Current and Future Use of Esophageal Capsule Endoscopy

Cascade-EC Network: Recognition of Gastrointestinal Multiple Lesions Based on EfficientNet and CA_stm_Retinanet

Capsule endoscopy (CE) is non-invasive and painless during gastrointestinal examination. However, capsule endoscopy can increase the workload of image reviewing for clinicians, making it prone to missed and misdiagnosed diagnoses. Current researches primarily concentrated on binary classifiers, multiple classifiers targeting fewer than four abnormality types and detectors within a specific segment of the digestive tract, and segmenters for a single type of anomaly. Due to intra-class variations, the task of creating a unified scheme for detecting multiple gastrointestinal diseases is particularly challenging. A cascade neural network designed in this study, Cascade-EC, can automatically identify and localize four types of gastrointestinal lesions in CE images: angiectasis, bleeding, erosion, and polyp. Cascade-EC consists of EfficientNet for image classification and CA_stm_Retinanet for lesion detection and location. As the first layer of Cascade-EC, the EfficientNet network classifies CE images. CA_stm_Retinanet, as the second layer, performs the target detection and location task on the classified image. CA_stm_Retinanet adopts the general architecture of Retinanet. Its feature extraction module is the CA_stm_Backbone from the stack of CA_stm Block. CA_stm Block adopts the split-transform-merge strategy and introduces the coordinate attention. The dataset in this study is from Shanghai East Hospital, collected by PillCam SB3 and AnKon capsule endoscopes, which contains a total of 7936 images of 317 patients from the years 2017 to 2021. In the testing set, the average precision of Cascade-EC in the multi-lesions classification task was 94.55%, the average recall was 90.60%, and the average F1 score was 92.26%. The mean mAP@ 0.5 of Cascade-EC for detecting the four types of diseases is 85.88%. The experimental results show that compared with a single target detection network, Cascade-EC has better performance and can effectively assist clinicians to classify and detect multiple lesions in CE images.

Detachable string magnetically controlled capsule endoscopy for the noninvasive diagnosis of esophageal diseases: A prospective, blind clinical study

BACKGROUND

Traditional esophagogastroduodenoscopy (EGD), an invasive examination method, can cause discomfort and pain in patients. In contrast, magnetically controlled capsule endoscopy (MCE), a noninvasive method, is being applied for the detection of stomach and small intestinal diseases, but its application in treating esophageal diseases is not widespread.

AIM

To evaluate the safety and efficacy of detachable string MCE (ds-MCE) for the diagnosis of esophageal diseases.

METHODS

Fifty patients who had been diagnosed with esophageal diseases were prospectively recruited for this clinical study and underwent ds-MCE and conventional EGD. The primary endpoints included the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of ds-MCE for patients with esophageal diseases. The secondary endpoints consisted of visualizing the esophageal and dentate lines, as well as the subjects' tolerance of the procedure.

RESULTS

Using EGD as the gold standard, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of ds-MCE for esophageal disease detection were 85.71%, 86.21%, 81.82%, 89.29%, and 86%, respectively. ds-MCE was more comfortable and convenient than EGD was, with 80% of patients feeling that ds-MCE examination was very comfortable or comfortable and 50% of patients believing that detachable string v examination was very convenient.

CONCLUSION

This study revealed that ds-MCE has the same diagnostic effects as traditional EGD for esophageal diseases and is more comfortable and convenient than EGD, providing a novel noninvasive method for treating esophageal diseases.

The Future of Minimally Invasive Capsule Panendoscopy: Robotic Precision, Wireless Imaging and AI-Driven Insights

In the early 2000s, the introduction of single-camera wireless capsule endoscopy (CE) redefined small bowel study. Progress continued with the development of double-camera devices, first for the colon and rectum, and then, for panenteric assessment. Advancements continued with magnetic capsule endoscopy (MCE), particularly when assisted by a robotic arm, designed to enhance gastric evaluation. Indeed, as CE provides full visualization of the entire gastrointestinal (GI) tract, a minimally invasive capsule panendoscopy (CPE) could be a feasible alternative, despite its time-consuming nature and learning curve, assuming appropriate bowel cleansing has been carried out. Recent progress in artificial intelligence (AI), particularly in the development of convolutional neural networks (CNN) for CE auxiliary reading (detecting and diagnosing), may provide the missing link in fulfilling the goal of establishing the use of panendoscopy, although prospective studies are still needed to validate these models in actual clinical scenarios. Recent CE advancements will be discussed, focusing on the current evidence on CNN developments, and their real-life implementation potential and associated ethical challenges.

New Techniques to Screen for Barrett Esophagus

Barrett esophagus (BE) is the only known precursor to esophageal adenocarcinoma (EAC), a cancer that continues to have a poor 5-year survival rate of 20%. Current BE screening strategies aim to detect BE and EAC at early, curable stages, but the majority of patients with EAC are diagnosed outside of BE screening and surveillance programs. Guidelines around the world suggest screening for BE in patients with gastroesophageal reflux disease (GERD) and additional demographic and clinical risk factors using high-definition white-light endoscopy (HDWLE). However, current strategies relying on HDWLE are problematic with high direct and indirect costs, procedural risks, and limitations in patient selection owing to the low sensitivity of GERD as a risk factor for detection of BE. In an effort to address these shortcomings, a variety of other screening strategies are under investigation, including risk prediction algorithms, noninvasive cell collection devices, and other new technologies to make screening more efficient and cost-effective. At this time, only cell collection devices have been integrated into professional guidelines, and clinical implementation of alternatives to endoscopy has lagged. In the future, screening may be personalized using a combination of different screening modalities. This article discusses the current state of BE screening and new approaches that may alter the future of screening.

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett’s esophagus screening and surveillance

Barrett’s esophagus (BE) is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal adenocarcinoma. Current guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness, availability of a trained specialist, patient logistics and cost. Trans-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and costs. Non-endoscopic modalities, in comparison, require minimal intervention, can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance, particularly in patents at low risk for BE. These include newer generations of esophageal capsule endoscopy which provides direct visualization of BE, and tethered capsule endomicroscopy which can obtain high-resolution images of the esophagus. Various cell collection devices coupled with biomarkers have been used for BE screening. Cytosponge, in combination with TFF3, as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various biomarkers. Other modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable outcomes. Use of these cell collection methods for BE surveillance is a potential area of future research.

Dynamic tracking effect of a magnetic navigated dual hemisphere capsule robot

For diagnostic and therapeutic applications in spacious spots of the gastrointestinal (GI) tract, the single rigid body capsule clinically applied is difficult to realize the fix-point posture adjustment function manipulated by the external permanent magnet system using the static balance control because the posture alignment and the locomotion interfere with each other. To realize this function easily, the dual hemisphere capsule robot (DHCR) is proposed, based on tracking effect—the axis of DHCR keeps tracking the normal orientation of the spatial universal rotating magnetic vector (SURMV). Since tracking effect employs dynamic balance control, dynamic stability of the DHCR system affects posture alignment performance. This paper focuses on posture alignment dynamic modeling and the influence of the magnetic flux density and the angular velocity of the SURMV, along with the damping coefficient of the GI tract surface on stability, obtaining the stability domains of parameters. Furthermore, to reduce error due to the uncertainties in complex GI tract environment, the sliding mode controller based on nominal model is proposed to achieve more accurate dynamic tracking, and Lyapunov theorem is employed to assess stability of controller. Finally, the tracking effect is verified through simulations and experiments, indicating that the fix-point posture adjustment can be realized with higher accuracy and efficiency.

Proton pump inhibitor in the prevention of upper gastrointestinal mucosal injury associated with dual antiplatelet therapy after coronary artery bypass grafting (DACAB-GI-2): study protocol for a randomized controlled trial

Background

Dual antiplatelet therapy (DAPT) is recommended in secondary prevention after coronary artery bypass grafting (CABG), but it is inevitably associated with the risk of bleeding, of which gastrointestinal bleeding accounts for more than half. Proton pump inhibitors (PPIs) may increase the risk of major cardiovascular adverse events when reducing the risk of upper gastrointestinal bleeding. Therefore, the optimal duration of a PPI in combination with DAPT is unclear.

Methods

The “Proton Pump Inhibitor Preventing Upper Gastrointestinal Injury in Patients on Dual Antiplatelet Therapy after CABG” (DACAB-GI-2) study is a prospective, single-center, open-label, parallel, randomized controlled trial. A total of 232 eligible subjects who are scheduled or initiated on DAPT (clopidogrel plus aspirin or ticagrelor plus aspirin) for 12 months immediately after CABG will be enrolled and be randomized in a 1:1 ratio to either a 12-month pantoprazole treatment arm or a 1-month treatment arm. The primary outcome is to assess the rate of gastroduodenal erosions and ulcers evaluated by esophagogastroduodenoscopy (EGD) within 12 months after randomization, based on the modified Lanza score. Secondary outcomes include reflux esophagitis and upper gastrointestinal bleeding. Other pre-specified outcomes include major adverse cardiovascular events, graft failure, and all-cause death.

Discussion

This study aims to compare the efficacy and safety of 12 months and 1 month of pantoprazole treatment in preventing DAPT-related upper gastrointestinal mucosal injury after CABG.

Trial registration

ClinicalTrials.gov NCT03908593.

Capsule endoscopy - a non-invasive modality to investigate the GI tract: out with the old and in with the new?

INTRODUCTION

Capsule endoscopy has had significant development since it was introduced into the field of medicine in 2000. It is non-invasive, well tolerated, does not require sedation and is a first-line small bowel investigative modality. As it transits through the entire gastrointestinal (GI) tract, it has the potential to provide a pan-enteric examination.

AREAS COVERED

In this review we will discuss the new diagnostic modalities along with traditional methods which have been used for examination of the gastro intestinal (GI) tract. The main focus of this review will be on the use of capsule endoscopy for pan-enteric examination.

EXPERT OPINION

Capsule endoscopy is an accepted first-line investigation for the small bowel. Diagnostic sensitivity of the colon capsule is comparable to colonoscopy in controlled trials and is being evaluated in high-risk patients in routine clinical practice in national programs. Preliminary data suggest that a magnetic-controlled examination of the upper GI tract could be developed to enable a complete upper GI examination.

Development and Application of Magnetically Controlled Capsule Endoscopy in Detecting Gastric Lesions

In the past 20 years, several magnetically controlled capsule endoscopes (MCCE) have been developed for the evaluation of gastric lesions, including NaviCam (ANKON), MiroCam-Navi (Intromedic), Endocapsule MGCE (Olympus and Siemens), SMCE (JIFU), and FAMCE (Jinshan). Although limited to observing esophageal and duodenal lesions and lacking the ability of biopsy, MCCE has the advantages of comfort, safety, no anesthesia, no risk of cross-infection, and high acceptability. Several high-quality RCTs showed that the diagnostic accuracy of MCCE is comparable to the traditional gastroscopy. Due to the nonnecessity of anesthesia, MCCE may be more suitable for the elderly with obvious comorbidities as well as children. With more evidences accumulated and more innovative technologies developed, MCCE is expected to be an important tool for screening of early gastric cancer or the diagnosis of gastric diseases.

Applicability of colon capsule endoscopy as pan-endoscopy: From bowel preparation, transit, and rating times to completion rate and patient acceptance

Background and study aims  Colon capsule endoscopy (CCE) has the potential to explore the entire gastrointestinal tract. The aim of this study was to assess the applicability of CCE as pan-endoscopy. Patients and methods  Healthy participants received CCE with bowel preparation (bisacodyl, polyethylene electrolyte glycol (PEG) + ascorbic acid) and booster regimen (metoclopramide, oral sulfate solution (OSS)). For each segment of the gastrointestinal tract, the following quality parameters were assessed: cleanliness, transit times, reading times, patient acceptance and safety of the procedure. When all gastrointestinal segments had cleansing score good or excellent, cleanliness of the whole gastrointestinal tract was assessed as good. Participants' expected and perceived burden was assessed by questionnaires and participants were asked to grade the procedure (scale 0-10). All serious adverse events (SAEs) were documented. Results  A total of 451 CCE procedures were analyzed. A good cleansing score was achieved in the stomach in 69.6%, in the SB in 99.1 % and in the colon in 76.6 %. Cleanliness of the whole gastrointestinal tract was good in 52.8 % of the participants. CCE median transit time of the whole gastrointestinal tract was 583 minutes IQR 303-659). The capsule reached the descending colon in 94.7 %. Median reading time per procedure was 70 minutes (IQR 57-83). Participants graded the procedure with a 7.8. There were no procedure-related SAEs. Conclusions  CCE as pan-endoscopy has shown to be a safe procedure with good patient acceptance. When cleanliness of all gastrointestinal segments per patient, completion rate and reading time will be improved, CCE can be applied as a good non-invasive alternative to evaluate the gastrointestinal tract.

Innovations in Screening Tools for Barrett's Esophagus and Esophageal Adenocarcinoma

PURPOSE OF REVIEW

Esophageal adenocarcinoma (EAC) is a lethal disease with rapidly rising incidence. Screening for EAC and its metaplastic precursor, Barrett's esophagus (BE), followed by endoscopic surveillance and endoscopic treatment of dysplasia or early EAC are promising approaches to decreasing EAC incidence and EAC mortality. Historically, screening for EAC has been completed with a traditional per-oral esophagogastroduodenoscopy (EGD); however, this method has limitations including cost, tolerability, and accessibility. For this reason, much effort has been put forward to develop more effective, minimally invasive, and accessible BE and EAC screening tools. The purpose of this review is to describe recent developments of these novel tools.

RECENT FINDINGS

While endoscopic alternatives such as transnasal endoscopy are cheaper and well tolerated, they have not gained acceptance. Non-endoscopic modalities namely, swallowable cell collection devices coupled with biomarker analysis have been found to have excellent performance characteristics, tolerability, and cost effectiveness. In this article, we provide an update on innovative developments in EAC/BE screening modalities including transnasal endoscopy, capsule endomicroscopy, swallowable cell collection devices, and exhaled volatile organic compound analyses.

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.

Examination of Entire Gastrointestinal Tract: A Perspective of Mouth to Anus (M2A) Capsule Endoscopy

Capsule endoscopy (CE) is the only non-invasive diagnostic tool that enables the direct visualization of the gastrointestinal (GI) tract. Even though CE was initially developed for small-bowel investigation, its clinical application is expanding, and technological advances continue. The final iteration of CE will be a mouth to anus (M2A) capsule that investigates the entire GI tract by the ingestion of a single capsule. This narrative review describes the current developmental status of CE and discusses the possibility of realizing an M2A capsule and what needs to be overcome in the future.

Next-generation ingestible devices: sensing, locomotion and navigation

There is significant interest in exploring the human body's internal activities and measuring important parameters to understand, treat and diagnose the digestive system environment and related diseases. Wireless capsule endoscopy (WCE) is widely used for gastrointestinal (GI) tract exploration due to its effectiveness as it provides no pain and is totally tolerated by the patient. Current ingestible sensing technology provides a valuable diagnostic tool to establish a platform for monitoring the physiological and biological activities inside the human body. It is also used for visualizing the GI tract to observe abnormalities by recording the internal cavity while moving. However, the capsule endoscopy is still passive, and there is no successful locomotion method to control its mobility through the whole GI tract. Drug delivery, localization of abnormalities, cost reduction and time consumption are improvements that can be gained from having active ingestible WCEs. In this article, the current technological developments of ingestible devices including sensing, locomotion and navigation are discussed and compared. The main features required to implement next-generation active WCEs are explored. The methods are evaluated in terms of the most important features such as safety, velocity, complexity of design, control, and power consumption.

Novel Clinical Applications and Technical Developments in Video Capsule Endoscopy

Video capsule endoscopy is entering its third decade. After slow acceptance, it has become the gold standard in diagnosing small intestinal disorders. This article summarizes new practical applications for capsule endoscopy outside the small intestine. From 2 randomized controlled trials, it is becoming clear that it has a role in the management of patients with hematemesis and nonhematemesis bleeding. Under active investigation are novel applications of capsule technology, including the potential ability to sample luminal contents or tissue, self-propelled capsules, incorporation of other imaging techniques beyond white light, such as ultrasound and fluorescents, and the possibility of drug delivery.

Detachable string magnetically controlled capsule endoscopy for complete observation of the upper gastrointestinal tract

BACKGROUND

Wireless magnetically controlled capsule endoscopy (WMCCE) was feasible, well tolerated, highly acceptable, and had high consistency in diagnosis of gastric diseases with esophagogastroduodenoscopy (EGD). But WMCCE is not suitable for inspection of the esophagus. We developed detachable string magnetically controlled capsule endoscopy (DS-MCCE) to observe gastroesophageal diseases.

METHODS

A total of 60 volunteers were enrolled. Thirty participants underwent DS-MCCE, and the other 30 underwent WMCCE. The primary outcome measures included swallowing time, esophageal transit time, the whole examination time, grade of air-bubble interference on esophageal, gastric preparation, visualization of Z-line and gastric mucosa, and discomfort scores.

RESULTS

The esophageal time (222.53 ± 107.53 s vs. 49.50 ± 34.90 s, P < 0.001) and the whole examination time (26.53 ± 6.33 min vs. 15.97±4.90 min, P < 0.001) in DS-MCCE group were longer than in WMCCE group. DS-MCCE had a significantly better visualization of Z-line visualization. Visualization of the gastric mucosa was assessed as good in 24 (80%) participants for DS-MCCE and 26 (86.6%) for WMCCE, moderate in 6 (20%) with DS-MCCE as compared with 4 (13.3%) with WMCCE. The visualization of gastric cardia for DS-MCCE was better than for WMCCE (100 vs 80%, P = 0.024). The visualization of gastric angle, antrum, and pylorus in DS-MCCE group was not as good as in WMCCE group (80 vs. 100%, 80 vs. 100%, 83.3 vs. 100%, P = 0.024).

CONCLUSIONS

DS-MCCE is feasible and well tolerated in the diagnosis of gastroesophageal diseases. For people who cannot stand conventional EGD or with contraindication of EGD, DS-MCCE may be an excellent alternative screening modality.

Esophageal Cancer: An Updated Review

The incidence of esophageal cancer (EC) is on the rise. With the distinct subtypes of adenocarcinoma and squamous cell carcinoma comes specific risk factors, and as a result, people of certain regions of the world can be more prone to a subtype. For example, squamous cell carcinoma of the esophagus has the highest incidence in eastern Africa and eastern Asia, with smoking being a major risk factor, whereas adenocarcinoma is more prevalent in North America and western Europe, with gastroesophageal reflux disease being a leading risk factor. With that being said, adenocarcinoma and squamous cell carcinoma have similar and unfortunately poor survival rates, partly because EC is prone to early metastasis given that the esophagus does not have a serosa, as well as the superficial nature of its lymphatics compared with the rest of the gastrointestinal tract. This makes early detection of the utmost importance, and certain patients have been shown to have the benefit of screening/surveillance endoscopies, including those with Barrett's esophagus, lye-induced/caustic strictures, tylosis, and Peutz-Jeghers syndrome. Until treatments significantly improve, identifying EC at the earliest stage will have the best success for patient outcomes, and further elucidation of its pathogenesis and risk factors may lead to identifying other high-risk groups that should be screened.

Artificial intelligence and deep learning for small bowel capsule endoscopy

Capsule endoscopy is ideally suited to artificial intelligence-based interpretation given its reliance on pattern recognition in still images. Time saving viewing modes and lesion detection features currently available rely on machine learning algorithms, a form of artificial intelligence. Current software necessitates close human supervision given poor sensitivity relative to an expert reader. However, with the advent of deep learning, artificial intelligence is becoming increasingly reliable and will be increasingly relied upon. We review the major advances in artificial intelligence for capsule endoscopy in recent publications and briefly review artificial intelligence development for historical understanding. Importantly, recent advancements in artificial intelligence have not yet been incorporated into practice and it is immature to judge the potential of this technology based on current platforms. Remaining regulatory and standardization hurdles are being overcome and artificial intelligence-based clinical applications are likely to proliferate rapidly.

What is the effective clinical use of small bowel capsule endoscopy in real life?

Capsule endoscopy is a noninvasive and easy method for evaluating the gastrointestinal tract. Since the wireless capsule endoscopy system was first developed, many new technical improvements have been made in order to gain maximum benefit from the procedure. However, at this stage, it remains a diagnostic modality, the main indication for its use being obscure gastrointestinal bleeding. Capsule endoscopy is only contraindicated in symptomatic intestinal obstruction. New indications for use and therapeutic options may become possible with the further development of nanotechnologies.

USB capsule endoscope for retrograde imaging of the esophagus

SIGNIFICANCE

Endoscopes represent electro-optical devices that are used to visualize internal body cavities. The specialized endoscopic procedure of the upper gastrointestinal tract from the esophagus down to the duodenum is called an esophagogastroduodenoscopy.

AIM

We bring our newly developed capsule endoscopy device as a promising alternative diagnostic method for visualization of the upper gastrointestinal tract.

APPROACH

Capsule endoscopy has become an attractive method that uses a tiny wireless camera to take pictures of the digestive tract. Existing esophageal capsule endoscopy does not allow a retrograde view of the esophagus while retrograde scanning can provide information on the esophageal pathology.

RESULTS

In comparison to the existing esophageal capsule endoscopy, our system is much simpler and cheaper due to the need for fewer electronic devices. Moreover, its use is not limited by the capacity of the batteries used by existing capsule endoscopes. The new esophageal endoscopic system was created by combining the universal serial bus (USB) endoscope module with the thin power wires that are routed through the USB port to the computer.

CONCLUSIONS

The endoscope was tested on a volunteer without any side effects such as nausea, belching, and general discomfort. The examination of the patient is performed in a sitting position and the patient discomfort during the examination is minimal so it can be performed without anesthesia.

Recent advances in understanding and preventing oesophageal cancer

Oesophageal cancer is a common cancer that continues to have a poor survival. This is largely in part due to its late diagnosis and early metastatic spread. Currently, screening is limited to patients with multiple risk factors via a relatively invasive technique. However, there is a large proportion of patients diagnosed with oesophageal cancer who have not been screened. This has warranted the development of new screening techniques that could be implemented more widely and lead to earlier identification and subsequently improvements in survival rates. This article also explores progress in the surveillance of Barrett’s oesophagus, a pre-malignant condition for the development of oesophageal adenocarcinoma. In recent years, advances in early endoscopic intervention have meant that more patients are considered at an earlier stage for potentially curative treatment.

Better view by detachable string magnetically controlled capsule endoscopy for esophageal observation: a retrospective comparative study

Magnetically controlled capsule endoscopy (MCE) system has been used to screen gastric lesions. However, the visualization performance of MCE in the esophagus has not been investigated systematically. String method improved the ability of capsule endoscopy (CE) for esophageal observing; however, the string attachment is complicated and cannot be detached with the CE inside the esophagus. We used a modified string, called detachable string attached to MCE. The aim of the study was to compare the observation performance of MCE with and without the detachable string. A total of 238 participants with upper gastrointestinal symptoms and a healthy check who refused esophagogastroduodenoscopy examination were retrospectively divided into the detachable string MCE group and the MCE alone group from June 2016 to May 2018. A suction cap with a thin, hollow string was attached to the MCE system in the detachable string group. Circumferential visualization of the esophagus including the upper, middle, and lower esophagus and Z-line, and esophageal focal lesion, as well as the recording time, safety and tolerability of the procedure, were assessed. The circumferential visualization of the upper, middle, and lower esophagus and Z-line was more efficient in the detachable string MCE group than in the MCE alone group (P < 0.001). In all, 31 esophageal lesions were detected in the detachable string MCE group, which was more than that in the MCE alone group (10, P < 0.001). The mean recording time was 305 seconds in the string MCE group, which was longer than that in the MCE alone group (48.5 seconds, P < 0.001). In seven participants (6.1%) in the detachable string MCE group, the capsule could not be separated from the string. Detachable string MCE showed better performance in terms of observation of the esophagus. Detachable string MCE can be used to screen for esophageal diseases as an alternative method in the future.

Development and validation of a risk prediction model to diagnose Barrett's oesophagus (MARK-BE): a case-control machine learning approach

Background

Screening for Barrett's Oesophagus (BE) relies on endoscopy which is invasive and has a low yield. This study aimed to develop and externally validate a simple symptom and risk-factor questionnaire to screen for patients with BE.

Methods

Questionnaires from 1299 patients in the BEST2 case-controlled study were analysed: 880 had BE including 40 with invasive oesophageal adenocarcinoma (OAC) and 419 were controls. This was randomly split into a training cohort of 776 patients and an internal validation cohort of 523 patients. External validation included 398 patients from the BOOST case-controlled study: 198 with BE (23 with OAC) and 200 controls. Identification of independently important diagnostic features was undertaken using machine learning techniques information gain (IG) and correlation based feature selection (CFS). Multiple classification tools were assessed to create a multi-variable risk prediction model. Internal validation was followed by external validation in the independent dataset.

Findings

The BEST2 study included 40 features. Of these, 24 added IG but following CFS, only 8 demonstrated independent diagnostic value including age, gender, smoking, waist circumference, frequency of stomach pain, duration of heartburn and acid taste and taking of acid suppression medicines. Logistic regression offered the highest prediction quality with AUC (area under the receiver operator curve) of 0.87. In the internal validation set, AUC was 0.86. In the BOOST external validation set, AUC was 0.81.

Interpretation

The diagnostic model offers valid predictions of diagnosis of BE in patients with symptomatic gastroesophageal reflux, assisting in identifying who should go forward to invasive testing. Overweight men who have been taking stomach medicines for a long time may merit particular consideration for further testing. The risk prediction tool is quick and simple to administer but will need further calibration and validation in a prospective study in primary care.

Funding

Charles Wolfson Trust and Guts UK.

Reflux esophagitis, functional and non-functional

The pathogenesis of gastroesophageal reflux disease has been explained by acid-peptic model. However, related with the progress of the diagnostic modalities, another phenotypical group of patients were defined and called "functional disorders of the esophagus". These patients are important because diagnosis is particularly difficult, co-morbid disorders especially psychiatric diseases are common, proton pump inhibitor response is low, and surgical results are very poor. Simpler and translational science studies are required in functional groups in order to differentiate from acid-peptic disorders. New and more accurate diagnostic modalities as well as therapeutic approaches are strongly needed in this particularly new and exciting era, especially in the effect of neuromodulators. Current diagnostic modalities should also be evaluated and in fact, normal values should be established. New medications, especially acting at the level of esophageal epithelium and intercellular spaces, might shift the paradigm.

Gastrointestinal diagnosis using non-white light imaging capsule endoscopy

Capsule endoscopy (CE) has proved to be a powerful tool in the diagnosis and management of small bowel disorders since its introduction in 2001. However, white light imaging (WLI) is the principal technology used in clinical CE at present, and therefore, CE is limited to mucosal inspection, with diagnosis remaining reliant on visible manifestations of disease. The introduction of WLI CE has motivated a wide range of research to improve its diagnostic capabilities through integration with other sensing modalities. These developments have the potential to overcome the limitations of WLI through enhanced detection of subtle mucosal microlesions and submucosal and/or transmural pathology, providing novel diagnostic avenues. Other research aims to utilize a range of sensors to measure physiological parameters or to discover new biomarkers to improve the sensitivity, specificity and thus the clinical utility of CE. This multidisciplinary Review summarizes research into non-WLI CE devices by organizing them into a taxonomic structure on the basis of their sensing modality. The potential of these capsules to realize clinically useful virtual biopsy and computer-aided diagnosis (CADx) is also reported.

Follow-up on: optimizing lesion detection in small bowel capsule endoscopy and beyond: from present problems to future solutions

This review presents noteworthy advances in clinical and experimental Capsule Endoscopy (CE), focusing on the progress that has been reported over the last 5 years since our previous review on the subject. Areas covered: This study presents the commercially available CE platforms, as well as the advances made in optimizing the diagnostic capabilities of CE. The latter includes recent concept and prototype capsule endoscopes, medical approaches to improve diagnostic yield, and progress in software for enhancing visualization, abnormality detection, and lesion localization. Expert commentary: Currently, moving through the second decade of CE evolution, there are still several open issues and remarkable challenges to overcome.