High-resolution Endoscopy Research Articles

Design and Evaluation of ScanCap: A Low-Cost, Reusable Tethered Capsule Endoscope with Blue-Green Illumination Imaging for Unsedated Screening and Early Detection of Barrett's Esophagus.

Esophageal carcinoma is the sixth-leading cause of cancer death worldwide. A precursor to esophageal adenocarcinoma (EAC) is Barrett's Esophagus (BE). Early-stage diagnosis and treatment of esophageal neoplasia (Barrett's with high-grade dysplasia/intramucosal cancer) increase the five-year survival rate from 10% to 98%. BE is a global challenge; however, current endoscopes for early BE detection are costly and require extensive infrastructure for patient examination and sedation. We describe the design and evaluation of the first prototype of ScanCap, a high-resolution optical endoscopy system with a reusable, low-cost tethered capsule, designed to provide high-definition, blue-green illumination imaging for the early detection of BE in unsedated patients. The tethered capsule (12.8 mm diameter, 35.5 mm length) contains a color camera and rotating mirror and is designed to be swallowed; images are collected as the capsule is retracted manually via the tether. The tether provides electrical power and illumination at wavelengths of 415 nm and 565 nm and transmits data from the camera to a tablet. The ScanCap prototype capsule was used to image the oral mucosa in normal volunteers and ex vivo esophageal resections; images were compared to those obtained using an Olympus CV-180 endoscope. Images of superficial capillaries in intact oral mucosa were clearly visible in ScanCap images. Diagnostically relevant features of BE, including irregular Z-lines, distorted mucosa, and dilated vasculature, were clearly visible in ScanCap images of ex vivo esophageal specimens.

Optical fiber bundle differential compressive imaging.

We present a differential compressive imaging method for an optical fiber bundle (OFB), which provides a solution for an ultrathin bend-resistant endoscope with high resolution. This method uses an OFB and a diffuser to generate speckle illumination patterns. Differential operation is additionally applied to the speckle patterns to produce sensing matrices, by which the correlation between the matrices is greatly reduced from 0.875 to 0.0275, which ensures the high quality of image reconstruction. Pixilation artifacts from the fiber core arrangement are also effectively eliminated with this configuration. We demonstrate high-resolution reconstruction of images of 132 × 132 pixels with a compression rate of 12% using 77 fiber cores, the total diameter of which is only about 91 µm. An experimental verification proves that this method is tolerant to a limited degree of fiber bending, which provides a potential approach for robust high-resolution fiber endoscopy.

In vivo pilot study into superficial microcirculatory characteristics of colorectal adenomas using novel high-resolution magnifying endoscopy with blue laser imaging

BACKGROUND No studies have yet been conducted on changes in microcirculatory hemodynamics of colorectal adenomas in vivo under endoscopy. The microcirculation of the colorectal adenoma could be observed in vivo by a novel high-resolution magnification endoscopy with blue laser imaging (BLI), thus providing a new insight into the microcirculation of early colon tumors. AIM To observe the superficial microcirculation of colorectal adenomas using the novel magnifying colonoscope with BLI and quantitatively analyzed the changes in hemodynamic parameters. METHODS From October 2019 to January 2020, 11 patients were screened for colon adenomas with the novel high-resolution magnification endoscope with BLI. Video images were recorded and processed with Adobe Premiere, Adobe Photoshop and Image-pro Plus software. Four microcirculation parameters: Microcirculation vessel density (MVD), mean vessel width (MVW) with width standard deviation (WSD), and blood flow velocity (BFV), were calculated for adenomas and the surrounding normal mucosa. RESULTS A total of 16 adenomas were identified. Compared with the normal surrounding mucosa, the superficial vessel density in the adenomas was decreased (MVD: 0.95 ± 0.18 vs 1.17 ± 0.28 μm/μm2, P < 0.05). MVW (5.11 ± 1.19 vs 4.16 ± 0.76 μm, P < 0.05) and WSD (11.94 ± 3.44 vs 9.04 ± 3.74, P < 0.05) were both increased. BFV slowed in the adenomas (709.74 ± 213.28 vs 1256.51 ± 383.31 μm/s, P < 0.05). CONCLUSION The novel high-resolution magnification endoscope with BLI can be used for in vivo study of adenoma superficial microcirculation. Superficial vessel density was decreased, more irregular, with slower blood flow.

The Usefulness of the 3.1-mm-diameter 4K Rigid Endoscope for Intracerebral Hematoma Evacuation.

The indication for surgical intervention in spontaneous intracerebral hemorrhage remains controversial. Although many clinical trials have failed to demonstrate its efficacy over medical treatment, less invasive endoscopic treatment is expected to demonstrate its superiority. A novel endoscopic system for hematoma removal consisting of a 3.1-mm-diameter 4K high-resolution rigid endoscope was used.The system was used in eight cases of spontaneous intracerebral hemorrhage. It provided improved maneuverability of the surgical instrument while maintaining satisfactory image quality. The surgical goal was achieved in all cases without any complications, including perioperative rebleeding.Endoscopic hematoma removal using the 3.1 mm high-resolution endoscope is an alternative minimally invasive approach to spontaneous intracerebral hemorrhage with improved reliability.

ThTP2.2 Correlation between conventional endoscopic and histopathological diagnosis of Barrett’s oesophagus

Abstract Introduction The diagnosis of Barrett’s oesophagus is currently made with a combination of endoscopic appearances and presence of intestinal metaplasia (IM) on oesophageal biopsies. There have been minimum endoscopy and pathology reporting standards proposed by the British Society of Gastroenterologists and these include the use of high resolution endoscopy and the use of a comprehensive proforma for biopsies. This study compared the diagnosis of Barrett’s oesophagus between conventional endoscopy and histopathological analysis. Methods All patients who were due for surveillance endoscopy for Barrett’s oesophagus in 2022 were identified from a prospectively maintained waiting list. Endoscopy reports, biopsy results and outcomes were recorded. Correlation between endoscopic and histopathological results, with particular attention to the presence of intestinal metaplasia, was recorded. Results There were 192 patients identified for this study. All had endoscopic diagnosis of Barrett’s oesophagus (between 2016 and 2020) and were entered into a surveillance programme based on endoscopic diagnosis alone. 36 patients (19%) did not have a Prague classification (C and M grading) recorded on their primary endoscopy report and 55 patients (29%) did not have images available for review. None had HRE (all had conventional endoscopy). Only 127 patients (66%) had IM from original endoscopic biopsies and none had documentation of p53 status. Conclusion There was relatively poor compliance between current practice and gold-standard recommendations for endoscopy and pathology reporting. Just 66% of patients who had an endoscopic diagnosis of Barrett’s had IM on histopathology. These findings have implications for the accurate diagnosis and surveillance of Barrett’s oesophagus.

Surveillance in Barrett’s Esophagus: Challenges, Progress, and Possibilities

Endoscopic surveillance of Barrett's esophagus, aiming to detect prevalent dysplasia and adenocarcinoma, followed by effective endoscopic treatment, is an integral part of the esophageal adenocarcinoma prevention paradigm. However, several limitations, such as the subtle appearance of dysplasia, sampling error (inherent in current surveillance protocols), and noncompliance with surveillance recommendations, lead to missed dysplasia and neoplasia, reducing the effectiveness of surveillance as currently practiced. Careful endoscopic assessment with high-resolution white-light endoscopy, dye-based or electronic chromoendoscopy, and comprehensive sampling of the BE mucosa, remains the cornerstone of endoscopic surveillance. Emerging innovations in this area span the gamut of more efficient sampling methods, advanced imaging tools, artificial intelligence, and molecular marker-powered approaches as adjuncts, to identify prevalent and predict incident dysplasia or adenocarcinoma. Development and implementation of validated quality indicators will allow additional advancement of this critical field. These approaches will hopefully enable efficient and effective cancer prevention and treatment.

Chronic atrophic gastritis as a precancer: the evolution of ideas from the Sydney consensus to Maastricht VI

Aim. The purpose of the work is the evolution of systems and classifications of gastritis: Sydney Consensus (1990), Houston Modification (1994), OLGA/OLGIM (2008), Kyoto (2014), MAPS II (2019), Maastricht IV (2022). Materials and methods. During the work, 25 sources of information were used. Results. Chronic atrophic gastritis (ChAG) is a clinical and morphological diagnosis, and the presented clinical forms (types) of gastritis have characteristic morphological criteria. According to the Sydney system, changes in the antrum and body of the stomach are described separately. This has led to a lack of clear risk stratification criteria for CG and also complicates the objective analysis of regression of inflammation and atrophy. OLGA/OLGIM systems were proposed to determine the stage of atrophy and IM. The authors of the Kyoto consensus add and clarify the etiological section of ChAG. In MAPS II, ChAG and IM are considered precancerous conditions, as they increase the risk of developing gastric cancer and are the background for the occurrence of dysplasia and adenocarcinoma. For patients with dysplasia and the absence of visible changes in the mucous membrane, high-resolution endoscopy with staining is recommended. They should be examined after 6 months for a high degree of dysplasia and after 12 months for a low degree of dysplasia. Patients with IM and one localization have a high risk of developing gastric cancer. However, the high risk does not give the right to follow up in the majority of cases when high-quality endoscopy with biopsy does not show severe atrophy. Patients with IM of one location, with a family history of cancer, or with incomplete IM and persistence of H. pylori chromo endoscopy with biopsy must be done once every 3 years. Patients with extended fields of atrophic aggression (pronounced atrophic changes) or IM in the antrum and body, OLGA/OLGIM III/IV should be screened with chromoendoscopy with biopsy every 3 years. Patients with significant atrophy and familial cancer benefit from chromoendoscopy and biopsy every 1–2 years after initial diagnosis. Patients with autoimmune gastritis are recommended to be screened every 3–5 years. According to Maastricht VI, H. pylori is the main etiological factor of gastric adenocarcinoma, including proximal gastric cancer. Conclusions. After careful study and analysis, we came to the conclusion about the gradual development of the principles of evidence-based medicine in the issue of improving the clinical and morphological diagnosis of chronic atrophic gastritis as a precancerous of the stomach.

Gastric cancer in 2022: Is there still a role for endoscopic ultrasound?

Gastric cancer (GC) represents the fourth leading cause of cancer death worldwide and many factors can influence its development (diet, geographic area, genetic, Helicobacter pylori or Epstein-Barr virus infections). High quality endoscopy represents the modality of choice for GC diagnosis. The correct morphologic classification during a high-resolution endoscopy is fundamental for oncologic diagnosis, staging and therapeutic decisions. Since its initial introduction in clinical practice the endoscopic ultrasound (EUS) has been considered a valuable tool for tumor (T-) and lymph nodes (N-) staging also in GC, in order to establish the best therapeutic strategy for the patient (e.g., upfront surgery vs neoadjuvant treatments). EUS tools as elastography, Doppler and contrast administration can improve diagnosis mainly in case of malignant lymph node evaluation. EUS has a marginal role in disease staging but has a fundamental role in case of a pre-endoscopic resection management and in the new era of endoscopic mucosal resection or submucosal dissection as minimally invasive surgery. Diagnosis and locoregional staging of GC with EUS are a method of inarguable value for the assessment of gastric wall involvement and presence of infiltrated paragastric lymph nodes. EUS can also have a role in disease restaging in those patients who have undergone neoadjuvant treatment. EUS can also have a role in the advanced phases of the disease, in facilitating palliative, minimally-invasive treatments, such as gastroenterostomy or biliary drainages. This review intends to discuss the modern role of EUS in GC topic.

Specular Reflections Detection and Removal for Endoscopic Images Based on Brightness Classification.

Specular Reflections often exist in the endoscopic image, which not only hurts many computer vision algorithms but also seriously interferes with the observation and judgment of the surgeon. The information behind the recovery specular reflection areas is a necessary pre-processing step in medical image analysis and application. The existing highlight detection method is usually only suitable for medium-brightness images. The existing highlight removal method is only applicable to images without large specular regions, when dealing with high-resolution medical images with complex texture information, not only does it have a poor recovery effect, but the algorithm operation efficiency is also low. To overcome these limitations, this paper proposes a specular reflection detection and removal method for endoscopic images based on brightness classification. It can effectively detect the specular regions in endoscopic images of different brightness and can improve the operating efficiency of the algorithm while restoring the texture structure information of the high-resolution image. In addition to achieving image brightness classification and enhancing the brightness component of low-brightness images, this method also includes two new steps: In the highlight detection phase, the adaptive threshold function that changes with the brightness of the image is used to detect absolute highlights. During the highlight recovery phase, the priority function of the exemplar-based image inpainting algorithm was modified to ensure reasonable and correct repairs. At the same time, local priority computing and adaptive local search strategies were used to improve algorithm efficiency and reduce error matching. The experimental results show that compared with the other state-of-the-art, our method shows better performance in terms of qualitative and quantitative evaluations, and the algorithm efficiency is greatly improved when processing high-resolution endoscopy images.

A Comparative Study of Surgical Outcome in Endoscopic Endonasal Dacrocystorhinostomy with and without Stenting

Introduction To remove tears from people’s eyes’ – is one of the greatest challenges of lacrimal surgery. Epiphora is defined as watering eye due to inadequate drainage of normally produced tears. Dacryocystitis is the inflammation of the lacrimal drainage system which presents as acute dacryocystitis or a much commonly as chronic dacryocystitis. Other common causes of ephiphora are blepharitis, conjunctivitis, trichiasis, punctal eversion and foreign bodies. The conventional treatment for watering eyes due to Naso Lacrimal Duct (NLD) is the procedure of external dacryocystorhinostomy (DCR) which has its own limitations and disadvantages. With the introduction of high resolution endoscopes for paranasal sinuses, endoscopic endonasal DCR (EnDCR) is gaining popularity. The main advantages of the endoscopic technique are minimal morbidity, less intraoperative bleed, shorter operative time, preservation of pump function of orbicularis occuli muscle, presaccal fibers and medial canthal tendon and avoidance of cutaneous scar. In EnDCR the most common cause for failure of surgery is closure of rhinostoma and to prevent this silicone tube insertion is the most preferred method. It has also been claimed that silicone tubing would improve surgical results. But studies also indicate that silicone tubing itself results in certain problems like, foreign body sensation, increased granulation tissue leading to failure, prolapse of tube leading to injury to cornea, nasal migration of tube, fistula formation, pharyngitis and associated sinusitis & recurrent nose bleed. The present study was undertaken to compare the surgical results of endoscopic endonasal DCR with and without silicone stent. Aims & Objectives To compare the success rates of endonasal dacryocystorhinostomy and evaluate the presence of post-operative changes and their effect on the outcome of the surgery in endoscopic dacryocystorhinostomy with and without stenting. Material & Methods This Prospective randomized comparative study was carried out amongst the patients attending department of ENT and referred cases from ophthalmology department for chronic nasolacrimal duct obstruction, both as inpatients and outpatients with complaint of chronic epiphora. 50 patients divided into two groups of 25 each fulfilling inclusion and exclusion criteria were included using convenient sampling. Participants were divided into two groups of 25 each based on randomization technique. Group 1 includes patients undergoing EnDCR with stenting and Group 2 includes patients undergoing EnDCR without stenting. Patients were assessed for post-operative complications like granulations, size of the neo ostium and patency of the neo ostium were assessed on nasal endoscopy. Data was entered in MS Excel work sheet. Data was analyzed using appropriate statistical methods. Result This study had Female predominance in both the groups. No predominance for any side was observed. No major intra operative complications were observed. Duration of surgery was more in Group I which was statistically significant. Post-operative complications are seen more in group without stenting (64.0%) than in group with stenting (56%) with no statistical difference between the two groups. Granulations had no effect on the outcome of the. On subjective assessment of symptoms 92% of patients in group I and 88% of patients in group II showed improvement of symptoms post operatively. No statistical difference had been found between the results of both the groups. On objective assessment of size of the neo ostium, no statistical difference was seen between the two groups. The size of the neo ostium had no effect on the outcome of the surgery. On objective assessment of patency of the neo ostium was observed in 92% of patients in group I and 88% patients in group II with no statistical difference between the two groups. Conclusion As success rates of the surgery with stenting and without stenting are comparable and

Non-Ampullary Duodenal Tumors

Non-ampullary duodenal tumors refer to duodenal lesions that originate at sites other than the ampulla of Vater. They differ from ampullary duodenal tumors, which are typically associated with obstructive symptoms. Non-ampullary duodenal tumors are rare; therefore, standardized clinical management, including diagnostic and therapeutic modalities and the follow-up strategy remain unclear. An increase in the numbers of patients undergoing endoscopy during medical checkups and technological advances in endoscopic procedures, including high-resolution and image-enhanced endoscopy have led to an increase in detection rates of duodenal tumors recently. Currently, endoscopic resection of duodenal tumors is widely used and is a preferred therapeutic alternative to surgical excision. Some duodenal tumors of high malignant potential are associated with poor prognosis; therefore, accurate diagnosis and timely management are important. In this article, we review the current knowledge regarding non-ampullary duodenal tumors and the therapeutic approaches to these lesions.

Development of Advanced Imaging and Molecular Imaging for Barrett's Neoplasia.

Barrett esophagus (BE) is a precursor to a life-threatening esophageal adenocarcinoma (EAC). Surveillance endoscopy with random biopsies is recommended for early intervention against EAC, but its adherence in the clinical setting is poor. Dysplastic lesions with flat architecture and patchy distribution in BE are hardly detected by high-resolution endoscopy, and the surveillance protocol entails issues of time and labor and suboptimal interobserver agreement for diagnosing dysplasia. Therefore, the development of advanced imaging technologies is necessary for Barrett’s surveillance. Recently, non-endoscopic or endoscopic technologies, such as cytosponge, endocytoscopy, confocal laser endomicroscopy, autofluorescence imaging, and optical coherence tomography/volumetric laser endomicroscopy, were developed, but most of them are not clinically available due to the limited view field, expense of the equipment, and significant time for the learning curve. Another strategy is focused on the development of molecular biomarkers, which are also not ready to use. However, a combination of advanced imaging techniques together with specific biomarkers is expected to identify morphological abnormalities and biological disorders at an early stage in the surveillance. Here, we review recent developments in advanced imaging and molecular imaging for Barrett’s neoplasia. Further developments in multiple biomarker panels specific for Barrett’s HGD/EAC include wide-field imaging systems for targeting ‘red flags’, a high-resolution imaging system for optical biopsy, and a computer-aided diagnosis system with artificial intelligence, all of which enable a real-time and accurate diagnosis of dysplastic BE in Barrett’s surveillance and provide information for precision medicine.

H. pylori-associated chronic gastritis: status update on the problem

Chronic gastritis is a group of chronic diseases that are morphologically characterized by persistent inflammatory infiltrate and impaired cellular turnover with the development of intestinal metaplasia, atrophy, and epithelial dysplasia in the gastric mucosa. Numerous studies have shown that Helicobacter pylori (H. pylori) infection is the absolutely dominant etiological factor of CG worldwide. Given this fact, the Expert Council of the latest Maastricht VI 2022 consensus recommended that H. pylori is to be treated as a pathogen, which always results in the development of CG. The prevalence of H. pylori-associated CG is about 44.3–48.5%, however 80–90% of cases are asymptomatic. In H. pylori­infected patients with dyspepsia and no other pathology of the gastroduodenal region, which has been confirmed endoscopically, clinical manifestations can be interpreted as part of H. pylori­associated CG if a long-lasting remission of symptoms has been achieved after successful eradication therapy. While patients with persistent dyspeptic symptoms can be considered as patients with functional dyspepsia, despite successful eradication therapy. Advanced endoscopic techniques (narrow band imaging (NBI) endoscopy, high resolution endoscopy, chromoendoscopy, laser confocal endomicroscopy) are precise and reproducible methods for diagnosing precancerous changes in the mucous membrane. However, the diagnosis of CG requires that inflammatory cells have been histologically detected in the lamina propria. The CG therapy aims to reach a persistent relief of dyspeptic symptoms of the disease (if any), as well as resolution of inflammatory processes and prevention of the progression of precancerous changes in the gastric mucosa. The achievement of these goals is primarily determined by the timely diagnosis of H. pylori infection and successful eradication therapy.

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

Image-Enhanced Endoscopy and Molecular Biomarkers Vs Seattle Protocol to Diagnose Dysplasia in Barrett’s Esophagus

Dysplasia in Barrett's esophagus often is invisible on high-resolution white-light endoscopy (HRWLE). We compared the diagnostic accuracy for inconspicuous dysplasia of the combination of autofluorescence imaging (AFI)-guided probe-based confocal laser endomicroscopy (pCLE) and molecular biomarkers vs HRWLE with Seattle protocol biopsies. Barrett's esophagus patients with no dysplastic lesions were block-randomized to standard endoscopy (HRWLE with the Seattle protocol) or AFI-guided pCLE with targeted biopsies for molecular biomarkers (p53 and cyclin A by immunohistochemistry; aneuploidy by image cytometry), with crossover to the other arm after 6 to 12 weeks. The primary end point was the histologic diagnosis from all study biopsies (trial histology). A sensitivity analysis was performed for overall histology, which included diagnoses within 12 months from the first study endoscopy. Endoscopists were blinded to the referral endoscopy and histology results. The primary outcome was diagnostic accuracy for dysplasia by real-time pCLE vs HRWLE biopsies. Of 154 patients recruited, 134 completed both arms. In the primary outcome analysis (trial histology analysis), AFI-guided pCLE had similar sensitivity for dysplasia compared with standard endoscopy (74.3%; 95% CI, 56.7-87.5 vs 80.0%; 95% CI, 63.1-91.6; P= .48). Multivariate logistic regression showed pCLE optical dysplasia, aberrant p53, and aneuploidy had the strongest correlation with dysplasia (secondary outcome). This 3-biomarker panel had higher sensitivity for any grade of dysplasia than the Seattle protocol (81.5% vs 51.9%; P < .001) in the overall histology analysis, but not in the trial histology analysis (91.4% vs 80.0%; P= .16), with an area under the receiver operating curve of 0.83. Seattle protocol biopsies miss dysplasia in approximately half of patients with inconspicuous neoplasia. AFI-guided pCLE has similar accuracy to the current gold standard. The addition of molecular biomarkers could improve diagnostic accuracy.

P075 Neutrophils prevent rectal bleeding in Ulcerative Colitis by peptidyl-arginine deiminase-4-dependent immunothrombosis

Abstract Background Bleeding ulcers and erosions are hallmarks of active ulcerative colitis (UC). However, the mechanisms controlling bleeding and mucosal haemostasis remain elusive. Methods We used high resolution endoscopy and colon tissue samples of active UC (n = 36) as well as experimental models of physical and chemical mucosal damage in mice deficient for peptidyl-arginine deiminase-4 (PAD4), gnotobiotic mice and controls. We employed endoscopy, histochemistry, live-cell microscopy and flow cytometry to study eroded mucosal surfaces during mucosal haemostasis. Results Erosions and ulcerations in UC were covered by fresh blood, haematin or fibrin visible by endoscopy. Fibrin layers rather than fresh blood or haematin on erosions were inversely correlated with rectal bleeding in UC. Fibrin layers contained ample amounts of neutrophils co-aggregated with neutrophil extracellular traps (NETs) with detectable activity of peptidyl-arginine deiminases (PAD). Transcriptome analyses showed significantly elevated PAD4 expression in active UC. In experimentally inflicted wounds, we found that neutrophils underwent NET formation in a PAD4-dependent manner hours after formation of primary blood clots, and remodelled clots to immunothrombi containing citrullinated histones, even in the absence of microbiota. PAD4-deficient mice experienced an exacerbated course of DSS-induced colitis with markedly increased rectal bleeding (96 % vs 10 %) as compared to controls. PAD4-deficient mice failed to remodel blood clots on mucosal wounds eliciting impaired healing. Thus, NET-associated immunothrombi are protective in acute colitis, while insufficient immunothrombosis is associated with rectal bleeding. Conclusion Our findings uncover that neutrophils induce secondary immunothrombosis by PAD4-dependent mechanisms. Insufficient immunothrombosis may favor rectal bleeding in UC.

Neutrophils prevent rectal bleeding in ulcerative colitis by peptidyl-arginine deiminase-4-dependent immunothrombosis

ObjectiveBleeding ulcers and erosions are hallmarks of active ulcerative colitis (UC). However, the mechanisms controlling bleeding and mucosal haemostasis remain elusive.DesignWe used high-resolution endoscopy and colon tissue samples of active...

Chromoendoscopy Is Not Superior to White Light Endoscopy in Improving Adenoma Detection in Lynch Syndrome Cohort Undergoing Surveillance with High-Resolution Colonoscopy: A Real-World Evidence Study

Background: Endoscopic surveillance in patients with Lynch syndrome (LS) is crucial due to a genetically based high risk of colorectal cancer (CRC). We aimed to compare the adenoma detection rate (ADR) between high-resolution white light endoscopy (WLE) alone and WLE plus dye chromoendoscopy (CE) in a cohort of LS patients. Methods: In a context of real-world data, we retrospectively enrolled 50 LS patients who had non-randomly undergone WLE versus CE surveillance examinations from 2007 to 2019. The 2 groups were compared at baseline (BL) in terms of the rate of patients with lesions and the number of lesions, and at follow-up (FU), to evaluate a possible enhanced detection rate. Longitudinal analysis of the effect of the endoscopy type on the main outcomes was performed by generalized linear mixed models. Results: Forty-two patients had undergone at least one diagnostic colonoscopy. At BL and at FU analysis, we found no significant differences in detection rates and clinical-pathological features between WLE and CE groups. At the longitudinal analysis, an increase in the endoscopy rank (i.e., the position of each colonoscopy for all the colonoscopies that a patient had undergone) was associated with an increase in polyp detection rate (p = 0.006) and ADR (p = 0.005), while a trend toward significance (p = 0.069) was found for endoscopy type (CE vs. WLE) in the detection of serrated lesions. Conclusions: CE is not superior to high-resolution WLE in increasing the ADR. Even under standard WLE, an active and careful endoscopic surveillance of LS patients can prevent CRC.

Improving vision for surgeons during laparoscopy: the Enhanced Laparoscopic Vision System (ELViS).

For many abdominal surgical interventions, laparotomy has gradually been replaced by laparoscopy, with numerous benefits for the patient in terms of post-operative recovery. However, during laparoscopy, the endoscope only provides a single viewpoint to the surgeon, leaving numerous blind spots and opening the way to peri-operative adverse events. Alternative camera systems have been proposed, but many lack the requisite resolution/robustness for use during surgery or cannot provide real-time images. Here, we present the added value of the Enhanced Laparoscopic Vision System (ELViS) which overcomes these limitations and provides a broad view of the surgical field in addition to the usual high-resolution endoscope. Experienced laparoscopy surgeons performed several typical procedure steps on a live pig model. The time-to-completion for surgical exercises performed by conventional endoscopy and ELViS-assisted surgery was measured. A debriefing interview following each operating session was conducted by an ergonomist, and a System Usability Scale (SUS) score was determined. Proof of concept of ELVIS was achieved in an animal model with seven expert surgeons without peroperative adverse events related to the surgical device. No differences were found in time-to-completion. Mean SUS score was 74.7, classifying the usability of the ELViS as "good". During the debriefing interview, surgeons highlighted several situations where the ELViS provided a real advantage (such as during instrument insertion, exploration of the abdominal cavity or for orientation during close work) and also suggested avenues for improvement of the system. This first test of the ELViS prototype on a live animal model demonstrated its usability and provided promising and useful feedback for further development.

Real-Time High-Resolution MRI Endoscopy at up to 10 Frames per Second.

Objective. Atherosclerosis is a leading cause of mortality and morbidity. Optical endoscopy, ultrasound, and X-ray offer minimally invasive imaging assessments but have limited sensitivity for characterizing disease and therapeutic response. Magnetic resonance imaging (MRI) endoscopy is a newer idea employing tiny catheter-mounted detectors connected to the MRI scanner. It can see through vessel walls and provide soft-tissue sensitivity, but its slow imaging speed limits practical applications. Our goal is high-resolution MRI endoscopy with real-time imaging speeds comparable to existing modalities. Methods. Intravascular (3 mm) transmit-receive MRI endoscopes were fabricated for highly undersampled radial-projection MRI in a clinical 3-tesla MRI scanner. Iterative nonlinear reconstruction was accelerated using graphics processor units connected via a single ethernet cable to achieve true real-time endoscopy visualization at the scanner. MRI endoscopy was performed at 6-10 frames/sec and 200-300 μm resolution in human arterial specimens and porcine vessels ex vivo and in vivo and compared with fully sampled 0.3 frames/sec and three-dimensional reference scans using mutual information (MI) and structural similarity (3-SSIM) indices. Results. High-speed MRI endoscopy at 6-10 frames/sec was consistent with fully sampled MRI endoscopy and histology, with feasibility demonstrated in vivo in a large animal model. A 20-30-fold speed-up vs. 0.3 frames/sec reference scans came at a cost of ~7% in MI and ~45% in 3-SSIM, with reduced motion sensitivity. Conclusion. High-resolution MRI endoscopy can now be performed at frame rates comparable to those of X-ray and optical endoscopy and could provide an alternative to existing modalities, with MRI's advantages of soft-tissue sensitivity and lack of ionizing radiation.