Two cameras detect more lesions in the small-bowel than one

Endoscopic capsule robot-based diagnosis, navigation and localization in the gastrointestinal tract

The proliferation of video capsule endoscopy (VCE) would not have been possible without continued technological improvements in imaging and locomotion. Advancements in imaging include both software and hardware improvements but perhaps the greatest software advancement in imaging comes in the form of artificial intelligence (AI). Current research into AI in VCE includes the diagnosis of tumors, gastrointestinal bleeding, Crohn’s disease, and celiac disease. Other advancements have focused on the improvement of both camera technologies and alternative forms of imaging. Comparatively, advancements in locomotion have just started to approach clinical use and include onboard controlled locomotion, which involves miniaturizing a motor to incorporate into the video capsule, and externally controlled locomotion, which involves using an outside power source to maneuver the capsule itself. Advancements in locomotion hold promise to remove one of the major disadvantages of VCE, namely, its inability to obtain targeted diagnoses. Active capsule control could in turn unlock additional diagnostic and therapeutic potential, such as the ability to obtain targeted tissue biopsies or drug delivery. With both advancements in imaging and locomotion has come a corresponding need to be better able to process generated images and localize the capsule’s position within the gastrointestinal tract. Technological advancements in computation performance have led to improvements in image compression and transfer, as well as advancements in sensor detection and alternative methods of capsule localization. Together, these advancements have led to the expansion of VCE across a number of indications, including the evaluation of esophageal and colon pathologies including esophagitis, esophageal varices, Crohn’s disease, and polyps after incomplete colonoscopy. Current research has also suggested a role for VCE in acute gastrointestinal bleeding throughout the gastrointestinal tract, as well as in urgent settings such as the emergency department, and in resource-constrained settings, such as during the COVID-19 pandemic. VCE has solidified its role in the evaluation of small bowel bleeding and earned an important place in the practicing gastroenterologist’s armamentarium. In the next few decades, further improvements in imaging and locomotion promise to open up even more clinical roles for the video capsule as a tool for non-invasive diagnosis of lumenal gastrointestinal pathologies.

Novel Clinical Applications and Technical Developments in Video Capsule Endoscopy

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

Double-headed small-bowel capsule endoscopy: Real-world experience from a multi-centre British study

INTRODUCTION

Capsule endoscopy (CE) is well established the investigation of small-bowel (SB) pathology. We compared the use of double-headed (DH) capsules, to conventional single-headed (SH), in a real-world patient cohort in the first multicentre British study.

METHODS

Over 9 months, patients referred for routine SBCE at 4 tertiary referral centres in the UK underwent DH CE instead of conventional SH using MiroCam^Ⓡ MC2000 as per local protocols. One head (L/R) was chosen at random and reported by an expert reviewer. The DH recordings, anonymised and randomised, reported by another expert or re-read after a 4-week interval. For each CE, numbers and types of findings and overall conclusion/diagnosis were compared between SH and DH examinations.

RESULTS

211 CEs were performed. 7 failed to reach the SB; 204 analysed. Indications were: SB bleeding (n = 94); ?SB inflammation or reassessment of known inflammatory bowel disease (IBD) (n = 84); ?SB neoplasia including suspicious radiological imaging (n = 15); and, others e.g. ?celiac disease (n = 11). For SB bleeding: 27/94 (28.7%) examinations reported differences between SH and DH readings. In 17 (18.1%) the findings were clinically significant. SH CE missed angiectasias (5 pts), SB inflammation (7 pts), oesophagitis (2 pts) and SB masses (2 pts). In 1 patient, the extent of angiectasias seen was greater on the DH reading. For IBD: findings differed in 30/84 (35.7%) of CEs; 11 (13.1%) were clinically significant. In 5, signs of active inflammation were missed by the SH reading. In 6, assessment of extent/severity differed. For?SB neoplasia findings differed in 2/15 (13.3%) of examinations. Both were clinically significant. For others: 1/11 (9.1%) examinations differed; however, not deemed clinically significant. Overall, use of DH CE impacted the diagnosis in 30/204 (14.7%).

CONCLUSIONS

The use of DH CE provides more information with the potential to change clinical diagnosis and therefore management. Therefore, the routine adoption of DH CE in SB assessment should be considered.

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.

Current Status of Interpretation of Small Bowel Capsule Endoscopy

Capsule endoscopy (CE) has revolutionized direct small bowel imaging and is widely used in clinical practice. Remote visualization of bowel images enables painless, well-tolerated endoscopic examinations. Small bowel CE has a high diagnostic yield and the ability to examine the entire small bowel. The diagnostic yield of CE relies on lesion detection and interpretation. In this review, issues related to lesion detection and interpretation of CE have been addressed, and the current status of automated reading software development has been reviewed. Clinical significance of an external real-time image viewer has also been described.

Upper gastrointestinal tract capsule endoscopy using a nurse-led protocol: First reported experience

AIM

To test the feasibility and performance of a novel upper gastrointestinal (GI) capsule endoscope using a nurse-led protocol.

METHODS

We conducted a prospective cohort analysis of patients who declined gastroscopy (oesophagogastroduodenoscopy, OGD) but who consented to upper GI capsule endoscopy. Patients swallowed the upper GI capsule following ingestion of 1 liter of water (containing simethicone). A series of positional changes were used to exploit the effects of water flow and move the upper GI capsule from one gravity-dependent area to another using a nurse-led protocol. Capsule transit time, video reading time, mucosal visualisation, pathology detection and patient tolerance was evaluated.

RESULTS

Fifty patients were included in the study. The mean capsule transit times in the oesophagus and stomach were 28 s and 68 min respectively. Visualisation of the following major anatomical landmarks was achieved (graded 1-5: Poor to excellent): Oesophagus, 4.8 (± 0.5); gastro-oesophageal junction (GOJ), 4.8 (± 0.8); cardia, 4.8 (± 0.8); fundus, 3.8 (± 1.2); body, 4.5 (± 1); antrum, 4.5 (± 1); pylorus, 4.7 (± 0.8); duodenal bulb, 4.7 (± 0.7); second part of the duodenum (D2), 4.7 (± 1). The upper GI capsule reached D2 in 64% of patients. The mean video reading time was 48 min with standard playback mode and 20 min using Quickview (P = 0.0001). No pathology was missed using Quickview. Procedural tolerance was excellent. No complications were seen with the upper GI capsule.

CONCLUSION

The upper GI capsule achieved excellent views of the upper GI tract. Future studies should compare the diagnostic accuracy between upper GI capsule and OGD.

Evaluation of 4 three-dimensional representation algorithms in capsule endoscopy images

AIM: To evaluate the three-dimensional (3-D) representation performance of 4 publicly available Shape-from-Shading (SfS) algorithms in small-bowel capsule endoscopy (SBCE).

METHODS: SfS techniques recover the shape of objects using the gradual variation of shading. There are 4 publicly available SfS algorithms. To the best of our knowledge, no comparative study with images obtained during clinical SBCE has been performed to date. Three experienced reviewers were asked to evaluate 54 two-dimensional (2-D) images (categories: protrusion/inflammation/vascular) transformed to 3-D by the aforementioned SfS 3-D algorithms. The best algorithm was selected and inter-rater agreement was calculated.

RESULTS: Four publicly available SfS algorithms were compared. Tsai’s SfS algorithm outperformed the rest (selected as best performing in 45/54 SBCE images), followed by Ciuti’s algorithm (best performing in 7/54 images) and Torreão’s (in 1/54 images). In 26/54 images; Tsai’s algorithm was unanimously selected as the best performing 3-D representation SfS software. Tsai’s 3-D algorithm superiority was independent of lesion category (protrusion/inflammatory/vascular; P = 0.678) and/or CE system used to obtain the 2-D images (MiroCam^®/PillCam^®; P = 0.558). Lastly, the inter-observer agreement was good (kappa = 0.55).

CONCLUSION: 3-D representation software offers a plausible alternative for 3-D representation of conventional capsule endoscopy images (until optics technology matures enough to allow hardware enabled-“real” 3-D reconstruction of the gastrointestinal tract).

First clinical trial of a newly developed capsule endoscope with panoramic side view for small bowel: a pilot study

BACKGROUND AND STUDY AIMS

Capsule endoscopy is the first-line diagnostic technique for the small bowel. However, the inability to visualize the duodenal papilla is an inherent limitation of this method. In the present study, we evaluated feasibility of a newly developed CapsoCam SV1 capsule.

PATIENTS AND METHODS

This is a prospective dual center study of a newly developed video capsule CapsoCam SV1 from Capsovision, CA, providing panoramic 360° imaging. A high frequency of 20 frames occurs per second for the first 2 h and thereafter 12 frames/s, with a battery life of 15 h. We evaluated feasibility and completeness of small bowel examination together with secondary endpoints of duodenal papilla detection in 33 patients. Patients swallowed the capsules following colonoscopy or were prepared with 2 L of polyethylene glycol solution prior to the examination. All patients swallowed 20 mg of metoclopramide and 160 mg of simethicone 30 min before ingestion of the capsule.

RESULTS

Thirty-one of the 33 patients' data could be evaluated. Small bowel examination was complete in all procedures. Mean time to pass the small bowel was 258 ± 136 min. Average small bowel cleanliness was 3.3 ± 0.5. In 71% of the patients, we identified the duodenal papilla. No adverse reaction in relation to the capsule examination was observed.

CONCLUSIONS

CapsoCam SV1 is a safe and efficient tool in small bowel examination. The duodenal papilla as the only landmark in small bowel is detected in more than 70% of the patients.

Video capsule endoscopy of the small bowel

PURPOSE OF REVIEW

Small bowel capsule endoscopy (SBCE) was introduced 13 years ago by Given Imaging (Yokneam, Israel). It has become one of the most important investigational tools of the small bowel. The capsule is swallowed with water after a 12 h fast, propelled via peristalsis through the gastrointestinal tract and excreted naturally. A nonvideo patency capsule was developed to confirm functional patency of the gastrointestinal tract.

RECENT FINDINGS

Four additional companies have introduced competitive small bowel video capsules, some of which are Food and Drug Admistration (FDA) approved. Due to the easiness of the procedure, SBCE has become a first-line tool to detect small bowel abnormalities. The main indications for SBCE include obscure gastrointestinal bleeding, suspected Crohn's disease, small bowel tumors and practically any abnormal small bowel imaging. New indications are emerging like small bowel motility and monitoring of drug therapy and mucosal healing. The present review will describe the available capsules in the market, the procedure itself, present indications and future expectations. It will focus on the PillCam SB of Given Imaging as it is the one on which most of the literature is written.

SUMMARY

Over the past 10 years, SBCE has become a routine, first-line investigational tool of many small bowel pathologies.

What we have learned and what to expect from capsule endoscopy

Capsule endoscopy was conceived by Gabriel Iddan and Paul Swain independently two decades ago. These applications include but are not limited to Crohn’s disease of the small bowel, occult gastrointestinal bleeding, non steroidal anti inflammatory drug induced small bowel disease, carcinoid tumors of the small bowel, gastro intestinal stromal tumors of the small bowel and other disease affecting the small bowel. Capsule endoscopy has been compared to traditional small bowel series, computerized tomography studies and push enteroscopy. The diagnostic yield of capsule endoscopy has consistently been superior in the diagnosis of small bowel disease compared to the competing methods (small bowel series, computerized tomography, push enteroscopy) of diagnosis. For this reason capsule endoscopy has enjoyed a meteoric success. Image quality has been improved with increased number of pixels, automatic light exposure adaptation and wider angle of view. Further applications of capsule endoscopy of other areas of the digestive tract are being explored. The increased transmission rate of images per second has made capsule endoscopy of the esophagus a realistic possibility. Technological advances that include a double imager capsule with a nearly panoramic view of the colon and a variable frame rate adjusted to the movement of the capsule in the colon have made capsule endoscopy of the colon feasible. The diagnostic rate for the identification of patients with polyps equal to or larger than 6 mm is high. Future advances in technology and biotechnology will lead to further progress. Capsule endoscopy is following the successful modern trend in medicine that replaces invasive tests with less invasive methodology.

New vision in video capsule endoscopy: current status and future directions

Now, more than 10 years after the approval of video capsule endoscopy (VCE), the technology has become an essential component in the management of several clinical conditions. Currently, two capsules are approved in the USA for visualizing the small bowel mucosa, one capsule is authorized for oesophageal assessment and several others are in use or under evaluation worldwide. New investigations have focused on optical improvements, advances in intestinal cleansing and risk reduction strategies to optimize VCE methodologies in clinical care. Established indications diagnosed using VCE include unexplained gastrointestinal bleeding, small bowel Crohn's disease (in adults and children >10 years old), localization of small bowel tumours and a broad range of miscellaneous abnormalities. Investigations are ongoing to determine the utility of VCE in colon cancer screening, assessment of oesophageal disorders and diagnosis of coeliac disease. Active research is in progress into ways to improve the efficacy of VCE recording interpretation, prolong imaging time and further enhance optics and imaging methods. To expand the potential utility of VCE, novel devices that can manoeuvre within or insufflate the gut lumen, tag or biopsy suspect lesions, or target drug delivery to specific sites are in development. To facilitate these advances, consortia have been organized to promote innovative VCE technologies.

Colon capsule endoscopy: Advantages, limitations and expectations. Which novelties?

Since the first reports almost ten years ago, wireless capsule endoscopy has gained new fields of application. Colon capsule endoscopy represents a new diagnostic technology for colonic exploration. Clinical trials have shown that colon capsule endoscopy is feasible, accurate and safe in patients suffering from colonic diseases and might be a valid alternative to conventional colonoscopy in selected cases such as patients refusing conventional colonoscopy or with contraindications to colonoscopy or when colonoscopy is incomplete. Despite the enthusiasm surrounding this new technique, few clinical and randomized controlled trials are to be found in the current literature, leading to heterogeneous or controversial results. Upcoming studies are needed to prove the substantial utility of colon capsule endoscopy for colon cancer screening, especially in a low prevalence of disease population, and for other indications such as inflammatory bowel disease. Possible perspectives are critically analysed and reported in this paper.