Standing-type magnetically guided capsule endoscopy versus gastroscopy for gastric examination: multicenter blinded comparative trial

A Deep Learning Application of Capsule Endoscopic Gastric Structure Recognition Based on a Transformer Model

BACKGROUND

Gastric structure recognition systems have become increasingly necessary for the accurate diagnosis of gastric lesions in capsule endoscopy. Deep learning, especially using transformer models, has shown great potential in the recognition of gastrointestinal (GI) images according to self-attention. This study aims to establish an identification model of capsule endoscopy gastric structures to improve the clinical applicability of deep learning to endoscopic image recognition.

METHODS

A total of 3343 wireless capsule endoscopy videos collected at Nanfang Hospital between 2011 and 2021 were used for unsupervised pretraining, while 2433 were for training and 118 were for validation. Fifteen upper GI structures were selected for quantifying the examination quality. We also conducted a comparison of the classification performance between the artificial intelligence model and endoscopists by the accuracy, sensitivity, specificity, and positive and negative predictive values.

RESULTS

The transformer-based AI model reached a relatively high level of diagnostic accuracy in gastric structure recognition. Regarding the performance of identifying 15 upper GI structures, the AI model achieved a macroaverage accuracy of 99.6% (95% CI: 99.5-99.7), a macroaverage sensitivity of 96.4% (95% CI: 95.3-97.5), and a macroaverage specificity of 99.8% (95% CI: 99.7-99.9) and achieved a high level of interobserver agreement with endoscopists.

CONCLUSIONS

The transformer-based AI model can accurately evaluate the gastric structure information of capsule endoscopy with the same performance as that of endoscopists, which will provide tremendous help for doctors in making a diagnosis from a large number of images and improve the efficiency of examination.

Positioning exercises in improving the quality of magnetic-controlled capsule endoscopy

BACKGROUND

Good gastric preparation is indispensable for Magnetic-controlled Capsule Endoscopy (MCE) examination, but there is no consensus yet. We aim to explore the clinical application value of positioning exercises in improving the quality of MCE examination.

METHODS

Clinical data of 326 patients who underwent MCE examination from January 2020 to December 2023 were collected. The included patients were divided into two groups: the conventional medication preparation group (CMP group, accepted mucosal cleansing medication only) and the positioning exercises group (PE group, accepted mucosal cleansing medication plus positioning exercises). A comparison was made between the two groups in terms of gastric cavity cleanliness score, visibility score, and detection rate of positive lesions.

RESULTS

The examination time was (21.29 ± 5.82) minutes in the PE group and (30.54 ± 6.37) minutes in the CMP group, showing a significant difference between the two groups (P < 0.001). The total cleanliness score and visibility score in the CMP group were 15.89 ± 2.82 and 10.93 ± 2.12, respectively. In contrast, the total cleanliness score and visibility score in the PE group were 19.52 ± 2.26 and 15.09 ± 2.31, respectively. The PE group showed significantly better cleanliness scores and visibility scores in all six anatomical regions compared to the CMP group (All P < 0.001). However, there was no significant difference in the detection rate of positive lesions between the two groups (All P > 0.05).

CONCLUSION

Positioning exercises before MCE examination can improve the quality of gastric mucosal images and reduce the duration of the examination for patients.

Optimal Motion Control of a Capsule Endoscope in the Stomach Utilizing a Magnetic Navigation System with Dual Permanent Magnets

We propose a method to control the motion of a capsule endoscope (CE) in the stomach utilizing either a single external permanent magnet (EPM) or dual EPMs to extend the examination of the upper gastrointestinal tract. When utilizing the conventional magnetic navigational system (MNS) with a single EPM to generate tilting and rotational motions of the CE, undesired translational motion of the CE may prevent accurate examination. We analyzed the motion of the CE by calculating the magnetic torque and magnetic force applied to the CE using the point-dipole approximation model. Using the proposed model, we propose a method to determine the optimal position and orientation of the EPM to generate tilting and rotational motions without undesired translational motion of the CE. Furthermore, we optimized the weight of dual EPMs to develop a lightweight MNS. We prototyped the proposed MNS and experimentally verified that the developed MNS can generate tilting and rotational motions of the CE without any translational motion.

Capsule endoscopy and panendoscopy: A journey to the future of gastrointestinal endoscopy

In 2000, the small bowel capsule revolutionized the management of patients with small bowel disorders. Currently, the technological development achieved by the new models of double-headed endoscopic capsules, as miniaturized devices to evaluate the small bowel and colon [pan-intestinal capsule endoscopy (PCE)], makes this non-invasive procedure a disruptive concept for the management of patients with digestive disorders. This technology is expected to identify which patients will require conventional invasive endoscopic procedures (colonoscopy or balloon-assisted enteroscopy), based on the lesions detected by the capsule, i.e., those with an indication for biopsies or endoscopic treatment. The use of PCE in patients with inflammatory bowel diseases, namely Crohn's disease, as well as in patients with iron deficiency anaemia and/or overt gastrointestinal (GI) bleeding, after a non-diagnostic upper endoscopy (esophagogastroduodenoscopy), enables an effective, safe and comfortable way to identify patients with relevant lesions, who should undergo subsequent invasive endoscopic procedures. The recent development of magnetically controlled capsule endoscopy to evaluate the upper GI tract, is a further step towards the possibility of an entirely non-invasive assessment of all the segments of the digestive tract, from mouth-to-anus, meeting the expectations of the early developers of capsule endoscopy.

A systematic review on diagnosis and treatment of gastrointestinal diseases by magnetically controlled capsule endoscopy and artificial intelligence

Background

Magnetically controlled capsule endoscopy (MCCE) is a non-invasive, painless, comfortable, and safe equipment to diagnose gastrointestinal diseases (GID), partially overcoming the shortcomings of conventional endoscopy and wireless capsule endoscopy (WCE). With advancements in technology, the main technical parameters of MCCE have continuously been improved, and MCCE has become more intelligent.

Objectives

The aim of this systematic review was to summarize the research progress of MCCE and artificial intelligence (AI) in the diagnosis and treatment of GID.

Data Sources and Methods

We conducted a systematic search of PubMed and EMBASE for published studies on GID detection of MCCE, physical factors related to MCCE imaging quality, the application of AI in aiding MCCE, and its additional functions. We synergistically reviewed the included studies, extracted relevant data, and made comparisons.

Results

MCCE was confirmed to have the same performance as conventional gastroscopy and WCE in detecting common GID, while it lacks research in detecting early gastric cancer (EGC). The body position and cleanliness of the gastrointestinal tract are the main factors affecting imaging quality. The applications of AI in screening intestinal diseases have been comprehensive, while in the detection of common gastric diseases such as ulcers, it has been developed. MCCE can perform some additional functions, such as observations of drug behavior in the stomach and drug damage to the gastric mucosa. Furthermore, it can be improved to perform a biopsy.

Conclusion

This comprehensive review showed that the MCCE technology has made great progress, but studies on GID detection and treatment by MCCE are in the primary stage. Further studies are required to confirm the performance of MCCE.

Clinical guideline on magnetically controlled capsule gastroscopy (2021 edition)

With the development and generalization of endoscopic technology and screening, clinical application of magnetically controlled capsule gastroscopy (MCCG) has been increasing. In recent years, various types of MCCG are used globally. Therefore, establishing relevant guidelines on MCCG is of great significance. The current guidelines containing 23 statements were established based on clinical evidence and expert opinions, mainly focus on aspects including definition and diagnostic accuracy, application population, technical optimization, inspection process, and quality control of MCCG. The level of evidence and strength of recommendations were evaluated. The guidelines are expected to guide the standardized application and scientific innovation of MCCG for the reference of clinicians.

In vivo animal study of the magnetic navigation system for capsule endoscope manipulation within the esophagus, stomach, and colorectum

BACKGROUND/PURPOSES

Magnetic navigation capsule endoscopy (MNCE) is considered to be an important means to realize the controllable and precise examination of capsule endoscopy (CE) in the unstructured gastrointestinal (GI) tract. For the current magnetic navigation system (MNS), due to the limitation of workspace, driving force, and control method of the CE, only clinical application in the stomach has been realized, whereas the examination of other parts of the GI tract is still in the experimental stage. More preclinical studies are needed to achieve the multisite examination of the GI tract.

METHODS

Based on the MNS (Supiee) developed in the laboratory, an X-ray imaging system with magnetic shielding and a commercial CE are integrated to form the MNCE system. Then, in vivo GI tract experiments with a porcine model are performed to verify the clinical feasibility and safety of this system. Moreover, the effects of different control modes on the efficiency and effect of GI tract examination are studied.

RESULTS

Animal experiments demonstrate that with the MNCE system, it is convenient to achieve steering control in any direction and multiple reciprocating movements of CE in the GI tract. Benefiting from the flexibility of the three basic control modes, the achieved swing movement pattern of CE can effectively reduce the inspection time. It is demonstrated that the esophageal examination time can be reduced from 13.2 to 9.2 min with a maximum movement speed of 5 mm/s.

CONCLUSION

In this paper, the feasibility, safety, and efficacy of the MNCE system for a one-stop examination of the in vivo GI tract (esophagus, stomach, and colorectum) is first demonstrated. In addition, complex movement patterns of CE such as the swinging are proved to effectively improve examination efficiency and disease detection rates. This study is crucial for the clinical application of the MNCE system.

Feasibility and safety of a novel string magnetically controlled capsule endoscopy for esophageal and gastric examination in a porcine model

BACKGROUND

Currently used magnetically controlled capsule gastroscope has many shortcomings, such as low resolution and frame rate, incomplete examination of the esophagus due to rapid passage, and risk of capsule retention. A novel string magnetically controlled capsule endoscopy with high frame rate and resolution can examine the esophagus comprehensively, and has no risk of capsule retention.

AIM

To verify the feasibility and safety of a novel string magnetically controlled capsule endoscopy for esophageal and gastric examination by animal experiments.

METHODS

Magnetically controlled capsule endoscopy (MCE) and traditional gastroscopy were performed on three Bama minipigs successively. The examination time for the esophagus and stomach was recorded. The MCE maneuverability and mucosal visualization in each part of the esophagus and stomach (upper, middle, and lower part of the esophagus, Z-line, and gastric cardia, fundus, body, angulus, antrum, and pylorus). Routine blood and biochemistry parameters of experimental animals before and after examination were analyzed, and adverse reactions occurring during the experiment were recorded.

RESULTS

Compared with traditional gastroscopy, MCE showed no significant difference in esophageal examination time (104.67 s ± 7.02 s vs 88.33 s ± 3.51 s, P = 0.093). The gastric examination time of MCE was longer than that of traditional gastroscopy (25.67 min ± 5.69 min vs 6.00 min ± 1.00 min, P = 0.019). The MCE maneuverability and mucosal visualization were better in the esophagus, Z-line, and gastric body, antrum, and pylorus than in the gastric cardia and fundus. No obvious adverse reactions occurred in experimental animals.

CONCLUSION

The novel string magnetically controlled capsule endoscopy has satisfactory feasibility and safety for esophageal and gastric examination in the porcine model.

Magnetically Guided Capsule Endoscopy and Magnetic Resonance Enterography in Children With Crohn's Disease: Manifestations and the Value of Assessing Disease Activity

Objective: To investigate the value of magnetically guided capsule endoscopy (MGCE) and magnetic resonance enterography (MRE) in assessing the activity of pediatric Crohn's disease. Methods: Clinical data from 82 subjects with pediatric Crohn's disease, who underwent MGCE and MRE from October 2018 to March 2021 were analyzed retrospectively. Pairwise comparisons of several indexes, including MaRIA, CECDAI, PCDAI, and SES-CD, were performed by Spearman's rank correlation test and kappa consistency analysis. CECDAI and MaRIA values predicted whether patients were moderately or severely active (PCDAI ≥30) clinically by logistic regression analysis. The area under the receiver operating characteristic curve (AUC) quantified the evaluation value of moderate to severe activity of pediatric CD. Results: In judging the severity of CD in the small intestine, the correlation coefficient between CECDAI and MaRIA was 0.406 (p < 0.05), and the kappa value of the consistency analysis was 0.299 (p < 0.05). MaRIA was weakly correlated with PCDAI (r = 0.254, p < 0.05), and they were weakly consistent in assessing the activity of Crohn's disease (kappa = 0.135, p < 0.05). For predicting clinically moderate to severe activity, the fitted AUC based on CECDAI and MarRIA was 0.917, which was higher than applying a single parameter (CECDAI = 0.725, MarRIA = 0.899, respectively). MaRIA and serum albumin were significantly and negatively correlated (r = -1.064, p < 0.05). The consistency of the detection rate of gastric ulcers by MGCE and gastroscopy was moderate (kappa = 0.586, p < 0.05), and the detection rate of ulcers in the terminal ileum between MGCE and colonoscopy showed high consistency (kappa = 0.609, p < 0.05). Conclusions: MGCE and MRE are valuable, non-invasive methods for evaluating small bowel lesions in children with CD. The combined application of MGCE and MRE can better characterize the disease activity.

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.

Capsule Endoscopy for Gastric Evaluation

Wireless capsule endoscopy was first developed to observe the small intestine. A small capsule can be swallowed and images of gastrointestinal tract are taken with natural movement of peristalsis. Application of capsule endoscopy for observing the stomach has also received much attention as a useful alternative to esophagogastroduodenoscopy, but anatomical characteristics of the stomach have demanded technical obstacles that need to be tackled: clear visualization and active movements that could be controlled. Different methods of controlling the capsule within stomach have been studied and magnetic manipulation is the only system that is currently used in clinical settings. Magnets within the capsule can be controlled with a hand-held magnet paddle, robotic arm, and electromagnetic coil system. Studies on healthy volunteers and patients with upper gastrointestinal symptoms have shown that it is a safe and effective alternative method of observing the stomach. This work reviews different magnetic locomotion systems that have been used for observation of the stomach as an emerging new application of wireless capsule endoscopy.

Fully automated magnetically controlled capsule endoscopy for examination of the stomach and small bowel: a prospective, feasibility, two-centre study

BACKGROUND

The use of magnetically controlled capsules for gastroscopy is in the early stages of clinical adoption. We aimed to evaluate the safety and efficacy of a fully automated magnetically controlled capsule endoscopy (FAMCE) system in clinical practice for gastroscopy and small bowel examination.

METHODS

We did a prospective, comparative study to evaluate the safety and efficacy of FAMCE. Patients from two hospitals in Chongqing, China were consecutively enrolled. Eligible participants were aged 18-80 years with suspected gastric pathology and no previous surgery. Participants underwent FAMCE for screening of gastric lesions, then conventional transoral gastroscopy 2 h later, and stomach examination results were compared. The primary outcome was the rate of complete detection of gastric anatomy landmarks (cardia, fundus, body, angulus, antrum, and pylorus) by FAMCE. Secondary outcomes were the time required for gastric completion by FAMCE, the rate of detection of gastric lesions by FAMCE compared with conventional transoral gastroscopy, and the rate of complete small bowel examination. Adverse events were also evaluated. The study was registered in the Chinese Clinical Trial Registry, ChiCTR2000040507.

FINDINGS

Between May 12 and Aug 17, 2020, 114 patients (mean age 44·0 years [IQR 34·0-55·0]; 63 [55%] female) were enrolled. The rate of complete detection of gastric anatomical structures by FAMCE was 100% (95% CI 99·3-100·0). The concordance between FAMCE and conventional transoral gastroscopy was 99·61% (99·45-99·78). The mean completion time of a gastroscopy with FAMCE was 19·17 min (SD 1·43; median 19·00, IQR 19·00-20·00), compared with 5·21 min (2·00; 5·18, 3·68-6·45) for conventional transoral gastroscopy. In 114 enrolled patients, 214 lesions were detected by FAMCE and conventional transoral gastroscopy. Of those, 193 were detected by both modalities. FAMCE missed five pathologies (four cases of gastritis and one polyp), whereas conventional transoral gastroscopy missed 16 pathologies (12 cases of gastritis, one polyp, one fundal xanthoma, and two antral erosions). FAMCE was able to provide a complete small bowel examination for all 114 patients and detected intestinal lesions in 50 (44%) patients. During the study, two (2%) patients experienced adverse events. No serious adverse events were recorded, and there was no evidence of capsule retention.

INTERPRETATION

The performance of FAMCE is similar to conventional transoral gastroscopy in completion of gastric examination and lesion detection. Furthermore, it can provide a complete small bowel examination. Therefore, FAMCE could be effective method for examination of the gastrointestinal tract.

FUNDING

Chinese National Key Research and Development Program.

Current status and future developments of upper gastrointestinal tract capsule endoscopy

Capsule endoscopy has been widely used for the diagnosis of small bowel diseases due to its safety, noninvasiveness, and acceptability. Despite the potential benefits of capsule endoscopy, there are obvious challenges to capsule endoscopy application in the upper gastrointestinal tract, due to the fast transit speed in the esophagus and large space of the gastric cavity. With the development of innovative technologies, such as magnetic navigation and tethered capsule endoscopy, the indications for capsule endoscopy have recently been expanded. Various capsule endoscopes have been applied to clinical practice, and several state-of-the-art research-oriented designs and devices provide hope for further use in the diagnosis of upper gastrointestinal diseases. In this review, we will summarize the current status and future developments of upper gastrointestinal tract capsule endoscopy.

Magnetically Controlled Capsule Endoscopy Versus Conventional Gastroscopy: A Systematic Review and Meta-Analysis

BACKGROUND

The introduction of magnetically controlled capsule endoscopy overcame the restriction of passive capsule endoscopy movement, thus allowing an improved visualization of the gastrointestinal lumen, where other imaging studies seem to be unhelpful. The aim of this study is to systematically review the performance of magnetically controlled capsule endoscopy and evaluate its potential as a less invasive diagnostic method in the detection of gastric lesions.

METHODS

A systematic search was performed in PubMed (Medline), EMBASE, Google Scholar, Scopus, Who Global Health Library (GHL), Virtual Health Library (VHL), Clinicaltrials.gov, Cochrane Library, and ISI Web of Science databases. Proportion meta-analyses were performed to estimate the pooled sensitivity of magnetically controlled capsuled endoscopy in the detection of gastrointestinal lesions.

RESULTS

Among the 3026 studies that were initially assessed, 7 studies were finally included, with a total of 916 patients and 745 gastric lesions. The mean capsule endoscopy examination time was 21.92±8.87 minutes. The pooled overall sensitivity of magnetically controlled capsule endoscopy was 87% [95% confidence interval (CI), 84%-89%]. Subgroup analysis showed that the sensitivity of identifying gastric ulcers was 82% (95% CI: 71%-89%), gastric polyps was 82% (95% CI: 76%-87%), and gastric erosions was 95% (95% CI: 86%-98%). In general, magnetically controlled capsule endoscopy was well tolerated by the participants with minimal adverse events.

CONCLUSION

The magnetically controlled capsule endoscopy demonstrated an acceptable sensitivity of identifying gastric lesions. Further prospective comparative studies are needed to identify the risks and benefits of this new technique, as well as to determine its role as a replacement for conventional gastroscopy.

Screening for gastric cancer in China: Advances, challenges and visions

Gastric cancer (GC) is one of the major cancers in China and all over the world. Most GCs are diagnosed at an advanced stage with unfavorable prognosis. Along with some other countries, China has developed the government-funded national screening programs for GC and other major cancers. GC screening has been shown to effectively decrease the incidence of and mortality from GC in countries adopting nationwide screening programs (Japan and Korea) and in studies based on selected Chinese populations. The screening of GC relies mostly on gastroendoscopy, the accuracy, reliability and safety of which have been indicated by previous studies. However, considering its invasive screening approach, requirements on skilled endoscopists and pathologists, and a high cost, developing noninvasive methods to amend endoscopic screening would be highly needed. Numerous studies have examined biomarkers for GC screening and the combination of biomarkers involving pepsinogen, gastrin, and Helicobacter pylori antibodies has been proposed for risk stratification, seeking to narrow down the high-risk populations for further endoscopy. Despite all the achievements of endoscopic screening, evidence on appropriate screening age, intervals for repeated screening, novel biomarkers promoting precision prevention, and health economics need to be accumulated to inform policymakers on endoscopic screening in China. With the guide of Health China 2030 Planning Outline, we have golden opportunities to promote prevention and control of GC. In this review, we summarize the characteristics of screening programs in China and other East Asian countries and introduce the past and current approaches and strategies for GC screening, aiming for featuring the latest advances and key challenges, and illustrating future visions of GC screening.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.