Conventional Endoscopy Research Articles

Prospective randomized trial of a new multibending versus conventional ultra-slim endoscope for peroral cholangioscopy without device or endoscope assistance (with video)

Currently available peroral cholangioscopy (POC) is a duodenoscopy-assisted procedure that does not involve directly inserting an endoscope into the biliary tree. A prototype multibending (MB) ultra-slim endoscope has been developed as a dedicated cholangioscope to overcome the technical difficulties of direct POC. Inthis study, we evaluated the efficacy of the new MB ultra-slim endoscope compared with a conventional ultra-slim endoscope for free-hand insertion of an endoscope into the bile duct for direct POC without the assistance of accessories. Ninety-two patients with biliary disease requiring diagnostic and/or therapeutic direct POC were assigned randomly to groups examined using an MB ultra-slim endoscope (MB group, n=46) versus a conventional ultra-slim endoscope (conventional group, n=46). The primary outcome was the technical success of free-hand insertion of the endoscope during direct POC, defined as successful insertion of the endoscope through the ampulla of Vater and advancement of the endoscope up to the bifurcation or to the obstructed segment of the biliary tree without any accessories within 15 minutes. Free-hand biliary insertion of the endoscope for direct POC was technically successful in 41 patients (89.1%)in the MB group, which was significantly higher than the rate (14 patients, 30.4%) in the conventional group (P< .001). The procedure time (mean ± standard deviation) of direct POC using free-hand biliary insertion of the endoscope was significantly shorter in the MB group than in the conventional group (3.2 ± 1.8 vs 6.0 ± 3.0 minutes, P= .004). Adverse events were observed in 3 patients (6.5%) in the MB group and 2 patients (4.3%) in the conventional group (P= .500), all of whom were treated conservatively. The technical success rates of the diagnostic or therapeutic intervention were not significantly different between the 2 groups in patients undergoing successful direct POC. Free-hand biliary insertion of the MB ultra-slim endoscope showed a high technical success rate without severe adverse events and effectively decreased procedure time compared with a conventional ultra-slim endoscope. Direct POC using the MB ultra-slim endoscope can be used for novel diagnostic and therapeutic procedures of the biliary tree without the assistance of another endoscope or accessory. (Clinical trial registration number: NCT02189421.).

Computational endoscopy-a framework for improving spatial resolution in fiber bundle imaging.

This Letter presents a framework for computational imaging (CI) in fiber-bundle-based endoscopy systems. Multiple observations are acquired of objects spatially modulated with different random binary masks. Sparse-recovery algorithms then reconstruct images with more resolved pixels than individual fibers in the bundle. Object details lying within the diameter of single fibers are resolved, allowing images with 41,663 resolvable points to be generated through a bundle with 2,420 fibers. Computational fiber bundle imaging of micro- and macro-scale objects is demonstrated using fluorescent standards and biological tissues, including in vivo imaging of a human fingertip. In each case, CI recovers details that conventional endoscopy does not provide.

Full-field quantitative phase and polarisation-resolved imaging through an optical fibre bundle.

Flexible optical fibres, used in conventional medical endoscopy and industrial inspection, scramble phase and polarisation information, restricting users to amplitude-only imaging. Here, we exploit the near-diagonality of the multi-core fibre (MCF) transmission matrix in a parallelised fibre characterisation architecture, enabling accurate imaging of quantitative phase (error rad) and polarisation-resolved (errors %) properties. We first demonstrate accurate recovery of optical amplitude and phase in two polarisations through the MCF by measuring and inverting the transmission matrix, and then present a robust Bayesian inference approach to resolving 5 polarimetric properties of samples. Our method produces high-resolution (m amplitude, phase; m polarimetric) full-field images at working distances up to 1mm over a field-of-view up to 750×750μm2 using an MCF with potential for flexible operation. We demonstrate the potential of using quantitative phase for computational image focusing and polarisation-resolved properties in imaging birefringence.

Use of video capsule endoscopy to identify gastrointestinal lesions in dogs with microcytosis or gastrointestinal hemorrhage.

BackgroundVideo capsule endoscopy (VCE) is a noninvasive imaging modality that can identify mucosal lesions not detected with traditional endoscopy or abdominal sonography. In people, VCE is used in diagnostic and management protocols of various gastrointestinal (GI) disorders, particularly in GI bleeding of obscure origin or unexplained iron deficiency anemia (IDA).ObjectiveTo evaluate the utility of VCE in the identification of mucosal lesions in dogs with evidence of GI hemorrhage.AnimalsSixteen client‐owned dogs that underwent VCE.MethodsRetrospective case‐control study. Medical records were reviewed to include dogs with microcytosis, low normal mean corpuscular volume, or clinical GI bleeding that received VCE.ResultsMedian age of dogs was 8.7 years (range, 8 months to 15 years) with a median weight of 21.7 kg (range, 6.9‐62.5 kg). Abdominal ultrasound (16), abdominal radiography (4), and abdominal CT (1) did not identify a cause for GI blood loss. Gastric mucosal lesions were identified by VCE in 15 of 16 dogs and small intestinal lesions in 12 of 14 dogs, with 2 capsules remaining in the stomach. Endoscopy was performed in 2 dogs before VCE; 1 dog had additional small intestinal lesions identified through the use of VCE.Conclusions and Clinical ImportanceVideo capsule endoscopy is a minimally invasive diagnostic tool that can identify GI lesions in dogs presenting with microcytosis with or without GI hemorrhage when ultrasonography is inconclusive; however, the majority of lesions identified would have been apparent with conventional endoscopy.

Deep-learning based detection of gastric precancerous conditions

Conventional white-light endoscopy has high interobserver variability for the diagnosis of gastric precancerous conditions. Here we present a deep-learning (DL) approach for the diagnosis of atrophic gastritis developed and trained...

Prevalence of Neuroendocrine Tumors in the Gastrointestinal and Hepatobiliary Systems

Background: Carcinoid tumors are the most common neuroendocrine tumors. In recent years, these tumors have had an increasein incidence, which is probably due to a higher number of them being incidentally found as a result of the rise of preventivemedicine.Objectives: This study aimed to analyze a series of digestive carcinoid tumors detected by conventional endoscopy and/or echoendoscopyto evaluate the prevalence of those located in the colon and rectum, and subsequently make a comparison with data availablein the literature.Methods: In this retrospective, multicenter study (two centers), the clinical records of 100 white patients with more than 100 digestivecarcinoid tumors (some multiple) diagnosed from 1994 to 2018 were reviewed.Results: The mean age of presentation was 52 years and 57% of the patients were men. The mean tumor size was 10 mm. The localizationof the tumors was: stomach 43% (n = 43); duodenum 5% (n = 5); intestine 8% (n = 8); appendix 14% (n = 14); colon 4% (n = 4);rectum 19% (n = 19); pancreas 3% (n = 3); liver 2% (n = 2); gallbladder 1% (n = 1); primary tumor of unknown origin 1% (n = 1). Mostmultifocal tumors were in the stomach (20%; n = 20), followed by the duodenum (1%; n = 1) and intestine (1%; n = 1). Metastases andcarcinoid syndrome were observed in 6% and 5% of the cases, respectively. General survival at the closure of the study was 80%.Conclusions: Age and sex were similar to those described in the literature, while the colon and rectum represented 23% of all carcinoidtumors. There was a predominance of gastroduodenal and rectal carcinoid tumors, probably because the series analyzedwas essentially endoscopic. In comparison with the literature, less cases of metastases or carcinoid syndrome were recorded andsurvival was greater, perhaps due to earlier diagnosis and treatment.

Current Status of Endoscopic Ultrasonography in Gastrointestinal Subepithelial Tumors.

Gastrointestinal subepithelial tumors (GSTs) are usually detected incidentally on endoscopic or radiologic examinations. In conventional endoscopy, a GST usually presents as a protuberant lesion with an intact mucosal surface. As the lesion is located beneath the mucosal layer of the gastrointestinal tract, conventional biopsy typically does not reveal the pathologic diagnosis. First, a GST should be differentiated from an extrinsic compression through the positional change of the patient during conventional endoscopic examination. In cases of GSTs originating from the gastrointestinal wall, endoscopic ultrasonography (EUS) can be beneficial for narrowing the differential diagnosis through delineation of echo findings and by determining the layer of origin. EUS findings can also help determine the management strategies for GSTs by making a differential diagnosis according to malignant potential.

An Automatic Navigation and Pressure Monitoring for Guided Insertion Procedure.

Navigation is an important feature needed for medical insertion procedures. It is required to guide the medical device in the right direction at the right time. Navigation techniques used in the Wireless Capsule Endoscopy and conventional endoscopy fields are based on image-guided systems that require a large amount of data to be transferred and processed computationally. These issues increase system complexity as well as the overall system and procedure costs. Moreover, these systems cannot provide the required information in dark or liquid areas. To improve the medical internal inspections capabilities, we present a pressure direction measurement system that can be implemented for a capsule endoscope; ordinary endoscopy; and any other insertion procedure where navigation and safety are required. The system can operate in dark and liquid areas because no visualization is required. The system consists of a pressure sensor placed on a semi-hemisphere on top of the steering device to detect azimuth and polar angle variation according to the direction at any differentiable path.

Investigation of Current Control for a New Bi-directional Linear Capsule Robot.

In this paper, a bi-directional linear capsule robot (capsulbot) for potential applications in Gastrointestinal (GI) tract inside human body is studied. Compared with the conventional endoscope limited by its poor locomotion and steering capabilities, active locomotion actuator will play an important role in the diagnosis of narrow organ tract of the human body in the future. This paper studies a new simple-structured actuator that can realize bi-directional linear motion by properly controlling the supplied current profile. It is demonstrated that the linear motion of the new capsulbot is affected by three main factors: current waveform, current duty ratio, and current amplitude. The optimized current profile that can maximize the capsulbot displacement is verified experimentally on a prototype capsulbot.

Tu1050 ANTEGRADE VERSUS RETROGRADE SINGLE BALLOON ENTEROSCOPY- IS THERE A DIFFERENCE IN PERFORMANCE?

Single balloon enteroscopy (SBE) is a widely used method of examining the portion of small bowel where conventional upper endoscopy and colonoscopy fail to reach. There are 2 major approaches of single balloon enteroscopy- through mouth or ante-grade approach (AG) or through anus or retrograde (RG)approach. Aim of this study was to assess the differences in performance and complications of both these approaches.

Computer-Aided Diagnosis of Laryngeal Cancer Via Deep Learning Based on Laryngoscopic Images

Background: Laryngeal cancer (LCA) is a common malignancy of the head and neck region. Early diagnosis of LCA is very difficult because of its subtle abnormalities in early stage, especially for the inexperienced endoscopists with conventional white-light endoscopy. Computer-aided diagnosis were used for several diseases in recent years. This study was to develop a deep convolutional neural network (DCNN) that can automatically detect LCA in laryngoscopic images. Methods: A DCNN-based diagnostic system was constructed and trained using 15,239 laryngoscopic images of LCA, precancerous laryngeal lesions (PRELCA), benign laryngeal tumors (BLT) and normal tissues (NORM). An independent test set of 1,200 laryngoscopic images was applied to the constructed DCNN to evaluate its performance against experienced endoscopists. Findings: In the training set, the DCCN achieved the sensitivity of 0.920, the specificity of 0.716, the AUC of 0.922, and the overall accuracy of 0.858 for detecting LCA and PRELCA among all lesions and normal tissues. When compares to human experts in an independent test set, the DCCN' s performance on detection of LCA and PRELCA achieved the sensitivity of 0.933, the specificity of 0.797, the AUC of 0.952, and the overall accuracy of 0.901, which is comparable to that of experienced human expert with 10-20 years of work experience. Moreover, the overall accuracy of DCNN for detection of LCA is 0.786, which is also comparable to that of experienced human expert with 10-20 years of work experience and exceed the experts with less than 10 years of work experience. Interpretation: The DCNN had high sensitivity and specificity for automated detection of LCA and PRELCA from BLT and NORM in laryngoscopic images. This novel and effective approach facilitates earlier diagnosis of early LCA, resulting in improved clinical outcomes and reducing the burden of endoscopists. Funding: None. Declaration of Interest: The authors have no conflict of interests. Ethical Approval: The study was approved by the ethical review board of Sun Yat-sen Memorial Hospital, Sun Yat-sen University.

Virtual reality simulation training in endoscopy: a Cochrane review and meta-analysis.

Endoscopy programs are increasingly integrating simulation training. We conducted a systematic review to determine whether virtual reality (VR) simulation training can supplement and/or replace conventional patient-based endoscopy training for health professional trainees with limited or no prior endoscopic experience. We searched medical, educational, and computer literature databases in July 2017 for trials that compared VR simulation training with no training, conventional training, another form of simulation training, or an alternative method of VR training. We screened, abstracted data, and performed quantitative analysis and quality assessment through Cochrane methodology. We included 18 trials with 3817 endoscopic procedures. VR training provided no advantage over no training or conventional training based on the primary outcome of composite score of competency. VR training was advantageous over no training based on independent procedure completion (relative risk [RR] = 1.62, 95 % confidence interval [CI] 1.15 - 2.26, moderate-quality evidence), overall rating of performance (mean difference [MD] 0.45, 95 %CI 0.15 - 0.75, very low-quality evidence), and mucosal visualization (MD 0.60, 95 %CI 0.20 - 1.00, very low-quality evidence). Compared with conventional training, VR training resulted in fewer independent procedure completions (RR = 0.45, 95 %CI 0.27 - 0.74, low-quality evidence). We found no differences between VR training and no training or conventional training for other outcomes. Based on qualitative analysis, we found no significant differences between VR training and other forms of simulation training. VR curricula based in educational theory provided benefit with respect to composite score of competency, compared with unstructured curricula. CONCLUSIONS : VR simulation training is advantageous over no training and can supplement conventional endoscopy training. There is insufficient evidence that simulation training provides benefit over conventional training.

Mapping the distribution of small bowel angioectasias

Background: Angioectasias are a prominent cause of small bowel (SB) bleeding frequently identified during capsule endoscopy (CE). Subsequent management depends upon grade/severity and location. There is increasing evidence that the location of SB angioectasias is not random. We aimed to map the distribution of SB angioectasias, and assess whether this impacted clinical outcomes.Materials and methods: Retrospective study examining CEs performed over a 10-year period at a tertiary referral centre. Information regarding number, location, and Saurin classification (P0–2) of SB angioectasias was collected. Clinically significant angioectasias (P1/P2) and active SB bleeding were analysed further. Outcomes of patients with P2 angioectasias or active SB bleeding were recorded.Results: 164 SBCE examinations reported angioectasias. 554 P1-2 angioectasias and active bleeds were seen, 435 (78.52%) within the first tertile of SB transit time (SBTT). 277 (50%) angioectasias were identified within the first 10% of SBTT. 40/75 (53.3%) patients with >1 P2 angioectasia and/or active bleed were referred for intervention. Of initial interventions, 24 patients underwent upper GI endoscopy; 13 underwent double balloon enteroscopy (DBE). 9/37(24.3%) had no identifiable angioectasias on endoscopy. Of those receiving ablative therapy, 20/28 (71.4%) re-presented with iron-deficiency anaemia or bleeding. In this group, average angioectasia position was 15.6% of SBTT, compared with 7.9% in those who did not re-represent (p = 0.344). Patients who re-presented had an average 1.6 additional P1 angioectasias, compared with 7.6 amongst those who did not return (p = 0.017).Conclusions: Clinically significant angioectasias are overwhelmingly located within the proximal SB. The majority are within reach of conventional endoscopy. However, AEs are often multiple and many patients re-present following intervention.

Prospective comparison of conscious nasal versus oral video upper GI endoscopy in adults

Background: Endoscopy procedures are now becoming a mandate for any upper or lower abdominal conditions in addition to any radiological investigations. Patients have reluctance. It's mainly because of the painful experience they come across during upper GI endoscopy. If pain can be addressed during endoscope then all patients would smile after this procedure. The main objective of the study is to compare nasal endoscopy vs conventional endoscopy in gastrointestinal disorders.Methods: This prospective study was conducted in the department in the department of bariatric and metabolic surgery, Apollo Spectra Hospitals, Chennai. Totally 200 cases were included in the study for the study. Nasal packing was done with xylocaine and oxymetazoline without oral spraying of 10% xylocaine. Oral mouth gag was not inserted in nasal cases. Pain score was primarily used as a scoring method.Results: Comparative study was done for both groups for pain score, gag reflux, nausea, comfort level, voice change, image clarity, intervention procedures, and overall scoring was done. There was a significant advantage in the nasal endoscopy group.Conclusions: More screening endoscopies can be done for a large patient population to diagnose Gastro diseases at an early stage if a painless endoscopy can be offered instead of regular endoscopy hereafter. But however, the endoscopy suite should have regular scope for therapeutic procedures.

Effect of chromoendoscopy in the proximal colon on colorectal neoplasia detection in Lynch syndrome: a multicenter randomized controlled trial

Patients with Lynch syndrome (LS) undergo regular surveillance by colonoscopy because of an increased risk of colorectal neoplasia, particularly in the proximal colon. Chromoendoscopy (CE) has been reported to improve neoplasia detection compared with conventional white-light endoscopy (WLE), but evidence is limited. Our aim was to investigate the effect of CE in the proximal colon on detection of neoplastic lesions during surveillance in LS. This was a multicenter prospective randomized controlled trial of 246 patients with LS who were randomly assigned (1:1) to conventional WLE (n= 123) or colonoscopy with CE in the proximal colon (n= 123), stratified for previous colorectal adenomas and enrolling center. Two years after baseline colonoscopy, patients underwent colonoscopy with CE in the proximal colon. The primary outcome was the proportion of patients with at least one neoplastic lesion at baseline and after 2 years. Neoplasia detection rates at baseline colonoscopy were 27% for WLE versus 30% for CE (odds ratio [OR], 1.23; 95% confidence interval [CI], 0.69-2.2; P= .56). In the proximal colon, neoplasia detection rates were 16% for WLE versus 24% for CE (OR, 1.6; 95% CI, 0.9-3.1; P= .13). Total procedure time was 9 minutes longer in the CE group. At follow-up after 2 years, neoplasia detection rates were similar in both groups: 26% for the original WLE group versus 28% for the CE group (OR, 1.1; P= .81). CE in the proximal colon for LS surveillance was not superior to WLE with respect to the initial detection of neoplasia, and not associated with reduced neoplasia detection rates after 2 years. The value of CE remains to be established. (Clinical trial registration number: NCT00905710.).

Clinical diagnostic value of digestive endoscopic narrow-band imaging in early esophageal cancer.

Clinical diagnostic value of digestive endoscopic narrow-band imaging in early esophageal cancer (EC) and benign lesions was explored. Retrospective analysis was carried out on the clinical data of 186 patients with early EC and benign lesions diagnosed by the Department of Gastroenterology in Cangzhou Central Hospital from February 2011 to April 2018. Among them, 102 patients examined by Narrow Band Imaging (NBI) were regarded as the research group. Eighty-four patients examined by conventional white light staining endoscopy were regarded as the control group. The lesion boundary definition, image clarity, sensitivity, specificity, positive predictive value, negative predictive value, diagnostic compliance rate, detection rate of lesions and adverse reactions were compared between the groups after examination. The results showed that the lesion boundary definition in the research group was higher than that in the control group (P<0.05). The 4-points of image clarity in the research group was higher than that in the control group (P<0.05). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic compliance rate of the early EC and benign lesions in the research group were higher than those in the control group (P<0.05). The detection rate of the upper, middle and lower segments of lesions in the research group was higher than that in the control group. In conclusion, NBI has higher sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic compliance rate for the diagnosis of early EC and benign lesions. Also it has more accuracy in the detection of lesions and fewer adverse reactions, the screening of early EC and benign lesions is effective, and worth promoting clinically.

Study on the endoscopic inspection of ITER thermal shield cooling pipes

A novel endoscope is developed for the inspection of long and complex-shaped cooling pipe of ITER Thermal Shield (TS). The mechanical design of the endoscope is improved for its easier insertion into long pipe routing. Main break-through is to reduce the cable friction against metal pipe surface as well as to maintain the elastic rigidity of the cable for the insertion. Spacers are attached on both the camera head and the cable to reduce the friction. Plate spring tube is used to protect signal wire and to maintain elastic rigidity of the cable. The conceived endoscope was tested to the pipe routing mock-up, which is similar to the longest and most complex TS pipe routing. Special device is also presented for making the endoscope insertion be easier. The insertion test result is compared with that of a conventional endoscope. Several endoscopic images are also discussed for typical pipe samples and for the curved region of pipe routing.

Laparoscopic removal of large trichobezoar

Trichobezoar is a rare condition that may pose a diagnostic challenge. Patients with this condition are commonly young females who often have an underlying psychiatric disorder such as trichotillomania, or the compulsive urge to pull one's own hair out. Several treatment options are proposed, including removal by conventional laparotomy, laparoscopy, or endoscopy. Up to the best of our knowledge few cases only had complete removal of trichobezoar without the need for the various modifications in the extraction of trichobezoar such as suprapubic incision, inguinal crease incision, extending the port-site incision or gastropexy to abdominal wall. We report an eleven-year-old boy with a large gastro-duodenal trichobezoar who underwent complete laparoscopic removal without complications.

Confocal Laser Endomicroscopy in the Evaluation of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, can be effectively monitored with the use of endoscopy. The additional application of small field imaging technology such as confocal laser endomicroscopy CLE during ongoing endoscopic evaluation has led to real-time visualization of mucosal abnormalities and thus in vivo histology. The endomicroscopy (CLE) can improve IBD endoscopic evaluation by identifying seemingly normal-appearing mucosa, assessing the function of the intestinal barrier of the epithelium and vascular permeability, and by characterizing any mucosal lesions, including dysplastic lesions. CLE used during conventional endoscopy could especially facilitate the evaluation of mucosal healing in IBD. In addition, future developments in molecular imaging in IBD may optimize therapeutic approaches by identifying mucosal targets for therapy and determining the reasons for lack of response to specific therapy or subsequent loss of the response.

Fluorescent Polymer Dots for Tracking SKOV3 Cells in Living Mice with Probe-Based Confocal Laser Endomicroscopy.

Probe-based confocal laser endomicroscopy (pCLE) is a novel technique allowing real-time and high-resolution imaging in vivo. It provides microscopic images and increases the penetration depth of tissues compared with conventional white light endoscopy. The aim of the present study was to track ovarian cancer cells in organs by fluorescent polymer dots based on pCLE. SKOV3-mCherry cells were incubated with polymer dots for 24h in a serum-free culture medium. Labeled cells were administrated to nude mice via intravenous, intraperitoneal, and lymph node injection. The fluorescent signals of labeled cells in organs were observed by pCLE. Furthermore, the results were confirmed by frozen section analysis. pCLE displayed fluorescence signals of labeled cells in the vessels of organs. Besides, the accumulations of labeled cells visualized in detoxification organs like the spleen and kidney were increased with time. In this article, we present a real-time and convenient method for tracking SKOV3-mCherry in living mice by combined fluorescent polymer dots with pCLE.