Each undertook a standardized simulated polypectomy and completed a seven-point Likert scale questionnaire examining its realism. Results In all, 17 participants completed the questionnaire: 15 (88.2%) gastroenterologists, one (5.9%) colorectal surgeon and one (5.9%) experienced endoscopic nurse specialist. Of the gastroenterologists, seven (46.7%) were consultants and eight (53.3%) were senior trainees or Post CCT (Certificate of Completion of Training) fellows. The mean number of real-life polypectomies performed by the cohort was 156 (95% CI 35–355). The highest scores were for ‘mucosal realism’ (median score 6.0, P = 0.001), ‘endoscopic snare control’ (median score 6.0, P = 0.001), ‘handling the polyp’ (median score 6.0, P = 0.001) and ‘raising mucosa’ (median score 6.0, P < 0.001). Of the 15 parameters examined only three were not statistically significant in favour of the simulator. These were ‘anatomical realism of sessile polyps’, ‘resistance of scope movement’ and ‘paradoxical motion’. The overall score for the simulation was 6.0 (P < 0.001). There was no significant difference between the level of difficulty of the simulator compared with real life (median score 4.0, P = 0.559). Conclusion The WIMAT colonoscopy suitcase model has excellent content validity for several parameters. This may have potential applications in medical training and assessment

Can endoscopists accurately self-assess performance during simulated colonoscopic polypectomy? A prospective, cross-sectional study

Background The aim of this study was to establish if endoscopists can reliably self-assess their ability to perform simulated colonic polypectomy. Methods Novices, intermediates, advanced, and experts performed a video-recorded polypectomy task using the Welsh Institute for Minimal Access Therapy (WIMAT) colonoscopy suitcase simulator. This involved removal of a simple polyp (A) and a complex polyp (B). Participants self-assessed themselves using a Direct Observation of Polypectomy Skills (DOPyS) assessment form. Two blinded, independent, Joint Advisory Group on Gastrointestinal Endoscopy (JAG) accredited assessors graded each performance using the same DOPyS scoring. The Spearman coefficient was used to determine the correlation between self and assessors' scores. Results Eighty participants completed the task. There was a weak correlation between assessors' scores and self-assessment scores for all groups (novices: ρ = −.44, P = .85; intermediates: ρ = −.16, P = .51; advanced: ρ = .16, P = .50; and experts: ρ = .07, P = .76). There was a strong correlation between scores from assessor 1 and 2 for polyp A (ρ = .80, P ≤ .01) and polyp B (ρ = .80, P ≤ .01). Conclusions The correlation between self-assessment and assessors' scores is weak. Novices and intermediates underestimate performance, whereas advanced and experts overestimate performance. Regular feedback may improve accuracy

The Welsh Institute for Minimal Access Therapy colonoscopy suitcase has construct and concurrent validity for colonoscopic polypectomy skills training: a prospective, cross-sectional study

Background The Welsh Institute for Minimal Access Therapy (WIMAT) colonoscopy suitcase is an ex vivo porcine simulator for polypectomy training. Objective To establish whether this model has construct and concurrent validity. Design Prospective, cross-sectional study. Setting Endoscopic training center. Participants Twenty novice (N), 20 intermediate (I), 20 advanced (Ad), and 20 expert (E) colonoscopists. Intervention A simulated polypectomy task aimed at removing 2 polyps; A (simple), B (complex). Main Outcome Measurements Two accredited colonoscopists, blinded to group allocation, scored performances according to Direct Observation of Polypectomy Skills (DOPyS) assessment parameters. Group performances were compared. Real-life DOPyS scores were correlated to simulator DOPyS results. Results Median overall DOPyS scores for novices were 1.00 (1.00-1.87) for A and 0.50 (0.00-1.00) for B (A vs B; P < .01). Intermediates scored 2.50 (2.00-2.88) for A and 2.00 (1.13-2.50) for B (A vs B; P = .03). The advanced group scored 3.00 (2.50-3.50) for A and 2.50 (2.00-3.00) for B (A vs B; P = .01). Experts scored 3.00 (3.00-3.88) for A and 3.00 (2.50-3.50) for B (A vs B; P = .47). Intergroup comparisons for A were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P < .01, I vs E; P < .01, and Ad vs E; P = .46. Intergroup comparisons for B were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P = .03, I vs E; P <.01, and Ad vs E; P = .06. There was no difference between real-life DOPyS scores and simulator scores (0.07). Limitations The model does not have inbuilt assessment parameters. Conclusion This simulator demonstrates construct and concurrent validity for colon polypectomy training

The expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 in human macrophages is inhibited by the anti-atherogenic cytokine transforming growth factor-β and requires Smads, p38 mitogen-activated protein kinase and c-Jun

Atherosclerosis is an inflammatory disorder of the vasculature that is orchestrated by the action of cytokines. Macrophages play a prominent role in all stages of this disease, including foam cell formation, production of reactive oxygen species, modulation of the inflammatory response and the regulation of the stability of atherosclerotic plaques. The role of the matrix metalloproteinase family in the control of plaque stability is well established. A disintegrin and metalloproteinase with thrombospondin motif (ADAMTS) family has been implicated in several diseases and the expression of ADAMTS-4 in macrophages of atherosclerotic lesions has suggested a potential role for this protease in atherosclerosis. However, the action of cytokines on the expression of ADAMTS-4 in macrophages is poorly understood. We have investigated here the effect of transforming growth factor-β (TGF-β) on ADAMTS-4 expression in macrophages along with the regulatory mechanisms underlying its actions. Consistent with the anti-atherogenic role of TGF-β, this cytokine decreased the expression of ADAMTS-4 mRNA and protein in human macrophages. Transient transfection assays showed that the −100 to +10 promoter region contained the minimal TGF-β response elements. Small-interfering RNA-mediated knockdown revealed a critical role for Smads, p38 mitogen-activated protein kinase and c-Jun in the action of TGF-β on ADAMTS-4 mRNA expression. These studies show for the first time that TGF-β inhibits the expression of ADAMTS-4 in human macrophages and identifies the signalling pathways underlying this response. The inhibition of macrophage ADAMTS-4 expression is likely to contribute to the anti-atherogenic, plaque stabilisation action of TGF-β