Maneuverability and safety of a magnetic-controlled capsule endoscopy system to examine the human colon under real-time monitoring by colonoscopy: a pilot study (with video)

A novel intelligent chromo capsule endoscope for the diagnosis of neoplastic lesions in the gastrointestinal tract

Background

Chromoendoscopy has not been fully integrated into capsule endoscopy. This study aimded to develop and validate a novel intelligent chromo capsule endoscope (ICCE).

Methods

The ICCE has two modes: a white-light imaging (WLI) mode and an intelligent chromo imaging (ICI) mode. The performance of the ICCE in observing colors, animal tissues, and early gastrointestinal (GI) neoplastic lesions in humans was evaluated. Images captured by the ICCE were analysed using variance of Laplacian (VoL) values or image contrast evaluation.

Results

For color observation, conventional narrow-band imaging endoscopes and the ICI mode of the ICCE have similar spectral distributions. Compared with the WLI mode, the ICI mode had significantly higher VoL values for animal tissues (2.154 ± 1.044 vs 3.800 ± 1.491, P = 0.003), gastric precancerous lesions and early gastric cancers (2.242 ± 0.162 vs 6.642 ± 0.919, P < 0.001), and colon tumors (3.896 ± 1.430 vs 11.882 ± 7.663, P < 0.001), and significantly higher contrast for differentiating tumor and non-tumor areas (0.069 ± 0.046 vs 0.144 ± 0.076, P = 0.005). More importantly, the sensitivity, specificity, and accuracy of the ICI mode for early GI tumors were 95.83%, 91.67%, and 94.64%, respectively, which were significantly higher than the values of the WLI mode (78.33% [P < 0.001], 77.08% [P = 0.01], and 77.98% [P < 0.001], respectively).

Conclusions

We successfully integrated ICI into the capsule endoscope. The ICCE is an innovative and useful tool for differential diagnosis based on contrast-enhanced images and thus has great potential as a superior diagnostic tool for early GI tumor detection.

The efficient of application of a fine magnetic traction system simplifies colorectal endoscopic submucosal dissection: A porcine study

BACKGROUND

Sometimes it is difficult to maintain good visualization of the submucosal layer during colorectal endoscopic submucosal dissection (ESD). This study aimed to evaluate the feasibility and efficacy of a novel traction method, the fine magnetic traction system (FMTS), in colorectal ESD.

METHODS

ESD was performed 10, 15, or 30 cm from the anus in the colorectums of 10 Bama miniature pigs with or without FMTS. The circumcision and dissection per unit time (cm²/min), en bloc resection, perforation and bleeding rates, size and integrity of the specimen and submucosal injection times were analysed.

RESULTS

A total of 60 ESD procedures were performed with or without FMTS assistance. The en bloc resection rates were 100% at 10 and 15 cm from the anus in both the control group (conventional ESD) and the FMTS group. However, at 30 cm from the anus, these rates were only 10% and 70% (p = 0.006). The resection speeds (control vs. FMTS) at the 10, 15, and 30 cm points were 0.35 ± 0.07 cm²/min vs. 0.39 ± 0.19 cm²/min (p = 0.56), 0.30 ± 0.09 cm²/min vs. 0.38 ± 0.02 cm²/min (p = 0.04), and 0.11 cm²/min vs. 0.26 ± 0.10 cm²/min, respectively.

CONCLUSIONS

The FMTS provides effective counter-traction and efficiently reduces the risks and difficulties of difficult colonic ESD in the porcine model.

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.

Application of robotic technologies in lower gastrointestinal tract endoscopy: A systematic review

BACKGROUND

Conventional optical colonoscopy is considered the gold standard investigation for colorectal tract pathology including colorectal malignancy, polyps and inflammatory bowel disease. Inherent limitations exist with current generation endoscopic technologies, including, but not limited to, patient discomfort, endoscopist fatigue, narrow field of view and missed pathology behind colonic folds. Rapid developments in medical robotics have led to the emergence of a variety of next-generation robotically-augmented technologies that could overcome these limitations.

AIM

To provide a comprehensive summary of recent developments in the application of robotics in lower gastrointestinal tract endoscopy.

METHODS

A systematic review of the literature was performed from January 1, 2000 to the January 7, 2021 using EMBASE, MEDLINE and Cochrane databases. Studies reporting data on the use of robotic technology in ex vivo or in vivo animal and human experiments were included. In vitro studies (studies using synthetic colon models), studies evaluating non-robotic technology, robotic technology aimed at the upper gastrointestinal tract or paediatric endoscopy were excluded. System ergonomics, safety, visualisation, and diagnostic/therapeutic capabilities were assessed.

RESULTS

Initial literature searching identified 814 potentially eligible studies, from which 37 were deemed suitable for inclusion. Included studies were classified according to the actuation modality of the robotic device(s) as electromechanical (EM) (n = 13), pneumatic (n = 11), hydraulic (n = 1), magnetic (n = 10) and hybrid (n = 2) mechanisms. Five devices have been approved by the Food and Drug Administration, however most of the technologies reviewed remain in the early phases of testing and development. Level 1 evidence is lacking at present, but early reports suggest that these technologies may be associated with improved pain and safety. The reviewed devices appear to be ergonomically capable and efficient though to date no reports have convincingly shown diagnostic or therapeutic superiority over conventional colonoscopy.

CONCLUSION

Significant progress in robotic colonoscopy has been made over the last couple of decades. Improvements in design together with the integration of semi-autonomous and autonomous systems over the next decade will potentially result in robotic colonoscopy becoming more commonplace.

Automatic lumen detection and magnetic alignment control for magnetic-assisted capsule colonoscope system optimization

We developed a magnetic-assisted capsule colonoscope system with integration of computer vision-based object detection and an alignment control scheme. Two convolutional neural network models A and B for lumen identification were trained on an endoscopic dataset of 9080 images. In the lumen alignment experiment, models C and D used a simulated dataset of 8414 images. The models were evaluated using validation indexes for recall (R), precision (P), mean average precision (mAP), and F1 score. Predictive performance was evaluated with the area under the P-R curve. Adjustments of pitch and yaw angles and alignment control time were analyzed in the alignment experiment. Model D had the best predictive performance. Its R, P, mAP, and F1 score were 0.964, 0.961, 0.961, and 0.963, respectively, when the area of overlap/area of union was at 0.3. In the lumen alignment experiment, the mean degrees of adjustment for yaw and pitch in 160 trials were 21.70° and 13.78°, respectively. Mean alignment control time was 0.902 s. Finally, we compared the cecal intubation time between semi-automated and manual navigation in 20 trials. The average cecal intubation time of manual navigation and semi-automated navigation were 9 min 28.41 s and 7 min 23.61 s, respectively. The automatic lumen detection model, which was trained using a deep learning algorithm, demonstrated high performance in each validation index.

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.

Linear-array EUS improves the accuracy of predicting deep submucosal invasion in non-pedunculated rectal polyps compared with radial EUS: a prospective observational study

BACKGROUND

Radial endoscopic ultrasound (EUS) is typically used to estimate the depth of rectal polyp invasion, however, there are no data on linear EUS in this setting and its relative accuracy compared to radial EUS.

METHODS

In this prospective cohort study, 89 patients with non-pedunculated rectal polyp who underwent linear EUS or radial EUS were prospectively enrolled. The invasion depth was measured for each polyp and categorized as mucosal to shallow submucosal(SM_s) or deep submucosal(SM_d) invasion. Invasion measurements were compared with the final diagnosis on histopathology.

RESULTS

A total of 58 patients underwent radial EUS and 31 patients underwent linear EUS examination. There were 38 lesions correctly diagnosed in the radial EUS group and 29 correctly diagnosed lesions in the linear EUS group. The diagnostic accuracy of SM_d invasion for linear EUS was significantly higher than radial EUS (0.936 vs. 0.655, p = 0.003). A significant difference was also noted for specificity between the two groups (0.963 vs. 0.659, p = 0.003). Univariate analysis showed radial EUS type (OR 0.131, 95% CI 0.028-0.606, p = 0.009) to be an independent predictor for incorrect diagnosis. The area under the receiver operating curve (ROC) was 0.856 and 0.651 for linear EUS and radial EUS, respectively. It was noted that four patients underwent unnecessary surgery for radial EUS while there were no such patients in the linear EUS group.

CONCLUSIONS

Linear EUS was more accurate for determining SM_d invasion and contributed to the selection of appropriate treatment modalities in patients with non-pedunculated rectal polyp.

Predictive Tilt Compensation for Robot Assisted Magnetic Capsule Endoscope

Wireless capsule endoscopes provide a painless and non-invasive alternative to the flexible endoscope in various applications of the gastrointestinal tract diagnosis. Operating a wireless capsule endoscope in the colon may benefit from an active position control as the large colon diameter can lead to uncontrollable and unpredictable capsule trajectory. Robot assisted magnetic steering is an attractive technique that is being explored by researchers worldwide. This paper presents the implications of a novel capsule geometry to markedly improve capsule stabilization and locomotion compared to the cylinder-based capsule geometry that is commonly used.

Strategies for Colorectal Cancer Screening

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

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.

A global perspective on capsule endoscopy

A search of the internet today to quantify the estimated value of capsules from a global perspective, easily delivers figures stating around $200 million in 2014 to about $400 million by 2020, which would be approximately 10% of the gastrointestinal endoscopic market. Is this a steep rise within just six years or could the capsule market do even better? What chances does this offer and what are the key aspects for future success? By 2020, more than 1 billion people are aged sixty or older and around one third of them will live in what the UN calls "more developed regions". Naturally, this brings an increased demand for colorectal cancer screening and surgery. But keeping in mind that basically every healthcare system, in any country, is already operating at its limits, how do we secure future treatment for a growing community? Surely more competition will steadily bring down prices for capsules. However, that does not ease the amount of time that is spent to properly read any video and issue a valid diagnosis for every patient. This article intends to give an overview about the current global market for capsule endoscopy (CE) with a perspective on typical patients, their indications, and how the capsules are used and by whom. Further aspects, such as standardization of training, reading and future trends will also be elaborated on.

Colon capsule endoscopy: toward the future

Colon capsule endoscopy is a wireless and minimally invasive technique for visualization of the whole colon. With recent improvements of technical features in second-generation systems, a more important role for colon capsule endoscopy is rapidly emerging. Although several limitations and drawbacks are yet to be resolved, its usefulness as a tool for colorectal cancer screening and monitoring disease activity in inflammatory bowel diseases has become more apparent with increased use. Further investigations, including multicenter trials, are required to evaluate the substantial role of the colon capsule in managing colorectal diseases.

Review: capsule colonoscopy-a concise clinical overview of current status

The colon capsule endoscopy (CCE) was first introduced in 2007. Currently, the main clinical indications for CCE are completion of incomplete colonoscopy, polyp detection and investigation of inflammatory bowel disease (IBD). Although conventional colonoscopy is the gold standard in bowel cancer screening, incomplete colonoscopy remains a problem as lesions are missed. CCE compares favourably to computer tomography colonography (CTC) in adenoma detection and has therefore been proposed as a method for completing colonoscopy. However the data on CCE remains sparse and current evidence does not show its superiority over CTC or conventional colonoscopy in bowel cancer screening. CCE also seems to show good correlation with conventional colonoscopy when used to evaluate IBD, but there are not many published studies at present. Other significant limitations include the need for aggressive bowel preparation and the labour-intensiveness of CCE reading. Therefore, much further software and hardware development is required to enable CCE to fulfill its potential as a minimally-invasive and reliable method of colonoscopy.