Effect of virtual endoscopy simulator training on performance of upper gastrointestinal endoscopy in patients: a randomized controlled trial.

BACKGROUND: Skills in gastrointestinal endoscopy mainly depend on experience and practice. Patients upon whom trainees perform their first endoscopic examinations are likely to suffer more discomfort and prolonged procedures. Training on endoscopy simulators may reduce the time required to reach competency in patient endoscopy. PATIENTS AND METHODS: Residents in internal medicine without experience of endoscopy were randomized to a group who trained on a simulator before conventional training (group S) or one that received conventional training only (group C) before starting upper gastrointestinal endoscopy in patients. After endoscopy, discomfort and pain were evaluated by patients, who were blind to the beginners' training status. Results in terms of time, technique (intubation, pyloric passage, J-maneuver), and diagnosis of pathological entities were evaluated by experts. RESULTS: From 2003 to 2007, 28 residents were enrolled. Comparing group S with group C in their first ten endoscopic examinations in patients, time taken to reach the duodenum (239 seconds (range 50 - 620) vs. 310 seconds (110 - 720; P < 0.0001) and technical accuracy ( P < 0.02) were significantly better in group S. Diagnostic accuracy did not differ between the groups. Fourteen residents (7 simulator-trained, 7 not simulator-trained) continued endoscopy training. After 60 endoscopic examinations, investigation time was still shorter in group S. Technical and diagnostic accuracy improved during on-patient training in both groups; here differences between groups were no longer observable. There were no significant differences in discomfort and pain scores between the groups after 10 and after 60 endoscopies. Discomfort and pain were higher than for endoscopy performed by experts. CONCLUSION: This randomized controlled trial shows that virtual simulator training significantly affects technical accuracy in the early and mid-term stages of endoscopic training. It helps reduce the time needed to reach technical competency, but clinically the effect is limited. Simulator training could be useful in an endoscopy training curriculum but cannot replace on-patient training.

Esophageal damage during radiofrequency ablation of atrial fibrillation: impact of energy settings, lesion sets, and esophageal visualization.

INTRODUCTION: Atrioesophageal fistula is an uncommon but often lethal complication of atrial fibrillation (AF) ablation. The purpose of our study was to prospectively investigate the incidence of esophageal ulcerations (ESUL) as well as the impact of energy settings, radiofrequency lesion sets, and direct visualization of the esophagus on esophageal wall injury. METHODS AND RESULTS: One hundred seventy-five patients, 57.1% paroxysmal AF, 78.5% male, underwent AF ablation and esophagoscopy 24 hours thereafter. We performed a 2:1:1-randomization as follows: CONTROL GROUP: Ablation without visualization of the esophagus using 25 Watt (W) power limit on the posterior wall, n = 70. Visualization and 15 W maximum: Ablation guided by barium visualization of the esophageal course using a limit of 15 W, n = 35. Visualization and 25 W "short burns": Ablation guided by barium visualization using 25 W and "short burns" (max. 5 sec), n = 35. Patients performed under general anesthesia (n = 35) were separated as a nasogastric tube for visualization of the esophagus was used. In total, we found 2.9% of patients (5/175) presenting ESUL. Parameters discriminating the development of ESUL in a specific patient were type of AF, maximum energy delivered, usage of a nasogastric tube, and additional left atrial lines. Visualization of the esophageal course by barium contrast was not able to prevent ESUL. CONCLUSION: ESUL is a rare finding when using a reasonable energy maximum of 25 W with open-irrigated tip catheters at the posterior wall. Lower energy settings may increase safety without losing efficacy. Additional linear radiofrequency lesions increase the risk of ESUL development.

Multicenter retrospective evaluation of capsule endoscopy in clinical routine.

BACKGROUND AND STUDY AIMS: The small bowel is anatomically difficult to examine; disease conditions are rarely located in it, but can be serious. Neither conventional radiography nor push enteroscopy has sufficient sensitivity and specificity to detect distinct lesions. Wireless capsule endoscopy can theoretically allow imaging of the entire small bowel, with only minimal discomfort for the patient. PATIENTS AND METHODS: Between November 2001 and May 2003, 191 patients received 195 capsules. Data were collected retrospectively from consecutive patients in three centers. The indications for capsule endoscopy were obscure or occult bleeding, suspected Crohn's disease, or other reasons in 151, 25, and 15 patients, respectively. The clinical outcome after 6 months was evaluated on the basis of interviews with patients or relatives. RESULTS: Visualization of the entire small bowel was adequate in 78.4 % of the examinations. The colon was not reached in 16.9 % of cases, and there were minor technical problems in 4.6 %. Relevant pathological findings were identified in 56.2 % of 151 patients with obscure bleeding or iron-deficiency anemia (64 % of whom received blood transfusions). The most common findings were angiodysplasia in 39.7 % of cases and ulcers of the small bowel in 7.3 %. In addition, individual cases of tumors and parasitic worms were detected. Seven of the 25 patients with suspected Crohn's disease (28 %) had the disease confirmed. Three of five patients with polyposis syndrome of the colon were found to have polyps in the small bowel. CONCLUSIONS: Wireless capsule endoscopy can be recommended as part of the routine work-up in patients with obscure bleeding or iron-deficiency anemia. In patients with Crohn's disease, the method may be helpful in establishing or ruling out the diagnosis.

Evaluation of a virtual endoscopy simulator for training in gastrointestinal endoscopy.

BACKGROUND AND STUDY AIMS: Skills in gastrointestinal endoscopy mainly depend on experience and practice. Training on endoscopy simulators may decrease the time needed to reach competency in endoscopy. The purpose of the study was to determine whether the GI-Mentor, a virtual reality endoscopy simulator, can distinguish between beginners and experts in endoscopy and to assess whether training improves the performance of beginners. METHODS: A total of 13 beginners and 11 experts (more than 1,000 procedures) in gastrointestinal endoscopy were included. The baseline assessment consisted of virtual endoscopies and skill tests. The beginners were randomly allocated to receive training (n = 7) or no training (n = 6). The training group was allowed to practice using the simulator for 2 hours per day. After 3 weeks participants were re-evaluated with two new virtual endoscopy cases and one virtual skill test. Insertion time, correctly identified pathologies, adverse events and skill test performance were recorded. RESULTS: The baseline assessment revealed significant differences favoring the experts for virtual endoscopies and skill tests. Significant differences in favor of experts were found for successful retroflection during esophagogastroduodenoscopy (EGD) (P < 0.005); adverse events during colonoscopy (P < 0.02); insertion time (P < 0.001); correctly identified pathologies in gastroscopy and colonoscopy (P < 0.02); and skill test performance (P < 0.01). The final evaluation showed significant differences between training and no-training groups, in favor of the training group, for the number of adverse events during virtual endoscopy (P < 0.04), for the insertion time during colonoscopy (P < 0.03); and for skill test performance (P < 0.01). The training group improved its abilities on the simulator significantly. Differences between experts and the training group were no longer seen. CONCLUSION: This virtual endoscopy simulator is capable of identifying differences between beginners and experts in gastrointestinal endoscopy. A 3-week training improves the performance of beginners significantly. This quite fast improvement in endoscopic skills certainly cannot be seen in clinical practice; no conclusions can be made about the impact of virtual simulator training on real-life endoscopy, and this must be evaluated.

Forceps biopsy and brush cytology during endoscopic retrograde cholangiopancreatography for the diagnosis of biliary stenoses.

BACKGROUND: For evaluating pancreaticobiliary stenoses during endoscopic retrograde cholangiopancreatography (ERCP) tissue sampling techniques may be important. Brush cytology and forceps biopsy during ERCP are two potential, but so far only incompletely evaluated, tools for the diagnosis of malignant biliary or pancreatic stenoses. METHODS: Between 1992 and 1995 we acquired 133 cytologic and/or histologic samples from 119 patients who underwent ERCP because of biliary duct stenoses. Sixteen patients had to be excluded from the study due to insufficient follow-up information. After papillotomy, brush cytology was performed in 65 cases (63 patients), and forceps biopsy in 119 cases (106 patients under fluoroscopic guidance. Both methods were applied in combination 51 times (48 patients). The nature of the stenoses was confirmed by surgery, autopsy, or by the subsequent clinical course. RESULTS: The sensitivity was 46.7% for brush cytology and 64.9% for forceps biopsy. The combined application of both methods resulted in superior sensitivity (70.4%). Specificity was 100% for all methods. CONCLUSIONS: These numbers lead us to recommend a combined and more frequent application of brush cytology and forceps biopsy of bile duct stenoses to enhance the diagnostic yield whenever substantial influence on therapy can be expected.

Two cases of fractured esophageal nitinol stents.

We report here on two cases of fractured nitinol stents in the esophagus. In case 1, the correctly inserted stent broke spontaneously shortly after insertion. In a second case, a nitinol stent broke after laser application due to tumor ingrowth with massive bleeding. In both cases, a second stent was implanted in order to reestablish food passage. The fracture of the stent in case 1 seemed to be caused by defective material, whilst in case 2 the stent broke because of thermal overstrain during laser application. The use of electrocoagulation or laser in the stent area should therefore be avoided; argon plasma coagulation may offer an effective alternative in treating tumor ingrowth. As there was a risk from piercing broken filaments with the second stent, covering a fracture using stents with tight walls or plastic tubes seems to be a more effective approach than the inserting an uncovered stent type.