Capsule endoscopy versus colonoscopy for the detection of polyps and cancer

Screening for Colorectal Cancer

Colorectal cancer remains the third leading cause of cancer death in the United States. Colorectal cancer screening allows for prevention and early detection of precancerous and cancerous lesions, and screening has been shown to be effective in preventing colorectal cancer deaths. Screening recommendations vary by patient risk profile. A variety of screening modalities exist.

Diagnostic accuracy of multimodal noninvasive follow-up for pediatric ulcerative colitis: A single-center prospective study

OBJECTIVES

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) often requiring endoscopic evaluations, which can be uncomfortable and costly, especially for children. This study aimed to evaluate the diagnostic accuracy of a noninvasive approach combining fecal calprotectin (FCP), colonic ultrasonography (US), and colon capsule endoscopy (CCE) compared with standard ileocolonoscopy in pediatric UC.

METHODS

UC children were enrolled and underwent FCP and US on Day 0, followed by CCE on Day 1 and ileocolonoscopy on Day 2. All procedures were performed by operators who were blinded to the patient's clinical history and all test results. The accuracy for disease activity and extension of each technique and their combination was assessed and compared. Tolerability and safety were also evaluated.

RESULTS

Thirty-two patients were enrolled (15 males, mean age 13.2 ± 3.2 years). CCE showed a sensitivity of 95% and specificity of 100% in detecting colonic inflammation, with positive predictive value (PPV) and negative predictive value (NPV) of 100% and 92%, respectively. US demonstrated a sensitivity of 85% and specificity of 92%, with PPV and NPV of 94% and 79%. The combination of FCP, US, and CCE achieved 95% sensitivity and 100% specificity, with PPV of 100% and NPV of 92%. The noninvasive approach was better tolerated than colonoscopy (p < 0.05), and no serious adverse events were reported.

CONCLUSION

The noninvasive approach combining fecal calprotectin (FCP), ultrasonography, and colon capsule endoscopy demonstrated high diagnostic accuracy and better tolerability compared with standard ileocolonoscopy in pediatric ulcerative colitis follow-up. Further multicenter studies are needed to confirm these findings and evaluate the reproducibility of this noninvasive approach.

What Is the Optimal Bowel Preparation for Capsule Colonoscopy and Pan-intestinal Capsule Endoscopy? A Systematic Review and Meta-Analysis

BACKGROUND

The rate of adequate cleansing (ACR) and complete examinations (CR) are key quality indicators in capsule colonoscopy (CC) and pan-intestinal capsule endoscopy (PCE).

AIMS

To evaluate the efficacy of bowel preparation protocols regarding ACR and CR.

METHODS

We conducted a systematic review and meta-analysis, search terms regarding colon capsule preparation, publication date from 2006/01, and date of search 2021/12, in six bibliographic databases. Multiple steps of the cleansing protocol were assessed: diet, adjunctive laxatives, purgative solution, use of prokinetic agents, and "booster". The meta-analytical frequency of ACR and CR was estimated, and subgroup analyses performed. Strategies associated with higher ACR and CR were explored using meta-analytical univariable and multivariable regression models.

RESULTS

Twenty-six observational studies and five RCTs included (n = 4072 patients). The pooled rate of ACR was 72.5% (95% C.I. 67.8-77.5%; I2 = 92.4%), and the pooled rate of CR was 83.0% (95% C.I. 78.7-87.7%; I2 = 96.5%). The highest ACR were obtained using a low-fibre diet [78.5% (95% C.I. 72.0-85.6%); I2 = 57.0%], adjunctive laxatives [74.7% (95% C.I. 69.8-80.1%); I2 = 85.3%], and split dose < 4L polyethylene glycol (PEG) as purgative [77.5% (95% C.I. 68.4-87.8%); I2 = 47.3%]. The highest CR were observed using routine prokinetics prior to capsule ingestion [84.4% (95% C.I. 79.9-89.2%); I2 = 89.8%], and sodium phosphate (NaP) as "booster" [86.2% (95% C.I. 82.3-90.2%); I2 = 86.8%]. In univariable models, adjunctive laxatives were associated with higher ACR [OR 1.81 (95% C.I. 1.13; 2.90); p = 0.014]. CR was higher with routine prokinetics [OR 1.86 (95% C.I. 1.13; 3.05); p = 0.015] and split-dose PEG purgative [OR 2.03 (95% C.I. 1.01; 4.09), p = 0.048].

CONCLUSIONS

Main quality outcomes (ACR, CR) remain suboptimal for CC and PCE. Despite considerable heterogeneity, our results support low-fibre diet, use of adjunctive sennosides, split dose < 4L PEG, and routine prokinetics, while NaP remains the most consistent option as booster.

A review on model-based and model-free approaches to control soft actuators and their potentials in colonoscopy

Colorectal cancer (CRC) is the third most common cancer worldwide and responsible for approximately 1 million deaths annually. Early screening is essential to increase the chances of survival, and it can also reduce the cost of treatments for healthcare centres. Colonoscopy is the gold standard for CRC screening and treatment, but it has several drawbacks, including difficulty in manoeuvring the device, patient discomfort, and high cost. Soft endorobots, small and compliant devices thatcan reduce the force exerted on the colonic wall, offer a potential solution to these issues. However, controlling these soft robots is challenging due to their deformable materials and the limitations of mathematical models. In this Review, we discuss model-free and model-based approaches for controlling soft robots that can potentially be applied to endorobots for colonoscopy. We highlight the importance of selecting appropriate control methods based on various parameters, such as sensor and actuator solutions. This review aims to contribute to the development of smart control strategies for soft endorobots that can enhance the effectiveness and safety of robotics in colonoscopy. These strategies can be defined based on the available information about the robot and surrounding environment, control demands, mechanical design impact and characterization data based on calibration.

Evaluating clinical diversity and plausibility of synthetic capsule endoscopic images

Wireless Capsule Endoscopy (WCE) is being increasingly used as an alternative imaging modality for complete and non-invasive screening of the gastrointestinal tract. Although this is advantageous in reducing unnecessary hospital admissions, it also demands that a WCE diagnostic protocol be in place so larger populations can be effectively screened. This calls for training and education protocols attuned specifically to this modality. Like training in other modalities such as traditional endoscopy, CT, MRI, etc., a WCE training protocol would require an atlas comprising of a large corpora of images that show vivid descriptions of pathologies, ideally observed over a period of time. Since such comprehensive atlases are presently lacking in WCE, in this work, we propose a deep learning method for utilizing already available studies across different institutions for the creation of a realistic WCE atlas using StyleGAN. We identify clinically relevant attributes in WCE such that synthetic images can be generated with selected attributes on cue. Beyond this, we also simulate several disease progression scenarios. The generated images are evaluated for realism and plausibility through three subjective online experiments with the participation of eight gastroenterology experts from three geographical locations and a variety of years of experience. The results from the experiments indicate that the images are highly realistic and the disease scenarios plausible. The images comprising the atlas are available publicly for use in training applications as well as supplementing real datasets for deep learning.

A Head-to-Head Comparison of Computed Tomography Colonography, Optical Colonoscopy, and Colon Endoscopic Capsule for the Detection of Polyps After Partial Colectomy or Rectosigmoidectomy for Colorectal Cancer: A Pilot Study

Background and objective Optical colonoscopy is the gold standard method for the diagnosis of colorectal cancer (CRC) and it allows for biopsy and resection, as well as documentation of synchronous lesions. CT colonography (CTC) and colon endoscopic capsule (CEC) are also recommended as alternative minimally invasive or non-invasive procedures. Prospective studies comparing these three approaches are scarce in the current literature. In light of this, the aim of this pilot study was to compare the efficacy of polyp detection between these three methods in patients with a history of curative surgical resection of CRC. Methods Patients were consecutively recruited and all procedures were sequentially conducted on the same day. The primary endpoint was the detection rate of polyps, whereas secondary endpoints were the detection of polyps according to size and location, and the adverse events caused by these procedures. Results A total of 21 patients were consecutively included and all of them underwent all three interventions. No adverse events, local recurrences, or metachronous lesions were detected. In two cases with elevated carcinoembryonic antigen (CEA), CTC unveiled distant metastasis. Optical colonoscopy registered a mean of 0.4 polyp >6 mm and 1.3 polyps <6 mm per patient. CTC unveiled only 0.5 polyp >6 mm/patient and no smaller lesions were documented, whereas findings for the colon capsule comprised an average of 0.4 polyps >6 mm and 0.7 polyps <6 mm per patient. Statistical difference was not demonstrated, except for virtual colonoscopy in terms of the total number of polyps detected in comparison to optical colonoscopy. Conclusions Optical colonoscopy showed superior results in comparison to virtual colonoscopy while there was no statistical difference in comparison to colon capsule. Notwithstanding occasional difficulties, all three techniques were well tolerated. Hence, decisions concerning the use of each diagnostic method should be based on their availability, professional expertise, contraindications, and patient preferences.

Colon Cancer Screening Methods: 2023 Update

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. National screening guidelines have been implemented to identify and remove precancerous polyps before they become cancer. Routine CRC screening is advised for people with average risk starting at age 45 because it is a common and preventable malignancy. Various screening modalities are currently in use, ranging from stool-based tests (fecal occult blood test (FOBT), fecal immunochemical test (FIT), and FIT-DNA test), radiologic tests (computed tomographic colonography (CTC), double contrast barium enema), and visual endoscopic examinations (flexible sigmoidoscopy (FS), colonoscopy, and colon capsule endoscopy (CCE)) with their varying sensitivity and specificity. Biomarkers also play a vital role in assessing the recurrence of CRC. This review offers a summary of the current screening options, including biomarkers available to detect CRC, highlighting the benefits and challenges encompassing each screening modality.

Enhanced segmentation of gastrointestinal polyps from capsule endoscopy images with artifacts using ensemble learning

BACKGROUND

Endoscopy artifacts are widespread in real capsule endoscopy (CE) images but not in high-quality standard datasets.

AIM

To improve the segmentation performance of polyps from CE images with artifacts based on ensemble learning.

METHODS

We collected 277 polyp images with CE artifacts from 5760 h of videos from 480 patients at Guangzhou First People’s Hospital from January 2016 to December 2019. Two public high-quality standard external datasets were retrieved and used for the comparison experiments. For each dataset, we randomly segmented the data into training, validation, and testing sets for model training, selection, and testing. We compared the performance of the base models and the ensemble model in segmenting polyps from images with artifacts.

RESULTS

The performance of the semantic segmentation model was affected by artifacts in the sample images, which also affected the results of polyp detection by CE using a single model. The evaluation based on real datasets with artifacts and standard datasets showed that the ensemble model of all state-of-the-art models performed better than the best corresponding base learner on the real dataset with artifacts. Compared with the corresponding optimal base learners, the intersection over union (IoU) and dice of the ensemble learning model increased to different degrees, ranging from 0.08% to 7.01% and 0.61% to 4.93%, respectively. Moreover, in the standard datasets without artifacts, most of the ensemble models were slightly better than the base learner, as demonstrated by the IoU and dice increases ranging from -0.28% to 1.20% and -0.61% to 0.76%, respectively.

CONCLUSION

Ensemble learning can improve the segmentation accuracy of polyps from CE images with artifacts. Our results demonstrated an improvement in the detection rate of polyps with interference from artifacts.

Endoscopy Lifetime Systems Architecture: Scoping Out the Past to Diagnose the Future Technology

Systems engineering captures the desires and needs of the customer to conceptualize a system from the overall goal down to the small details prior to any physical development. While many systems projects tend to be large and complicated (i.e., cloud-based infrastructure, long-term space travel shuttles, missile defense systems), systems engineering can also be applied to smaller, complex systems. Here, the system of interest is the endoscope, a standard biomedical screening device used in laparoscopic surgery, screening of upper and lower gastrointestinal tracts, and inspection of the upper airway. Often, endoscopic inspection is used to identify pre-cancerous and cancerous tissues, and hence, a requirement for endoscopic systems is the ability to provide images with high contrast between areas of normal tissue and neoplasia (early-stage abnormal tissue growth). For this manuscript, the endoscope was reviewed for all the technological advancements thus far to theorize what the next version of the system could be in order to provide improved detection capabilities. Endoscopic technology was decomposed into categories, using systems architecture and systems thinking, to visualize the improvements throughout the system's lifetime from the original to current state-of-the-art. Results from this review were used to identify trends in subsystems and components to estimate the theoretical performance maxima for different subsystems as well as areas for further development. The subsystem analysis indicated that future endoscope systems will focus on more complex imaging and higher computational requirements that will provide improved contrast in order to have higher accuracy in optical diagnoses of early, abnormal tissue growth.

Colon Capsule Endoscopy in the Diagnosis of Colon Polyps: Who Needs a Colonoscopy?

Colon screening programs have reduced colon cancer mortality. Population screening should be minimally invasive, safe, acceptably sensitive, cost-effective, and scalable. The range of screening modalities include guaiac or immunochemical fecal occult blood testing and CT colonography and colonoscopy. A number of carefully controlled studies concur that second-generation capsule endoscopy has excellent sensitivity for polyp detection and a high negative predictive value. Colon capsules fulfill the screening expectation of safety, high sensitivity for polyp detection, and patient acceptance, and appear to straddle the divide between occult blood testing and colonoscopy. While meeting these criteria, there remains the challenges of scaling, capsule practitioner training, resource allocation, and implementing change of practice. Like CT colonography, capsule screening presents the clinician with a decision on the threshold for colonoscopy referral. Overall, colon capsules are an invaluable tool in polyp detection and colon screening and offer a filter that determines “who needs a colonoscopy?”.

Colorectal Cancer and Polyp Detection Using a New Preparation-Free, Colon-Scan Capsule: A Pilot Study of Safety and Patient Satisfaction

BACKGROUND

Current strategies to prevent colorectal cancer (CRC) vary considerably regarding safety, invasiveness, and patient satisfaction. A known deterrent for patients is the required bowel cleansing for colonoscopy. A new colon-scan capsule system is a unique preparation-free approach that provides structural information on colonic mucosa intended for detection of colorectal polyps and masses.

AIMS

The aim of this study was to determine safety and patient satisfaction with the colon-scan capsule.

METHODS

Prospective single-arm pilot study conducted at two tertiary care centers. Patients with a pre-scheduled colonoscopy for CRC screening or surveillance were included. Patients participating in this study underwent the colon-scan capsule and colonoscopy. Safety was defined by the occurrence of procedure or device-related adverse events. Satisfaction was based on survey questionnaires using a scoring system 1 (strongly disagree) to 5 (strongly agree). Patient satisfaction with the colon-scan capsule was compared to colonoscopy.

RESULTS

Forty patients were included (52.9 [5.7] years; 64.1% females). There were no serious adverse events and no occurrences of capsule retention. The most common (12.5%) complaint was self-limiting abdominal cramping. Satisfaction questionnaires were completed by more than 87% of patients, with patients likely to recommend the capsule (score 4.1 [1.03]) compared to colonoscopy (score 2.8 [1.2]), p = 0.001.

CONCLUSIONS

The new prepless colon-scan capsule system is an innovative, minimally invasive technology with demonstrated safety and high patient satisfaction. A multicenter pivotal study is planned to validate the performance, safety, and accuracy of polyp detection using the capsule system in comparison with colonoscopy.

Artificial intelligence and machine learning in colorectal cancer

Colorectal cancer (CRC) is a heterogeneous illness characterized by various epigenetic and microenvironmental changes and is the third-highest cause of cancer-related death in the US. Artificial intelligence (AI) with its ability to allow automatic learning and improvement from experiences using statistical methods and Deep learning has made a distinctive contribution to the diagnosis and treatment of several cancer types. This review discusses the uses and application of AI in CRC screening using automated polyp detection assistance technologies to the development of computer-assisted diagnostic algorithms capable of accurately detecting polyps during colonoscopy and classifying them. Furthermore, we summarize the current research initiatives geared towards building computer-assisted diagnostic algorithms that aim at improving the diagnostic accuracy of benign from premalignant lesions. Considering the evolving transition to more personalized and tailored treatment strategies for CRC, the review also discusses the development of machine learning algorithms to understand responses to therapies and mechanisms of resistance as well as the future roles that AI applications may play in assisting in the treatment of CRC with the aim to improve disease outcomes. We also discuss the constraints and limitations of the use of AI systems. While the medical profession remains enthusiastic about the future of AI and machine learning, large-scale randomized clinical trials are needed to analyze AI algorithms before they can be used.

CC-CLEAR (Colon Capsule Cleansing Assessment and Report): the novel scale to evaluate the clinical impact of bowel preparation in capsule colonoscopy - a multicentric validation study

BACKGROUND

Colon Capsule Cleansing Assessment and Report (CC-CLEAR) is a novel quantitative bowel preparation scale for colon capsule.

AIM

The aim of this study is to validate the association between CC-CLEAR's classification and major CC outcomes: lesion detection rate, surveillance recommendations and post-CC endoscopic treatment.

METHODS

Multicentric cohort of consecutive CCs. An expert's panel decided post-CC recommendations. Data included CC-CLEAR and Leighton-REX scales. Major CC outcomes were associated with the different cleansing grades.

RESULTS

From 168 CC's included, findings were reported in 123 (73.2%), 67 (54.4%) of those being colorectal polyps. CC-CLEAR influenced CC's lesion detection (OR 1.25 95% IC [1.07-1.46], p-value .004) and polyp detection rate (OR 1.22 95% IC [1.04-1.43], p-value.014). Thirty-two (19%) post-CC colonoscopies were recommended, including 22 (68.75%) with at least one polypectomy. CC-CLEAR was associated with post-CC colonoscopy treatment (OR 1.40 95% IC [1.07-1.84], p-value .015). Regarding surveillance, CC-CLEAR influenced the decision for immediate CC repetition (OR 0.21 95% IC [0.12-0.36], p-value < .001) and the recommendation for CC in 3-5 years' time (OR 1.47 95% IC [1.50-1.86], p-value < .002). The Leighton-Rex scale was not correlated with major CC outcomes.

CONCLUSION

CC-CLEAR impacts major CC outcomes: lesion detection, surveillance recommendations and post-CC endoscopic treatment.

Safety and importance of colonoscopy in nonagenarians

BACKGROUND

With the growth of the aging population, the need for colonoscopies in nonagenarians is rising. However, few data on colonoscopies in extremely elderly individuals are available. To better acknowledge the role of colonoscopies in this specific group of patients, we conducted this study to evaluate the safety and clinical impact of colonoscopy in nonagenarian patients.

METHODS

We performed a retrospective cohort study comparing nonagenarians who received colonoscopy in a tertiary medical center in Taiwan in 2016 with 76- to 80-year-old patients (relatively elderly patients) who were 1:1 propensity score matched by sex as the control subjects. The postcolonoscopy 30-day adverse events, mortality, and long-term survival were recorded.

RESULTS

A total of 137 nonagenarians and 137 relatively elderly patients were included. The nonagenarians receiving colonoscopy were more likely to be hospitalized (40.1% vs 19.7%, p < 0.001), and the adjusted colonoscopy completion rates were comparable in both groups (92.0% vs 97.1%, p = 0.063). The overall adverse event rate and postcolonoscopy 30-day mortality rates were low in both groups (2.9% vs 1.5%, p = 0.409 and 2.2% vs 1.5%, p = 0.652, respectively). A total of 18.2% of the nonagenarians were diagnosed with advanced neoplasia. Among the nonagenarians diagnosed with colorectal cancer, the patients receiving surgery had a significantly lower risk of death than the patients receiving conservative management (hazards ratio 0.1044, 0.01275-0.8529, p = 0.0352).

CONCLUSION

Colonoscopy in patients older than 90 years is generally safe. Colonoscopy findings that led to surgery in nonagenarians diagnosed with colorectal cancer were associated with survival benefits.

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.

Diagnostic Accuracy of Wireless Capsule Endoscopy in Polyp Recognition Using Deep Learning: A Meta-Analysis

AIM

As the completed studies have small sample sizes and different algorithms, a meta-analysis was conducted to assess the accuracy of WCE in identifying polyps using deep learning.

METHOD

Two independent reviewers searched PubMed, Embase, the Web of Science, and the Cochrane Library for potentially eligible studies published up to December 8, 2021, which were analysed on a per-image basis. STATA RevMan and Meta-DiSc were used to conduct this meta-analysis. A random effects model was used, and a subgroup and regression analysis was performed to explore sources of heterogeneity.

RESULTS

Eight studies published between 2017 and 2021 included 819 patients, and 18,414 frames were eventually included in the meta-analysis. The summary estimates for the WCE in identifying polyps by deep learning were sensitivity 0.97 (95% confidence interval (CI), 0.95-0.98); specificity 0.97 (95% CI, 0.94-0.98); positive likelihood ratio 27.19 (95% CI, 15.32-50.42); negative likelihood ratio 0.03 (95% CI 0.02-0.05); diagnostic odds ratio 873.69 (95% CI, 387.34-1970.74); and the area under the sROC curve 0.99.

CONCLUSION

WCE uses deep learning to identify polyps with high accuracy, but multicentre prospective randomized controlled studies are needed in the future.

Screening for Colorectal Cancer Leading into a New Decade: The "Roaring '20s" for Epigenetic Biomarkers?

Colorectal cancer (CRC) has an important bearing (top five) on cancer incidence and mortality in the world. The etiology of sporadic CRC is related to the accumulation of genetic and epigenetic alterations that result in the appearance of cancer hallmarks such as abnormal proliferation, evasion of immune destruction, resistance to apoptosis, replicative immortality, and others, contributing to cancer promotion, invasion, and metastasis. It is estimated that, each year, at least four million people are diagnosed with CRC in the world. Depending on CRC staging at diagnosis, many of these patients die, as CRC is in the top four causes of cancer death in the world. New and improved screening tests for CRC are needed to detect the disease at an early stage and adopt patient management strategies to decrease the death toll. The three pillars of CRC screening are endoscopy, radiological imaging, and molecular assays. Endoscopic procedures comprise traditional colonoscopy, and more recently, capsule-based endoscopy. The main imaging modality remains Computed Tomography (CT) of the colon. Molecular approaches continue to grow in the diversity of biomarkers and the sophistication of the technologies deployed to detect them. What started with simple fecal occult blood tests has expanded to an armamentarium, including mutation detection and identification of aberrant epigenetic signatures known to be oncogenic. Biomarker-based screening methods have critical advantages and are likely to eclipse the classical modalities of imaging and endoscopy in the future. For example, imaging methods are costly and require highly specialized medical personnel. In the case of endoscopy, their invasiveness limits compliance from large swaths of the population, especially those with average CRC risk. Beyond mere discomfort and fear, there are legitimate iatrogenic concerns associated with endoscopy. The risks of perforation and infection make endoscopy best suited for a confirmatory role in cases where there are positive results from other diagnostic tests. Biomarker-based screening methods are largely non-invasive and are growing in scope. Epigenetic biomarkers, in particular, can be detected in feces and blood, are less invasive to the average-risk patient, detect early-stage CRC, and have a demonstrably superior patient follow-up. Given the heterogeneity of CRC as it evolves, optimal screening may require a battery of blood and stool tests, where each can leverage different pathways perturbed during carcinogenesis. What follows is a comprehensive, systematic review of the literature pertaining to the screening and diagnostic protocols used in CRC. Relevant articles were retrieved from the PubMed database using keywords including: "Screening", "Diagnosis", and "Biomarkers for CRC". American and European clinical trials in progress were included as well.

Small-Bowel Capsule Endoscopy-Optimizing Capsule Endoscopy in Clinical Practice

The small bowel is the longest organ within the gastrointestinal tract. The emergence of small bowel capsule endoscopy (SBCE) over the last 20 years has revolutionized the investigation and diagnosis of small bowel pathology. Its utility as a non-invasive and well-tolerated procedure, which can be performed in an outpatient setting, has made it a valuable diagnostic tool. The indications for SBCE include obscure gastrointestinal bleeding, small bowel Crohn's disease, and, less frequently for screening in polyposis syndromes, celiac disease, or other small bowel pathology. Currently, there are several small bowel capsules on the market from different manufacturers; however, they share many technological features. The European Society of Gastrointestinal Endoscopy (ESGE) only recently developed a set of key quality indicators to guide quality standards in this area. Many of the technical aspects of capsule endoscopy still feature a degree of uncertainty in terms of optimal performance. Incomplete studies due to slow transit through the bowel, poor imaging secondary to poor preparation, and the risk of capsule retention remain frustrations in its clinical utility. Capsule review is a time-consuming process; however, artificial intelligence and machine learning offer opportunities to improve this. This narrative review examines our current standing in a number of these aspects and the potential to further the application of SBCE in order to maximize its diagnostic utility.

Image-Enhanced Capsule Endoscopy Improves the Identification of Small Intestinal Lesions

Image-enhanced endoscopy is useful for diagnosing and identifying lesions in the gastrointestinal tract. Recently, image-enhanced endoscopy has become a breakthrough technology that has attracted significant attention. This image enhancing technology is available for capsule endoscopy, which is an effective tool for small intestinal lesions and has been applied in flexible spectral color enhancement technology and in contrast capsule like narrow-band imaging. In this field, most researchers focus on improving the visibility and detection of small intestinal lesions. This review summarizes previous studies on image-enhanced capsule endoscopy and aims to evaluate the efficacy of this technology.

Efficacy of bowel preparation regimens for colon capsule endoscopy: a systematic review and meta-analysis

Background and study aims  Colon capsule endoscopy (CCE) is an alternative to conventional colonoscopy (CC) in specific clinical settings. High completion rates (CRs) and adequate cleanliness rates (ACRs) are fundamental quality parameters if CCE is to be widely implemented as a CC equivalent diagnostic modality. We conducted a systematic review and meta-analysis to investigate the efficacy of different bowel preparations regimens on CR and ACR in CCE. Patients and methods  We performed a systematic literature search in PubMed, Embase, CINAHL, Web of Science, and the Cochrane Library. Data were independently extracted per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The primary outcome measures (CR, ACR) were retrieved from the individual studies and pooled event rates were calculated. Results  Thirty-four observational (OBS) studies (n = 3,789) and 12 randomized clinical trials (RCTs) (n = 1,214) comprising a total 5,003 patients were included. The overall CR was 0.798 (95 % CI, 0.764-0.828); the highest CRs were observed with sodium phosphate (NaP) + gastrografin booster (n = 2, CR = 0.931, 95 % CI, 0.820-0.976). The overall ACR was 0.768 (95 % CI, 0.735-0.797); the highest ACRs were observed with polyethylene glycol (PEG) + magnesium citrate (n = 4, ER = 0.953, 95 % CI, 0.896-0.979). Conclusions  In the largest meta-analysis on CCE bowel preparation regimens, we found that both CRs and ACRs are suboptimal compared to the minimum recommended standards for CC. PEG laxative and NaP booster were the most commonly used but were not associated with higher CRs or ACRs. Well-designed studies on CCE should be performed to find the optimal preparation regimen.

Diagnostic Yields and Clinical Impacts of Capsule Endoscopy

Observing the entire small bowel is difficult due to the presence of complex loops and a long length. Capsule endoscopy (CE) provides a noninvasive and patient-friendly method for visualizing the small bowel and colon. Small bowel capsule endoscopy (SBCE) has a critical role in the diagnosis of small bowel disorders through the direct observation of the entire small bowel mucosa and is becoming the primary diagnostic tool for small bowel diseases. Recently, colon capsule endoscopy (CCE) was also considered safe and feasible for obtaining sufficient colonic images in patients with incomplete colonoscopy, in the absence of bowel obstruction. This review article assesses the current status of CE in terms of the diagnostic yield and the clinical impact of SBCE in patients with obscure gastrointestinal bleeding, who have known or suspected Crohn's disease, small bowel tumor and inherited polyposis syndrome, celiac disease, and those who have undergone CCE.

Quantitative Assessment of Radiologically Indeterminate Local Colonic Wall Thickening on Iodine Density Images Using Dual-Layer Spectral Detector CT

RATIONALE AND OBJECTIVES

To assess local colonic wall thickening (LCWT, thicknesses: >3 mm, lengths: <5 cm) quantitatively on iodine density images using dual-layer spectral detector computed tomography (DLSCT).

MATERIALS AND METHODS

This retrospective study included 80 patients who underwent both conventional contrast-enhanced CT and colonoscopy within one month. The region of interest was delineated on the chosen images with the iodine density image model. The iodine concentration (IC), normalized IC (NIC), and thickness of the colonic wall in the lesion area were compared between the pathological and nonpathological groups.

RESULTS

There were 50 patients whose area of LCWT discovered at CT scans displayed colon neoplasia at colonoscopy. The other 30 patients with LCWT on CT images showed normal appearances during colonoscopy. There was no significant difference in colonic wall thickness between the pathological and nonpathological (p> 0.05) LCWT groups. The IC and NIC of patients with colon neoplasms were significantly higher than those with nonpathologic LCWT (both p< 0.001). The ROC curve showed that when IC and NIC was 1.49 mg/mL and 0.33, the sensitivity and specificity for diagnosing colon neoplasm were 91.5% and 75.8%, 85.1% and 84.8%, respectively.

CONCLUSION

IC and NIC values from DLSCT could provide a satisfied diagnostic value to identify LCWT caused by colon neoplasia.

Lavage, Simethicone, and Prokinetics-What to Swallow with a Video Capsule

The development of new capsules now allows endoscopic diagnosis in all segments of the gastrointestinal tract and comes with new needs for differentiated preparation regimens. Although the literature is steadily increasing, the results of the conducted trials on preparation are sometimes conflicting. The ingestion of simethicone before gastric and small bowel capsule endoscopy for prevention of air bubbles is established. The value of a lavage before small bowel capsule endoscopy (SBCE) is recommended, although not supported by all studies. Ingestion in the morning before the procedure seems useful for the improvement of mucosa visualization. Lavage after swallowing of the capsule seems to improve image quality, and in some studies also diagnostic yield. Prokinetics has been used with first generation capsules to shorten gastric transit time and increase the rate of complete small bowel visualization. With the massively prolonged battery capacity of the new generation small bowel capsules, prokinetics are only necessary in significantly delayed gastric emptying as documented by a real-time viewer. Lavage is crucial for an effective colon capsule or pan-intestinal capsule endoscopy. Mainly high or low volume polyethylene glycol (PEG) is used. Apart from achieving optimal cleanliness, propulsion of the capsule by ingested boosts is required to obtain a complete passage through the colon within the battery lifetime. Boosts with low volume sodium picosulfate (NaP) or diatrizoate (gastrografin) seem most effective, but potentially have more side effects than PEG. Future research is needed for more patient friendly but effective preparations, especially for colon capsule and pan-intestinal capsule endoscopy.

Colon capsule endoscopy in clinical practice: lessons from a national 5-year observational prospective cohort

Background and study aims  Colon capsule endoscopy (CCE) has been proposed as an alternative to colonoscopy for screening patients at average risk of colorectal cancer (CRC). A prospective national cohort was developed to assess relevance of CCE in real-life practice and its short- and long-term impacts on clinical management. Patients and methods  All patients who underwent a CCE in France were prospectively enrolled from January 2011 to May 2016 and reached annually by phone until May 2017. All CCE and colonoscopy reports were systematically collected. Results  During the study period, 689 CCEs were analyzed from 14 medical centers. Median follow-up time was 35 months [IQR: 12-50]. Indication for CCE was mainly for elderly patients (median age: 70 years, IQR: [61-79]) due to anesthetic or colonoscopy contraindication (n = 307; 44.6 %). Only 337 CCEs (48.9 %) were both complete and with adequate bowel preparation. Advanced neoplasia (adenoma with high-grade dysplasia or CRC) was diagnosed following 32 CCEs (4.6 %). Among patients who underwent colonoscopy or therapeutic surgery following CCE, 18.8 % of all advanced neoplasias (6/32) had not been diagnosed by CCE mainly due to technical issues. Performing a colonoscopy in the case of significant polyps or insufficient bowel cleansing or after an incomplete CCE allowed the diagnosis of 96.9 % of all identified advanced neoplasias (31/32). Conclusions  Outside the scope of academic trials, improvement is needed to increase the reliability of CCE as less than half were considered optimal i. e. complete with adequate bowel cleansing. Most of missed colonic advanced neoplasia were due to incomplete CCE with distal neoplasia location.

Castor oil as booster for colon capsule endoscopy preparation reduction: A prospective pilot study and patient questionnaire

BACKGROUND

Preparation for colon capsule endoscopy (CCE) requires a large liquid laxative volume for capsule excretion, which compromises the procedure's tolerability.

AIM

To assess the safety and utility of castor oil-boosted bowel preparation.

METHODS

This prospective cohort study including 20 patients (age range, 16-80 years; six men and 14 women) suspected of having colorectal disease was conducted at Kindai University Hospital from September 2017 to August 2019. All patients underwent CCE because of the following inclusion criteria: previous incomplete colonoscopy in other facility (n = 20), history of abdominal surgery (n = 7), or organ abnormalities such as multiple diverticulum (n = 4) and adhesion after surgery (n = 6). The exclusion criteria were as follows: Dysphagia, history of allergic reactions to the drugs used in this study (magnesium citrate, polyethylene glycol, metoclopramide, and castor oil), possibility of pregnancy, possibility of bowel obstruction or stenosis based on symptoms, or scheduled magnetic resonance imaging within 2 wk after CCE. The primary outcome was the capsule excretion rate within the battery life, as evaluated by the total large bowel observation rate, large bowel transit time, and bowel creasing level using a five-grade scale in different colorectal segments. The secondary outcomes were complications, colorectal lesion detection rates, and patients’ tolerability.

RESULTS

The castor oil-based regimen was implemented in 17 patients. Three patients cancelled CCE because they could tolerate castor oil, but not liquid laxatives. The capsule excretion rate within the battery life was 88% (15/17). The mean large bowel transit time was 236 min. Approximately 70% of patients had satisfactory colon cleansing levels. CCE detected colon polyps (14/17, 82%) and colonic diverticulum (4/12, 33%). The sensitivity, specificity, and diagnostic accuracy rates for detecting colorectal polyps (size ≥ 6 mm) were 76.9%, 75.0%, and 76.4%, respectively. The sensitivity, specificity, and diagnostic accuracy rates for detection of diverticulum were 100% each. Twelve patients (71%) rated CCE as more than “good”, confirming the new regimen’s tolerability. No serious adverse events occurred during this study.

CONCLUSION

The castor oil-based regimen could reduce bowel preparation dose and improve CCE tolerability.

The Differential Diagnosis of Colorectal Polyps Using Colon Capsule Endoscopy

Objective Although colorectal polyps (CPs) can be observed with colon capsule endoscopy (CCE), it is difficult to determine the type of polyp using CCE. The objective of this study was to differentiate adenomatous polyps (APs) from hyperplastic polyps (HPs) with CCE. Methods In this single-center retrospective study, an analysis was conducted on the same CPs with both CCE and colonoscopy (CS) and histopathologically diagnosed as AP or HP. The color difference (ΔE) between the polyp surface and the surrounding mucosa was calculated using the CIE1976 L*a*b* color space method on white light (WL), flexible spectral imaging color enhancement (FICE), and blue mode (BM) CP images. We investigated the ability of the ratio of the color differences (ΔE') to differentiate between APs and HPs. Results The size of all 51 polyps (34 APs, 17 HPs) was 7.5±4.6 mm with CCE and 7.3±4.2 mm with CS, and this difference was not significant (p=0.28). The FICEΔE' of APs was 3.3±1.8, which was significantly higher than the FICEΔE' of HPs (1.3±0.6; p<0.001). A receiver operating characteristic analysis showed that FICEΔE' was useful for differentiating between APs and HPs, with an area under the curve of 0.928 (95% confidence interval, 0.843-1). The sensitivity was 91.2%, and the specificity was 88.2% with a cut-off value of 1.758. Conclusion Using FICE on CCE images of CPs and applying the CIELAB color space method, we were able to differentiate between APs and HPs with high accuracy. This method has the potential to reduce unnecessary CS procedures.

Scoring Systems for Clinical Colon Capsule Endoscopy-All You Need to Know

In the constantly developing era of minimal diagnostic invasiveness, the role of colon capsule endoscopy in colonic examination is being increasingly recognised, especially in the context of curtailed endoscopy services due to the COVID-19 pandemic. It is a safe diagnostic tool with low adverse event rates. As with other endoscopic modalities, various colon capsule endoscopy scores allow the standardisation of reporting and reproducibility. As bowel cleanliness affects CCE’s diagnostic yield, a few operator-dependent scores (Leighton–Rex and CC-CLEAR scores) and a computer-dependent score (CAC score) have been developed to grade bowel cleanliness objectively. CCE can be used to monitor IBD mucosal disease activity through the UCEIS and the panenteric CECDAIic score for UC and CD, respectively. CCE may also have a role in CRC screening, given similar sensitivity and specificity rates to conventional colonoscopy to detect colonic polyps ≥ 10 mm and CRC. Given CCE’s diagnostic yield and reproducible clinical scores with high inter-observer agreements, CCE is fast becoming a suitable alternative to conventional colonoscopy in specific patient populations.

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.

Artificial Intelligence in Colorectal Cancer Screening, Diagnosis and Treatment. A New Era

The development of artificial intelligence (AI) algorithms has permeated the medical field with great success. The widespread use of AI technology in diagnosing and treating several types of cancer, especially colorectal cancer (CRC), is now attracting substantial attention. CRC, which represents the third most commonly diagnosed malignancy in both men and women, is considered a leading cause of cancer-related deaths globally. Our review herein aims to provide in-depth knowledge and analysis of the AI applications in CRC screening, diagnosis, and treatment based on current literature. We also explore the role of recent advances in AI systems regarding medical diagnosis and therapy, with several promising results. CRC is a highly preventable disease, and AI-assisted techniques in routine screening represent a pivotal step in declining incidence rates of this malignancy. So far, computer-aided detection and characterization systems have been developed to increase the detection rate of adenomas. Furthermore, CRC treatment enters a new era with robotic surgery and novel computer-assisted drug delivery techniques. At the same time, healthcare is rapidly moving toward precision or personalized medicine. Machine learning models have the potential to contribute to individual-based cancer care and transform the future of medicine.

Role of Capsule Endoscopy in Inflammatory Bowel Disease

In Crohn disease (CD), the use of capsule endoscopy (CE) for suspected versus established disease is very different. Most patients with CD are diagnosed with ileocolonoscopy. In patients with a negative ileocolonoscopy, CE is the next best test in suspected CD. In patients with established CD, the potential benefits of CE are rating severity of disease, establishing extent and distribution, and following mucosal healing in a treat to target strategy. In those with proximal small bowel disease, CE can help in diagnosis and prognostication. In ulcerative colitis, CE has a limited role, but that may change with evolving technology.

The Role of Video Capsule Endoscopy in Liver Disease

In the setting of chronic liver disease, capsule endoscopy is safe and well tolerated, making it an appealing diagnostic procedure. It is used mainly for the surveillance of esophageal varices, investigation of anemia, and exploration of the small bowel for complications of portal hypertension. Capsule endoscopy is recognized as a viable alternative in patients unable or unwilling to undergo upper gastrointestinal endoscopy for investigations of esophageal varices. In evaluating the small bowel of patients with liver disease and unexplained anemia, capsule endoscopy increases recognition of mucosal abnormalities, although their clinical significance is often unclear.

Second-generation colon capsule endoscopy for detection of colorectal polyps: Systematic review and meta-analysis of clinical trials

Background and study aims  Adherence to colorectal cancer (CRC) screening is still unsatisfactory in many countries, thereby limiting prevention of CRC. Colon capsule endoscopy (CCE), a minimally invasive procedure, could be an alternative to fecal immunochemical tests or optical colonoscopy for CRC screening, and might increase adherence in CRC screening. This systematic review and meta-analysis evaluates the diagnostic accuracy of CCE compared to optical colonoscopy (OC) as the gold standard, adequacy of bowel preparation regimes and the patient perspective on diagnostic measures. Methods  We conducted a systematic literature search in PubMed, EMBASE and the Cochrane Register for Clinical Trials. Pooled estimates for sensitivity, specificity and the diagnostic odds ratio with their respective 95 % confidence intervals (CI) were calculated for studies providing sufficient data. Results  Of 840 initially identified studies, 13 were included in the systematic review and up to 9 in the meta-analysis. The pooled sensitivities and specificities for polyps ≥ 6 mm were 87 % (95 % CI: 83 %-90 %) and 87 % (95 % CI: 76 %-93 %) in 8 studies, respectively. For polyps ≥ 10 mm, the pooled estimates for sensitivities and specificities were 87 % (95 % CI: 83 %-90 %) and 95 % (95 % CI: 92 %-97 %) in 9 studies, respectively. A patients' perspective was assessed in 31 % (n = 4) of studies, and no preference of CCE over OC was reported. Bowel preparation was adequate in 61 % to 92 % of CCE exams. Conclusions  CCE provides high diagnostic accuracy in an adequately cleaned large bowel. Conclusive findings on patient perspectives require further studies to increase acceptance/adherence of CCE for CRC screening.

Diagnostic yield of colon capsule endoscopy for Crohn's disease lesions in the whole gastrointestinal tract

BACKGROUND

Crohn's disease (CD) can involve the upper gastrointestinal (GI) tract as well as the small and large bowel. PillCam colon capsule endoscopy (PCCE-2) enables observation of the whole GI tract, but its diagnostic yield for CD lesions in the whole GI tract remains unknown.

AIM

To elucidate the diagnostic yield of PCCE-2 in patients with CD.

METHODS

Patients with CD who underwent PCCE-2 and double-balloon endoscopy (DBE) using oral and anal approaches were evaluated for CD lesions in the whole GI tract. We divided the small bowel into three segments (jejunum, ileum, and terminal ileum), and the large bowel into four segments (right colon, transverse colon, left colon, rectum). Detection of ulcer scars, erosion, ulcers, bamboo joint-like appearance, and notch-like appearance was assessed in each segment. The diagnostic yield of PCCE-2 was analyzed based on the DBE results as the gold standard.

RESULTS

Of the total 124 segments, the sensitivities of PCCE-2 for ulcer scars, erosion, and ulcers were 83.3%, 93.8%, and 88.5%, respectively, and the specificities were 76.0%, 78.3%, and 81.6%, respectively. For the 60 small bowel segments, the sensitivities were 84.2%, 95.5%, and 90.0%, respectively, and the specificities were 63.4%, 86.8%, and 87.5%, respectively. For the 64 large bowel segments, the sensitivities were 80.0%, 90.0%, and 83.3%, respectively, and the specificities were 84.7%, 72.2%, and 77.6%, respectively.

CONCLUSION

PCCE-2 provides a high diagnostic yield for lesions in the whole GI tract of patients with CD. Thus, we recommend its use as a pan-enteric tool in clinical settings.

Deep learning for wireless capsule endoscopy: a systematic review and meta-analysis

BACKGROUND AND AIMS

Deep learning is an innovative algorithm based on neural networks. Wireless capsule endoscopy (WCE) is considered the criterion standard for detecting small-bowel diseases. Manual examination of WCE is time-consuming and can benefit from automatic detection using artificial intelligence (AI). We aimed to perform a systematic review of the current literature pertaining to deep learning implementation in WCE.

METHODS

We conducted a search in PubMed for all original publications on the subject of deep learning applications in WCE published between January 1, 2016 and December 15, 2019. Evaluation of the risk of bias was performed using tailored Quality Assessment of Diagnostic Accuracy Studies-2. Pooled sensitivity and specificity were calculated. Summary receiver operating characteristic curves were plotted.

RESULTS

Of the 45 studies retrieved, 19 studies were included. All studies were retrospective. Deep learning applications for WCE included detection of ulcers, polyps, celiac disease, bleeding, and hookworm. Detection accuracy was above 90% for most studies and diseases. Pooled sensitivity and specificity for ulcer detection were .95 (95% confidence interval [CI], .89-.98) and .94 (95% CI, .90-.96), respectively. Pooled sensitivity and specificity for bleeding or bleeding source were .98 (95% CI, .96-.99) and .99 (95% CI, .97-.99), respectively.

CONCLUSIONS

Deep learning has achieved excellent performance for the detection of a range of diseases in WCE. Notwithstanding, current research is based on retrospective studies with a high risk of bias. Thus, future prospective, multicenter studies are necessary for this technology to be implemented in the clinical use of WCE.

Colon Capsule Endoscopy: Indications, Findings, and Complications - Data from a Prospective German Colon Capsule Registry Trial (DEKOR)

Background/Aims

Reliable and especially widely accepted preventive measures are crucial to further reduce the incidence of colorectal cancer (CRC). Colon capsule endoscopy (CCE) might increase the screening numbers among patients unable or unwilling to undergo conventional colonoscopy. This registry trial aimed to document and determine the CCE indications, findings, complications, and adverse events in outpatient practices and clinics throughout Germany.

Methods

Patients undergoing CCE between 2010 and 2015 were enrolled in this prospective multicenter registry trial at six German centers. Patient demographics, outcomes, and complications were evaluated.

Results

A total of 161 patients were included. Of the CCE evaluations, 111 (68.9%) were considered successful. Pathological findings in the colon (n=92, 60.1%) and in the remaining gastrointestinal tract (n=38, 24.8%) were recorded. The main finding was the presence of polyps (n=52, 32.3%). Furthermore, five carcinomas (3.1%) were detected and histologically confirmed later. Adequate bowel cleanliness was more likely to be achieved in the outpatient setting (p<0.0001). Interestingly, 85 patients (55.6%) chose to undergo CCE based on personal motivation.

Conclusions

CCE seems to be a reliable and safe endoscopic tool for screening for CRC and detecting other diseases. Its patient acceptance and feasibility seems to be high, especially in the outpatient setting.

Applications of paper as a support material in biomedical sciences: A decadal review

In human history, the paper has long been used as a platform to record and preserve information. However, over the decades, paper has found its application in Biomedical Sciences, too. Both paper-based microfluidic devices (μPADs) and paper-based cultures and scaffolds have shown immense potential to be used as a sensor as well as a supporting material for in vitro tissue engineering. μPADs can be used to perform low-cost and fast biomolecular assays at Point-Of-Care (POC). They are being used to detect various biomarkers like viral proteins, metabolites, oncogenes, and antigens; and conditions like Venous Thromboembolism (VTE). On the other hand, the paper has also been used to develop paper-based 3D cultures and scaffolds to test drugs, and monitor cytotoxic effects in vitro cell microenvironments and also as implantable tissues. In this review, we intend to enumerate the development in the field of μPADs, paper-based cell cultures, and paper-based scaffolds and their plethora of applications over the last decade.

Colon capsule endoscopy

There are multiple indications for luminal imaging of the colon. From assessment of known disease, to diagnosing new pathology; intra-luminal visualisation is the mainstay of gastrointestinal diagnosis. Colonoscopy and radiological imaging are currently the most frequently deployed diagnostic methods. However, both have an associated risk profile, have significant resource pressures and are not universally tolerated. Colon capsule endoscopy (CCE) offers an adjunct to these diagnostic options. In this narrative review the utility of CCE is described. Its current uses, potential benefits and future developments are also discussed.

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.

Accuracy of Colon Capsule Endoscopy for Colorectal Neoplasia Detection in Individuals Referred for a Screening Colonoscopy

Backround

Capsule colonoscopy might present an alternative to colonoscopy for colorectal neoplasia screening.

Aim

To assess the accuracy of second-generation capsule colonoscopy (CCE2) for colorectal neoplasia detection compared with conventional colonoscopy (CC).

Methods

From 2011-2015, we performed a multicenter, prospective, cross-over study evaluating the use of CCE2 as a possible colorectal cancer (CRC) screening test based on the assessment of the method's characteristics (accuracy) and safety and patient acceptance of the routine. Enrolled participants fulfilled the CRC screening population criteria if they were asymptomatic, were older than 50, and had no personal or familial history of colorectal neoplasia. The primary outcome was accuracy for the detection of polyps ≥ 6 mm. Secondary outcomes were accuracy for all polyps, polyps ≥ 10 mm, adenomas ≥ 10 mm, and cancers, the quality of bowel cleansing, safety, and CCE2 acceptability by the screening population.

Results

A total of 236 individuals were examined; 11 patients (5%) were excluded. Therefore, 225 subjects (95%) were considered in the intention-to-screen (ITS) group. A total of 201 patients (89%) completed both examinations successfully (per protocol group). In the ITS group, polyps were diagnosed during CC in 114 subjects (51%); polyps ≥ 6 mm, polyps ≥ 10 mm, and adenomas ≥ 10 mm were diagnosed in 34 (15%), 16 (7%), and 11 (5%) patients, respectively. The sensitivity of CCE2 for polyps ≥ 6 mm, polyps ≥ 10 mm, and adenomas ≥ 10 mm was 79% (95% confidence interval (CI): 62-91%), 88% (95% CI: 62-98%), and 100% (95% CI: 72-100%), respectively.

Conclusion

Second-generation capsule colonoscopy is a safe, noninvasive, and sensitive method for colorectal neoplasia detection although CC remains the preferred method for considerable proportion of subjects. CCE2 may therefore be accepted as the primary screening test for colorectal cancer screening.

On Structural Entropy and Spatial Filling Factor Analysis of Colonoscopy Pictures

Colonoscopy is the standard device for diagnosing colorectal cancer, which develops from little lesions on the bowel wall called polyps. The Rényi entropies-based structural entropy and spatial filling factor are two scale- and resolution-independent quantities that characterize the shape of a probability distribution with the help of characteristic curves of the structural entropy–spatial filling factor map. This alternative definition of structural entropy is easy to calculate, independent of the image resolution, and does not require the calculation of neighbor statistics, unlike the other graph-based structural entropies.The distant goal of this study was to help computer aided diagnosis in finding colorectal polyps by making the Rényi entropy based structural entropy more understood. The direct goal was to determine characteristic curves that can differentiate between polyps and other structure on the picture. After analyzing the distribution of colonoscopy picture color channels, the typical structures were modeled with simple geometrical functions and the structural entropy–spatial filling factor characteristic curves were determined for these model structures for various parameter sets. A colonoscopy image analying method, i.e., the line- or column-wise scanning of the picture, was also tested, with satisfactory matching of the characteristic curve and the image.

Multicenter feasibility study of bowel preparation with castor oil for colon capsule endoscopy

BACKGROUND AND AIM

Extensive use of laxatives and incomplete excretion rates are problematic for colon capsule endoscopy (CCE). The aim of the present study was to determine the effectiveness of castor oil as a booster.

METHODS

At four Japanese hospitals, 319 examinees undergoing CCE were enrolled retrospectively. Before and after the introduction of castor oil, other preparation reagents were unchanged.

RESULTS

Of 319 examinees who underwent CCE, 152 and 167 examinees took regimens with castor oil (between November 2013 and June 2016) and without castor oil (between October 2015 and September 2017), respectively. Capsule excretion rates within its battery life in the groups with and without castor oil were 97% and 81%, respectively (P < 0.0001). Multivariate analysis showed that ages younger than 65 years (adjusted odds ratio [OR], 3.00; P = 0.0048), male gender (adjusted OR, 3.20; P = 0.0051), and use of castor oil (adjusted OR, 6.29; P = 0.0003) were predictors of capsule excretion within its battery life. Small bowel transit time was shorter and total volume of lavage and fluid intake was lower with castor oil than without (P = 0.0154 and 0.0013, respectively). Overall adequate cleansing level ratios with and without castor oil were 74% and 83%, respectively (P = 0.0713). Per-examinee sensitivity for polyps ≥6 mm with and without castor oil was 83% and 85%, respectively, with specificities of 80% and 78%, respectively.

CONCLUSION

Bowel preparation with castor oil was effective for improving capsule excretion rate and reducing liquid loading.

Automatic Classification of Label-Free Cells from Small Cell Lung Cancer and Poorly Differentiated Lung Adenocarcinoma with 2D Light Scattering Static Cytometry and Machine Learning

Small cell lung cancer (SCLC) needs to be classified from poorly differentiated lung adenocarcinoma (PDLAC) for appropriate treatment of lung cancer patients. Currently, the classification is achieved by experienced clinicians, radiologists and pathologists based on subjective and qualitative analysis of imaging, cytological and immunohistochemical (IHC) features. Label-free classification of lung cancer cell lines is developed here by using two-dimensional (2D) light scattering static cytometric technique. Measurements of scattered light at forward scattering (FSC) and side scattering (SSC) by using conventional cytometry show that SCLC cells are overlapped with PDLAC cells. However, our 2D light scattering static cytometer reveals remarkable differences between the 2D light scattering patterns of SCLC cell lines (H209 and H69) and PDLAC cell line (SK-LU-1). By adopting support vector machine (SVM) classifier with leave-one-out cross-validation (LOO-CV), SCLC and PDLAC cells are automatically classified with an accuracy of 99.87%. Our label-free 2D light scattering static cytometer may serve as a new, accurate, and easy-to-use method for the automatic classification of SCLC and PDLAC cells. © 2018 International Society for Advancement of Cytometry.

PillCamColon2 after incomplete colonoscopy - A prospective multicenter study

AIM

To evaluate the ability of PillCamColon2 to visualize colonic segments missed by incomplete optical colonoscopy (OC) and to assess the diagnostic yield.

METHODS

This prospective multicentre study included 81 patients from nine centres who underwent second-generation colon capsule endoscopy (CCE) following incomplete OC performed by an experienced gastroenterologist (> 1000 colonoscopies). Patients with stenosis were excluded. According to patient preferences, CCE was performed the following day (protocol A) after staying on clear liquids and 0.75 L Moviprep in the morning or within 30 d after new split-dose Moviprep (protocol B). Boosts consisted of 0.75 L and 0.25 L Moviprep, and phospho-soda was given as a rescue if the capsule was not excreted after seven hours.

RESULTS

Seventy-four patients were analysed (51% of them in group A; 49% in group B). Bowel cleansing was adequate in 67% of cases, and CCE could visualize colonic segments missed by incomplete colonoscopy in 90% of patients under protocol A and 97% of patients under protocol B (P = 0.35, n.s.). Significant polyps including adenocarcinoma were detected in 24% of cases. Detection rates for all polyps and significant polyps per patient were similar in both protocols. Polyps were found predominantly in the right colon (86%) in segments that were not reached by OC. Extracolonic findings - such as reflux esophagitis, suspected Barrett esophagus, upper GI-bleeding, gastric polyps, gastric erosions and angiectasia - were detected in eight patients. PillCamColon2 capsule was retained in the ileum of one patient (1.4%) without symptoms and removed during an uneventful resection for unknown Crohn’s disease that was diagnosed as the cause of anemia, which was the indication for colonoscopy. CCE was well tolerated. One patient suffered from self-limiting vomiting after consuming the phospho-soda.

CONCLUSION

Second-generation CCE using a low-volume preparation is useful after incomplete OC, and it allows for the detection of additional relevant findings, but cleansing efficiency could be improved.