Effect of oral erythromycin on gastric and small bowel transit time of capsule endoscopy

Aim: To determine the effect of oral erythromycin on gastric and small bowel transit time of capsule endoscopy. Methods: Consecutive patients who underwent capsule endoscopy during the 16-mo study period were either given 250 mg oral erythromycin, 1 h prior to swallowing the capsule endoscope or nothing. The gastric and small bowel transit time, and the small bowel image quality were compared. Results: Twenty-four patients received oral erythromycin whereas 14 patients were not given any prokinetic agent. Patients who received erythromycin had a significantly lower gastric transit time than control (16 min vs 70 min, P = 0.005), whereas the small bowel transit time was comparable between the two groups (227 min vs 183 min, P = 0.18). Incomplete small bowel examination was found in three patients of the control group and in one patient of the erythromycin group. There was no significant difference in the overall quality of small bowel images between the two groups. A marked reduction in gastric transit time was noted in two patients who had repeat capsule endoscopy after oral erythromycin. Conclusion: Use of oral erythromycin significantly reduces the gastric transit time of capsule endoscopy. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

A multicenter, prospective, randomized comparison of a novel signal transmission capsule endoscope to an existing capsule endoscope.

BACKGROUND: MiroCam, a capsule endoscope, uses a novel transmission technology, electric-field propagation, which uses the human body as a conduction medium for data transmission. OBJECTIVE: To compare the ability of the MiroCam (MC) and PillCam (PC) to identify sources of obscure GI bleeding (OGIB). DESIGN: Prospective, multicenter, comparative study. SETTING: Six academic hospitals. PATIENTS: A total of 105 patients with OGIB. INTERVENTION: Patients ingested both the MC and PC capsules sequentially in a randomized fashion. MAIN OUTCOME MEASUREMENTS: Concordance of rates in identifying a source of OGIB, operational times, and rates of complete small-bowel examination. RESULTS: Data analysis resulted in 43 (48%) abnormal cases identifying a source of OGIB by either capsule. Twenty-four cases (55.8%) were positive by both capsules. There was negative agreement in 46 of 58 cases (79.3%). The κ index was 0.547 (χ(2) = 1.32; P = .36). In 12 cases, MC positively identified a source that was not seen on PC, whereas in 7 cases, PC positively identified a source that was not seen on MC. MC had a 5.6% higher rate of detecting small-bowel lesions (P = .54). MC captured images at 3 frames per second for 11.1 hours, and PC captured images at 2 frames per second for 7.8 hours (P \u3c .0001). Complete small-bowel examination was achieved in 93.3% for MC and 84.3% for PC (P = .10). LIMITATIONS: Readers were not blinded to the particular capsule they were reading. CONCLUSION: A positive diagnostic finding for OGIB was identified by either capsule in 48% of cases. The concordance rate between the 2 capsules was comparable to that of prior studies in identifying sources of small-bowel bleeding. The longer operational time of the MC may result in higher rates of complete small-bowel examination, which may, in turn, translate into a higher rate of detecting small-bowel lesions. (Clinical trial registration number: NCT00878982.)

Use of N-acetylcysteine plus simethicone to improve mucosal visibility in upper digestive endoscopy via systematic alphanumeric-coded endoscopy: a randomized, double-blind controlled trial

Background: The use of antifoaming and mucolytic agents prior to upper gastrointestinal (GI) endoscopy and a thorough systematic review are essential to optimize lesion detection. This study evaluated the effect of simethicone and N-acetylcysteine on the adequate mucosal visibility (AMV) of the upper GI tract by an innovative systematic method. Methods: This randomized, double-blind controlled trial included consecutive patients who underwent diagnostic upper GI endoscopy for screening for early neoplasms between August 2019 and December 2019. The upper GI tract was systematically assessed by systematic alphanumeric- coded endoscopy. Patients were divided into 4 groups: 1) water; 2) only simethicone; 3) N-acetylcysteine + simethicone; and 4) only N-acetylcysteine. The following parameters were assessed in each group: age, sex, body mass index, level of adequate mucosal visibility, and side- effects. Results: A total of 4564 images from upper GI areas were obtained for evaluation. The mean AMV in the 4 groups was 93.98±7.36%. The N-acetylcysteine + simethicone group had a higher cleaning percentage compared with the other groups (P=0.001). There was no significant difference among the remaining groups, but several areas had better cleaning when a mucolytic or antifoam alone was used. No side-effects were found in any group. Conclusion: The combination of N-acetylcysteine plus simethicone optimizes the visibility of the mucosa of the upper GI tract, which could potentially increase diagnostic yield

Brief Education on Microvasculature and Pit Pattern for Trainees Significantly Improves Estimation of the Invasion Depth of Colorectal Tumors

Objectives. This study was performed to evaluate the effectiveness of education for trainees on the gross findings identified by conventional white-light endoscopy (CWE), the microvascular patterns identified by magnifying narrow-band imaging endoscopy (MNE), and the pit patterns identified by magnifying chromoendoscopy (MCE) in estimation of the invasion depth of colorectal tumors. Methods. A total of 420 endoscopic images of 35 colorectal tumors were used. Five trainees estimated the invasion depth of the tumors by reviewing the CWE images before education. Afterwards, the trainees estimated the invasion depth of the same tumors after brief education on CWE, MNE and MCE images, respectively. Results. The initial diagnostic accuracy for deep submucosal invasion before education and after education on CWE, MNE, and MCE findings was 54.3%, 55.4%, 67.4%, and 76.6%, respectively. The diagnostic accuracy increased significantly after MNE education (P=0.028). The specificity for deep submucosal invasion before education and after education on CWE, MNE, and MCE findings was 47.9%, 45.7%, 65.0%, and 80.7%, respectively. The specificity increased significantly after MNE (P=0.002) and MCE (P=0.005) education. Conclusion. Brief education on microvascular pattern identification by MNE and pit pattern identification by MCE significantly improves trainees’ estimations of the invasion depth of colorectal tumors

Endoscopic Assessment and Treatment of Barrett’s Oesophagus

Oesophageal cancer worldwide is the eighth commonest cancer and carries a poor prognosis. Barrett’s oesophagus is the only known risk factor for oesophageal adenocarcinoma. Cancer progresses along a metaplasia-dysplasia pathway. Dysplastic changes may be seen on endoscopic assessment. This thesis presents evidence that i-Scan virtual chromoendoscopy together with acetic acid chromoendoscopy can improve dysplasia detection using a simple classification system. Superficial lesions, without deeper invasion (low and high grade dysplasia, early cancers) have a low risk of distant metastasis. Endoscopic resection and ablation techniques have been demonstrated to have an excellent efficacy and safety profile. The current standard of care for early Barrett’s neoplasia is endoscopic management rather than surgical intervention. Surgery for oesophageal cancer is centred in specialist units due to improved outcomes in high volume centres. The UK radiofrequency ablation registry collects outcomes for patients undergoing endoscopic therapy for Barrett’s neoplasia. This thesis demonstrates that there is no difference in dysplasia or intestinal metaplasia resolution rates or dysplasia recurrence between low and high volume centres. Learning curve analysis suggests that there is a change point at 18 cases, when the observed successful treatment rate of the centre becomes better than the expected rate. Centres should complete 20 cases before competency can be achieved. Treatment of Barrett’s neoplasia involves endoscopic resection of visible lesions. Due to the high risk of metachronous lesions, the remaining Barrett’s epithelium undergoes field ablation, commonly with radiofrequency ablation. Following successful treatment the risk of dysplasia recurrence is 6%. The risk increases with increasing length of the initial Barrett segment and with increasing age. The risk of untreated islands of Barrett’s IM is unknown but this thesis demonstrates that it does not seem to confer an increased risk of recurrence and may not require further ablation if unresponsive to treatment

Clinical utility of capsule endoscopy in gastrointestinal bleeding

Introduction Capsule endoscopy (CE) is a first-line diagnostic tool for known or suspected small bowel bleeding (SBB), and its use has over time been expanded to include panenteric imaging. It offers advantages over conventional endoscopy in minimal invasiveness and ease of use. However several drawbacks remain including the lack of modalities other than imaging, inability to control or propel the capsule, lesser image quality compared to conventional endoscopy and labour-intensiveness of data interpretation. Aims and objectives This thesis aims to explore the ways in which use of CE can be optimised in the current clinical or “real world” context, focusing on its use in gastrointestinal bleeding and working within current resource and technological limitations. Methods A review and analysis of the existing literature was undertaken, examining the present state of CE technology and identifying current gaps in knowledge. Meta-analyses were undertaken examining the effectiveness of the two main methods of image enhancement in CE: the use of bowel preparation and currently available rudimentary computer-aided diagnosis. The following studies then looked into how to better select patients who should be prioritised for CE examination – a pertinent issue in today’s resource-stretched healthcare systems. A retrospective study was carried out to examine the effects of altering the timing of CE examination in patients referred for likely SBB, using cases carried out at our tertiary care centre over the past decade. Outcomes were compared between patients who had undergone CE following negative bidirectional endoscopies, or negative upper gastrointestinal tract endoscopy only. Furthermore, building on existing work, a second study was undertaken using a prospectively-designed database to collect multicentre data on findings and outcomes in young patients referred for CE with iron deficiency anaemia. This study investigated factors predictive of small bowel neoplasia in this patient group. Finally, the effect of image visualisation quality on diagnostic certainty was investigated. CE images were processed to alter image parameters, and the resulting images presented to an iii international group of expert CE readers in order to determine thresholds for acceptable image quality and the effects of differing image quality in the parameters examined. Results Currently-available image enhancement techniques: (1) Use of bowel preparation: Laxative use did not improve the diagnostic yield of CE with odds ratio (OR) 1.1 for both overall and significant findings when comparing laxative use with pre-procedural fast only. However, subjectively-determined small bowel visualisation quality improved with the use of laxatives (OR 1.60 (95%CI 1.08–2.06)), NNT 14. (2) Use of suspected blood indicator (SBI): The overall sensitivity of SBI for bleeding or potentially bleeding lesions was 0.553, specificity 0.578, DOR 12.354. The sensitivity of SBI for active bleeding was 0.988, specificity 0.646, DOR 229.89. (3) Use of FICE digital image enhancement: Overall, the use of the three FICE modes did not significantly improve image delineation or detection rate in CE. For pigmented lesions only, FICE setting 1 performed better in lesion delineation and detection. Patient selection and CE pathways: The earlier use of CE in inpatients with melena or IDA, no signs of lower gastrointestinal pathology and negative UGIE resulted in shortened hospital stays, significant diagnostic yield from both small bowel and upper gastrointestinal tract, and two-thirds less unnecessary colon investigations without affecting clinical outcomes. In young patients (age <50 years) with IDA and negative bidirectional GI endoscopy, the overall diagnostic yield of CE for clinically significant findings was 32.3%. 5% of our cohort was diagnosed with SB neoplasia; lower MCV and weight loss were associated with higher diagnostic yield for significant SB pathology. Effects of visualisation quality on diagnostic certainty: Poor visualisation quality in all parameters affected mostly neoplastic lesions. Software to increase contrast and sharpen images can improve visualisation quality; smart frame rate adaptation could improve the number of high-quality frames obtained. Thoroughness in small bowel cleansing was found to be most important when there is suspicion of neoplasia. Conclusions The data in this thesis show that CE could be employed earlier in the diagnostic pathway for patients presenting clinically with SBB, as an effective diagnostic and triage tool in the semi acute setting. Although the overall diagnostic yield of CE is lower in younger patients, young patients with IDA and no significant findings on bidirectional endoscopy are also more likely to have significant small bowel findings, and should perhaps be referred preferentially for CE. This would help increase the efficiency of resource utilisation. Of the currently available image enhancement techniques in CE, digital image enhancement and diagnostic tools such as SBI and FICE remain of limited validity; however they show the most promise for vascular lesions and active GI bleeding, which supports their use in the acute to semi-acute setting to improve efficiency of CE reading. Image enhancement with both laxatives and digital means is the most crucial when patients are suspected of having more subtle small bowel findings such as small bowel neoplasia

Endoscopic causes and characteristics of missed gastric cancers after endoscopic submucosal dissection

富山大学博士（医学）Article富山大学・富医薬博乙第103号・島田 清太郎・2023/11/22doctoral thesi

Magnetically Assisted Capsule Endoscopy: A Viable Alternative to Conventional Flexible Endoscopy of the Stomach?

INTRODUCTION: Oesophagogastroduodenoscopy is the investigation of choice to identify mucosal lesions of the upper gastrointestinal tract, but it is poorly tolerated by patients. A simple non-invasive technique to image the upper gastrointestinal tract, which could be made widely available, would be beneficial to patients. Capsule endoscopy is well tolerated by patients but the stomach has proved difficult to visualise accurately with capsule technology due to its’ capacious nature and mucosal folds, which can obscure pathology. MiroCam Navi (Intromedic Ltd, Seoul, Korea) is a capsule endoscope containing a small amount of magnetic material which has been made available with a handheld magnet which might allow a degree of control. This body of work aims to address whether this new technology could be a feasible alternative to conventional flexible endoscopy of the stomach. METHODS: Four studies were conducted to test this research question. The first explores the feasibility of magnetically assisted capsule endoscopy of the stomach and operator learning curve in an ex vivo porcine model. This was followed by a randomised, blinded trial comparing magnetically assisted capsule endoscopy to conventional flexible endoscopy in ex vivo porcine stomach models. Subsequently a prospective, single centre randomised controlled trial in humans examined whether magnetically assisted capsule endoscopy could enhance conventional small bowel capsule endoscopy by reducing gastric transit time. Finally a blinded comparison of diagnostic yield of magnetically assisted capsule endoscopy compared to oesophagogastroduodenoscopy was performed in patients with recurrent or refractory iron deficiency anaemia. RESULTS: In the first study all stomach tags were identified in 87.2% of examinations and a learning curve was demonstrated (mean examination times for the first 23 and second 23 procedures 10.28 and 6.26 minutes respectively (p<0.001). In the second study the difference in sensitivities between oesophagogastroduodenoscopy and conventional flexible endoscopy for detecting beads within an ex vivo porcine stomach model was 1.11 (95% CI 0.06, 28.26) proving magnetically assisted capsule endoscopy to be non-inferior to flexible endoscopy. In the first human study, although there was no significant difference in gastric transit time or capsule endoscopy completion rate between the two groups (p=0.12 and p=0.39 respectively), the time to first pyloric image was significantly shorter in the intervention group (p=0.03) suggesting that magnetic control hastens capsular transit to the gastric antrum but cannot impact upon duodenal passage. In the last study, a total of 38 pathological findings were identified in this comparative study of magnetically assisted capsule endoscopy and conventional endoscopy. Of these, 16 were detected at both procedures, while flexible endoscopy identified 14 additional lesions not seen at magnetically assisted capsule endoscopy and magnetically assisted capsule endoscopy detected 8 abnormalities not seen by oesophagogastroduodenoscopy. No adverse events occurred in either of the human trials. Finally magnetically steerable capsule endoscopy induced less procedural pain, discomfort and distress than oesophagogastroduodenoscopy (p=0.0009, p=0.001 and p=0.006 respectively). CONCLUSION: Magnetically assisted capsule endoscopy is safe, well tolerated and a viable alternative to conventional endoscopy. Further research to develop and improve this new procedure is recommended