Feasibility of stomach exploration with a guided capsule endoscope

A novel method of cardia visualization and comfort level enhancement during magnetic capsule gastroscopy via sugar-glued tether-assisted technique: a randomized pilot study inspired by a Chinese snack-making process (with video)

BACKGROUND

Magnetic capsule gastroscopy (MCG) is a non-invasive diagnostic method for the digestive tract. However, its efficiency in visualizing the gastric cardia is often compromised due to the capsule's rapid passage. This study introduces a novel sugar-glued tether-assisted technique inspired by a traditional Chinese snack-making process to enhance cardia visualization and patient comfort during MCG.

METHODS

This pilot, open-label, single-center, randomized controlled, non-inferiority study was conducted at Binzhou Medical University Hospital. Seventy-eight patients were enrolled and divided into three groups: conventional MCG, suction cup tether-assisted MCG, and sugar-glued tether-assisted MCG. The primary outcomes included safety, comfort level, and gastric cardia visualization quality. Secondary outcomes assessed technique-associated performance and clinical factors.

RESULTS

The sugar-glued tether-assisted MCG demonstrated comparable cardia visualization quality to the suction cup method, with significantly better results than conventional MCG. Comfort levels were significantly higher in the sugar-glued group compared to the suction cup group. The number of swallow attempts was significantly lower in the sugar-glued group, with no adverse events reported. Secondary outcomes showed no significant differences in MCG assembly time and ingestion-to-detachment period between the suction cup and sugar-glued groups.

CONCLUSION

The sugar-glued tether-assisted MCG is a feasible and safe modification that enhances gastric cardia visualization while improving patient comfort. This technique provides a cost-effective alternative to the suction cup method, warranting further investigation in larger, multi-center studies.

Robotic wireless capsule endoscopy: recent advances and upcoming technologies

Wireless capsule endoscopy (WCE) offers a non-invasive evaluation of the digestive system, eliminating the need for sedation and the risks associated with conventional endoscopic procedures. Its significance lies in diagnosing gastrointestinal tissue irregularities, especially in the small intestine. However, existing commercial WCE devices face limitations, such as the absence of autonomous lesion detection and treatment capabilities. Recent advancements in micro-electromechanical fabrication and computational methods have led to extensive research in sophisticated technology integration into commercial capsule endoscopes, intending to supersede wired endoscopes. This Review discusses the future requirements for intelligent capsule robots, providing a comparative evaluation of various methods' merits and disadvantages, and highlighting recent developments in six technologies relevant to WCE. These include near-field wireless power transmission, magnetic field active drive, ultra-wideband/intrabody communication, hybrid localization, AI-based autonomous lesion detection, and magnetic-controlled diagnosis and treatment. Moreover, we explore the feasibility for future "capsule surgeons".

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.

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.

Clinical Benefits and Challenges in Application of Novel Portable Gastric Capsule Endoscopy for Home Healthcare Patients

Portable magnetic-assisted capsule endoscopy (MACE) provides satisfactory patient experience and safety with comparable performance in diagnosis of organic lesions when compared to conventional upper gastrointestinal endoscopy. In this study, a total of 58 homecare patients were included for MACE either in the hospital (n = 42) or at home (n = 16), with mean age of 71.1 ± 12.4 years. A total of 55 patients (94.83%) had completed the MACE with diagnosis of reflux esophagitis (43.6%), gastritis (54.5%), erosions (21.8%), fundic polyps (14.5%), peptic ulcers (25.9%), etc. Most patients (n = 47, 85.5%) were satisfied with the experience, and all patients who received MACE at home (n = 15, 100%) appreciated the convenience of endoscopy at home. Less than half of the patients (n = 24, 43.6%) could afford MACE if the expense was not covered by health insurance (USD 714). Time consumption from both traffic and capsule manipulation was also challenging for the physicians, as it took an average of 24.7 min to complete MACE, but it added up to a total of 92.7 min at home, which is about 15 times that of conventional endoscopy in hospital. More efforts are needed to ease the financial burden of patients, and optimization of workflow in community practice may help lift the obstacles revealed in this study.

First prospective European study for the feasibility and safety of magnetically controlled capsule endoscopy in gastric mucosal abnormalities

BACKGROUND

While capsule endoscopy (CE) is the gold standard diagnostic method of detecting small bowel (SB) diseases and disorders, a novel magnetically controlled capsule endoscopy (MCCE) system provides non-invasive evaluation of the gastric mucosal surface, which can be performed without sedation or discomfort. During standard SBCE, passive movement of the CE may cause areas of the complex anatomy of the gastric mucosa to remain unexplored, whereas the precision of MCCE capsule movements inside the stomach promises better visualization of the entire mucosa.

AIM

To evaluate the Ankon MCCE system’s feasibility, safety, and diagnostic yield in patients with gastric or SB disorders.

METHODS

Of outpatients who were referred for SBCE, 284 (male/female: 149/135) were prospectively enrolled and evaluated by MCCE. The stomach was examined in the supine, left, and right lateral decubitus positions without sedation. Next, all patients underwent a complete SBCE study protocol. The gastric mucosa was explored with the Ankon MCCE system with active magnetic control of the capsule endoscope in the stomach, applying three standardized pre-programmed computerized algorithms in combination with manual control of the magnetic movements.

RESULTS

The urea breath test revealed Helicobacter pylori positivity in 32.7% of patients. The mean gastric and SB transit times with MCCE were 0 h 47 min 40 s and 3 h 46 min 22 s, respectively. The average total time of upper gastrointestinal MCCE examination was 5 h 48 min 35 s. Active magnetic movement of the Ankon capsule through the pylorus was successful in 41.9% of patients. Overall diagnostic yield for detecting abnormalities in the stomach and SB was 81.9% (68.6% minor; 13.3% major pathologies); 25.8% of abnormalities were in the SB; 74.2% were in the stomach. The diagnostic yield for stomach/SB was 55.9%/12.7% for minor and 4.9%/8.4% for major pathologies.

CONCLUSION

MCCE is a feasible, safe diagnostic method for evaluating gastric mucosal lesions and is a promising non-invasive screening tool to decrease morbidity and mortality in upper gastro-intestinal diseases.

Upper gastrointestinal video capsule endoscopy: The state of the art

BACKGROUND

Video capsule can illuminate the entire gastrointestinal mucosa. Upper gastrointestinal capsule endoscopy (UGICE) has the potential to survey for oesophageal, gastric and duodenal pathology and determine whether biopsy or intervention is indicated.

AIMS

This review traces the evolution of foregut video capsule endoscopy.

METHODS

A broad literature research was performed independently by two investigators. Extracted articles were organized and evaluated to interpret all current data.

RESULTS

In contrast to small bowel capsule, UGICE required sequential innovations to deal with rapid oesophageal transit, the irregular shape of the stomach and unpredictable gastric peristalsis. Oesophageal capsule endoscopy required the development of a two-camera device operating at a high frame rate, and postural change was developed to improve image capture, especially at the level of the Z-line, thus providing good imaging of Barrett's oesophagus, erosive oesophagitis and oesophageal varices, with optimal patients' tolerance. UGICE in patients presenting to the emergency room with acute bleeding has demonstrated accuracy when deciding on the need for emergency intervention. The latest development of a high frame rate UGICE, designed to image the oesophagus, stomach and duodenum has overtaken dedicated oesophageal capsule development. Capsule control is possible by exposing a magnetised capsule to an external magnetic field, and early reports indicate high accuracy in the oesophagus and stomach with high levels of patient acceptability. There is little information on cost-benefit.

CONCLUSIONS

Capsule endoscopy offers gastroenterologists a new device to investigate the upper gastrointestinal tract with promising future potential.

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.

In vitro models to evaluate ingestible devices: Present status and current trends

Orally ingestible medical devices offer significant opportunity in the diagnosis and treatment of gastrointestinal conditions. Their development necessitates the use of models that simulate the gastrointestinal environment on both a macro and micro scale. An evolution in scientific technology has enabled a wide range of in vitro, ex vivo and in vivo models to be developed that replicate the gastrointestinal tract. This review describes the landscape of the existing range of in vitro tools that are available to characterize ingestible devices. Models are presented with details on their benefits and limitations with regards to the evaluation of ingestible devices and examples of their use in the evaluation of such devices is presented where available. The multitude of models available provides a suite of tools that can be used in the evaluation of ingestible devices that should be selected on the functionality of the device and the mechanism of its function.

The Application of Magnetic-Controlled Capsule Gastroscopy in Patients Refusing C-EGD: A Single-Center 5-Year Observational Study

Background and Aims

Screening for gastric diseases in symptomatic outpatients with conventional esophagogastroduodenoscopy (C-EGD) is expensive and has poor compliance. We aimed to explore the efficiency and safety of magnetic-controlled capsule gastroscopy (MCCG) in symptomatic outpatients who refused C-EGD.

Methods

We performed a retrospective study of 76794 consecutive symptomatic outpatients from January 2014 to October 2019. A total of 2318 adults (F/M = 1064/1254) in the MCCG group who refused C-EGD were matched with adults in the C-EGD group using propensity-score matching (PSM). The detection rates of abnormalities were analyzed to explore the application of MCCG in symptomatic patients.

Results

Our study demonstrated a prevalence of gastric ulcers (GUs) in patients with functional dyspepsia- (FD-) like symptoms of 8.14%. The detection rate of esophagitis and Barrett's esophagus was higher in patients with typical gastroesophageal reflux disease (GERD) symptoms than in patients in the other four groups (P < 0.01). The detection rates of gastric ulcers in the five groups (abdominal pain, bloating, heartburn, follow-up, and bleeding) were significantly different (P = 0.015). The total detection rate of gastric ulcers in symptomatic patients was 9.7%. A total of 7 advanced carcinomas were detected by MCCG and confirmed by endoscopic or surgical biopsy. The advanced gastric cancer detection rate was not significantly different between the MCCG group and the C-EGD matched group in terms of nonhematemesis GI bleeding (2 vs. 2, P = 1.00). In addition, the overall focal lesion detection rate in the MCCG group was superior to that in the C-EGD matched group (224 vs. 184, P = 0.038). MCCG gained a clinically meaningful small bowel diagnostic yield of 54.8% (17/31) out of 31 cases of suspected small bowel bleeding. No patient reported capsule retention at the two-week follow-up.

Conclusion

MCCG is well tolerated, safe, and technically feasible and has a considerable diagnostic yield. The overall gastric diagnostic yield of gastric focal lesions with MCCG was comparable to that with C-EGD. MCCG offered a supplementary diagnosis in patients who had a previously undiagnostic C-EGD, indicating that MCCG could play an important role in the routine monitoring and follow-up of outpatient. MCCG shows its safety and efficiency in symptomatic outpatient applications.

Gastric examination using a novel three-dimensional magnetically assisted capsule endoscope and a hand-held magnetic controller: A porcine model study

Magnetically assisted capsule endoscopy (MACE) is a noninvasive procedure and can overcome passive capsule movement that limits gastric examination. MACE has been studied in many trials as an alternative to upper endoscopy. However, to increase diagnostic accuracy of various gastric lesions, MACE should be able to provide stereoscopic, clear images and to measure the size of a lesion. So, we conducted the animal experiment using a novel three-dimensional (3D) MACE and a new hand-held magnetic controller for gastric examination. The purpose of this study is to assess the performance and safety of 3D MACE and hand-held magnetic controller through the animal experiment. Subsequently, via the dedicated viewer, we evaluate whether 3D reconstruction images and clear images can be obtained and accurate lesion size can be measured. During real-time gastric examination, the maneuverability and visualization of 3D MACE were adequate. A polypoid mass lesion was incidentally observed at the lesser curvature side of the prepyloric antrum. The mass lesion was estimated to be 10.9 x 11.5 mm in the dedicated viewer, nearly the same size and shape as confirmed by upper endoscopy and postmortem examination. Also, 3D and clear images of the lesion were successfully reconstructed. This animal experiment demonstrates the accuracy and safety of 3D MACE. Further clinical studies are warranted to confirm the feasibility of 3D MACE for human gastric examination.

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.

Navigation of a magnetic micro-robot through a cerebral aneurysm phantom with magnetic particle imaging

Cerebral aneurysms are potentially life threatening and nowadays treated by a catheter-guided coiling or by a neurosurgical clipping intervention. Here, we propose a helically shaped magnetic micro-robot, which can be steered by magnetic fields in an untethered manner and could be applied for a novel coiling procedure. This is shown by navigating the micro-robot through an additively manufactured phantom of a human cerebral aneurysm. The magnetic fields are applied with a magnetic particle imaging (MPI) scanner, which allows for the navigation and tomographic visualization by the same machine. With MPI the actuation process can be visualized with a localization accuracy of 0.68 mm and an angiogram can be acquired both without any radiation exposure. First in-vitro phantom experiments are presented, showing an idea of a robot conducted treatment of cerebral aneurysms.

Feasibility of Upper Gastrointestinal Examination in Home Care Setting with a Magnetically Assisted Capsule Endoscopy System: A Retrospective Study

The magnetic assisted capsule endoscope (MACE) with a hand-held magnetic field navigator (MFN) for upper gastrointestinal examination achieved satisfactory results in a healthy volunteer study. We evaluated the feasibility of upper gastrointestinal examination in the home care setting with the MACE system. Home care patients with upper gastrointestinal symptoms that received an MACE exam were enrolled in the study. MACE procedure time; completeness of observation of important anatomical landmarks; endoscopic diagnosis; patient tolerance during the procedure; and patient data, including age, sex, comorbidities, symptoms, body weight, and height, were retrieved from hospital information system for data analysis. A total of 16 participants were enrolled with a mean age 74.3 ± 15.4 years (47 to 99 years). One patient failed to swallow the capsule and was excluded. The average procedure time was 23.7 ± 10.0 min (14.1 to 42.5 min) to complete each endoscopic exam for the remaining 15 patients. The overall maneuverability in the esophagus, stomach, and duodenum was 93.75%, 87.5%, and 75%, respectively. Overall completeness in the aforementioned regions was 93.75%, 81.25%, and 75%, respectively. No severe adverse events were noted. The results clearly demonstrate the promise of using this MACE system to perform endoscopic examination outside the hospital for patients confined to the community and home.

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.

Feasibility of a second-generation colon capsule in visualization of the upper gastrointestinal tract

Background

Capsule endoscopy for visualization of the entire gastrointestinal tract is a challenge. A second-generation colon capsule endoscopy system (CCE-2) performed well in the colon and small intestine, but its utility in the upper gastrointestinal duct is not clear. We evaluated the use of the CCE-2 in the visualization of the upper gastrointestinal tract.

Methods

We performed a retrospective study and further evaluated CCE-2 images using the typical landmarks of esophagus and stomach. The two imagers located at each end of the CCE-2 system were defined as imager1 (green) and imager2 (yellow). Two endoscopists read the images, and they were blinded to the other reader’s results. All of the images from the two imagers were separately reviewed.

Results

Images from 127 subjects were analyzed. This study demonstrated the comprehensive visualization of 71.7% of esophageal landmarks and 89.8% of gastric landmarks using the CCE-2. The two CCE-2 imagers were not identical, and the lighter imager (imager2, yellow) was superior to the heavier imager (imager1, green) (78% vs. 33.1%) in the stomach. Compared with the use of one imager, the use of two imagers was superior (two-imager vs. imager1, 89.8% vs. 33.1%; two-imager vs. imager2, 89.8% vs. 78%) in the stomach. Two-imager combination analysis detected a total of 160 positive findings. In contrast, single-imager analysis with imager1 and imager2 detected 133 and 137 findings, respectively. Two-imager combination analysis provided 20.3% and 16.8% more findings than imager1 and imager2, respectively. The two imagers complemented each other to detect more lesions.

Conclusions

The CCE-2 system is feasible for use in the upper gastrointestinal tract and may be considered an optional tool for upper gastrointestinal imaging. This system may represent a good choice for complete gastrointestinal duct screening. Compared with the use of one imager, the two-imager combination provided improved upper gastrointestinal tract mucosal visualization.

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.

Adverse events of video capsule endoscopy over the past two decades: a systematic review and proportion meta-analysis

BACKGROUND

A full spectrum of video capsule endoscopy (VCE) adverse events over the past two decades has not been evaluated. We aimed to determine pooled rates, predictors and temporal-trend of VCE adverse events over the past two decades.

METHODS

Systematic search of PubMed and EMBASE for English-language publications reporting VCE adverse events (January 1, 2000 to March 31, 2019). Data were extracted independently by two investigators. Pooled VCE adverse event rates were calculated using the random or fixed model as appropriate. Predictors and temporal-trend of each adverse event were performed by meta-regression analyses.

RESULTS

In total, 402 studies were identified, including 108,079 VCE procedures. Rate of retention, swallow disorder, aspiration, technical failure, and procedural adverse events were 0.73% (95% confidence interval [CI] 0.59-0.89%), 0.75% (95% CI 0.43-1.13%), 0.00% (95% CI 0.00-0.00%), 0.94% (95% CI 0.65-1.28%), 0.67% (95% CI 0.32-1.10%), respectively; incomplete examination rate of esophagus, stomach, small bowel, and colon were 9.05%, 7.69%, 12.08%, 19.19%, respectively. Patency capsule reduced retention rate by 5.04%, whereas known inflammatory bowel disease increased retention rate by 4.29%. Elder was the risk and protective factor for small bowel incomplete examination (0.30%) and swallow disorder (- 0.72%), respectively. Rates of retention and small bowel incomplete examination significantly declined over time (P = .0006 and P < .0001)..

CONCLUSIONS

VCE adverse event rates were generally low, and retention and small bowel incomplete examination rates declined over the past two decades. Patients with known inflammatory bowel disease or elder should be alerted to high risk of retention or small bowel incomplete examination (PROSPERO: CRD42019139595).

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.

A New Active Locomotion Capsule Endoscopy under Magnetic Control and Automated Reading Program

Capsule endoscopy (CE) is the first-line diagnostic modality for detecting small bowel lesions. CE is non-invasive and does not require sedation, but its movements cannot be controlled, it requires a long time for interpretation, and it has lower image quality compared to wired endoscopy. With the rapid advancement of technology, several methods to solve these problems have been developed. This article describes the ongoing developments regarding external CE locomotion using magnetic force, artificial intelligence-based interpretation, and image-enhancing technologies with the CE system.

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

AIM

To compare feasibility and safety after gastrointestinal checkup by standing-type magnetically controlled capsule endoscopy (SMCE) and conventional gastroscopy.

METHODS

This was a prospective multicenter, blinded study that compared SMCE with gastroscopy in patients from April 2018 to July 2018. All patients first underwent SMCE and then subsequently had gastroscopy with i.v. anesthesia. We calculated the compliance rates of gastric lesion detection by SMCE using gastroscopy as the standard. Capsule retention rate, incidence of adverse events, and patient satisfaction were documented throughout the study.

RESULTS

One hundred and sixty-one patients who completed SMCE and gastroscopy were included in the analysis. Positive compliance rate among SMCE and gastroscopy was 92.0% (95% CI: 80.77%-97.78%). Negative compliance rate was 95.5% (89.80%, 98.52%). Moreover, overall compliance rate was 94.41% (89.65%, 97.41%). Sixty-four pathological outcomes were identified. Of these 64 outcomes, 50 were detected by both procedures. The gastroscopy method neglected seven findings (such as five erosions, one polyp, and one ulcer). Furthermore, SMCE also overlooked seven lesions (i.e. one erosion, two polyps, one atrophy, and three submucosal tumors). Capsule retention or related adverse events were not reported.

CONCLUSION

Standing-type magnetically controlled capsule endoscopy provides equivalent agreement with gastroscopy and may be useful for screening of gastric illnesses without any anesthesia.

The future of endoscopy: Advances in endoscopic image innovations

The latest state of the art technological innovations have led to a palpable progression in endoscopic imaging and may facilitate standardisation of practice. One of the most rapidly evolving modalities is artificial intelligence with recent studies providing real-time diagnoses and encouraging results in the first randomised trials to conventional endoscopic imaging. Advances in functional hypoxia imaging offer novel opportunities to be used to detect neoplasia and the assessment of colitis. Three-dimensional volumetric imaging provides spatial information and has shown promise in the increased detection of small polyps. Studies to date of self-propelling colonoscopes demonstrate an increased caecal intubation rate and possibly offer patients a more comfortable procedure. Further development in robotic technology has introduced ex vivo automated locomotor upper gastrointestinal and small bowel capsule devices. Eye-tracking has the potential to revolutionise endoscopic training through the identification of differences in experts and non-expert endoscopist as trainable parameters. In this review, we discuss the latest innovations of all these technologies and provide perspective into the exciting future of diagnostic luminal endoscopy.

Robotic endoscopy. A review of the literature

Purpose

To present new endoscopic robotic devices in the context of minimally invasive procedures with high precision and automation.

Methods

Review of the literature by December 2018 on robotic endoscopy.

Results

We present the studies and investments for robotic implementation and flexible endoscopy evolution. We divided them into forceps manipulation platforms, active endoscopy and endoscopic capsule. They try to improve forceps handling and stability and to promote active movement.

Conclusion

The implementation and propagation of robotic models depend on doing what the endoscopist is unable to. The new devices are moving forward in this direction.

Simultaneous Independent Translational and Rotational Feedback Motion Control System for a Cylindrical Magnet using Planar Arrays of Magnetic Sensors and Cylindrical Coils

This letter describes an electromagnetic feedback control system for rigid-body motion control of a magnet. Its novel features are that sensing and actuation using magnetometer sensors and actuator coils operate simultaneously, and magnetic field models from the controlled magnet and each of the actuator coil currents are used together to calculate the 3D position and orientation of the magnet to control motion simultaneously and independently in multiple degrees of freedom including planar translation and two in rotation, leaving rotation about the cylindrical axis of magnetization uncontrolled. The system configuration and the localization and actuation methods are presented with experimental results of magnet localization with constant and varying coil currents, and during feedback control of trajectory following motion of the magnet in multiple directions on a planar surface and with controlled changes in orientation. The intended application of the system is for motion control of magnetic endoscope capsules and other miniature medical devices inside the human body.

Optimizing the performance of magnet-controlled capsule endoscopy based on radiological and gastroscopic modeling

Routine use of magnet-controlled capsule endoscopy of the stomach has been limited by the inadequate views of specific stomach regions. In the present study, radiology and upper gastrointestinal endoscopy (UGIE) were used to determine optimal subject body positioning and suitable external control magnet placement for capsule endoscopy. Healthy adult volunteers were subjected to upper gastrointestinal X-ray radiography (n=5), spiral computed tomography with volume reconstruction (n=4) or UGIE (n=1). Stomach fundus-to-body (FB) and body-to-antrum (BA) angles were compared when subjects were supine, prone, lying on their left side and on their right side, and when they were standing upright. Vertical distances from the surface of the body to the distal points of the fundus and antrum were also compared in this range of subject positions. Obtuse angles were considered the most beneficial for capsule movement and short vertical distances were considered desirable for optimizing magnetic force. The FB angle was sharply acute in the supine position, relatively open where subjects were on their side, and almost 180° in the standing position. The BA angle was obtuse in the standing position but acute in all other positions. With the subject in any position, the left lower lateral chest had the shortest distance to the fundus, while the ventral wall was closest to the antrum. The present modeling analysis indicates that standing is superior to all decubitus positions for magnetic-capsule endoscopy, including the commonly used supine position. Both the abdominal anterior wall and left lateral lower chest appeared to be advantageous locations for external control magnet placement.

Human gastric magnet-controlled capsule endoscopy conducted in a standing position: the phase 1 study

Background

Current magnet-controlled capsule endoscopy (MCE) for the stomach is not yet satisfactory with respect to navigation control, especially in the gastric fundus and cardia. A newly developed MCE system conducted in a standing rather than supine position may improve capsule maneuverability within the stomach. The aim of this phase 1 study was to assess the feasibility and safety of this system for examining the human stomach in healthy volunteers.

Methods

A cohort of 31 healthy volunteers were enrolled. Each swallowed a capsule after drinking water and gas producing agents intended to produce distention. Under the newly developed standing MCE system, subjects were examined endoscopically while standing with external guide magnets placed on the abdominal wall and left lower chest. Safety, gastric preparation, maneuverability, visualization of anatomical landmarks and the gastric mucosa, and examination time were the primary parameters assessed. The gastric preparation and examination procedures were well accepted by the subjects and there were no adverse events.

Results

Gastric examination took 27.8 ± 8.3 min (12–45 min). Gastric cleanliness was good in 24 participants (77.4%) and moderate in 7 participants (22.6%). Gastric distention was good in all of 31 participants (100%). Capsule maneuverability was also graded as good in all 31 subjects (100%), and manipulation in the fundus and cardia regions was as easy as that in the antrum and body. Visualization of the gastric cardia, fundus, body, angulus, antrum and pylorus was assessed subjectively as complete in all 31 subjects (100%). Visualization of the gastric mucosa was also good (> 75%) in all 31 subjects (100%). In areas where the mucosa could not be visualized, the low visibility was due to opaque fluid or foam. Polyps and erosive lesions were found in 25 subjects.

Conclusion

MCE of the stomach conducted in a standing position is feasible and safe with satisfactory maneuverability.

Magnetically assisted capsule endoscopy in suspected acute upper GI bleeding versus esophagogastroduodenoscopy in detecting focal lesions

BACKGROUND AND AIMS

Acute upper GI bleeding is common and requires investigation with EGD, but endotherapy is not always necessary. Magnetically assisted capsule endoscopy (MACE) uses a capsule steerable by an external magnet and allows examination of the upper GI tract and small bowel, but its role in acute upper GI bleeding has not been assessed.

METHODS

We conducted a prospective cohort study comparing the diagnostic yield of MACE and EGD in patients with suspected acute upper GI bleeding. Patient tolerance, mucosal visibility by MACE, and frequency of small-bowel bleeding were assessed. Whether or not MACE could safely predict discharge of patients was also determined.

RESULTS

Thirty-three patients were included for analysis (median age, 60 years; 75.8% male). MACE detected more focal lesions (peptic, vascular, and fresh/altered blood without a clear source) than EGD (40 versus 25, respectively, P = .02) but statistical significance was not reached for significant lesions (considered to be the bleeding source; 14 vs 13, respectively, P = 1). Capsule endoscopy identified an additional cause for bleeding in the small bowel in 18%. Visualization by MACE was excellent in most areas; views of the esophagus, gastroesophageal junction, fundus, and duodenal bulb were suboptimal. MACE was better tolerated than unsedated EGD and correctly identified patients who were safe for discharge.

CONCLUSIONS

MACE had higher diagnostic yield for focal lesions and was better tolerated than EGD. It also correctly predicted safe discharge for patients with acute upper GI bleeding. (Clinical trials registration number: NCT02690376.).

Magnetically Guided Capsule Endoscopy in Pediatric Patients with Abdominal Pain

Background and Aims

Magnetically guided capsule endoscopy (MGCE) offers a noninvasive method of evaluating both the gastric cavity and small intestine; however, few studies have evaluated MGCE in pediatric patients. We investigated the diagnostic efficacy of MGCE in pediatric patients with abdominal pain.

Patients and Methods

We enrolled 48 patients with abdominal pain aged 6–18 years. All patients underwent MGCE to evaluate the gastric cavity and small intestine.

Results

The cleanliness of the gastric cardia, fundus, body, angle, antrum, and pylorus was assessed satisfactorily in 100%, 85.4%, 89.6%, 100%, 97.9%, and 100% of patients, respectively. The subjective percentage visualization of the gastric cardia, fundus, body, angle, antrum, and pylorus was 84.8%, 83.8%, 88.5%, 87.7%, 95.2%, and 99.6%, respectively. Eighteen (37.5%) patients had 19 gastrointestinal tract lesions: one esophageal, three in the gastric cavity, and 15 in the small intestine. No adverse events occurred during follow-up.

Conclusions

MGCE is safe, convenient, and tolerable for evaluating the gastric cavity and small intestine in pediatric patients. MGCE can effectively diagnose pediatric patients with abdominal pain.

Clinical application of magnetically controlled capsule gastroscopy in gastric disease diagnosis: recent advances

Magnetically controlled capsule gastroscopy (MCCG) is a novel system primarily used for the diagnosis of gastric disease. It consists of an endoscopic capsule with magnetic material inside, external guidance magnet equipment, data recorder and computer workstation. Several clinical trials have demonstrated that MCCG is comparable in accuracy in diagnosing gastric focal disease when compared to conventional gastroscopy. Further clinical studies are needed to test the diagnostic accuracy and improve the functioning of MCCG. This novel MCCG system could be a promising alternative for screening for gastric diseases, with the advantages of no anesthesia required, comfort and high acceptance across populations.

Magnetic-Guided Capsule Endoscopy in the Diagnosis of Gastrointestinal Diseases in Minors

Objective

This study aimed at investigating the clinical value of magnetic-guided capsule endoscopy (MGCE) in the diagnosis of gastrointestinal diseases in minors.

Methods

Eighty-four minor patients hospitalized in the pediatric department at Ruijin Hospital between June 2015 and January 2018 were enrolled for this study. Following bowel preparation, all patients underwent MGCE. The feasibility, safety, diagnostic yield, and sensitivity of MGCE were analyzed. Patients were followed up for more than 2 weeks.

Results

The main indications for MGCE in minors were Crohn's disease, gastrointestinal bleeding, and abdominal pain. The main causes of gastric disease were gastric inflammatory hyperplasia, exudative gastritis, and polyps. The most common small bowel diseases in minors were Crohn's disease, Henoch-Schonlein purpura, and polyps. The diagnostic yield in the stomach and small intestine was 13.1% and 28.6%, respectively, and the sensitivity was 100% and 96.0%, respectively. No adverse events occurred.

Conclusion

MGCE is a safe, effective, and well-tolerated procedure with good sensitivity and has a potential clinic value for the diagnosis of gastrointestinal diseases in minors.

Evaluation of Gastric Disease with Capsule Endoscopy

The clinical indication for capsule endoscopy has expanded from small bowel evaluation to include esophagus or colon evaluation.Nevertheless, the role of capsule endoscopy in evaluation of the stomach is very limited because of the large volume and surface.However, efforts to develop an active locomotion system for capsule manipulation in detailed gastric evaluation are ongoing, becausethe technique is non-invasive, convenient, and safe, and requires no sedation. Studies have successfully reported gastric evaluation usinga magnetic-controlled capsule endoscopy system. Advances in technology suggest that capsule endoscopy will have a major role notonly in the evaluation of gastric disorders but also in the pathologic diagnosis, intervention, and treatment of any gastrointestinal tractdisorder.

Robotic Endoscopy

Endoscopes extend the eyes of the physician into the patient's body. They are widely used in gastrointestinal (GI) diagnostics and minimally invasive surgery. Endoscopes can be classified into 3 types: rigid, flexible, and capsule endoscopes. Rigid and flexible endoscopes are traditionally held and manipulated by the physician to visualize the region of interest, while capsule endoscopes move passively along with the GI peristalsis. With the advancement of technology, robotic endoscopy has been increasingly developed and accepted. In this work, robotic endoscopy from 3 categories (robot-assisted rigid endoscopy, robot-assisted flexible endoscopy, and active GI endoscopy including active flexible colonoscopy and active capsule endoscopy) is reviewed by PubMed search with the criteria ('Robotics' OR 'Robot') and ('Endoscopy' OR 'Endoscope').

Association between patient characteristics and magnetically controlled capsule endoscopy findings

BACKGROUND/AIM

Magnetically-controlled capsule endoscopy (MCE) is a potential option for the evaluation of gastric diseases in cases that are unsuited for conventional endoscopy, avoiding discomfort, sedation, and related complications. This retrospective study investigated associations between MCE findings and patient gender, age, and inpatient/outpatient status.

PATIENTS AND METHODS

The data of 580 consecutive patients who underwent MCE from 2015 to 2016 were analyzed. Data included age, gender, indication for MCE, inpatient/outpatient status, overall coverage of gastric anatomical landmarks, and comorbid conditions.

RESULTS

Compared with outpatients, inpatients had a higher rate of overall significant MCE findings (P = 0.014), polyp (P = 0.03), and ulceration (P = 0.003). MCE findings of the inpatient men and women were similar. Considering all patients, the percentage with ulceration was significantly higher in men than in women (P = 0.004), and men were younger (P < 0.001). Compared with younger patients, those aged ≥60 years had significantly higher rates of overall significant findings, mainly polyp and angiodysplasia.

CONCLUSIONS

Compared with outpatients, the inpatients showed higher overall significant findings. Men undergoing MCE were younger than the women, and more likely to have ulcerations. Older patients, whether outpatient or inpatient, had higher rates of significant findings, mainly polyp and angiodysplasia.

Gastric preparation for magnetically controlled capsule endoscopy: A prospective, randomized single-blinded controlled trial

BACKGROUND AND AIMS

Magnetically controlled capsule endoscopy (MCE) is a novel technique for which there is no agreed gastric preparation. We aimed to determine an optimal standardized gastric preparation regimen.

METHODS

120 patients referred for MCE were randomly assigned to gastric preparation with either water alone (A), water with simethicone (B) or water, simethicone and pronase (C). Image quality was assessed using cleanliness and visualization scores, higher scores equating to better image quality.

RESULTS

The total cleanliness scores were (mean±SD) 15.83±2.41 (A), 21.35±1.23 (B), and 20.82±1.90 (C). The total visualization scores (mean±SD) were 10.75±2.02 (A), 15.20±1.32 (B), and 15.08±1.86 (C). While the image quality of the whole stomach in groups B and C were significantly better than group A (P<0.0001), there was no statistical difference between group B and C (P>0.05). MCE detected positive findings in 21 (52.5%), 27 (67.5%) and 21 (53.8%) patients in group A, B and C respectively, with no significant difference between groups (P>0.5).

CONCLUSIONS

Simethicone swallowed with water prior to MCE produced the optimal gastric mucosal image quality. The addition of pronase had no demonstrable additional benefit.

Feasibility and safety of a novel magnetic-assisted capsule endoscope system in a preliminary examination for upper gastrointestinal tract

BACKGROUND AND STUDY AIM

Current capsule endoscopy procedures are ineffective for upper gastrointestinal (GI) tract examination because they do not allow for operator-controlled navigation of the capsule. External controllability of a capsule endoscope with an applied magnetic field is a possible solution to this problem. We developed a novel magnetic-assisted capsule endoscope (MACE) system to visualize the entire upper GI tract. The present study evaluated the safety and feasibility of the MACE system for the examination of the upper GI tract, including the esophagus, stomach, and duodenum.

METHODS

The present open clinical study enrolled ten healthy volunteers. All participants swallowed a MACE, and an external magnetic field navigator was used for magnetic capsule manipulation in the upper GI tract. We assessed the maneuverability of the magnetic capsule and completeness of the MACE examination as well as the safety and tolerability of the procedure.

RESULTS

The present study enrolled ten healthy volunteers with a mean age and body mass index of 47.7 years and 25.6 kg/m², respectively. One volunteer withdrew because of difficulty in swallowing the capsule. In total, nine volunteers underwent the MACE examination. The average examination time was 27.1 min. The maneuverability of the capsule was assessed as good and fair in 55.6 and 44.4% of the participants, respectively. The overall completeness of the examination in the esophagus, stomach, and duodenum was 100, 85.2, and 86.1%, respectively. No severe adverse events occurred during this study. All participants exhibited satisfactory tolerance of the MACE examination.

CONCLUSION

The MACE system has satisfactory maneuverability and visualization completeness with excellent acceptance and tolerance.

Magnetically guided capsule endoscopy

Wireless capsule endoscopy (WCE) is a powerful tool for medical screening and diagnosis, where a small capsule is swallowed and moved by means of natural peristalsis and gravity through the human gastrointestinal (GI) tract. The camera-integrated capsule allows for visualization of the small intestine, a region which was previously inaccessible to classical flexible endoscopy. As a diagnostic tool, it allows to localize the sources of bleedings in the middle part of the gastrointestinal tract and to identify diseases, such as inflammatory bowel disease (Crohn's disease), polyposis syndrome, and tumors. The screening and diagnostic efficacy of the WCE, especially in the stomach region, is hampered by a variety of technical challenges like the lack of active capsular position and orientation control. Therapeutic functionality is absent in most commercial capsules, due to constraints in capsular volume and energy storage. The possibility of using body-exogenous magnetic fields to guide, orient, power, and operate the capsule and its mechanisms has led to increasing research in Magnetically Guided Capsule Endoscopy (MGCE). This work shortly reviews the history and state-of-art in WCE technology. It highlights the magnetic technologies for advancing diagnostic and therapeutic functionalities of WCE. Not restricting itself to the GI tract, the review further investigates the technological developments in magnetically guided microrobots that can navigate through the various air- and fluid-filled lumina and cavities in the body for minimally invasive medicine.

Where do I see minimally invasive endoscopy in 2020: clock is ticking

Since it was introduced 17 years ago, capsule endoscopy has become an important diagnostic tool for the small bowel. Three generations of the original small bowel capsule have been developed since (PillCam SB3, Medtronic, USA), and four competitors were introduced for the small bowel. A non-video patency capsule (Agile patency capsule, Medtronic, USA) was also developed, in order to confirm patency and thus avoid retention in the GI tract. Moreover, capsules viewing other organs of the body (esophagus, colon) as well as three different magnetic guided capsules that visualize the stomach as good as optical endoscopy (OE) have been developed. Over 2,000 articles looking at the efficacy of the small bowel capsule in different clinical situations were published since then. Studies are comparing capsule endoscopy versus other modalities in various indications, looking at preparations aiming to improve the diagnostic yield and at technical aspects. The present paper, describes the available capsules in the market and my biased future expectations.

Ingestible Sensors

Ingestible sensing capsules are fast emerging as a critical technology that has the ability to greatly impact health, nutrition, and clinical areas. These ingestible devices are noninvasive and hence are very attractive for customers. With widespread access to smart phones connected to the Internet, the data produced by this technology can be readily seen and reviewed online, and accessed by both users and physicians. The outputs provide invaluable information to reveal the state of gut health and disorders as well as the impact of food, medical supplements, and environmental changes on the gastrointestinal tract. One unique feature of such ingestible sensors is that their passage through the gut lumen gives them access to each individual organ of the gastrointestinal tract. Therefore, ingestible sensors offer the ability to gather images and monitor luminal fluid and the contents of each gut segment including electrolytes, enzymes, metabolites, hormones, and the microbial communities. As such, an incredible wealth of knowledge regarding the functionality and state of health of individuals through key gut biomarkers can be obtained. This Review presents an overview of the gut structure and discusses current and emerging digestible technologies. The text is an effort to provide a comprehensive overview of ingestible sensing capsules, from both a body physiology point of view as well as a technological view, and to detail the potential information that they can generate.

Combination of Five Body Positions Can Effectively Improve the Rate of Gastric Mucosa's Complete Visualization by Applying Magnetic-Guided Capsule Endoscopy

Objectives. Achieving a comprehensive view of gastric mucosa has been a challenge for magnetic-guided capsule endoscopy (MGCE) for years. This study works on optimizing the performance of MGCE by changing the conventional positions to the five body positions. Methods. Sixty patients were enrolled in the study and underwent MGCE. All patients were asked to adopt five body positions (left lateral, supine, right lateral, knee-chest, and sitting). In each position, the ability to visualize the six gastric landmarks (cardia, fundus, body, angulus, antrum, and pylorus) was assessed. Rates of complete visualization were calculated for different position combinations. Results. Supine position was the best for cardia and body visualization (91.7% and 86.7%, resp., p < 0.001). Left lateral position was the best for fundus visualization (91.7%, p < 0.001). Knee-chest position was the best for angulus observation (80.0%, p < 0.001). Right lateral and sitting positions were the best for antrum observation (88.3% and 90.0%, resp., p < 0.001). Right lateral position was the best for pylorus observation (81.7%, p < 0.001). The supine + right lateral + knee-chest combination achieved better angulus visualization than conventional 3-position combination (93.3% versus 63.3%, p < 0.001). Five-position combination significantly improved the comprehensive gastric landmark visualization (93.3%, p < 0.001). Conclusion. Compared with 3-position combination, 5-position combination should be adopted for gastric mucosal visualization by MGCE.

Accuracy of Magnetically Controlled Capsule Endoscopy, Compared With Conventional Gastroscopy, in Detection of Gastric Diseases

BACKGROUND & AIMS

Diseases of the stomach, including gastric cancer and peptic ulcer, are the most common digestive diseases. It is impossible to visualize the entire stomach with the passive capsule currently used in practice because of the large size of the gastric cavity. A magnetically controlled capsule endoscopy (MCE) system has been designed to explore the stomach. We performed a prospective study to compare the accuracy of detection of gastric focal lesions by MCE vs conventional gastroscopy (the standard method).

METHODS

We performed a multicenter blinded study comparing MCE with conventional gastroscopy in 350 patients (mean age, 46.6 y), with upper abdominal complaints scheduled to undergo gastroscopy at a tertiary center in China from August 2014 through December 2014. All patients underwent MCE, followed by conventional gastroscopy 2 hours later, without sedation. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of detection of gastric focal lesions by MCE, using gastroscopy as the standard.

RESULTS

MCE detected gastric focal lesions in the whole stomach with 90.4% sensitivity (95% confidence interval [CI], 84.7%-96.1%), 94.7% specificity (95% CI, 91.9%-97.5%), a positive predictive value of 87.9% (95% CI, 81.7%-94.0%), a negative predictive value of 95.9% (95% CI, 93.4%-98.4%), and 93.4% accuracy (95% CI, 90.83%-96.02%). MCE detected focal lesions in the upper stomach (cardia, fundus, and body) with 90.2% sensitivity (95% CI, 82.0%-98.4%) and 96.7% specificity (95% CI, 94.4%-98.9%). MCE detected focal lesions in the lower stomach (angulus, antrum, and pylorus) with 90.6% sensitivity (95% CI, 82.7%-98.4%) and 97.9% specificity (95% CI, 96.1%-99.7%). MCE detected 1 advanced gastric carcinoma, 2 malignant lymphomas, and 1 early stage gastric tumor. MCE did not miss any lesions of significance (including tumors or large ulcers). Among the 350 patients, 5 reported 9 adverse events (1.4%) and 335 preferred MCE over gastroscopy (95.7%).

CONCLUSIONS

MCE detects focal lesions in the upper and lower stomach with comparable accuracy with conventional gastroscopy. MCE is preferred by almost all patients, compared with gastroscopy, and can be used to screen gastric diseases without sedation. Clinicaltrials.gov number: NCT02219529.

Current and future role of magnetically assisted gastric capsule endoscopy in the upper gastrointestinal tract

Capsule endoscopy first captivated the medical world when it provided a means to visualize the small bowel, which was previously out of endoscopic reach. In the subsequent decade and a half we continue to learn of the true potential that capsule endoscopy has to offer. Of particular current interest is whether capsule endoscopy has any reliable investigative role in the upper gastrointestinal tract. Much research has already been dedicated to enhancing the diagnostic and indeed therapeutic properties of capsule endoscopy. Specific modifications to tackle the challenges of the gut have already been described in the current literature. In the upper gastrointestinal tract, the capacious anatomy of the stomach represents one of many challenges that capsule endoscopy must overcome. One solution to improving diagnostic yield is to utilize external magnetic steering of a magnetically receptive capsule endoscope. Notionally this would provide a navigation system to direct the capsule to different areas of the stomach and allow complete gastric mucosal examination. To date, several studies have presented promising data to support the feasibility of this endeavour. However the jury is still out as to whether this system will surpass conventional gastroscopy, which remains the gold standard diagnostic tool in the foregut. Nevertheless, a minimally invasive and patient-friendly alternative to gastroscopy remains irresistibly appealing, warranting further studies to test the potential of magnetically assisted capsule endoscopy. In this article the authors would like to share the current state of magnetically assisted capsule endoscopy and anticipate what is yet to come.