Applicability of second-generation colon capsule endoscope to ulcerative colitis: a clinical feasibility study

Pan-Enteric Capsule Endoscopy: Current Applications and Future Perspectives

Background

The role of capsule endoscopy in the evaluation of the small bowel is well established, and current guidelines position it as a first-line test in a variety of clinical scenarios. The advent of double-headed capsules further enabled the endoscopic assessment of colonic mucosa and the opportunity for a one-step noninvasive examination of the entire bowel (pan-enteric capsule endoscopy [PCE]).

Summary

We reviewed the technical procedure and preparation of patients for PCE, as well as its current clinical applications and future perspectives. In non-stricturing and non-penetrating Crohn's disease affecting the small bowel and colon, PCE monitors disease activity by assessing mucosal healing, a major treatment outcome, with a higher diagnostic yield than cross-sectional imaging or conventional colonoscopy. Also in ulcerative colitis, double-headed capsules have been used to monitor disease activity noninvasively. Currently, validated scoring systems have been specifically devised for these double-headed capsules and permit a standardized assessment of the inflammatory burden. In suspected mid-lower digestive bleeding, some exploratory studies have demonstrated the feasibility and high diagnostic yield of PCE, which may work as a filter indicating which patients may benefit of further invasive procedures, namely, for planned hemostatic procedures. The possibility of using PCE is also discussed in the context of polyposis syndromes with simultaneous involvement of the small intestine and colon.

Key Messages

PCE is a feasible, effective, and safe diagnostic procedure to evaluate the small bowel and colon. It has been increasingly explored in the setting of inflammatory bowel diseases and, more recently, in suspected mid-lower digestive bleeding. PCE is expected to reduce the demand for invasive procedures and expand the scope of noninvasive intestinal evaluation in the coming future.

Clinical utility of colon capsule endoscopy: a moving target?

The purpose of this article is to provide an overview of white light colon capsule endoscopy's current clinical application, concentrating on its most recent developments. Second-generation colon capsule endoscopy (CCE2) is approved by the FDA for use as an adjunctive test in patients with incomplete colonoscopy and within Europe in patients at average risk, those with incomplete colonoscopies or those unwilling to undergo conventional colonoscopies. Since the publication of European Society of GI Endoscopy guidelines on the use of CCE, there has been a significant increase in comparative studies on the diagnostic yield of CCE. This paper discusses CCE2 in further detail. It explains newly developed colon capsule system and the current status on the use of CCE, it also provides a comprehensive summary of systematic reviews on the implementation of CCE in colorectal cancer screening from a methodological perspective. Patients with ulcerative colitis can benefit from CCE2 in terms of assessing mucosal inflammation. As part of this review, performance of CCE2 for assessing disease severity in ulcerative colitis is compared with colonoscopy. Finally, an assessment if CCE can become a cost-effective clinical service overall.

Artificial intelligence and colon capsule endoscopy: Automatic detection of ulcers and erosions using a convolutional neural network

BACKGROUND AND AIM

Colon capsule endoscopy (CCE) has become a minimally invasive alternative for conventional colonoscopy. Nevertheless, each CCE exam produces between 50 000 and 100 000 frames, making its analysis time-consuming and prone to errors. Convolutional neural networks (CNNs) are a type of artificial intelligence (AI) architecture with high performance in image analysis. This study aims to develop a CNN model for the identification of colonic ulcers and erosions in CCE images.

METHODS

A CNN model was designed using a database of CCE images. A total of 124 CCE exams performed between 2010 and 2020 in two centers were reviewed. For CNN development, a total of 37 319 images were extracted, 33 749 showing normal colonic mucosa and 3570 showing colonic ulcers and erosions. Datasets for CNN training, validation, and testing were created. The performance of the algorithm was evaluated regarding its sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve.

RESULTS

The network had a sensitivity of 96.9% and a specificity of 99.9% specific for the detection of colonic ulcers and erosions. The algorithm had an overall accuracy of 99.6%. The area under the curve was 1.00. The CNN had an image processing capacity of 90 frames per second.

CONCLUSIONS

The developed algorithm is the first CNN-based model to accurately detect ulcers and erosions in CCE images, also providing a good image processing performance. The development of these AI systems may contribute to improve both the diagnostic and time efficiency of CCE exams, facilitating CCE adoption to routine clinical practice.

The diagnostic yield of pan-enteric capsule endoscopy in inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Capsule endoscopy (CE) is a non-invasive diagnostic modality enabling real time video imaging of the gastrointestinal (GI) mucosa. Pan-enteric capsule endoscopy (PCE) is now able to thoroughly assess the entire GI tract, including for inflammatory bowel disease (IBD). Our aim was to evaluate the diagnostic accuracy of PCEs in IBD.

METHODS

We comprehensively searched electronic databases (MEDLINE, SCOPUS, EMBASE, and Cochrane Central Register of Controlled Trials) for studies comparing the diagnostic accuracy of PCE with endoscopic evaluation, intestinal ultrasound or magnetic resonance enterography (MRE). Data were analyzed by calculating forest plots and the use of the I² statistic for heterogeneity.

RESULTS

Fourteen studies were identified, with seven studies evaluating PCE diagnostic yield in Crohn's disease (CD) and seven studies in ulcerative colitis (UC). In CD, there was a trend to superiority of PCE over MRE and colonoscopy with a pooled odds ratio (OR) of 1.25 (95% CI, 0.85-1.86%) for the detection of CD. This translates to an increased diagnostic yield of 5% and 7% for PCE compared with MRE and colonoscopy, respectively. PCEs had a diagnostic sensitivity for the detection of UC of 93.8% (95% CI, 87.6-97.0%) and a specificity of 69.8% (95% CI, 38.2-89.6%).

CONCLUSION

PCEs have a comparable diagnostic yield to colonoscopy and MRE in Crohn's disease. The major difficulty remains standardization of PCE scoring systems and the lack of transmural assessment. In UC, PCE has an excellent diagnostic sensitivity and positive predictive value, but there are limitations to its use including the lack of histologic assessment and poor specificity.

Automated evaluation of colon capsule endoscopic severity of ulcerative colitis using ResNet50

Capsule endoscopy has been widely used as a non-invasive diagnostic tool for small or large intestinal lesions. In recent years, automated lesion detection systems using machine learning have been devised. This study aimed to develop an automated system for capsule endoscopic severity in patients with ulcerative colitis along the entire length of the colon using ResNet50. Capsule endoscopy videos from patients with ulcerative colitis were collected prospectively. Each single examination video file was partitioned into four segments: the cecum and ascending colon, transverse colon, descending and sigmoid colon, and rectum. Fifty still pictures (576 × 576 pixels) were extracted from each partitioned video. A patch (128 × 128 pixels) was trimmed from the still picture at every 32-pixel-strides. A total of 739,021 patch images were manually classified into six categories: 0) Mayo endoscopic subscore (MES) 0, 1) MES1, 2) MES2, 3) MES3, 4) inadequate quality for evaluation, and 5) ileal mucosa. ResNet50, a deep learning framework, was trained using 483,644 datasets and validated using 255,377 independent datasets. In total, 31 capsule endoscopy videos from 22 patients were collected. The accuracy rates of the training and validation datasets were 0.992 and 0.973, respectively. An automated evaluation system for the capsule endoscopic severity of ulcerative colitis was developed. This could be a useful tool for assessing topographic disease activity, thus decreasing the burden of image interpretation on endoscopists.

Deep learning and colon capsule endoscopy: automatic detection of blood and colonic mucosal lesions using a convolutional neural network

Background and study aims  Colon capsule endoscopy (CCE) is a minimally invasive alternative to conventional colonoscopy. However, CCE produces long videos, making its analysis time-consuming and prone to errors. Convolutional neural networks (CNN) are artificial intelligence (AI) algorithms with high performance levels in image analysis. We aimed to develop a deep learning model for automatic identification and differentiation of significant colonic mucosal lesions and blood in CCE images. Patients and methods  A retrospective multicenter study including 124 CCE examinations was conducted for development of a CNN model, using a database of CCE images including anonymized images of patients with normal colon mucosa, several mucosal lesions (erosions, ulcers, vascular lesions and protruding lesions) and luminal blood. For CNN development, 9005 images (3,075 normal mucosa, 3,115 blood and 2,815 mucosal lesions) were ultimately extracted. Two image datasets were created and used for CNN training and validation. Results  The mean (standard deviation) sensitivity and specificity of the CNN were 96.3 % (3.9 %) and 98.2 % (1.8 %) Mucosal lesions were detected with a sensitivity of 92.0 % and a specificity of 98.5 %. Blood was detected with a sensitivity and specificity of 97.2 % and 99.9 %, respectively. The algorithm was 99.2 % sensitive and 99.6 % specific in distinguishing blood from mucosal lesions. The CNN processed 65 frames per second. Conclusions  This is the first CNN-based algorithm to accurately detect and distinguish colonic mucosal lesions and luminal blood in CCE images. AI may improve diagnostic and time efficiency of CCE exams, thus facilitating CCE adoption to routine clinical practice.

Review: Colon Capsule Endoscopy in Inflammatory Bowel Disease

The COVID-19 pandemic has caused considerable disruption in healthcare services and has had a substantial impact on the care of patients with chronic diseases, such as inflammatory bowel disease. Endoscopy services were significantly restricted, resulting in long waiting lists. There has been a growing interest in the use of capsule endoscopy in the diagnostic pathway and management of these patients. This review explores the published literature on the role of colon capsule endoscopy in ulcerative colitis and Crohn’s disease as a method for mucosal assessment of extent, severity, and response to treatment. Colon capsule preparation regimens and scoring systems are reported. The studies indicate that, despite inherent limitations of minimally invasive capsule endoscopy, there is increasing evidence to support the use of the second-generation colon capsule in inflammatory bowel disease evaluation, providing an additional pathway to expedite investigation of appropriate patients especially during and after the pandemic.

Capsule Endoscopy in Inflammatory Bowel Disease: When? To Whom?

Capsule endoscopy (CE) has proven to be a valuable diagnostic modality for small bowel diseases over the past 20 years, particularly Crohn's disease (CD), which can affect the entire gastrointestinal tract from the mouth to the anus. CE is not only used for the diagnosis of patients with suspected small bowel CD, but can also be used to assess disease activity, treat-to-target, and postoperative recurrence in patients with established small bowel CD. As CE can detect even mildly non-specific small bowel lesions, a high diagnostic yield is not necessarily indicative of high diagnostic accuracy. Moreover, the cost effectiveness of CE as a third diagnostic test employed usually after ileocolonoscopy and MR or CT enterography is an important consideration. Recently, new developments in colon capsule endoscopy (CCE) have increased the utility of CE in patients with ulcerative colitis (UC) and pan-enteric CD. Although deflation of the colon during the examination and the inability to evaluate dysplasia-associated lesion or mass results in an inherent risk of overestimation or underestimation, the convenience of CCE examination and the risk of flare-up after colonoscopy suggest that CCE could be used more actively in patients with UC.

Current status of colon capsule endoscopy

While both the annual incidence and mortality of colorectal cancer are slowly but steadily decreasing in the United States, the incidence of such malignancy is increasing in Japan. Thus, controlling colorectal cancer in Japan is a major concern. In 2006, colon capsule endoscopy was first introduced by Eliakim et al. First-generation colon capsule endoscopy had a moderate sensitivity for detecting polyps of more than 6 mm. Thus, second-generation colon capsule endoscopy was developed to achieve higher sensitivity. Colonoscopy is the gold standard tool for colorectal cancer surveillance. With an improvement in the imaging function, the performance of second-generation colon capsule endoscopy is almost as satisfactory as that of colonoscopy. Certain situations, such as incomplete colonoscopy and contraindication for use of sedation, can benefit from colon capsule endoscopy. Colon capsule endoscopy requires a more extensive bowel preparation than colonoscopy and computed tomography colonography because it requires laxatives not only for bowel cleansing but also for promoting the excretion of the capsule. Another problem with colon capsule endoscopy includes the burden of reading and interpretation and overlook of the lesions. Currently, the development of automatic diagnosis of colon capsule endoscopy using artificial intelligence is still under progress. Although the available guidelines do not support the use of colon capsule endoscopy for inflammatory bowel disease, the possible application of colon capsule endoscopy is ulcerative colitis. This review article summarizes and focuses on the current status of colon capsule endoscopy for colorectal cancer screening and the possibility for its applicability on inflammatory bowel disease.

Second-generation colon capsule endoscopy for detection of colorectal polyps: A meta-analysis

Background: Colorectal cancer counts as the third prevalent type of cancer and the fourth cause of death worldwide. The second-generation colon capsule endoscopy (CCE-2) is a new technology for the diagnosis of colon cancer. The aim of this review was to provide information on the diagnostic accuracy (diagnostic effectiveness) of the second-generation colon capsule endoscopy compared to colonoscopy for the diagnosis of colon cancer and disorders.

Methods: A systematic review of literature in PubMed, Scopus, Science Direct, and Cochrane Library and Iranian databases, such as MagIran, SID, Irandoc, the grey literature (via Google Scholar) was conducted on February 30, 2018. QUADAS-2 was used to assess the quality of the studies. MetaDiSc 2.0 software was used for the meta-analysis.

Results: In this review, 480 records were identified. Eight prospective cohort articles were included among which 7 included in the meta-analysis. For the diagnosis of colorectal polyps with a diameter of 6-10 mm, the pooled sensitivity and specificity were 84% (95% CI, 80% -88%) and 88% (95%CI, 85% -90%). For the diagnosis of 10 mm or bigger colorectal polyps, the pooled sensitivity and specificity were 84% (95% CI, 76%-89%) and 96% (95% CI, 94 %-97%). The sensitivity and specificity of the capsule in the detection of any size polyps were 93% (95% CI, 97%-84%) and 66% (95% CI, 48%-81%), respectively.

Conclusion: There is little evidence to show the accuracy of CCE-2. Nevertheless, this review showed that the second-generation colon capsule endoscopy has good accuracy in the detection of polyps and colorectal cancer among high- and middle-risk patients.

Capsule endoscopy in inflammatory bowel disease: when and how

Capsule endoscopy (CE) is emerging as an important investigation in inflammatory bowel disease (IBD); common types include the standard small bowel CE and colon CE. More recently, the pan-enteric CE was developed to assess the large and small bowel in patients with Crohn’s disease (CD). Emerging indications include noninvasive assessment for mucosal healing (both in the small bowel and the colon) and detection of postoperative recurrence in patients with CD. Given the increasing adoption, several CE scoring systems have been specifically developed for IBD. The greatest concern with performing CE, particularly in CD, is capsule retention, but this can be overcome by performing cross-sectional imaging such as magnetic resonance enterography and using patency capsules before performing the procedure. The development of software for automated detection of mucosal abnormalities typically seen in IBD may further increase its adoption.

Colon Capsule Endoscopy for Inflammatory Bowel Disease

Colon capsule endoscopy was initially introduced in 2006. Since the results of a prospective study to evaluate first-generation colon capsule endoscopy efficacy for the detection of colonic neoplasia were unsatisfactory, second-generation colon capsule endoscopy was developed and reported in 2009. In this review article, we provide an overview of the current state of colon capsule endoscopy for evaluation of inflammatory bowel disease in a clinical setting and describe our clinical experience with this technology and its application. Among the various types of inflammatory bowel diseases, ulcerative colitis is the primary target for application of colon capsule endoscopy. Nevertheless, the initial results of studies using first-generation colon capsule endoscopy to evaluate inflammation were unclear. More recently, second-generation colon capsule endoscopy has provided higher accuracy for assessment of inflammation in patients with ulcerative colitis. Colon capsule endoscopy enables noninvasive observation (with reduced volume preparation) of mucosal inflammation severity in patients with ulcerative colitis.

Comparison of small-bowel colon capsule endoscopy system to conventional colonoscopy for the evaluation of ulcerative colitis activity

Background and aims  Diagnosis and monitoring of ulcerative colitis (UC) includes conventional colonoscopy. This procedure is invasive and does not exclude small-bowel Crohn's disease (CD). Current therapeutic goals include mucosal healing which may lead to an increased number of endoscopic procedures in many patients. The small-bowel colon capsule endoscopy (SBC-CE) system visualizes the small bowel and colon. The aim of this study was to evaluate the performance and adverse events of SBC-CE in patients with UC. Methods  This was a prospective, feasibility study involving two study sites. Patients with active UC underwent SBC-CE and colonoscopy. Kappa statistics were performed to assess the agreement between SBC-CE and colonoscopy. Adverse events (AEs) data were collected throughout and following the procedure. Results  In total, 30 consecutive patients were recruited, and 23 of those were included in the final analysis. For the primary end point, evaluation of the extent of UC disease in the colon, the percent agreement between SBC-CE and colonoscopy was moderate (56.5 %); kappa coefficient 0.42. The percent agreement between SBC-CE and colonoscopy for UC disease activity, based on Mayo endoscopic sub-score, was 95.7 %; kappa coefficient 0.86. Disease activity in the more proximal small bowel was detected in two patients with SBC-CE. No SBC-CE device-related AEs were reported. Conclusions  When comparing SBC-CE to conventional colonoscopy, there was a moderate agreement for the extent of UC disease and a very good overall agreement between the two modalities for UC disease activity.

Capsule endoscopy for small-intestinal disorders: Current status

Small-bowel capsule endoscopy (SBCE) is used widely because of its non-invasive and patient-friendly nature. SBCE can visualize entire small-intestinal mucosa and facilitate detection of small-intestinal abnormalities. In this review article, we focus on the current status of SBCE. Several platforms for SBCE are available worldwide. Third-generation SBCE (PillCam^® SB3) has a high-resolution camera equipped with an adaptive frame rate system. Several software modes have been developed to reduce the reading time for capsule endoscopy and to minimize the possibility of missing lesions. The main complication of SBCE is capsule retention. Thus, the main contraindication for SBCE is known or suspected gastrointestinal obstruction unless intestinal patency is proven. Possible indications for SBCE are obscure gastrointestinal bleeding, Crohn's disease, small-intestinal polyps and tumors, and celiac disease. Colon capsule endoscopy (CCE) can observe inflamed colonic mucosa non-invasively, and allows for the continuous and non-invasive observation of the entire intestinal tract (pan-endoscopy). Recently, application of CCE as pan-enteric endoscopy for inflammatory bowel diseases (including Crohn's disease) has been reported. In the near future, reading for CE will be assisted by artificial intelligence, and reading CE videos for long periods will not be required.

Best practices on immunomodulators and biologic agents for ulcerative colitis and Crohn's disease in Asia

The Asia-Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, under the auspices of the Asia-Pacific Association of Gastroenterology with the goal of improving inflammatory bowel disease care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn's and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in conjunction with conventional treatments for ulcerative colitis and Crohn's disease in Asia. These statements also address how pharmacogenetics influences the treatments of ulcerative colitis and Crohn's disease and provides guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of inflammatory bowel disease workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing, and future revisions are likely as new data continue to emerge.

Best practices on immunomodulators and biologic agents for ulcerative colitis and Crohn's disease in Asia

The Asia-Pacific Working Group on inflammatory bowel disease (IBD) was established in Cebu, Philippines, under the auspices of the Asian Pacific Association of Gastroenterology with the goal of improving IBD care in Asia. This consensus is carried out in collaboration with Asian Organization for Crohn’s and Colitis. With biologic agents and biosimilars becoming more established, it is necessary to conduct a review on existing literature and establish a consensus on when and how to introduce biologic agents and biosimilars in the conjunction with conventional treatments for ulcerative colitis (UC) and Crohn’s disease (CD) in Asia. These statements also address how pharmacogenetics influence the treatments of UC and CD and provide guidance on response monitoring and strategies to restore loss of response. Finally, the review includes statements on how to manage treatment alongside possible hepatitis B and tuberculosis infections, both common in Asia. These statements have been prepared and voted upon by members of IBD workgroup employing the modified Delphi process. These statements do not intend to be all-encompassing and future revisions are likely as new data continue to emerge.

Evaluating mucosal healing using colon capsule endoscopy predicts outcome in patients with ulcerative colitis in clinical remission

AIM

To examine whether second generation of colon capsule endoscopy (CCE-2) is acceptable for assessing the severity of mucosal inflammation and evaluating mucosal healing using CCE-2 is able to predict outcome in ulcerative colitis (UC) patients, especially in clinical remission.

METHODS

A total of 30 consecutive UC patients in clinical remission were enrolled to undergo CCE-2. Clinical remission was defined as clinical activity index (CAI) ≤ 4 according to Rachmilewitz index. The rate of total colon observation and colon cleansing level were evaluated. Severity of mucosal inflammation in UC was assessed according to the Mayo endoscopic subscore (MES) and Ulcerative Colitis Endoscopic Index of Severity (UCEIS). Relapse-free survival was assessed. Acceptability of CCE-2 was assessed using a questionnaire survey.

RESULTS

The rate of total colon observation within its battery life was 93.3%. The proportion of “excellent” plus “good” cleansing level was 73.3%. The rate of mucosal healing (MES 0, 1) assessed by CCE-2 was 77.0%. The relapse-free survival rate was significantly higher in MES 0, 1 than in MES 2, 3 (P = 0.0435), and in UCEIS 0-3 than in UCEIS 4-8 (P = 0.0211), whereas there was no significant difference between CAI 0 and CAI 1-4 groups. A questionnaire survey revealed an overall acceptability of CCE.

CONCLUSION

CCE-2 is acceptable for assessing the severity of mucosal inflammation in UC patients, especially in clinical remission. Evaluating mucosal healing using CCE-2 was able to predict outcome.

Establishment of a Novel Scoring System for Colon Capsule Endoscopy to Assess the Severity of Ulcerative Colitis-Capsule Scoring of Ulcerative Colitis

BACKGROUND

The usefulness of second-generation colon capsule endoscopy (CCE-2) for ulcerative colitis (UC) has not been fully demonstrated. This study aimed to develop an endoscopic severity score of UC for CCE-2.

METHODS

Patients diagnosed with UC were enrolled prospectively and underwent colonoscopy and CCE-2 on the same day. The collected CCE-2 videos were adopted for the development of the score. These videos were scored by 4 blinded inflammatory bowel disease experts. The items validated with the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) were used as the candidate items, some of which were automatically assessed using the workstation. Each item was divided into proximal and distal parts at the splenic flexure and then individually assessed. The image readers simultaneously evaluated the inflammation severity using the visual analog scale (VAS). The descriptors that contribute to this scale were evaluated, and a model to predict the VAS was constructed. The UCEIS was scored by other endoscopists using colonoscopy videos. The correlation coefficients with fecal calprotectin, blood tests, and Lichtiger index were calculated.

RESULTS

The final scoring system was fixed as "vascular pattern sum (proximal + distal) + bleeding sum + erosions and ulcers sum (minimum-maximum, 0-14)" and was named Capsule Scoring of Ulcerative Colitis (CSUC). The correlation coefficient of CSUC with biomarkers and clinical score was similar to that of the UCEIS.

CONCLUSIONS

We developed a new simple score using the 3 descriptors of CCE-2.

Colon capsule endoscopy for inflammatory bowel disease

Colon capsule endoscopy (CCE) is designed for direct visualization of the colonic mucosa through passive propulsion. The role of CCE in the detection of colonic polyps has been extensively evaluated. As mucosal healing has emerged as a pivotal target for treatment of inflammatory bowel disease (IBD), there is increasing data to suggest that CCE can also be used in the monitoring of mucosal inflammation in patients with active IBD, particularly in ulcerative colitis (UC) and Crohn's disease (CD). Despite advantages such as its non-invasive nature, patient's comfort, safety, and access to anatomical regions not easily reached by conventional endoscopy, CE has limitations including the lack of ability to obtain biopsies or therapeutic capabilities and no control over movement. In this review, the role and diagnostic value of CCE on diagnosis and monitoring of UC and CD patients, its safety and limitations are discussed.

Recent Advance in Colon Capsule Endoscopy: What's New?

Colon capsule endoscopy (CCE) is a relatively new diagnostic procedure for patients with suspected colonic diseases. This convenient,noninvasive method enables the physician to explore the entire colon without significant discomfort to the patient. However, while CCEcan be performed painlessly without bowel air insufflation, the need for vigorous bowel preparation and other technical limitationsexist. Due to such limitations, CCE has not replaced conventional colonoscopy. In this review, we discuss historical and recentadvances in CCE including technical issues, ideal bowel preparation, indications and contraindications and highlight further technicaladvancements and clinical studies which are needed to develop CCE as a potential diagnostic tool.

A prospective study on second-generation colon capsule endoscopy to detect mucosal lesions and disease activity in ulcerative colitis (with video)

BACKGROUND AND AIMS

Mucosal healing is the goal for ulcerative colitis (UC) therapy, but it needs to be confirmed via colonoscopy. Colon capsule endoscopy (CCE) is a noninvasive technique for colon investigation. Our study investigated the accuracy of second-generation CCE (CCE-2) in assessing mucosal lesions and disease activity in UC.

METHODS

In this prospective study, CCE-2 and conventional colonoscopy were performed on the same day. CCE-2 reviewers and colonoscopists used the Mayo endoscopic subscore (MES) and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) to assess disease activity, and they were blinded to each other's findings. Diagnostic parameters of CCE-2 for identifying mucosal lesions were evaluated by using colonoscopy as the reference.

RESULTS

A total of 150 patients were enrolled. Of the 150 patients, 108 were included for per-patient analysis. CCE-2 and colonoscopy showed substantial agreement in measuring MES (intraclass correlation coefficient [ICC] 0.69; 95% confidence interval [CI], 0.46-0.81; P < .001) and UCEIS (ICC 0.64; 95% CI, 0.38-0.78; P < .001). CCE-2 had a sensitivity of 97% and 94% to detect mucosal inflammation (MES >0) and moderate to severe inflammation (MES >1), respectively. In per-segment analysis, the negative predictive values of CCE-2 to detect mucosal inflammation, including vascular pattern loss, bleeding, and erosions reached 94% to 95%. Interobserver agreement between 2 independent CCE-2 readers for both scoring systems was good (ICC > .80). The sensitivity and specificity of CCE-2 in detecting postinflammatory polyps were 100% and 91%, respectively. CCE-2 was better tolerated and preferred by patients than was colonoscopy.

CONCLUSIONS

CCE-2 yields high accuracy in detecting mucosal lesions and determining disease severity in UC. It represents a well-tolerated and reliable tool for disease monitoring in UC. (Clinical trial registration number: NCT02469103.).

Feasibility of a novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy

Bowel preparation regimens for colon capsule endoscopy are not yet standardized since they are not well optimized. The aim of the present study was to evaluate the feasibility of a novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy. A total of 31 patients were prospectively enrolled. In the novel regimen, on the day prior to examination, a low-fiber diet was permitted, 5 mg mosapride citrate was administered twice (1 h prior to lunch and supper) and 1 l polyethylene glycol was administered in the evening. On the day of the examination, an additional 1 l polyethylene glycol, 5 mg mosapride citrate and 200 mg simethicone were administered before capsule ingestion. Polyethylene glycol booster (0.5 l) was administered twice, at 1 and 4 h following capsule ingestion. Colon cleansing levels, ileocecal valve transit time and completion rate were evaluated. A total of 29 patients were included in the final analysis, 90% of whom achieved adequate preparation of the overall colon. Ileocecal valve transit time was 2.35±0.82 h and completion rate was 79.3%. The results revealed that the novel low-volume and sodium phosphate-free bowel preparation regimen for colon capsule endoscopy was feasible, with adequate colon cleansing and completion rates, and has the potential to be used as an alternative regimen.

Colon capsule endoscopy: toward the future

Colon capsule endoscopy is a wireless and minimally invasive technique for visualization of the whole colon. With recent improvements of technical features in second-generation systems, a more important role for colon capsule endoscopy is rapidly emerging. Although several limitations and drawbacks are yet to be resolved, its usefulness as a tool for colorectal cancer screening and monitoring disease activity in inflammatory bowel diseases has become more apparent with increased use. Further investigations, including multicenter trials, are required to evaluate the substantial role of the colon capsule in managing colorectal diseases.

Review: capsule colonoscopy-a concise clinical overview of current status

The colon capsule endoscopy (CCE) was first introduced in 2007. Currently, the main clinical indications for CCE are completion of incomplete colonoscopy, polyp detection and investigation of inflammatory bowel disease (IBD). Although conventional colonoscopy is the gold standard in bowel cancer screening, incomplete colonoscopy remains a problem as lesions are missed. CCE compares favourably to computer tomography colonography (CTC) in adenoma detection and has therefore been proposed as a method for completing colonoscopy. However the data on CCE remains sparse and current evidence does not show its superiority over CTC or conventional colonoscopy in bowel cancer screening. CCE also seems to show good correlation with conventional colonoscopy when used to evaluate IBD, but there are not many published studies at present. Other significant limitations include the need for aggressive bowel preparation and the labour-intensiveness of CCE reading. Therefore, much further software and hardware development is required to enable CCE to fulfill its potential as a minimally-invasive and reliable method of colonoscopy.

Video capsule endoscopy in inflammatory bowel disease

Video capsule endoscopy (VCE) has evolved to become an important tool for the non-invasive examination of the small bowel, which hitherto had been relatively inaccessible to direct visualisation. VCE has been shown to play a role in monitoring the activity of small bowel Crohn’s disease and can be used to assess the response to anti-inflammatory treatment in Crohn’s disease. For those patients with Crohn’s disease who have undergone an intestinal resection, VCE has been assessed as a tool to detect post-operative recurrence. VCE may also aid in the reclassification of patients with a diagnosis of Inflammatory Bowel Disease Unclassified to Crohn’s disease. The evolution of colon capsule endoscopy (CCE) has expanded the application of this technology further. The use of CCE to assess the activity of ulcerative colitis has been described. This advance in capsule technology has also fuelled interest in its potential role as a minimally invasive tool to assess the whole of GI tract opening the possibility of its use for the panenteric assessment of Crohn’s disease. VCE is a safe procedure. However, the risk of a retained capsule is higher in patients with suspected or confirmed Crohn’s disease compared with patients having VCE examination for other indications. A retained video capsule is rare after successful passage of a patency capsule which may be utilised to pre-screen patients undergoing VCE. This paper describes the use of VCE in the assessment of inflammatory bowel disease.

PillCam COLON 2© in Crohn’s disease: A new concept of pan-enteric mucosal healing assessment

AIM: To evaluate mucosal healing in patients with small bowel plus colonic Crohn’s disease (CD) with a single non-invasive examination, by using PillCam COLON 2^© (PCC2).

METHODS: Patients with non-stricturing nonpenetrating small bowel plus colonic CD in sustained corticosteroid-free remission were included. At diagnosis, patients had undergone ileocolonoscopy to identify active CD lesions, such as ulcers and erosions, and small bowel capsule endoscopy to assess the Lewis Score (LS). After ≥ 1 year of follow-up, patients underwent entire gastrointestinal tract evaluation with PCC2. The primary endpoint was assessment of CD mucosal healing, defined as no active colonic CD lesions and LS < 135.

RESULTS: Twelve patients were included (7 male; mean age: 32 years), and mean follow-up was 38 mo. The majority of patients (83.3%) received immunosuppressive therapy. Three patients (25%) achieved mucosal healing in both the small bowel and the colon, while disease activity was limited to either the small bowel or the colon in 5 patients (42%). It was possible to observe the entire gastrointestinal tract in 10 of the 12 patients (83%) who underwent PCC2.

CONCLUSION: Only three patients in sustained corticosteroid-free clinical remission achieved mucosal healing in both the small bowel and the colon, highlighting the limitations of clinical assessment when stratifying disease activity, and the need for pan-enteric endoscopy to guide therapeutic modification.

Wireless capsule endoscopy of the small intestine in children

Wireless capsule endoscopy (CE) for the diagnosis of small-bowel disease has been in clinical use for more than a decade, and is no longer an emerging technology, but rather one that has reached fruition. This noninvasive technology has been readily embraced by both physicians and patients. Used in the diagnosis of inflammatory bowel disease, for locating sources of obscure gastrointestinal bleeding, and for assessing small-bowel polyp burden in polyposis syndromes as well as for less common indications, CE has transformed the diagnostic algorithms of small-bowel investigations. Although already in widespread use, the technology incorporated into the various CE platforms continues to improve and expand. Here, we briefly review the indications, limitations, and advances in video capsule technology, with an emphasis on its use in pediatrics.

Recent trends in diagnostic techniques for inflammatory bowel disease

Although ileocolonoscopy is the gold standard for diagnosis of inflammatory bowel disease and is useful for assessing the disease severity in the colon and terminal ileum, several alternative diagnostic techniques have been developed recently. For ulcerative colitis (UC), magnification colonoscopy, endocytoscopy, and confocal laser endomicroscopy enable assessment of histological inflammation without the need for biopsy. Capsule endoscopy is useful for detection of small intestinal and colonic lesions in both female and male patients. For UC, capsule endoscopy may be useful for evaluating colonic inflammation in patients with a previous poor colonoscopy experience, while it should be used only in Crohn's disease (CD) patients with unexplained symptoms when other examinations are negative. Magnetic resonance enterography (MRE) is particularly useful for detecting transmural inflammation, stenosis, and extraintestinal lesions, including abscesses and fistulas. MRE is also useful when evaluating small and large intestinal lesions, even in cases with severe strictures in which full evaluation of the small bowel would be virtually impossible using other devices. Therefore, the appropriate diagnostic devices for detecting CD lesions in the small and large intestine should be used.

Colon capsule endoscopy

Colon capsule endoscopy (CCE) is a minimally invasive technique specifically designed to explore the colon without sedation and air insufflation. CCE may overcome some of the limitations of colonoscopy. Second-generation CCE (CCE-2) was proved accurate in detecting colonic neoplastic lesions when used in average-risk individuals. The evidence to date supports the use of CCE-2 in cases of colonoscopy failure, in patients unwilling to undergo colonoscopy, and when colonoscopy is contraindicated. Other potential applications, such as colorectal cancer screening or diagnostic surveillance of inflammatory bowel disease, require clarification.

Current status of capsule endoscopy through a whole digestive tract

More than a decade has passed since small-bowel capsule endoscopy (CE) was first reported. Small-bowel CE is a non-invasive tool that allows visualization of the entire small-intestinal mucosa and facilitates detection of small-intestinal abnormalities. Several studies have shown benefit of small-bowel CE for certain disorders. Because it is non-invasive, CE has been applied to other organs including the esophagus, stomach, and colon. The main indications for esophageal CE (ECE) are screening for gastroesophageal reflux disease/Barrett's esophagus, and esophageal varices. However, the clinical benefit of ECE is unconfirmed. Magnetically guided CE (MGCE) was developed to visualize the gastric mucosa. MGCE is a new concept with room for improvement of capsule navigation and the preparation protocol. Recently, two new small-bowel CE tools were released. First-generation colon CE (CCE-1) has moderate sensitivity and specificity compared with colonoscopy for colorectal neoplasia surveillance. To obtain higher accuracy, a second-generation CCE (CCE-2) was developed with a high sensitivity for detecting clinically relevant polypoid lesions. A possible application of CCE is for inflammatory bowel disease. In the near future, CE may include diagnostic and therapeutic functions such as magnifying endoscopy systems, targeted biopsy forceps, and drug delivery systems.

The role of capsule endoscopy in assessing mucosal inflammation in ulcerative colitis

Assessment of mucosal inflammation is important in the management of patients with ulcerative colitis (UC). Colon capsule endoscopy (CCE) has recently been shown to be effective in colorectal polyp detection. However, its role in the evaluation of mucosal inflammation in UC is unclear. This systematic review aims to clarify the state of the art with an evidence-based summary of current studies on the utility of CCE in UC. The overall results show that the accuracy of CCE for assessment of mucosal inflammation in UC appeared to be comparable with that of colonoscopy. Long-term follow-up studies with larger sample size are needed to further validate the utility of CCE in the management of UC subjects in clinical practice.

Video capsule endoscopy: Perspectives of a revolutionary technique

Video capsule endoscopy (VCE) was launched in 2000 and has revolutionized direct endoscopic imaging of the gut. VCE is now a first-line procedure for exploring the small bowel in cases of obscure digestive bleeding and is also indicated in some patients with Crohn’s disease, celiac disease, and polyposis syndrome. A video capsule has also been designed for visualizing the esophagus in order to detect Barrett’s esophagus or esophageal varices. Different capsules are now available and differ with regard to dimensions, image acquisition rate, battery life, field of view, and possible optical enhancements. More recently, the use of VCE has been extended to exploring the colon. Within the last 5 years, tremendous developments have been made toward increasing the capabilities of the colon capsule. Although colon capsule cannot be proposed as a first-line colorectal cancer screening procedure, colon capsule may be used in patients with incomplete colonoscopy or in patients who are unwilling to undergo colonoscopy. In the near future, new technological developments will improve the diagnostic yield of VCE and broaden its therapeutic capabilities.

Colon capsule endoscopy: What we know and what we would like to know

Colonoscopy is usually perceived as an invasive and potentially painful procedure, being also affected by a small, but definite, risk of major complications (cardiopulmonary complications, perforation, hemorrhage) and even mortality. To improve both acceptability and safety, PillCam Colon Capsule Endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) has been developed. CCE represents a non-invasive technique that is able to explore the colon without sedation and air insufflation. The Second Generation of Colon Capsule Endoscopy (PillCam Colon 2) (CCE-2) was proven to be an accurate tool to detect colonic neoplastic lesions when used in average risk individuals. To date, the evidence supports the use of CCE-2 in case of colonoscopy failure, in patients unwilling to perform colonoscopy and when colonoscopy is contraindicated. Other potential applications, such as colorectal cancer screening or diagnostic surveillance of inflammatory bowel disease need to be clarified. In this paper, the current “state of the art”, potential application of CCE and future needs are evaluated.

Capsule endoscopy in pediatrics: A 10-years journey

Video capsule endoscopy (CE) for evaluation the esophagus (ECE), small bowel (SBCE) and the colon (CCE) is particularly useful in pediatrics, because this imaging modality does not require ionizing radiation, deep sedation or general anesthesia. The risk of capsule retention appears to be dependent on indication rather than age and parallels the adult experience by indication, making SBCE a relatively safe procedure with a significant diagnostic yield. The newest indication, assessment of mucosal change, greatly enhances and expands its potential benefit. The diagnostic role of CE extends beyond the SB. The use of ECE also may enhance our knowledge of esophageal disease and assist patient care. Colon CCE is a novel minimally invasive and painless endoscopic technique allowing exploration of the colon without need for sedation, rectal intubation and gas insufflation. The limited data on ECE and CCE in pediatrics does not yet allow the same conclusions regarding efficacy; however, both appear to provide safe methods to assess and monitor mucosal change in their respective areas with little discomfort. Moreover, although experience has been limited, the patency capsule may help lessen the potential of capsule retention; and newly researched protocols for bowel cleaning may further enhance CE’s diagnostic yield. However, further research is needed to optimize the use of the various CE procedures in pediatric populations.

Colon capsule endoscopy: Current status and future directions

Colon capsule endoscopy (CCE; PillCam Colon; Given Imaging; Yoqneam, Israel) is a minimally invasive wireless technique for the visualization of the colon. With the recent introduction of the second generation colon capsule the diagnostic accuracy of CCE for polyp detection has significantly improved and preliminary data suggest it may be useful to monitor mucosal inflammation in patients with inflammatory bowel disease. Limitations include the inability to take biopsies and the procedural costs. However, given the potentially higher acceptance within an average risk colorectal cancer (CRC) screening population, its usefulness as a screening tool with regard to CRC prevention should be further evaluated.

Current applications and potential future role of wireless capsule technology in Crohn's disease

BACKGROUND

The development of capsule technology has modified our approach to the diagnosis of gastrointestinal disease. The relatively rapid uptake of capsule endoscopy as an important clinical tool can be largely ascribed to a number of key factors, including the fact that it is a relatively easy examination to perform in an outpatient setting. It has been established as an integral part of the investigation pathway for obscure gastrointestinal bleeding and suspected small bowel Crohn's disease (CD). CURRENT USE OF CAPSULE ENDOSCOPY: Small bowel CD can be a challenging entity to diagnose. Capsule endoscopy has been shown to be both useful and safe in patients with both suspected and established small bowel CD. In suspected disease, capsule endoscopy has both a high diagnostic yield and negative predictive value. Capsule findings lead to changes in management in up to 73% of patients with established CD. However, while the technology appears capable of detecting subtle mucosal changes not readily apparent on alternate imaging modalities, the question of what actually constitutes small bowel CD as described by capsule is an issue that remains unresolved to date. Thus, capsule endoscopy is best utilised in tandem with advanced imaging and endoscopic techniques such as balloon- assisted enteroscopy.

FUTURE DEVELOPMENTS

The development of a capsule capable of viewing the colon coupled with improvements in image quality and battery life are likely to lead to the increasing uptake of this technology. In the future, 'interactive' capsules with the ability to view the entire gastrointestinal tract may be a reality.

Is there a role for colon capsule endoscopy beyond colorectal cancer screening? A literature review

Colon capsule endoscopy is recommended in Europe alternatively to colonoscopy for colorectal cancer screening in average risk individuals. The procedure has also been proposed to complete colon examination in cases of incomplete colonoscopy or when colonoscopy is contraindicated or refused by the patient. As tissue samples cannot be obtained with the current capsule device, colon capsule endoscopy has no place in diagnosing ulcerative colitis or in dysplasia surveillance. Nevertheless, data are accumulating regarding its feasibility to examine ulcerative colitis disease extent and to monitor disease activity and mucosal healing, even though reported results on the capsule's performance in this field vary greatly. In this review we present the currently available evidence for the use of colon capsule endoscopy to complement colonoscopy failure to reach the cecum and its use to evaluate ulcerative colitis disease activity and extent. Moreover, we provide an outlook on issues requiring further investigation before the capsule becomes a mainstream alternative to colonoscopy in such cases.

Wireless capsule endoscopy of the large intestine: a review with future projections

PURPOSE OF REVIEW

Video capsule endoscopy, which was initially developed for exploring the small bowel, has been adapted for investigating the colon. This review summarizes recent developments in colon capsule technology as well as indications for its use.

RECENT FINDINGS

Second-generation PillCam colon capsule endoscopy (CCE-2) has been recently developed and has significantly improved the sensitivity and specificity of colon capsules for detecting polyps and/or tumors in patients with suspected or known colonic lesions. The use of CCE-2 has been shown to be of value in patients with incomplete standard colonoscopy. The use of CCE-2 has also been investigated in patients with ulcerative colitis and in outpatient settings. Several trials have tried to simplify the colon preparation regimen.

SUMMARY

Colon capsule endoscopy is a novel technique for exploring the colon. CCE-2 has improved the diagnostic capability of this noninvasive method. There is still room for improvement and simplification of colon preparation regimens. Apart from detection of polyps or neoplasms, colon capsule endoscopy has also been assessed in patients with inflammatory bowel disease.

Modified bowel preparation regimen for use in second-generation colon capsule endoscopy in patients with ulcerative colitis

BACKGROUND AND AIM

We have reported that second-generation colon capsule endoscopy (CCE-2) might be feasible for assessing the severity of mucosal inflammation in ulcerative colitis (UC). However, because of the low rate (69%) of complete evaluation of the colon and owing to inadequate cleansing. We believe that the method of bowel preparation could be improved by reducing volume. In the present study, we attempted to improve the colon-cleansing regimen in order to optimize the usefulness of CCE-2 in the management of UC patients.

METHODS

Twenty patients with histologically confirmed UC were enrolled. Patients took a maximum 2.2 L lavage solution (polyethylene glycol solution and magnesium citrate) in two or three divided doses. To assess the effectiveness of the modified bowel preparation regimen, we evaluated the rate of total colonobservation, the effectiveness of bowel cleansing, andinterobserver agreement in assessing UC disease activity. We used a four-point grading scale (poor, fair, good, and excellent) for evaluating the quality of bowel cleansing. Matts' endoscopic score was used to evaluate disease activity.

RESULTS

The rate of total colon observation was 85%, and 15 patients (75%) excreted the CCE-2 within 8 h. The proportion of excellent plus good cleansing was approximately 60%. There was a substantial interobserver agreement (κ = 0.777) in assessment of overall cleansing, which was still substantial at the fair cleansing level (κ = 0.700).

CONCLUSION

Using CCE-2, the modified bowel preparation regimen, with reduced volume has the potential to succeed in the evaluation of mucosal severity in UC.

Role of capsule endoscopy in inflammatory bowel disease

Videocapsule endoscopy (VCE) has revolutionized our ability to visualize the small bowel mucosa. This modality is a valuable tool for the diagnosis of obscure small bowel Crohn’s disease (CD), and can also be used for monitoring of disease activity in patients with established small-bowel CD, detection of complications such as obscure bleeding and neoplasms, evaluation of response to anti-inflammatory treatment and postoperative recurrence following small bowel resection. VCE could also be an important tool in the management of patients with unclassified inflammatory bowel disease, potentially resulting in reclassification of these patients as having CD. Reports on postoperative monitoring and evaluation of patients with ileal pouch-anal anastomosis who have developed pouchitis have recenty been published. Monitoring of colonic inflammatory activity in patients with ulcerative colitis using the recently developed colonic capsule has also been reported. Capsule endoscopy is associated with an excellent safety profile. Although retention risk is increased in patients with small bowel CD, this risk can be significanty decreased by a routine utilization of a dissolvable patency capsule preceding the ingestion of the diagnostic capsule. This paper contains an overview of the current and future clinical applications of capsule endoscopy in inflammatory bowel disease.

Inflammatory bowel disease and novel endoscopic technologies

Conventional ileocolonoscopy and barium small bowel follow-through are useful techniques for assessing the extension and severity of disease in patients with inflammatory bowel disease (IBD). More recently, novel techniques to enable IBD diagnosis have been developed, such as capsule endoscopy (CE), balloon enteroscopy (BE), computed tomography enterography (CTE) and magnetic resonance enterography (MRE). The advantages of CE and BE are that they enable mucosal assessment directly whereas the usefulness of CTE/MRE is in its ability to enable detection of transmural inflammation, stenosis, and extraintestinal lesions including abscesses and fistulas. In ulcerative colitis (UC), colitis-associated dysplasia/cancer is one of the critical complications in patients with chronic disease. Detection of colitis-associated cancer is difficult in cases with inflammation. Magnification colonoscopy has been used to detect dysplasia in patients with chronic UC. Furthermore, colon CE and endocytoscopy have also developed and these might be used for selected patients in the near future.