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Background: Risk stratification and recommendation for surgery for intraductal papillary mucinous neoplasm (IPMN) are currently based on consensus guidelines. Risk stratification from presurgery histology is only potentially decisive owing to the low sensitivity of fine-needle aspiration. In this study, we developed and validated a deep learning-based method to distinguish between IPMN with low grade dysplasia and IPMN with high grade dysplasia/invasive carcinoma using endoscopic ultrasound (EUS) images., Methods: For model training, we acquired a total of 3355 EUS images from 43 patients who underwent pancreatectomy from March 2015 to August 2021. All patients had histologically proven IPMN. We used transfer learning to fine-tune a convolutional neural network and to classify "low grade IPMN" from "high grade IPMN/invasive carcinoma." Our test set consisted of 1823 images from 27 patients, recruiting 11 patients retrospectively, 7 patients prospectively, and 9 patients externally. We compared our results with the prediction based on international consensus guidelines., Results: Our approach could classify low grade from high grade/invasive carcinoma in the test set with an accuracy of 99.6 % (95 %CI 99.5 %-99.9 %). Our deep learning model achieved superior accuracy in prediction of the histological outcome compared with any individual guideline, which have accuracies between 51.8 % (95 %CI 31.9 %-71.3 %) and 70.4 % (95 %CI 49.8-86.2)., Conclusion: This pilot study demonstrated that deep learning in IPMN-EUS images can predict the histological outcome with high accuracy., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Background: Cap-assisted colonoscopy is frequently used to facilitate adenoma detection during endoscopy. However, data on how cap assistance influences polyp resection are scarce. We aimed to evaluate the impact of cap assistance with the Endocuff vision device (EVD) on the resection time for colorectal polyps in patients undergoing colonoscopy. METHODS : A randomized, prospective study was performed in a university hospital in Germany. A total of 250 patients were randomly assigned 1:1 to undergo either colonoscopy with the EVD (EVD arm) or standard colonoscopy without the use of a cap (standard arm). The primary outcome was the average duration of polypectomy. Secondary outcomes included adenoma detection rate, cecal and ileal intubation times, and propofol dosage., Results: The use of EVD led to a significant reduction in the median polypectomy time in the EVD vs. standard arm (54 vs. 80 seconds, respectively; P  = 0.02). This effect was strongest for polyps ≥ 6 mm. Compared with the standard group, Endocuff assistance also resulted in a shorter cecal intubation time (6 vs. 8 minutes; P  = 0.03) and overall colonoscopy time (23 vs. 27 minutes; P  = 0.02). In contrast, no difference in withdrawal time was observed. The polyp and adenoma detection rates did not differ significantly between the two groups., Conclusion: Endocuff-assisted colonoscopy reduces the duration of polypectomy, which may be due to a more stable scope position during resection. Further studies are needed to investigate whether comparable effects will be seen for other interventions, such as clipping or biopsy sampling., Competing Interests: None., (© Georg Thieme Verlag KG Stuttgart · New York.)

BACKGROUND : Use of a side-viewing endoscope is currently mandatory to examine the major duodenal papilla; however, previous studies have used cap-assisted endoscopy for complete examination of the papilla. The aim of this study was to compare cap-assisted endoscopy with side-viewing endoscopy for examination of the major duodenal papilla. METHODS : This was a prospective, randomized, blinded, controlled, noninferiority crossover study. Patients were randomized to undergo either side-viewing endoscopy followed by cap-assisted endoscopy or cap-assisted endoscopy followed by side-viewing endoscope. Photographs of the major duodenal papilla were digitally edited to mask the cap area before they were evaluated by three blinded external examiners. Our primary end point was complete visualization of the major duodenal papilla. Secondary end points were the ability to examine the mucosal pattern, the overview of the periampullary region, overall satisfaction, and time to locate the papilla. RESULTS : 62 patients completed the study. Complete visualization of the major duodenal papilla was achieved in 60 examinations by side-viewing endoscopy and in 59 by cap-assisted endoscopy (97 % vs. 95 %). The difference between the two examinations was 1.6 % with a two-sided 95 % confidence interval of -4.0 % to 7.3 %, which did not exceed the noninferiority margin of 8 %. Cap-assisted endoscopy achieved better scores regarding the examination of mucosal pattern and overall satisfaction, whereas side-viewing endoscopy had a better overview score ( P  < 0.001, P  = 0.004, and P  < 0.001, respectively). There was no relevant difference in the median times to locate the major duodenal papilla. CONCLUSION : Cap-assisted endoscopy and side-viewing endoscopy had similar success rates for complete visualization of the major duodenal papilla. Cap-assisted endoscopy is superior to side-viewing endoscopy regarding the mucosal pattern and overall satisfaction. Side-viewing endoscopy gives a better overview of the periampullary region., Competing Interests: None, (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aim: The aim of the study was to compare the latest narrow-band imaging (NBI) device with high-definition white light (HDWL) endoscopy for accuracy of real-time optical diagnosis of small colorectal polyps., Patients and Methods: We conducted a randomized, prospective, multicenter trial at three study sites in Germany. In the NBI arm, endoscopists used NBI for the prediction of polyp pathology on the basis of the NBI International Colorectal Endoscopic classification. In the HDWL arm, NBI was not used for optical classification of polyp histology. The primary outcome was accuracy of optical diagnoses (neoplastic vs. non-neoplastic) in small polyps measuring < 10 mm. Secondary end points included sensitivity and negative predictive value (NPV)., Results: A total of 380 patients were randomized 1:1 to either the NBI or HDWL arm. A total of 421 polyps measuring < 10 mm were detected (55.8 % neoplastic, 44.2 % non-neoplastic). Accuracy, sensitivity, and NPV were 73.7 %, 82.4 %, and 75.5 %, respectively, in the NBI arm and 79.2 %, 79.8 %, and 73.4 %, respectively, in the HDWL arm (P = 0.225, P = 0.667, P = 0.765). More polyps were assessed with high confidence in the HDWL arm (82.6 %) than in the NBI arm (73.7 %; P = 0.038). The NPV of the prediction of neoplastic histology in diminutive polyps (≤ 5 mm) rated with high confidence was 90.3 % in the NBI arm. We detected significant differences between the participating study sites in the performance data of predictions., Conclusion: The levels of accuracy for real-time prediction of polyp histology (< 10 mm) did not differ between NBI and HDWL for optical diagnosis. Variation in the performance of optical diagnosis was apparent between study centers., Trial Registration: ClinicalTrials.gov (NCT02009774)., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aim: The use of magnetic endoscope imaging (MEI) has been previously shown to facilitate colonoscopy procedures. We aimed to evaluate the benefits of MEI in terms of reduction in propofol dosage in patients undergoing routine colonoscopy., Methods: We conducted a randomized prospective trial in a university hospital in Germany. Endoscopists were randomly assigned 1:1 to use MEI during colonoscopy (MEI arm) or to conduct colonoscopy without the use of MEI (standard arm). The desired level of sedation was conscious sedation as assessed using the Observer's Assessment of Alertness and Sedation scores. After complete recovery, patient satisfaction was assessed using a numeric rating scale (NRS) ranging from 1 to 10 points. The primary outcome was total propofol dosage. Secondary outcome measures were patient satisfaction, patients' cooperation, and complication rates, as well as cecal intubation time and adenoma detection., Results: Among 334 randomized patients, no severe adverse events were observed. Median propofol dosage was significantly lower in the MEI arm compared with the standard arm (150 mg vs. 180 mg; P = 0.04). Deep sedation was observed in 7.8 % of patients in the MEI group and 3.6 % in the standard arm (P = 0.10). Patient satisfaction scores were higher in the MEI arm compared with standard procedures (9.0 vs. 8.5; P = 0.04). No significant differences in patients' cooperation, cecal intubation time, and adenoma detection were observed between the study arms., Conclusion: The use of MEI may be useful in reducing propofol dosage for colonoscopy and improving patient satisfaction.ClinicalTrials.gov identifier: NCT02121704., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aims: This was to determine whether intervention based on additional capnographic monitoring reduces the incidence of hypoxemia during midazolam and propofol sedation for endoscopic retrograde cholangiopancreatography (ERCP)., Methods: Patients (American Society of Anesthesiologists [ASA] I – IV) scheduled for ERCP under midazolam and propofol sedation were randomly assigned to a control arm with standard monitoring or an interventional arm with additional capnographic monitoring. In both arms detection of apnea prompted withholding of propofol administration, stimulation of the patient, insertion of a nasopharyngeal tube, or further measures. The primary study end point was incidence of hypoxemia (oxygen saturation [Sao 2] below 90 %); secondary end points included occurrences of severe hypoxemia (Sao 2 ≤ 85 %), bradycardia, and hypotension, and sedation quality (patient cooperation and satisfaction)., Results: 242 patients were enrolled at three German endoscopy centers. Intention-to-treat analysis revealed no significant reduction in hypoxemia incidence in the capnography arm compared with the standard arm (38.0 % vs. 44.4 %, P = 0.314). Apnea was more frequently detected in the capnography arm (64.5 % vs. 6.0 %, P < 0.001). There were no differences regarding rates of bradycardia and hypotension. Per-protocol analysis showed lower incidence of hypoxemia in the capnography arm compared with the standard arm (31.5 % vs. 44.8 %, P = 0.048). There was one death related to sedation in the standard arm. Sedation quality was similar in the two groups., Conclusion: Intention-to-treat analysis showed hypoxemia incidence was not significantly lower in the additional capnography arm compared with standard monitoring. Additional capnographic monitoring of ventilatory activity resulted in improved detection of apnea.

Aim: To evaluate the benefits of the left lateral position in avoiding hypoxemic events in patients undergoing colonoscopy., Methods: We conducted a randomized, prospective, controlled trial at two study sites in Germany. Patients undergoing colonoscopy under propofol sedation were randomized to either the supine or left lateral position. The primary outcome was oxygen desaturation (SaO2<90%). Secondary outcome measures were apneic events, hypotension, patient satisfaction, propofol dosage, cecal intubation time, and adenoma detection., Results: A total of 412 patients were randomized 1:1 to undergo colonoscopy in the supine or left lateral position. No severe adverse events were observed in either group. Intention-to-treat analysis revealed no significant difference in the frequency of desaturation in the left lateral arm compared with the supine arm (6.8% vs. 12.1%; P=0.064). Patients in the left lateral arm showed lower apnea rates (9.4% vs. 16.2%; P= .040), but had more episodes of hypotension (12.3% vs. 2.9%; P<0.001). The frequency of repositioning was higher in the left lateral group. No significant differences were observed in patient satisfaction and cooperation, propofol dosage, or adenoma detection rate. Patients who were repositioned to facilitate endoscope passage were excluded from per-protocol analysis. The incidence of hypoxemia was lower for the left lateral than for the supine group in per-protocol analysis (1.8% vs. 11.2%; P=0.003)., Conclusion: The positioning of patients in the left lateral position during propofol sedation for colonoscopy results in lower desaturation rates provided the position can be maintained throughout endoscopy. ClinicalTrials.gov NCT02001792., (© Georg Thieme Verlag KG Stuttgart · New York.)

Introduction: Bispectral index (BIS) monitoring provides a non-invasive measure of the level of sedation. The purpose of this randomized, single-blind clinical trial was to evaluate whether BIS monitoring of sedation would lead to improved oxygenation and a reduced rate of cardiopulmonary complications during endoscopy., Patients and Methods: Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) under procedural sedation with a combination of low dose midazolam and propofol were randomly assigned to either standard monitoring of sedation only (BIS-blinded arm) or an open arm in which additional BIS monitoring was available (BIS-open arm). In the BIS-open arm, propofol administration was to be withheld if BIS values were <55. The primary study end point was the mean oxygen saturation per patient. Secondary end points were the rates of cardiopulmonary complications, propofol dose, quality of sedation (patient cooperation as rated by the endoscopist and patient satisfaction), and recovery., Results: A total of 144 patients were enrolled and included in the intention-to-treat analysis. Mean oxygen saturation per patient was 97.7% in the BIS-open arm and 97.6% in the BIS-blinded arm (P=0.71). Total rates of cardiopulmonary complications, single numbers of hypoxemic, bradycardic, and hypotensive events, mean propofol doses, and quality of sedation also showed no statistically significant differences between the groups. However, BIS monitoring did result in faster recovery of patients as reflected by shorter times to eye opening (P=0.001), first verbal response (P=0.02), and leaving the procedure room (P<0.001)., Conclusions: The use of additional BIS monitoring did not lead to improved oxygenation or a reduced rate of cardiopulmonary complications. Recovery times after the procedure were shorter than with standard monitoring alone, but the clinical benefit for daily practice may be limited., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aims: Endoscopic submucosal injection of epinephrine may cause systemic effects on the cardiovascular system. The aim of this experimental study was to assess systemic hemodynamic changes after submucosal injection of epinephrine during upper gastrointestinal endoscopy in a porcine model., Methods: Measurements were taken from 12 pigs under general anesthesia. During gastroscopy 5 mL of normal saline, and 2.5 mL and 5 mL of epinephrine (1:10,000) were injected into the submucosal layers of the gastric antrum, corpus, and distal esophagus. After each injection, the cardiac index and global end diastolic volume index (GEDVI, reflecting preload) were measured every 3 minutes by transpulmonary thermodilution for a minimum of 12 minutes. The following parameters were also recorded: heart rate, mean arterial pressure (MAP), and systemic vascular resistance index (SVRI, reflecting afterload)., Results: Significant hemodynamic changes were observed after submucosal injection of epinephrine into the esophagus, including heart rate (maximum + 4 %) and MAP (maximum - 4%) after injection of 2.5 mL epinephrine, and stronger changes in heart rate (maximum +13%), cardiac index (maximum +21%), MAP (maximum -4%), and SVRI (maximum -12%) after the injection of 5 mL epinephrine. After submucosal injection of epinephrine into the gastric antrum and corpus, hemodynamic effects were less evident. Here significant changes were observed in heart rate (maximum +3%), MAP (maximum -2%), cardiac index (maximum +7%), and SVRI (maximum -8%) only after the injection of 5 mL epinephrine into the antrum., Conclusion: Endoscopic submucosal injection of epinephrine is associated with changes in systemic hemodynamic parameters, especially when performed in the esophagus, and the procedure might therefore induce harmful side effects., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Aims: The aim of this randomized trial in the acute porcine model was to compare the quality of transgastric peritoneoscopy with the use of low-pressure versus standard-pressure pneumoperitoneum and to evaluate the respective associated cardiopulmonary changes., Methods: For transgastric peritoneoscopy, carbon dioxide was insufflated via the endoscope for a constant intraperitoneal pressure of 6 mmHg or 12 mmHg in 9 pigs each. The quality of transgastric peritoneoscopy was rated on a visual analog scale (0 mm, min.; 100 mm, max.) by the endoscopist, who was blinded to the intraperitoneal pressure. The cardiac index and global end-diastolic volume index (GEDVI, reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. The following were also recorded: heart rate, mean arterial pressure (MAP), systemic vascular resistance index (SVRI, reflecting afterload), peak inspiratory pressure (PIP), pH, PCO (2), and PO (2)., Results: The quality of transgastric peritoneoscopy with the use of low-pressure pneumoperitoneum was not inferior to that obtained using standard-pressure pneumoperitoneum (87.0 mm vs. 87.3 mm; P<0.05). In both groups we observed a statistically significant rise in MAP and SVRI. The increase in SVRI was less pronounced during low-pressure peritoneum ( P=0.042), indicating a reduced stress response in comparison to standard-pressure peritoneum. There were no relevant differences between the groups in relation to cardiac index, GEDVI, and heart rate. An intra-abdominal pressure of 6 mmHg also led to better oxygenation ( P=0.031 for difference in PO (2) between the two groups) due to lower peak inspiratory pressure ( P<0.001 for difference). There were only slight differences between the groups with regard to pH and PCO (2)., Conclusions: Pneumoperitoneum of 12-16 mmHg is used for standard laparoscopy. For NOTES, low-pressure pneumoperitoneum is sufficient and is associated with an improved cardiopulmonary response compared to standard-pressure pneumoperitoneum., (© Georg Thieme Verlag KG Stuttgart · New York.)

Local endoscopic procedures are increasingly used and accepted treatments for unifocal superficial esophageal squamous cell carcinoma (SESCC). In multifocal SESCC, esophagectomy with or without chemoradiotherapy is often regarded as standard therapy. However, a combination of local endoscopic resection and new techniques such as radiofrequency ablation may play an increasing role in the treatment of selected patients with multifocal SESCC. The aim of this series was to evaluate the feasibility of a multimodal endoscopic approach. We report a case series of six consecutive patients from a European tertiary center who underwent endoscopic treatment for multifocal SESCC. The treatment comprised endoscopic mucosal resection using the cap technique or endoscopic submucosal dissection, in combination with radiofrequency ablation. The main outcome measure was complete tumor eradication after therapy and during the follow-up period. Using such an approach, complete eradication of cancer was achieved in all patients during follow-up. No major adverse events occurred. In conclusion, in selected patients with multifocal or residual SESCC, local resection techniques in combination with radiofrequency ablation may be safe and potentially curative alternative treatments., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background and Study Aims: Surveillance of Barrett's esophagus includes endoscopic inspection with biopsy of suspicious lesions followed by four-quadrant biopsy of the remaining mucosa. We assessed the ability of probe-based confocal laser endomicroscopy (pCLE) to replace biopsy in the endoscopic evaluation of patients with Barrett's esophagus in a prospective and controlled setting., Patients and Methods: A total of 68 patients who were referred for endoscopic assessment of Barrett's esophagus were included across three centers. pCLE recordings were interpreted live during the examination as well as in a blinded manner at least 3 months after endoscopy. pCLE diagnosis of neoplasia based on pre-defined criteria was compared with histopathology from suspicious as well as four-quadrant biopsies., Results: A total of 670 pairs of biopsies and pCLE video sequences were available for analysis, with neoplasia (high-grade dysplasia or cancer) being histologically diagnosed in 8.3 %. Specificity and negative predictive value of pCLE in excluding neoplasia was 0.97 (90 %CI 0.95 - 0.98) and 0.93 (0.91 - 0.95) for the blinded evaluation, and 0.95 (0.90 - 0.98) and 0.92 (0.90 - 0.94) for the on-site assessment. Positive predictive values (PPVs) and sensitivity were rather poor for both settings (46 %/28 % [blinded] and 18 %/12 % [on-site], respectively)., Conclusions: pCLE can be regarded as non-inferior to endoscopic biopsy in excluding neoplasia of Barrett's esophagus mucosa. However, due to its low PPV and sensitivity, pCLE may currently not replace standard biopsy techniques for the diagnosis of Barrett's esophagus and associated neoplasia. Further technical development of pCLE and a better understanding of its role in relation to other imaging technologies are necessary., (Georg Thieme Verlag KG Stuttgart.New York.)

Background and Study Aims: Physiological reactions during natural orifice transluminal endoscopic surgery (NOTES) mediastinoscopy may lead to cardiorespiratory depression. The aim of the current study was to assess cardiopulmonary changes during transesophageal mediastinoscopy in an acute porcine model., Methods: Transesophageal mediastinoscopy was performed under general anesthesia in eight female pigs with a bodyweight of 39 +/- 6 kg. Mediastinal access was achieved via a submucosal tunnel. The cardiac index and global end-diastolic volume index (reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. The following parameters were also recorded: mediastinal pressure, heart rate, mean arterial pressure, systemic vascular resistance index (SVRI; reflecting afterload), peak inspiratory pressure, pH, pCO (2), and pO (2)., Results: In three animals, small tears in the parietal pleura resulted in tension pneumothoraces. The associated cardioplumonary deterioration was fatal in one pig. The other two pigs recovered after decompression with a chest tube. In the remaining five animals there were only mild hemodynamic and respiratory changes during mediastinoscopy. There was a significant ( P = 0.005) but minor transient fall in cardiac index, which correlated with a small rise in SVRI (r = - 0.857, P < 0.001). In the pigs with uncomplicated mediastinoscopy, on-demand insufflation via the endoscope resulted in median mediastinal pressures of 4.5 mm Hg (range 2.3 - 10.2 mm Hg). Overall, mediastinal and thoracic structures could be identified without difficulty via the transesophageal approach., Conclusions: NOTES mediastinoscopy carries a substantial risk of inadvertent development of a pneumothorax. Otherwise, it leads to negligible hemodynamic and pulmonary changes. In conclusion, close monitoring for the presence of a pneumothorax during NOTES mediastinoscopy appears to be mandatory., (Georg Thieme Verlag KG Stuttgart.New York.)

Background and Aims: Anastomotic strictures are well-known complications after bilioenterostomy. Endoscopic procedures are usually not possible in patients with a bilioenterostomy. Hence, percutaneous transhepatic biliary drainage (PTBD) has become the treatment of choice for the management of these patients. The main goal of the present study was to analyze the long-term follow-up of PTBD in such patients., Methods and Patients: Between January 1996 and December 2006, 44 patients with benign anastomotic stricture after bilioenterostomy were identified by an analysis of the PTBD database, hospital charts, and cholangiograms., Results: In 27/44 patients the percutaneous transhepatic biliary drain was successfully removed after 19.9 +/- 16.1 months (treatment success in 61.4 %). During a mean follow-up of 53.7 +/- 28.4 months after removal of the drain, no evidence was found of recurrent strictures in these patients. Ten out of 44 patients carry permanent drains (22.6 % of patients with ongoing treatment, mean follow-up 46.4 +/- 54.7 months) without the option for further surgery owing to concomitant disease (n = 2) or because they refused further surgery (n = 8). In 7 out of 44 patients (16 %) PTBD treatment was deemed to have failed and the patients underwent repeat operation., Conclusions: PTBD should be considered the treatment of choice in patients with benign anastomotic stricture after bilioenterostomy, especially after stricturing of a hepatojejunostomy.

Background and Study Aims: Angiogenesis has been reported to be an essential step in the progression of cancers arising from Barrett's esophagus. Confocal laser scanning microscopy (CLM) has the potential to perform in vivo microscopy to detect angiogenesis and determine microvessel density (MVD). We aimed therefore to use this new promising imaging tool for the evaluation of MVD in Barrett's esophagus and associated neoplasia., Patients and Methods: We enrolled 20 patients with Barrett's esophagus. CLM sequences were recorded from pre-marked areas using argon beamer coagulation spots after intravenous application of fluorescein. Sequences had to be recorded within the first 8 minutes of injection. Biopsies were taken from the same areas for standard histopathology. All CLM sequences were put into a random order and analyzed by a single investigator who was blinded to any clinical or histopathological data. Five still images per sequence were analyzed for MVD using a specially designed software algorithm. The primary endpoint was determination of vessel diameter and MVD in relation to neoplastic or non-neoplastic Barrett's esophagus., Results: We evaluated 750 still CLM images from 150 sequences/biopsy sites. Histopathology revealed 69 biopsies as non-neoplastic Barrett's esophagus (46.0 %), 11 as neoplastic Barrett's esophagus (7.3 %), 64 as cardiac mucosa (42.7 %), and six as squamous mucosa (4.0 %). Mean vessel diameter as determined by CLM was similar in all four groups (P = 0.2). However, MVD was significantly higher in CLM sequences of neoplastic Barrett's esophagus compared with benign conditions (neoplastic Barrett's esophagus 23.6 %; Barrett's esophagus 14.2 %; cardiac mucosa 15.8 %; squamous epithelium 20.6 %; neoplastic Barrett's esophagus vs. Barrett's esophagus P < 0.001, T-test)., Conclusion: Fibered fluorescein-guided CLM helps to detect angiogenesis in malignant and non-malignant Barrett's esophagus in vivo. These data might help to improve the diagnostic yield of detecting Barrett's neoplasia but also to facilitate monitoring of antiangiogenetic therapy.

Introduction: Simulators facilitate the acquisition of technical skills for endoscopy. Here, we describe the development, introduction, and first evaluation of a novel generation of mechanical endoscopic retrograde cholangiopancreatography (ERCP) simulation models with simulated fluoroscopy, the X-Vision ERCP Training System., Methods: A custom-made modular ERCP simulation system was built with the use of universally obtainable materials and tools. The trainee controls ERCP activities on two screens: the aspect of the papilla and duodenum is shown on the conventional endoscopy monitor, and the trainee's actions in the equivalents of the pancreaticobiliary ducts are shown on the viewing screen of the model. Thereby, the latter screen serves as a substitute for fluoroscopy. Currently, four different models are available, allowing simulation of selective cannulation of the pancreatic or bile duct, intubation of differently arranged papillae, stent placement, and sphincterotomy of a biopapilla. The X-Vision ERCP Training System was first used during an ERCP course attended by 26 endoscopists. Trainees were supervised by an ERCP expert and an experienced ERCP nurse at each training model. The training system was evaluated by the participants and experts using a specific questionnaire., Results: During the course there were no technical problems related to the X-Vision ERCP Training System. After sphincterotomy the organic papillae could easily be exchanged within less than 15 seconds. Overall, the X-Vision ERCP Training System achieved favorable results in all categories assessed., Conclusion: The new X-Vision ERCP Training System is simple and effective. A first evaluation in the context of an ERCP course showed impressive results.

Background and Study Aims: The aim of this experimental study was to assess the effect of gastric insufflation on intra-abdominal pressure (IAP) and associated hemodynamic and respiratory changes during upper gastrointestinal endoscopy., Methods: Measurements were taken from pigs under general anesthesia with controlled ventilation. Gastroscopy was carried out with continuous insufflation of air by a standard endoscopic light source/insufflator. The cardiac index and global end-diastolic volume index (GEDVI; reflecting preload) were measured by transpulmonary thermodilution. IAP, heart rate, mean arterial pressure (MAP), central venous pressure, systemic vascular resistance index (SVRI; reflecting afterload), peak inspiratory pressure (PIP), and oxygenation (SaO (2)) were also recorded., Results: A total of 266 paired measurements (at the time of transpulmonary thermodilution) were taken from 14 animals. During air insufflation, we observed a significant rise in IAP in all animals up to intermittent values of 22 mm Hg. IAP and PIP correlated well (r = 0.666, P < 0.001), with the latter reaching values as high as 45 mbar in one pig, leading to respiratory compromise. Only marginal changes in heart rate, and a continuous, almost significant rise in MAP (due to a significant increase in SVRI) were recorded. We observed a slight increase in GEDVI, predominantly during the initial phase of air insufflation. The cardiac index showed no substantial changes. There were no episodes of hemodynamic instability, nor a decline in SaO (2)., Conclusions: Air insufflation during gastroscopy resulted in a significant increase in IAP. The main clinically relevant finding was a steady increase in SVRI. Major increments in PIP suggest a role of intra-abdominal hypertension in otherwise unexplained respiratory compromise during upper gastrointestinal endoscopy.

Background and Study Aim: Physiologic reactions during natural orifice transluminal endoscopic surgery (NOTES) may differ from those at laparoscopy. This experimental study assessed the effect of pneumoperitoneum induced by endoscope air pump on hemodynamics and inspiratory pressures during transgastric peritoneoscopy., Methods: Transgastric peritoneoscopy was performed in 11 female pigs (35 - 50 kg) under general anesthesia. Five pigs with controlled insufflation and no endoscopic intervention served as controls. Cardiac index and global end-diastolic volume index (GEDVI; reflecting preload) were measured every 3 minutes by transpulmonary thermodilution. We also recorded: intra-abdominal pressure (IAP), heart rate, mean arterial pressure (MAP), systemic vascular resistance index (SVRI; reflecting afterload), peak inspiratory pressure (PIP), and oxygenation., Results: One study group pig was excluded from analysis because of a major complication related to the gastric incision. In the remaining 15 animals we performed 264 paired measurements. On-demand insufflation in the study group produced wide variation in intra-abdominal pressures; the control group demonstrated minimal fluctuation around a predetermined value. In the study group, IAP and PIP correlated well ( R = 0.667, P = 0.000), with maximum PIP values of 40 mbar contrasting with the control group maximum of 26.5 mbar. Hemodynamically, there was a minor decrease of cardiac index in the study group (in contrast to the control group). Relative changes in cardiac index and IAP during transgastric peritoneoscopy correlated highly significantly ( R = - 0.416, P = 0.000). Neither group showed hemodynamic instability or decline in oxygen saturation., Conclusions: On-demand insufflation with a standard endoscopic light source/insufflator resulted in a marked median increase and wide variation in IAP throughout transgastric peritoneoscopy. Hemodynamic changes were moderate. However, major increases in PIP suggest a need for stricter control of intra-abdominal hypertension during NOTES.

Background and Study Aims: Natural orifice transluminal endoscopic surgery (NOTES) is an emerging technology. Apart from its therapeutic implications, this type of access to the peritoneal cavity might also be useful for targeted in vivo histological investigation by means of confocal fluorescence microscopy. In this study we therefore aimed to assess the feasibility of miniprobe-based confocal fluorescence microscopy during transgastric endoscopy in an acute porcine model., Materials and Methods: Transgastric in vivo histology was performed in five pigs, under general anesthesia. After incision of the anterior gastric wall, a double-channel video gastroscope was advanced into the peritoneal cavity. A flexible confocal miniprobe was introduced through the instrument channel of the endoscope after intravenous injection of 10 mL of fluorescein 1% in four of the pigs and of 50 mL of fluorescein isothiocyanate-dextran 150 000 4% in the fifth pig. The tip of the miniprobe was then placed on the peritoneal layer, the liver, and the spleen for confocal laser microscopy., Results: Probes were easily attached to the peritoneal layer, the liver, and the spleen under direct visualization with the endoscope. Dynamic microscopic images of these organs were obtained with a frame rate of 12 frames per second. The flow of erythrocytes through blood vessels could be seen. The microstructural components of organs, such as lobules of the liver, were also easily identified., Conclusions: In vivo histology in the peritoneal cavity is feasible during NOTES and this technique combines the minimally invasive approach to the intraperitoneal organs afforded by NOTES and real-time, in vivo acquisition of dynamic histological images.

Background and Study Aims: Some colorectal polyps cannot be adequately viewed using forward-viewing colonoscopes because of their location behind mucosal folds or bends in the bowel. We performed polypectomy using side-viewing duodenoscopes for these problematic polyps in order to avoid incomplete polypectomy or the need for surgical intervention., Patients and Methods: Between April 2000 and August 2003, polypectomy with a side-viewing endoscope was intended in 15 patients (seven men, eight women; mean age 63.7 years, median age 59 years, range 38-88 years) at our institution. In all these patients, polypectomy had been attempted previously with a forward-viewing colonoscope by at least one experienced endoscopist without success. The duodenoscope was advanced with slight bending of the tip to achieve a sloped forward view., Results: Colorectal polyps were macroscopically completely removed in 11/15 patients. One polyp near the ileocecal valve could only be partially removed with the side-viewing endoscope; and one large flat rectal adenoma, one recurrent rectal polyp (after a previous incomplete conventional polypectomy), and one polyp near the ileocecal valve could not be removed. We observed no procedure-related complications. Endoscopic follow-up was possible in seven of the 11 patients in whom the polyps were successfully resected, with no evidence of recurrence (mean follow-up 27 months)., Conclusions: Polypectomy with the side-viewing duodenoscope is a safe and effective method. It is a therapeutic option when polyps are not adequately accessible using a conventional approach.

Background and Study Aims: Sedation with propofol is associated with a high acceptance rate in upper gastrointestinal endoscopy. So far, however, there are no valid data on whether the use of propofol can increase the general quality of the endoscopic examination., Patients and Methods: A total of 60 patients referred for upper gastrointestinal endoscopy were randomized to receive sedation with either midazolam (n = 30) or propofol (n = 30). The maximum dosages permitted were 5 mg of midazolam and 500 mg of propofol. The examinations were recorded on videotapes, and the quality of upper endoscopy was assessed by videotape analysis by three experienced endoscopists who were all blinded to patient data and the medications used for sedation. A score sheet was used with 18 assessment items that each represented a step of upper gastrointestinal endoscopy and a global score for the entire examination. A scale ranging from 1 (excellent) to 6 (very poor) was used. Data were analyzed on an intention-to-investigate basis: inability to perform the procedure because of a patient's intolerance of the procedure, for example, was scored as 6 (i. e. very poor)., Results: Patients in the two groups were well matched with respect to demographic and clinical data. Four patients in the midazolam group could not be adequately examined. The median dosage used for sedation was 5 mg midazolam (range 2-5 mg) and 160 mg propofol (range 70-320 mg). When assessments by all three blinded examiners were added together, propofol sedation was found to result in significantly better scores for all parameters except for the assessments of "Z-line/cardia", "duodenal bulb", and "duodenal folds" (all P < 0.05, Mann-Whitney U test)., Conclusion: Sedation with propofol might increase the quality of upper endoscopy. This finding may have a significant impact on the selection of the type of sedation, not only in terms of increasing patients' acceptance of the procedure, but also for improving the diagnostic accuracy of upper gastrointestinal endoscopy.

We report about detailed hemodynamic changes and one major cardiac complication occurring after submucosal injection of epinephrine (1 : 10 000) for management of upper gastrointestinal bleeding in a series of four consecutive patients. Cardiac contractility and afterload, determined by the cardiac index and the systemic vascular resistence index (SVRI), were assessed by transpulmonary thermodilution using the Pulse Contour Cardiac Output monitoring system (PiCCO; Pulsion Medical Systems, Munich, Germany), and the mean arterial pressure and heart rate were recorded. We observed a distinct rise in both mean arterial pressure and heart rate, and this effect was pronounced in the three patients with esophageal lesions. The increase in the mean arterial pressure was caused by an elevation of the cardiac index in two patients, a rise in both cardiac index and SVRI in one patient, and a rise in the SVRI only in the fourth patient. One patient, who had received 30 ml epinephrine for treatment of a bleeding Mallory-Weiss tear, developed an acute myocardial infarction during the postprocedural follow-up period. In conclusion, submucosal injection of epinephrine may cause significant hemodynamic changes that can potentially lead to adverse cardiac events. Close cardiac monitoring during and after submucosal application of epinephrine therefore seems a prudent precaution. In the treatment of esophageal lesions, the total amount of epinephrine injected should be carefully titrated, so that the lowest possible volume that achieves adequate hemostasis is used.

Background and Study Aims: Globus sensation and/or sore throat have been associated with both gastroesophageal reflux disease and the presence of a gastric inlet patch. There have been no reports, however, on whether ablation of heterotopic mucosa in the cervical esophagus leads to improvement of chronic globus sensation., Patients and Methods: Ten patients with a histologically proved gastric inlet patch who complained of chronic globus sensation and/or sore throat were included in this prospective pilot study. After a thorough assessment, including videofluoroscopy, laryngoscopy, manometry, and 24-hour two-channel pH monitoring, patients underwent argon plasma coagulation (APC) to ablate the heterotopic mucosa. A questionnaire with a visual analog scale ranging from 0 to 10 was used for assessment of globus sensation, sore throat, and other typical or atypical reflux symptoms. Follow-up examinations (including symptom assessment) were performed 4 weeks and 8 weeks after APC therapy., Results: Ablation of the gastric inlet patch resulted in a significant reduction of median symptom scores for globus sensation (from 2.7 to 0) and sore throat (from 2.8 to 0) 8 weeks after therapy ( P < 0.05), but there was no improvement in other reflux-related symptoms. Acid reflux in the distal and proximal esophagus, determined by two-channel pH monitoring, did not change after therapy., Conclusions: Our preliminary data suggest that ablation of gastric inlet patches by APC can alleviate chronic globus sensation or sore throat. Acid reflux or its treatment is unlikely to influence these results. A randomized and blinded study is warranted.

Background and Study Aims: In spite of the many advances that have been made in understanding the molecular basis for diseases, a major obstacle to the treatment of human disorders remains the inability to express genes at specific sites in vivo. Recent progress in gene transfer technology has provided access to a variety of recombinant gene products that can be applied in clinical medicine for therapeutic purposes., Materials and Methods: In an animal model, we describe here the way in which a marker gene can be introduced into the colon using a double-balloon catheter. Cationic liposomes were used as vehicles to introduce DNA into the living organism. RSV-LacZ plasmid coding for the enzyme beta-galactosidase was used as a marker gene. Cells expressing beta-galactosidase can be stained using the chromogen X-gal. Positive cells show a blue coloration in the cytoplasm., Results: Both absorptive cells and goblet cells were successfully transduced with the marker gene. No evidence of similar staining was observed in control animals receiving a control plasmid or liposomes alone., Conclusions: The method used is a simple, safe, and nontoxic way of delivering genes of interest to specific sites in the colon. Gene transfer may offer fresh potential for endoscopic interventions in colonic disease.