Endoscopist-Level and Procedure-Level Factors Associated With Increased Adenoma Detection With the Use of a Computer-Aided Detection Device.

INTRODUCTION: To investigate the impact of procedure-related and endoscopist-related factors on the effectiveness of a computer-aided detection (CADe) device in adenomas per colonoscopy (APC) detection. METHODS: The SKOUT clinical trial was conducted at 5 US sites. We present prespecified analyses of procedure-related and endoscopist-related factors, and association with APC across treatment and control cohorts. RESULTS: There were numeric increases in APC between SKOUT vs standard colonoscopy in community-based endoscopists, withdrawal time of ≥8 minutes, for endoscopists with >20 years of experience, and endoscopists with baseline adenoma detection rate <45%. DISCUSSION: The application of CADe devices in clinical practice should be carefully evaluated. Larger studies should explore differences in endoscopist-related factors for CADe.

Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial.

BACKGROUND & AIMS: Colonoscopy for colorectal cancer screening is endoscopist dependent, and colonoscopy quality improvement programs aim to improve efficacy. This study evaluated the clinical benefit and safety of using a computer-aided detection (CADe) device in colonoscopy procedures. METHODS: This randomized study prospectively evaluated the use of a CADe device at 5 academic and community centers by US board-certified gastroenterologists (n = 22). Participants aged ≥40 scheduled for screening or surveillance (≥3 years) colonoscopy were included; exclusion criteria included incomplete procedure, diagnostic indication, inflammatory bowel disease, and familial adenomatous polyposis. Patients were randomized by endoscopist to the standard or CADe colonoscopy arm using computer-generated, random-block method. The 2 primary endpoints were adenomas per colonoscopy (APC), the total number of adenomas resected divided by the total number of colonoscopies; and true histology rate (THR), the proportion of resections with clinically significant histology divided by the total number of polyp resections. The primary analysis used a modified intention-to-treat approach. RESULTS: Between January and September 2021, 1440 participants were enrolled to be randomized. After exclusion of participants who did not meet the eligibility criteria, 677 in the standard arm and 682 in the CADe arm were included in a modified intention-to-treat analysis. APC increased significantly with use of the CADe device (standard vs CADe: 0.83 vs 1.05, P = .002; total number of adenomas, 562 vs 719). There was no decrease in THR with use of the CADe device (standard vs CADe: 71.7% vs 67.4%, P for noninferiority < .001; total number of non-neoplastic lesions, 284 vs 375). Adenoma detection rate was 43.9% and 47.8% in the standard and CADe arms, respectively (P = .065). CONCLUSIONS: For experienced endoscopists performing screening and surveillance colonoscopies in the United States, the CADe device statistically improved overall adenoma detection (APC) without a concomitant increase in resection of non-neoplastic lesions (THR). CLINICALTRIALS: gov registration: NCT04754347.

Lumen-apposing metal stents (with videos).

BACKGROUND AND AIMS: Lumen-apposing metal stents (LAMSs) are a novel class of devices that have expanded the spectrum of endoscopic GI interventions. LAMSs with their dumbbell configuration, short saddle length, and large inner luminal diameter provide favorable stent characteristics to facilitate anastomosis formation between the gut lumen and adjacent structures. METHODS: The MEDLINE database was searched through April 2021 for articles related to LAMSs by using additional relevant keywords such as "walled-off pancreatic necrosis," "pseudocysts," "pancreatic fluid collection," "cholecystitis," "gastroenterostomy," in addition to "endoscopic treatment" and "endoscopic management," among others. RESULTS: This technology review describes the full spectrum of LAMS designs and delivery systems, techniques for deployment, procedural outcomes, safety, training issues, and financial considerations. CONCLUSIONS: Although LAMSs were initially introduced for drainage of pancreatic pseudocysts and walled-off necrosis, the versatility of these devices has led to a variety of off-label uses including gallbladder drainage, enteric bypass with the creation of gastroenterostomies, and treatment of luminal GI strictures.

Endoscopic polypectomy devices.

Video 1Use of submucosal injection prior to en-bloc endoscopic mucosal resection.Video 2Use of a detachable loop ligating device prior to hot snare resection of a pedunculated polyp.

Devices and techniques for flexible endoscopic management of Zenker's diverticulum (with videos).

BACKGROUND AND AIMS: Zenker's diverticulum (ZD) has traditionally been treated with open surgery or rigid endoscopy. With the advances in endoscopy, alternative flexible endoscopic treatments have been developed. METHODS: This document reviews current endoscopic techniques and devices used to treat ZD. RESULTS: The endoscopic techniques may be categorized as the traditional flexible endoscopic septal division and the more recent submucosal tunneling endoscopic septum division, also known as peroral endoscopic myotomy for ZD. This document also addresses clinical outcomes, safety, and financial considerations. CONCLUSIONS: Flexible endoscopic approaches treat symptomatic ZD with results that are favorable compared with traditional open surgical or rigid endoscopic alternatives.

Enhanced EUS imaging (with videos).

BACKGROUND AND AIMS: EUS remains a primary diagnostic tool for the evaluation of pancreaticobiliary disease. Although EUS combined with FNA or biopsy sampling is highly sensitive for the diagnosis of neoplasia within the pancreaticobiliary tract, limitations exist in specific clinical settings such as chronic pancreatitis. Enhanced EUS imaging technologies aim to aid in the detection and diagnosis of lesions that are commonly evaluated with EUS. METHODS: We reviewed technologies and methods for enhanced imaging during EUS and applications of these methods. Available data regarding efficacy, safety, and financial considerations are summarized. RESULTS: Enhanced EUS imaging methods include elastography and contrast-enhanced EUS (CE-EUS). Both technologies have been best studied in the setting of pancreatic mass lesions. Robust data indicate that neither technology has adequate specificity to serve as a stand-alone test for pancreatic malignancy. However, there may be a role for improving the targeting of sampling and in the evaluation of peritumoral lymph nodes, inflammatory pancreatic masses, and masses with nondiagnostic FNA or fine-needle biopsy sampling. Further, novel applications of these technologies have been reported in the evaluation of liver fibrosis, pancreatic cysts, and angiogenesis within neoplastic lesions. CONCLUSIONS: Elastography and CE-EUS may improve the real-time evaluation of intra- and extraluminal lesions as an adjunct to standard B-mode and Doppler imaging. They are not a replacement for EUS-guided tissue sampling but provide adjunctive diagnostic information in specific clinical situations. The optimal clinical use of these technologies continues to be a focus of ongoing research.

Artificial intelligence in gastrointestinal endoscopy.

BACKGROUND AND AIMS: Artificial intelligence (AI)-based applications have transformed several industries and are widely used in various consumer products and services. In medicine, AI is primarily being used for image classification and natural language processing and has great potential to affect image-based specialties such as radiology, pathology, and gastroenterology (GE). This document reviews the reported applications of AI in GE, focusing on endoscopic image analysis. METHODS: The MEDLINE database was searched through May 2020 for relevant articles by using key words such as machine learning, deep learning, artificial intelligence, computer-aided diagnosis, convolutional neural networks, GI endoscopy, and endoscopic image analysis. References and citations of the retrieved articles were also evaluated to identify pertinent studies. The manuscript was drafted by 2 authors and reviewed in person by members of the American Society for Gastrointestinal Endoscopy Technology Committee and subsequently by the American Society for Gastrointestinal Endoscopy Governing Board. RESULTS: Deep learning techniques such as convolutional neural networks have been used in several areas of GI endoscopy, including colorectal polyp detection and classification, analysis of endoscopic images for diagnosis of Helicobacter pylori infection, detection and depth assessment of early gastric cancer, dysplasia in Barrett's esophagus, and detection of various abnormalities in wireless capsule endoscopy images. CONCLUSIONS: The implementation of AI technologies across multiple GI endoscopic applications has the potential to transform clinical practice favorably and improve the efficiency and accuracy of current diagnostic methods.

In high-risk patients with acute upper GI bleeding, urgent vs. early endoscopy did not differ for 30-day mortality.

SOURCE CITATION: Lau JY, Yu Y, Tang RS, et al. Timing of endoscopy for acute upper gastrointestinal bleeding. N Engl J Med. 2020;382:1299-308. 32242355.

Endoscopic devices and techniques for the management of bariatric surgical adverse events (with videos).

BACKGROUND AND AIMS: As the prevalence of obesity continues to rise, increasing numbers of patients undergo bariatric surgery. Management of adverse events of bariatric surgery may be challenging and often requires a multidisciplinary approach. Endoscopic intervention is often the first line of therapy for management of these adverse events. This document reviews technologies and techniques used for endoscopic management of adverse events of bariatric surgery, organized by surgery type. METHODS: The MEDLINE database was searched through May 2018 for articles related to endoscopic management of adverse events of bariatric interventions by using relevant keywords such as adverse events related to "gastric bypass," "sleeve gastrectomy," "laparoscopic adjustable banding," and "vertical banded sleeve gastroplasty," in addition to "endoscopic treatment" and "endoscopic management," among others. Available data regarding efficacy, safety, and financial considerations are summarized. RESULTS: Common adverse events of bariatric surgery include anastomotic ulcers, luminal stenoses, fistulae/leaks, and inadequate initial weight loss or weight regain. Devices used for endoscopic management of bariatric surgical adverse events include balloon dilators (hydrostatic, pneumatic), mechanical closure devices (clips, endoscopic suturing system, endoscopic plication platform), luminal stents (covered esophageal stents, lumen-apposing metal stents, plastic stents), and thermal therapy (argon plasma coagulation, needle-knives), among others. Available data, composed mainly of case series and retrospective cohort studies, support the primary role of endoscopic management. Multiple procedures and techniques are often required to achieve clinical success, and existing management algorithms are evolving. CONCLUSIONS: Endoscopy is a less invasive alternative for management of adverse events of bariatric surgery and for revisional procedures. Endoscopic procedures are frequently performed in the context of multidisciplinary management with bariatric surgeons and interventional radiologists. Treatment algorithms and standards of practice for endoscopic management will continue to be refined as new dedicated technology and data emerge.

Devices and techniques for endoscopic treatment of residual and fibrotic colorectal polyps (with videos).

BACKGROUND AND AIMS: Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging. METHODS: This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed. RESULTS: Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection. CONCLUSIONS: Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Computer-assisted assessment of colonic polyp histopathology using probe-based confocal laser endomicroscopy.

INTRODUCTION: Probe-based confocal laser endomicroscopy (pCLE) is a promising modality for classifying polyp histology in vivo, but decision making in real-time is hampered by high-magnification targeting and by the learning curve for image interpretation. The aim of this study is to test the feasibility of a system combining the use of a low-magnification, wider field-of-view pCLE probe and a computer-assisted diagnosis (CAD) algorithm that automatically classifies colonic polyps. METHODS: This feasibility study utilized images of polyps from 26 patients who underwent colonoscopy with pCLE. The pCLE images were reviewed offline by two expert and five junior endoscopists blinded to index histopathology. A subset of images was used to train classification software based on the consensus of two GI histopathologists. Images were processed to extract image features as inputs to a linear support vector machine classifier. We compared the CAD algorithm's prediction accuracy against the classification accuracy of the endoscopists. RESULTS: We utilized 96 neoplastic and 93 non-neoplastic confocal images from 27 neoplastic and 20 non-neoplastic polyps. The CAD algorithm had sensitivity of 95%, specificity of 94%, and accuracy of 94%. The expert endoscopists had sensitivities of 98% and 95%, specificities of 98% and 96%, and accuracies of 98% and 96%, while the junior endoscopists had, on average, a sensitivity of 60%, specificity of 85%, and accuracy of 73%. CONCLUSION: The CAD algorithm showed comparable performance to offline review by expert endoscopists and improved performance when compared to junior endoscopists and may be useful for assisting clinical decision making in real time.

ASGE guideline for endoscopic full-thickness resection and submucosal tunnel endoscopic resection.

With the development of reliable endoscopic closure techniques and tools, endoscopic full-thickness resection (EFTR) is emerging as a therapeutic option for the treatment of subepithelial tumors and epithelial neoplasia with significant fibrosis. EFTR may be categorized as "exposed" and "nonexposed." In exposed EFTR, the full-thickness resection is undertaken with a tunneled or nontunneled technique, with subsequent closure of the defect. In nonexposed EFTR, a secure serosa-to-serosa apposition is achieved before full-thickness resection of the isolated lesion. This document reviews current techniques and devices used for EFTR and reviews clinical applications and outcomes.

Advances in the diagnosis and surveillance of Barrett's esophagus (with videos).

BACKGROUND AND AIMS: Most patients diagnosed with esophageal adenocarcinoma do not carry a known diagnosis of Barrett's esophagus (BE), suggesting that an improved approach to screening may potentially be of benefit. The use of dysplasia as a biomarker and random biopsy protocols for its detection has limitations. In addition, detecting and appropriately classifying dysplasia in patients with known BE can be difficult. METHODS: This document reviews several technologies with a recently established or potential role in the diagnosis and/or surveillance of BE as well as risk stratification for progression to esophageal adenocarcinoma. RESULTS: Two technologies were reviewed for imaging or tissue sampling: (1) wide-area transepithelial sampling and (2) volumetric laser endomicroscopy. Four technologies were reviewed for molecular and biomarker technologies for diagnosis and risk stratification: (1) Cytosponge, (2) mutational load, (3) fluorescence in situ hybridization, and (4) immunohistochemistry. CONCLUSION: Several technologies discussed in this document may improve dysplasia detection in BE in a wide-field manner. Moreover, the addition of different biomarkers may aid in enhanced risk stratification to optimize approaches to surveillance or treatment for patients with BE.

Endoscopic simulators.

BACKGROUND AND AIMS: Simulation refers to educational tools that allow for repetitive instruction in a nonpatient care environment that is risk-free. In GI endoscopy, simulators include ex vivo animal tissue models, live animal models, mechanical models, and virtual reality (VR) computer simulators. METHODS: After a structured search of the peer-reviewed medical literature, this document reviews commercially available GI endoscopy simulation systems and clinical outcomes of simulation in endoscopy. RESULTS: Mechanical simulators and VR simulators are frequently used early in training, whereas ex vivo and in vivo animal models are more commonly used for advanced endoscopy training. Multiple studies and systematic reviews show that simulation-based training appears to provide novice endoscopists with some advantage over untrained peers with regard to endpoints such as independent procedure completion and performance time, among others. Data also suggest that simulation training may accelerate the acquisition of specific technical skills in colonoscopy and upper endoscopy early in training. However, the available literature suggests that the benefits of simulator training appear to attenuate and cease after a finite period. Further studies are needed to determine if meeting competency metrics using simulation will predict actual clinical competency. CONCLUSIONS: Simulation training is a promising modality that may aid in endoscopic education. However, for widespread incorporation of simulators into gastroenterology training programs to occur, simulators must show a sustained advantage over traditional mentored teaching in a cost-effective manner. Because most studies evaluating simulation have focused on novice learners, the role of simulation training in helping practicing endoscopists gain proficiency using new techniques and devices should be further explored.

Primary Sclerosing Cholangitis: A Concise Review of Diagnosis and Management.

Primary sclerosing cholangitis is a rare, chronic cholestatic liver disease characterized by progressive idiopathic stricturing of the biliary system, typically leading to cirrhosis, end-stage liver disease, and colonic or hepatobiliary malignancy. Its presentation is often that of asymptomatic alkaline phosphatase elevation. When symptoms are present, they typically include fatigue, pruritus, or jaundice. The diagnosis can be confirmed via cholangiography, either magnetic resonance cholangiography (MRCP) or endoscopic retrograde cholangiography if the former is inconclusive. The clinical course is marked by progressive liver disease leading to cirrhosis with its attendant complications of portal hypertension, often including recurrent episodes of cholangitis. Greater elevation in alkaline phosphatase or liver stiffness is associated with worse clinical outcomes. Management includes endoscopic treatment of symptomatic biliary strictures and evaluation of dominant strictures as no adequate medical treatment is available. Multiple medical therapies are under evaluation. Ultimately, liver transplantation may be necessary for management of decompensated cirrhosis or disabling symptoms. There is also a markedly increased risk of cancer, notably including cholangiocarcinoma and gallbladder and colorectal cancers (particularly in patients with colitis). Cancer screening can be done with semi-annual liver imaging (MRCP or ultrasound) and colonoscopy every 1-2 years in those with colitis.

Percutaneous transhepatic vs. endoscopic retrograde biliary drainage for suspected malignant hilar obstruction: study protocol for a randomized controlled trial.

BACKGROUND: The optimal approach to the drainage of malignant obstruction at the liver hilum remains uncertain. We aim to compare percutaneous transhepatic biliary drainage (PTBD) to endoscopic retrograde cholangiography (ERC) as the first intervention in patients with cholestasis due to suspected malignant hilar obstruction (MHO). METHODS: The INTERCPT trial is a multi-center, comparative effectiveness, randomized, superiority trial of PTBD vs. ERC for decompression of suspected MHO. One hundred and eighty-four eligible patients across medical centers in the United States, who provide informed consent, will be randomly assigned in 1:1 fashion via a web-based electronic randomization system to either ERC or PTBD as the initial drainage and, if indicated, diagnostic procedure. All subsequent clinical interventions, including crossover to the alternative procedure, will be dictated by treating physicians per usual clinical care. Enrolled subjects will be assessed for successful biliary drainage (primary outcome measure), adequate tissue diagnosis, adverse events, the need for additional procedures, hospitalizations, and oncological outcomes over a 6-month follow-up period. Subjects, treating clinicians and outcome assessors will not be blinded. DISCUSSION: The INTERCPT trial is designed to determine whether PTBD or ERC is the better initial approach when managing a patient with suspected MHO, a common clinical dilemma that has never been investigated in a randomized trial. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT03172832 . Registered on 1 June 2017.