Arjun D. Koch

Expert and construct validity of the Simbionix GI Mentor II endoscopy simulator for colonoscopy

ObjectivesThe main objectives of this study were to establish expert validity (a convincing realistic representation of colonoscopy according to experts) and construct validity (the ability to discriminate between different levels of expertise) of the Simbionix GI Mentor II virtual reality (VR) simulator for colonoscopy tasks, and to assess the didactic value of the simulator, as judged by experts.MethodsFour groups were selected to perform one hand–eye coordination task (EndoBubble level 1) and two virtual colonoscopy simulations on the simulator; the levels were: novices (no endoscopy experience), intermediate experienced (<200 colonoscopies performed before), experienced (200–1,000 colonoscopies performed before), and experts (>1,000 colonoscopies performed before). All participants filled out a questionnaire about previous experience in flexible endoscopy and appreciation of the realism of the colonoscopy simulations. The average time to reach the cecum was defined as one of the main test parameters as well as the number of times view of the lumen was lost.ResultsNovices (Nxa0=xa035) reached the cecum in an average time of 29:57 (min:sec), intermediate experienced (Nxa0=xa015) in 5:45, experienced (Nxa0=xa020) in 4:19 and experts (Nxa0=xa035) in 4:56. Novices lost view of the lumen significantly more often compared to the other groups, and the EndoBubble task was also completed significantly faster with increasing experience (Kruskal Wallis Test, pxa0<xa00.001). The group of expert endoscopists rated the colonoscopy simulation as 2.95 on a four-point scale for overall realism. Expert opinion was that the GI Mentor II simulator should be included in the training of novice endoscopists (3.51).ConclusionIn this study we have demonstrated that the GI Mentor II simulator offers a convincing realistic representation of colonoscopy according to experts (expert validity) and that the simulator can discriminate between different levels of expertise (construct validity) in colonoscopy. According to experts the simulator should be implemented in the training programme of novice endoscopists.

The prevalence of fat-soluble vitamin deficiencies and a decreased bone mass in patients with chronic pancreatitis

BACKGROUND/OBJECTIVESnIn chronic pancreatitis, malabsorption of fat is common due to loss of exocrine function. Consequently, these patients are at risk to acquire deficiencies of the fat-soluble vitamins, which may result in a decreased bone mineral density (BMD) and the development of osteopenia and osteoporosis.nnnMETHODSnWe prospectively enrolled all patients diagnosed with chronic pancreatitis, who visited our outpatient clinic between March and November 2011. Data were collected regarding demographic characteristics, symptoms, and pancreatic function. Serum concentrations of vitamins A, E, K, and D were determined, and BMD was assessed by means of bone densitometry. Results were analyzed according to pancreatic function status and enzyme use, and compared to reference data, when available.nnnRESULTSnForty patients were included (43% female; mean age of 52). Alcohol abuse was the major cause of pancreatitis (50%). Twenty-eight patients were exocrine insufficient (70%), of whom 19 used pancreatic enzymes. Vitamin A, D, E, and K deficiencies were present in 3, 53, 10, and 63% of patients, respectively. Osteopenia and osteoporosis were observed in 45% and 10% of patients. A decreased BMD was more frequently observed than expected, based on reference data, even in exocrine sufficient patients.nnnCONCLUSIONSnDeficiencies of fat-soluble vitamins and a decreased BMD are frequently present in chronic pancreatitis, even in exocrine sufficient patients. Consequently, all patients with chronic pancreatitis should be routinely screened for fat-soluble vitamin deficiencies and a decreased BMD.

Competence measurement during colonoscopy training: The use of self-assessment of performance measures

Objectives:We evaluated a new assessment technique for colonoscopy training.Methods:We prospectively evaluated colonoscopy skills during training using the Rotterdam Assessment Form for colonoscopy. The questionnaire covers cecal intubation, procedural time, and subjective grading of performance. Individual learning curves are compared with a group reference.Results:Nineteen trainees self-assessed 2,887 colonoscopies. The cecal intubation rate improved from 65% at baseline to 78% and 85% after 100 and 200 colonoscopies, respectively. In our training program the 90% threshold was reached after 280 colonoscopies on average. Cecal intubation time improved from 13:10 minutes at baseline to 9:30 and 8:30 after 100 and 200 colonoscopies, respectively.Conclusions:This novel self-assessment form allows individual learning curves to be compared with a group reference, provides data on the development of dexterity skills and individual training targets, and stimulates trainees to identify steps for self-improvement.

A second-generation virtual reality simulator for colonoscopy: validation and initial experience.

BACKGROUND AND STUDY AIMSnSimulators are increasingly used in skills training for physicians; however data on systematic evaluation of the performance of these simulators are scarce compared with those used in aviation. The objectives of this study were to determine the expert validity, the construct validity, and the training value of the novel Olympus simulator as judged by experts.nnnPATIENTS AND METHODSnParticipants were novices and experts. Novices had no prior experience in flexible endoscopy; experts had all performed more than 1000 colonoscopies. Participants filled out a questionnaire on their impression of the realism of the colonoscopy exercises performed. These included a dexterity exercise and a virtual colonoscopy. Test parameters used were points acquired in a game, time to reach the cecum, maximum insertion force, and patient pain.nnnRESULTSnNovices (n = 26) scored a median of 973 points (range--118-1393), experts (n = 23) scored 1212 points (range 89-1375). This difference did not reach significance (P = 0.073). Experts performed virtual colonoscopy significantly faster than novices (220 vs. 780 s, P < 0.001) but used more insertion force (11.8 vs. 11.6 N; P = 0.147). Maximum pain score was higher in the expert group: 86% vs. 73%. (P = 0.018). The realism was graded 6.5 on a 10-point scale. Experts considered the Olympus simulator beneficial for the training of novice endoscopists.nnnCONCLUSIONSnThe novel Olympus simulator discriminates excellently between the measured levels of expertise. The prototype offers a good realistic representation of colonoscopy according to experts. Although the software development is continuing, the device can already be implemented in the training program of novice endoscopists.

Acquiring basic endoscopy skills by training on the GI Mentor II

BackgroundAchieving proficiency in flexible endoscopy requires a great amount of practice. Virtual reality (VR) simulators could provide an effective alternative for clinical training. This study aimed to gain insight into the proficiency curve for basic endoscope navigation skills with training on the GI Mentor II.MethodsFor this study, 30 novice endoscopists performed four preset training sessions. In each session, they performed one EndoBubble task and managed multiple VR colonoscopy cases (two in first session and three in subsequent sessions). Virtual reality colonoscopy I-3 was repeatedly performed as the last VR colonoscopy in each session. The assignment for the VR colonoscopies was to visualize the cecum as quickly as possible without causing patient discomfort. Five expert endoscopists also performed the training sessions. Additionally, the performance of the novices was compared with the performance of 20 experienced and 40 expert endoscopists.ResultsThe novices progressed significantly, particularly in the time required to accomplish the tasks (pxa0<xa00.05, Friedman’s analysis of variance [ANOVA], pxa0<xa00.05, Wilcoxon signed ranks). The experts did not improve significantly, except in the percentage of time the patient was in excessive pain. For all the runs, the performance of the novices differed significantly from that of both the experienced and the expert endoscopists (pxa0<xa00.05, Mann–Whitney U). The performance of the novices in the latter runs differed less from those of both the experienced and the expert endoscopists.ConclusionsThe study findings demonstrate that training in both VR colonoscopy and EndoBubble tasks on the GI Mentor II improves the basic endoscope navigation skills of novice endoscopists significantly.