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Summary Background Computer-aided detection (CADe) techniques based on artificial intelligence algorithms can assist endoscopists in detecting colorectal neoplasia. CADe has been associated with an increased adenoma detection rate, a key quality indicator, but the utility of CADe compared with existing advanced imaging techniques and distal attachment devices is unclear. Methods For this systematic review and network meta-analysis, we did a comprehensive search of PubMed/Medline, Embase, and Scopus databases from inception to Nov 30, 2020, for randomised controlled trials investigating the effectiveness of the following endoscopic techniques in detecting colorectal neoplasia: CADe, high definition (HD) white-light endoscopy, chromoendoscopy, or add-on devices (ie, systems that increase mucosal visualisation, such as full spectrum endoscopy [FUSE] or G-EYE balloon endoscopy). We collected data on adenoma detection rates, sessile serrated lesion detection rates, the proportion of large adenomas detected per colonoscopy, and withdrawal times. A frequentist framework, random-effects network meta-analysis was done to compare artificial intelligence with chromoendoscopy, increased mucosal visualisation systems, and HD white-light endoscopy (the control group). We estimated odds ratios (ORs) for the adenoma detection rate, sessile serrated lesion detection rate, and proportion of large adenomas detected per colonoscopy, and calculated mean differences for withdrawal time, with 95% CIs. Risk of bias and certainty of evidence were assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Findings 50 randomised controlled trials, comprising 34 445 participants, were included in our main analysis (six trials of CADe, 18 of chromoendoscopy, and 26 of increased mucosal visualisation systems). HD white-light endoscopy was the control technique in all 50 studies. Compared with the control technique, the adenoma detection rate was 7·4% higher with CADe (OR 1·78 [95% CI 1·44–2·18]), 4·4% higher with chromoendoscopy (1·22 [1·08–1·39]), and 4·1% higher with increased mucosal visualisation systems (1·16 [1·04–1·28]). CADe ranked as the superior technique for adenoma detection (with moderate confidence in hierarchical ranking); cross-comparisons of CADe with other imaging techniques showed a significant increase in the adenoma detection rate with CADe versus increased mucosal visualisation systems (OR 1·54 [95% CI 1·22–1·94]; low certainty of evidence) and with CADe versus chromoendoscopy (1·45 [1·14–1·85]; moderate certainty of evidence). When focusing on large adenomas (≥10 mm) there was a significant increase in the detection of large adenomas only with CADe (OR 1·69 [95% CI 1·10–2·60], moderate certainty of evidence) when compared to HD white-light endoscopy; CADe ranked as the superior strategy for detection of large adenomas. CADe also seemed to be the superior strategy for detection of sessile serrated lesions (with moderate confidence in hierarchical ranking), although no significant increase in the sessile serrated lesion detection rate was shown (OR 1·37 [95% CI 0·65–2·88]). No significant difference in withdrawal time was reported for CADe compared with the other techniques. Interpretation Based on the published literature, detection rates of colorectal neoplasia are higher with CADe than with other techniques such as chromoendoscopy or tools that increase mucosal visualisation, supporting wider incorporation of CADe strategies into community endoscopy services. Funding None.

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Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.

Adenoma Detection Rate (ADR) is still the main surrogate outcome parameter of screening colonoscopy, but most of the studies included mixed indications and basic ADR is quite variable. We therefore looked at the control groups in randomized ADR trials using advanced imaging or mechanical methods to find out whether indications or other factors influence ADR levels.Patients in the control groups of randomized controlled trials (RCTs) on ADR increase using various methods were collected based on a systematic review; this control group had to use high-definition (HD) white-light endoscopy performed between 2008 and 2021. Random-effects meta-analysis was used to pool ADR in control groups and its 95% confidence interval (CI) according to the following parameters: clinical (indication and demographic), study setting (tandem/parallel, N° centers, sample size), and technical (type of intervention, withdrawal time). Inter-study heterogeneity was reported with I-squared statistic. Multivariable mixed-effects meta-regression was performed for potentially relevant variables.25,304 patients from 80 studies in the respective control groups were included. ADR in control arms varied between 8.2% and 68.1% with a high degree of heterogeneity (I2 = 95.1%; random-effect pooled value: 37.5% [34.6‒40.5]). There was no difference in ADR levels between primary colonoscopy screening (12 RCTs, 15%), and mixed indications including screening/surveillance and diagnostic colonoscopy; however, FIT as an indication for colonoscopy was an independent predictor of ADR (OR: 1.6 [1.1‒2.4]). Other well-known parameters were confirmed by our analysis such as age (OR: 1.038 [1.004‒1.074]) and sex (male sex: OR: 1.02 [1.01‒1.03) as well withdrawal time (OR: 1.1 [1.0‒1.1). The type of intervention (imaging vs. mechanical) had no influence, but methodological factors did: more recent year of publication and smaller sample size were associated with higher ADR.A high level of variability was found in the level of ADR in the controls of RCTs. With regards to indications, only FIT-based colonoscopy studies influenced basic ADR, primary colonoscopy screening appeared to be similar to other indications. Standardization for variables related to clinical, methodological, and technical parameters is required to achieve generalizability and reproducibility.

Zenker's diverticulum (ZD) is a rare outpouching of the esophageal mucosa herniating posteriorly through Killian's triangle. Treatments of ZD aim to dissect the cricopharyngeal muscle to remove the underlying dysfunctional condition. In the last decade, a septotomy performed utilizing a flexible endoscope has been reported as a safe and effective alternative to both open surgery and rigid endoscopic diverticulotomy. More recently, Li et al described a novel endoscopic technique to treat ZD, named "submucosal tunneling endoscopic septum division", inspired by the peroral endoscopic myotomy (POEM) procedure developed for achalasia. Subsequently, the term Z-POEM was introduced and has become the most frequently used acronym to define the tunneling technique for ZD. This article describes the flexible therapeutic endoscopic strategies for treating ZD, including the novel third space approach, which seems to show promising potential in terms of clinical efficacy and safety.

Abstract Introduction Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy (SAA) is technically challenging and associated with a significant number of failures. We examined the feasibility and efficacy of a novel technique for the management of bile duct stones (BDSs), called underwater cap-assisted ERCP (u-ERCP). Methods Between June 2019 and February 2020 all patients with SAA with jaundice or cholangitis secondary to BDSs who underwent u-ERCP were enrolled. The u-ERCP technique combines the underwater advancement of a pediatric colonoscope with a transparent cap fitted on the tip of the endoscope. We evaluated the technical success, clinical success, and adverse events associated with u-ERCP. Results We describe the technique itself and our initial experience in six patients. A complete and successful procedure was carried out in all patients, with the occurrence of no adverse events. None of the patients needed additional treatments for recurrence of symptoms during the follow-up period. Conclusions u-ERCP can be considered as a promising alternative for successful endoscopic management of biliary disease in patients with SAA.

Several studies have shown a significant adenoma miss rate up to 35% during screening colonoscopy, especially in patients with diminutive adenomas. The use of artificial intelligence (AI) in colonoscopy has been gaining popularity by helping endoscopists in polyp detection, with the aim to increase their adenoma detection rate (ADR) and polyp detection rate (PDR) in order to reduce the incidence of interval cancers. The efficacy of deep convolutional neural network (DCNN)-based AI system for polyp detection has been trained and tested in ex vivo settings such as colonoscopy still images or videos. Recent trials have evaluated the real-time efficacy of DCNN-based systems showing promising results in term of improved ADR and PDR. In this review we reported data from the preliminary ex vivo experiences and summarized the results of the initial randomized controlled trials.

Italy recorded its first case of confirmed acute respiratory illness because of coronavirus on February 18, 2020, soon after the initial reports in China. Since that time, Italy and nations throughout the world have adopted very stringent and severe measures to protect populations from spread of infection. Despite these measures, the number of infected people is growing exponentially, with a significant number of patients developing acute respiratory insufficiency. Endoscopy departments face significant risk for diffusion of respiratory diseases that can be spread via an airborne route, including aspiration of oral and fecal material via endoscopes. The purpose of this article is to discuss the measures, with specific focus on personal protection equipment and dress code modalities, implemented in our hospital to prevent further dissemination of COVID-19 infection.

Artificial intelligence (AI) tools aimed at improving polyp detection have been shown to increase the adenoma detection rate during colonoscopy. However, it is unknown how increased polyp detection rates by AI affect the burden of patient surveillance after polyp removal.We conducted a pooled analysis of 9 randomized controlled trials (5 in China, 2 in Italy, 1 in Japan, and 1 in the United States) comparing colonoscopy with or without AI detection aids. The primary outcome was the proportion of patients recommended to undergo intensive surveillance (ie, 3-year interval). We analyzed intervals for AI and non-AI colonoscopies for the U.S. and European recommendations separately. We estimated proportions by calculating relative risks using the Mantel-Haenszel method.A total of 5796 patients (51% male, mean 53 years of age) were included; 2894 underwent AI-assisted colonoscopy and 2902 non-AI colonoscopy. When following U.S. guidelines, the proportion of patients recommended intensive surveillance increased from 8.4% (95% CI, 7.4%-9.5%) in the non-AI group to 11.3% (95% CI, 10.2%-12.6%) in the AI group (absolute difference, 2.9% [95% CI, 1.4%-4.4%]; risk ratio, 1.35 [95% CI, 1.16-1.57]). When following European guidelines, it increased from 6.1% (95% CI, 5.3%-7.0%) to 7.4% (95% CI, 6.5%-8.4%) (absolute difference, 1.3% [95% CI, 0.01%-2.6%]; risk ratio, 1.22 [95% CI, 1.01-1.47]).The use of AI during colonoscopy increased the proportion of patients requiring intensive colonoscopy surveillance by approximately 35% in the United States and 20% in Europe (absolute increases of 2.9% and 1.3%, respectively). While this may contribute to improved cancer prevention, it significantly adds patient burden and healthcare costs.

Lumen-apposing metal stents (LAMS) are recently introduced devices that allow to create anastomoses. The indications for LAMS placement are increasing and currently these stents can be used in multiple clinical situations such as endoscopic drainage of pancreatic fluid collections (PFCs), endoscopic ultrasound-guided choledocho-duodenostomy (EUS-CDS), endoscopic ultrasound gallbladder drainage (EUS-GBD), endoscopic ultrasound gastrojejunostomy (EUS-GJ). Since their introduction, they have revealed to allow a higher rate of technical and clinical success, and potentially lower risk of adverse events (AEs) compared with previously available devices. Despite ongoing innovation, any advanced intervention carries risks of AEs. These AEs may occur during the deployment or can be delayed because of the consequent effects of the procedure and/or stent itself. This review represents an overview of current indications, technical and clinical results, with an extensive focus on safety issues related to placement and on long-term indwelling related ones.

ObjectiveEndoscopic submucosal dissection (ESD) in a curative intent for submucosa-invasive early (T1) colorectal cancers (T1-CRCs) often leads to subsequent surgical resection in case of histologic parameters indicating higher risk of nodal involvement. In some cases, however, the expected benefit may be offset by the surgical risks, suggesting a more conservative approach.DesignRetrospective analysis of consecutive patients with T1-CRC who underwent ESD at 13 centres ending inclusion in 2019 (n=3373). Cases with high risk of nodal involvement (non-curative ESD: G3, submucosal invasion>1000 µm, lymphovascular involvement, budding or incomplete resection/R1) were analysed if follow-up data (endoscopy/imaging) were available, regardless of the postendoscopic management (follow-up vs surgery) selected by the multidisciplinary teams in these institutions. Comorbidities were classified according to Charlson Comorbidity Index (CCI). Outcomes were disease recurrence, death and disease-related death rates in the two groups. Rate of residual disease (RD) at both the previous resection site and regional lymph nodes was assessed in the surgical cases as well as from follow-up in the follow-up group.ResultsOf 604 patients treated by colorectal ESD for submucosally invasive cancer, 207 non-curative resections (34.3%) were included (138 male; mean age 67.6±10.9 years); in 65.2% of cases, no complete resection was achieved (R1). Of the 207 cases, 60.9% (n=126; median CCI: 3; IQR: 2–4) underwent surgical treatment with RD in 19.8% (25/126), while 39.1% (n=81, median CCI: 5; IQR: 4–6) were followed up by endoscopy in all cases. Patients in the follow-up group had a higher overall mortality (HR=3.95) due to non-CRC causes (n=9, mean survival after ESD 23.7±13.7 months). During this follow-up time, tumour recurrence and disease-specific survival rates were not different between the groups (median follow-up 30 months; range: 6–105).ConclusionFollowing ESD for a lesion at high risk of RD, follow-up only may be a reasonable choice in patients at high risk for surgery. Also, endoscopic resection quality should be improved.Trial registration numberNCT03987828.

Contains fulltext : 252157.pdf (Publisher’s version ) (Open Access) BACKGROUND: Endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) is emerging as a complementary therapeutic approach for pancreatic solid masses. However, results of published data are difficult to interpret because of a retrospective design and small sample size. AIM: To systematically review data on EUS-RFA for solid lesions and to pool the results of the different experiences in order to provide more consistent evidence in terms of safety and efficacy. METHODS: A comprehensive systematic literature search on the main databases was performed to identify articles in which patients with pancreatic solid lesions underwent EUS-RFA. The primary outcomes were procedure-related adverse events (AEs) and mortality. Secondary outcomes were the technical success rate and the effects on primary tumor growth. Statistical analyses were performed using Stata version 14.0. RESULTS: In total, 14 studies were included, with 120 patients undergoing 153 ablations of 129 solid pancreatic lesions. The STARmed technology was used in seven studies, the Habib system in six studies, and the HybridTherm probe in one study. The pooled technical success rate was 99.0% (I (2): 25.82%). The pooled overall AE rate was 8.0% (I (2): 11.46%). Excluding mild AEs, the pooled rates of serious AEs was 1.0% (I (2): 0%). No mortality related to the procedure was reported. CONCLUSION: The present pooled analysis confirms the safety and feasibility of EUS-RFA.

EUS-guided biliary drainage (BD) through hepaticogastrostomy (HGS) is an option in case of ERCP failure. Available data suggest that this procedure may be challenging with possible severe adverse events (AEs) mainly due to stent migration. The aim of our pilot study was to prospectively assess the technical and clinical outcomes of EUS-HGS using a new dedicated partially covered self-expandable metal stent with anti-migratory systems.This is a single-center prospective study enrolling patients with malignant biliary obstruction undergoing EUS-HGS after failed ERCP, between June 2020 and March 2021. The primary endpoint was the technical success rate. Evaluation of specific stent-related technical features as compared with commonly used self-expandable metal stent, clinical success rate, and procedure-related AEs was also assessed.Twenty-two patients (15%-68.2%, female; mean age, 66.0 ± 10.0) were enrolled in the study analysis. Different causes of ERCP failure were infiltration of papilla by neoplastic tissue (4, 18.2%), unreachable papilla for duodenal stricture (9, 40.9%), surgically altered anatomy with Roux-en-Y reconstruction (4, 18.2%), and incomplete BD after transpapillary stent placement (5, 22.7%). Technical success was achieved in all patients, in a mean procedural time of 43.3 ± 26.8 min. Technical features were graded as high or medium in all cases. The clinical success rate was 91% (20/22, mean follow-up: 10.8 ± 3.1 months). There were no cases of stent misplacement or stent migration. Three (13.6%) cases of a hepatic abscess requiring percutaneous drainage and systemic antibiotics were reported, with no impact on clinical success and following oncologic treatments. No deaths occurred.EUS-HGS with a new dedicated stent with anti-migratory systems is feasible and effective, preventing stent migration, and misplacement. Although the persistent procedural challenges, dedicated devices may contribute to outcomes improvement and procedure diffusion.

From a mere diagnostic tool to an imperative treatment modality, endoscopic ultrasound (EUS) has evolved and revolutionized safer efficient options for vascular interventions. Currently it is an alternative treatment option in the management of gastrointestinal bleeding, primarily variceal type bleeding. Conventional treatment option prior to EUS incorporation had limited efficiency and high adverse events. The characterization and detail provided by EUS gives a cutting edge towards a holistically successful management choice. Data indicates that EUS-guided combination therapy of coil embolization and glue injection has the higher efficacy for the treatment of varices. Conversely, similar treatment options that exist for esophageal and other ectopic variceal bleeding was also outlined. In conclusion, many studies refer that a combination therapy of coil and glue injection under EUS guidance provides higher technical success with fewer recurrence and adverse events, making its adaptation in the guideline extremely favorable. Endo-hepatology is a novel disciple with a promising future outlook, we reviewed topics regarding portal vein access, pressure gradient measurement, and thrombus biopsy that are crucial interventions as alternative of radiological procedures. The purpose of this review is to provide an update on the latest available evidence in the literature regarding the role of EUS in vascular interventions. We reviewed the role of EUS in variceal bleeding in recent studies, especially gastric varices and novel approaches aimed at the portal vein.

In the last decade, flexible endoscopic septotomy has been reported as a well-tolerated and effective treatment for Zenker's diverticulum. More recently, novel endoscopic submucosal tunneling techniques, namely Zenker-PerOral Endoscopic Myotomy (Z-POEM) and PerOral Endoscopic Septotomy (POES) have been proposed to obtain complete muscular septum exposure and deeper myotomy. The aim of this study is to provide a systematic review with a meta-analysis of the first experiences of third space approaches for Zenker's diverticulum. Electronic databases (Medline, Scopus, EMBASE) were searched up to October 2020. Studies including patients with symptomatic Zenker's diverticulum who underwent endoscopic treatment by submucosal tunneling technique were eligible. Procedural, clinical and safety outcomes were assessed by pooling data with a random-effect model to obtain a proportion with a 95% confidence interval. Nine retrospective studies were eligible for inclusion (196 patients). Five studies were performed in the USA, two in Europe and two in Asia. Endoscopic treatment was feasible in 96.9% (I2 = 0%) of patients. The mean procedure duration was 36.4 ± 14.3 minutes. Clinical success was achieved after 93.4% (I2 = 0%) of procedures. The overall adverse events rate was 4.9% (I2 = 0%). No differences between the two approaches (Z-POEM vs POES) have been shown in terms of both efficacy and safety. Submucosal tunneling techniques appear to be feasible for symptomatic Zenker's diverticulum, with promising results in terms of efficacy and safety outcomes.

Reported experience from the recent worldwide covid-19 outbreak suggests that GI endoscopy is a potential source of infection for healthcare workers (HCW); less is known about patient risk through performance of GI endoscopy as a high-risk medical procedure. Two case series from Northern Italy were recorded, one on 851 patients from one large tertiary referral centre and the other on 968 HCWs from 41 hospitals in the area. All 851 patients endoscoped in Humanitas University Hospital between 27 January and 13 March received a 2-week follow-up call; the response rate was 94.2%. Of these 802 patients, only 1 became covid-19 positive; 7 further cases developed fever and cough (3 tested negative). None of these eight cases (1.0%) required hospitalisation. In the other study, 42 hospitals in Northern Italy were invited to join a survey with regard to covid-19 positivity among HCWs, and 41 responded; centres with positive cases were interviewed in detail. Of 968 HCWs in these centres, 42 (4.3%) were tested positive for covid-19, and 6 (0.6%) had to be temporarily hospitalised (for a mean of 8 days, none on intensive care unit (ICU)). Of these 42 cases, 85.7% occurred before the introduction of safety measures, including personal protective equipment (PPE) and case selection/reduction in GI endoscopy. Clustering of HCW infection (54.7% of all cases) was observed in three centres. This data suggest that GI endoscopy appears to be relatively safe for both patients and medical personnel when using adequate protective measures. As of 31 March 2020, Italy and especially its Northern regions became the epicentre of the novel coronavirus (severe acute respiratory syndrome-CoV-2) outbreak, with more than 100 000 documented infections and a higher mortality rate than that reported in other countries. According to recent data issued by the Italian Health Authority, more than 10% of all infections in …

Artificial intelligence has been shown to be effective in polyp detection, and multiple computer-aided detection (CADe) systems have been developed. False-positive (FP) activation emerged as a possible way to benchmark CADe performance in clinical practice. The aim of this study was to validate a previously developed classification of FPs comparing the performances of different brands of approved CADe systems.We compared 2 different consecutive video libraries (40 video per arm) collected at Humanitas Research Hospital with 2 different CADe system brands (CADe A and CADe B). For each video, the number of CADe false activations, cause, and time spent by the endoscopist to examine the area erroneously highlighted were reported. The FP activations were classified according to the previously developed classification of FPs (the NOISE classification) according to their cause and relevance.In CADe A 1021 FP activations were registered across the 40 videos (25.5 ± 12.2 FPs per colonoscopy), whereas in CADe B 1028 were identified (25.7 ± 13.2 FPs per colonoscopy; P = .53). Among them, 22.9 ± 9.9 (89.8% in CADe A) and 22.1 ± 10.0 (86.0% in CADe B) were because of artifacts from the bowel wall. Conversely, 2.6 ± 1.9 (10.2% in CADe A) and 3.5 ± 2.1 (14% in CADe B) were caused by bowel content (P = .45). Within CADe A each false activation required .2 ± .9 seconds, with 1.6 ± 1.0 FPs (6.3%) requiring additional time for endoscopic assessment. Comparable results were reported within CADe B with .2 ± .8 seconds spent per false activation and 1.8 ± 1.2 FPs per colonoscopy requiring additional inspection.The use of a standardized nomenclature provided comparable results with either of the 2 recently approved CADe systems. (Clinical trial registration number: NCT04399590.).

Artificial intelligence (AI) tools increase detection of precancerous polyps during colonoscopy and might contribute to long-term colorectal cancer prevention. The aim of the study was to investigate the incremental effect of the implementation of AI detection tools in screening colonoscopy on colorectal cancer incidence and mortality, and the cost-effectiveness of such tools.We conducted Markov model microsimulation of using colonoscopy with and without AI for colorectal cancer screening for individuals at average risk (no personal or family history of colorectal cancer, adenomas, inflammatory bowel disease, or hereditary colorectal cancer syndrome). We ran the microsimulation in a hypothetical cohort of 100 000 individuals in the USA aged 50-100 years. The primary analysis investigated screening colonoscopy with versus without AI every 10 years starting at age 50 years and finishing at age 80 years, with follow-up until age 100 years, assuming 60% screening population uptake. In secondary analyses, we modelled once-in-life screening colonoscopy at age 65 years in adults aged 50-79 years at average risk for colorectal cancer. Post-polypectomy surveillance followed the simplified current guideline. Costs of AI tools and cost for downstream treatment of screening detected disease were estimated with 3% annual discount rates. The main outcome measures included the incremental effect of AI-assisted colonoscopy versus standard (no-AI) colonoscopy on colorectal cancer incidence and mortality, and cost-effectiveness of screening projected for the average risk screening US population.In the primary analyses, compared with no screening, the relative reduction of colorectal cancer incidence with screening colonoscopy without AI tools was 44·2% and with screening colonoscopy with AI tools was 48·9% (4·8% incremental gain). Compared with no screening, the relative reduction in colorectal cancer mortality with screening colonoscopy with no AI was 48·7% and with screening colonoscopy with AI was 52·3% (3·6% incremental gain). AI detection tools decreased the discounted costs per screened individual from $3400 to $3343 (a saving of $57 per individual). Results were similar in the secondary analyses modelling once-in-life colonoscopy. At the US population level, the implementation of AI detection during screening colonoscopy resulted in yearly additional prevention of 7194 colorectal cancer cases and 2089 related deaths, and a yearly saving of US$290 million.Our findings suggest that implementation of AI detection tools in screening colonoscopy is a cost-saving strategy to further prevent colorectal cancer incidence and mortality.European Commission and Japan Society of Promotion of Science.

Introduction Multiple therapeutic modalities including surgery and rigid and flexible endoscopy have been adopted to manage Zenker's diverticulum (ZD). Minimally invasive flexible endoscopic septotomy (FES) techniques have been increasingly favored over the past 20 years; however, long-term data are still scanty. The aim of this study is to evaluate early and long-term outcomes of FES for naive ZD in a single-center setting. Methods From 2010 to 2017, ZD patients treated with FES were included in a prospectively maintained database (NCT03948438). Those who had already been treated surgically or endoscopically were excluded from the analysis. The Dakkak and Bennett dysphagia scale was used to rate the dysphagia. Persistent complete or near-complete resolution of symptoms (Dakkak and Bennett 0 or 1) was defined as clinical success. Postprocedural adverse events were reported according to ASGE lexicon. Results Overall, 256 consecutive patients were treated. Mean pouch size was 29.8 ± 11.3 mm. The procedure was successfully completed in all scheduled patients, with an early clinical success of 96.1%. Adverse events occurred in 3.5% (9/256) of patients. Eight of them were mild/moderate with no fatal events, whereas one patient required surgery. Recurrences occurred in 31.3% (80/256) of treated patients after a mean time of 9 ± 3 months and 95% of recurrences were treated by a second FES. At an average follow-up of 5.5 years, 95.3% of patients were asymptomatic after a mean number of 1.3 procedures. Discussion FES is a safe and effective treatment modality for patients with ZD. Recurrence rate is significant; however, endoscopic reintervention is associated with long-term relief of dysphagia.

Background and study aims Endoscopic retrograde cholangiopancreatography (ERCP) is a complex procedure with a relatively high rate of adverse events. Data on training of operators and fulfillment of quality indicators in Italy are scarce. The goal of this study was to assess the overall quality of ERCP in Italy compared to international standards. Patients and methods This was a prospective, observational study from different Italian centers performing ERCP. Operators answered a questionnaire, then recorded data on ERCPs over a 1-to 3-month period. Results Nineteen Italian centers participated in the study. The most common concern of operators about training was the lack of structured programs. Seven/19 centers routinely used conscious sedation for ERCP. Forty-one experienced operators and 21 trainees performed 766 ERCPs: a successful deep biliary cannulation in native-papilla patients was achieved in 95.1 % of cases; the post-ERCP pancreatitis (PEP) rate was 5.4 % in native-papilla patients; cholangitis rate was 1.0 %; bleeding and perforation occurred in 2.7 % and 0.4 % of the patients, respectively. Conclusions This study revealed that, overall, ERCP is performed in the participating Italian centers meeting good quality standards, but structured training and sedation practice are still subpar. The bleeding and perforation rate slightly exceeded the American Society of Gastrointestinal Endoscopy indicator targets but they are comparable to the reported rates from other international surveys.

BACKGROUND Barrett's endoscopic therapy (BET) is well established for neoplasia in Barrett's oesophagus using a concept of complete eradication of all Barrett's. However, long-term efficacy is not known. AIMS To perform a systematic review and meta-analysis to examine long-term efficacy of BET for Barrett's neoplasia. METHODS Electronic databases were searched for studies meeting stringent criteria: (a) subjects with high-grade dysplasia and/or superficial adenocarcinoma who underwent BET (ablation ± endoscopic mucosal resection); (b) BET completion by confirmation of complete eradication of neoplasia (CE-N) and intestinal metaplasia (CE-IM) with systematic sampling and (c) clearly defined follow-up (endoscopy and biopsy) protocol of ≥2 years thereafter for detection of recurrence. Pooled estimates of CE-N and CE-IM after BET completion and follow-up were analysed. RESULTS Eight studies met the stringent criteria (n = 794, males 89%, age 64.6 years). Despite high efficacy of BET at therapy completion (CE-N: 95.9 [91.7-98.7]%; CE-IM: 90.9 [83-96.6]%), this declined (CE-N: 89 [73.4-98.2]%; CE-IM: 77.8 [65.6-88]%) over 3.4 years of follow-up. There was considerable heterogeneity. Only two studies reported a post-BET follow-up of >5 years (CE-IM 50 [41.5%-58.5]%). Higher person years of follow-up seem to correlate with decrease in BET efficacy. CONCLUSION Using stringent criteria for appropriate study selection with sufficient follow-up, a lack of high-quality controlled intervention trials becomes evident for assessment of long-term durable remission rates of BET despite initial high success rates. We plea for a uniform documentation of study details which could be used in future trials.

Background and Aims Peroral endoscopic myotomy (POEM) has been recommended for achalasia treatment. To prevent the potential of infective risk, antibiotic prophylaxis is usually administered, whereas the additional need of antibiotic therapy after POEM is uncertain. The primary endpoint was to determine whether prophylaxis versus prophylaxis plus short therapy was needed after POEM. Methods Consecutive patients scheduled for POEM were randomly assigned (1:1) to group A (prophylactic cefazolin 2 g IV) or group B (prophylaxis + cefazolin 2 g IV × 3 followed by oral amoxicillin/clavulanate 3 g/day). Infective risk was assessed by means of host response, namely body temperature and serum levels of white blood cells and C-reactive protein; immune response (the cytokines interleukin [IL]-6, IL-1β, and tumor necrosis factor-α and microbial translocation mediators lipopolysaccharide binding protein and soluble CD14); and blood cultures at time points before (t0) and after (t1, t2) POEM. Results After POEM, none of the 124 enrolled patients (54.6 ± 12.6 years old; 64 men) developed any fever (body temperature: t0, 36.56± .49°C; t1, 36.53± .52°C; t2, 36.48± .41°C), without any differences between groups at any time point. Regarding systemic inflammation, no difference was reported between groups in serum levels of C-reactive protein and white blood cells. Considering microbial translocation mediated response, lipopolysaccharide binding protein (group A: t0, 1539 ± 168.6 pg/mL; t1, 1321 ± 149.1 pg/mL; t2, 2492 ± 283.2 pg/mL; group B: t0, 1318 ± 115.9 pg/mL; t1, 1492 ± 163.8 pg/mL; t2, 2600 ± 328.2 pg/mL) and soluble CD14 (group A: t0, 2.16 ± .15 μg/mL; t1, 1.89 ± .15 μg/mL; t2, 2.2 ± .15 μg/mL; group B: t0, 2.1 ± .13 μg/mL; t1, 2 ± .13 μg/mL; t2, 2.5 ± .2 μg/mL) were similar between the 2 groups; the immune response cytokines IL-6, IL-1β, and tumor necrosis factor-α also were similar in the 2 groups. In relation to blood cultures, at t1 the group B bacteremia rate was 3.2% (2/62) and group A was 1.6% (1/62) with no difference (P = .6). All subsequent blood cultures were negative at t2. Conclusions According to our study, postprophylactic short-term antimicrobial therapy after POEM is not required because of a very low residual infective risk. (Clinical trial registration number: NCT03587337 .)

Background The novel Coronavirus (SARS‐CoV‐2) has caused almost 2 million deaths worldwide. Both Food and Drug Administration and European Medicines Agency have recently approved the first COVID‐19 vaccines, and a few more are going to be approved soon. Methods Several different approaches have been used to stimulate the immune system in mounting a humoral response. As more traditional approaches are under investigation (inactivated virus vaccines, protein subunit vaccines, recombinant virus vaccines), more recent and innovative strategies have been tried (non‐replicating viral vector vaccines, RNA based vaccines, DNA based vaccines). Results Since vaccinations campaigns started in December 2020 in both the US and Europe, gastroenterologists will be one of the main sources of information regarding SARS‐CoV 2 vaccination for patients in their practice, including vulnerable patients such as those with Inflammatory Bowel Disease (IBD), patients with chronic liver disease, and GI cancer patients. Conclusions Thus, we must ourselves be well educated and updated in order to provide unambiguous counseling to these categories of vulnerable patients. In this commentary, we aim to provide a comprehensive review of both approved COVID‐19 vaccines and the ones still under development, and explore potential risks, benefits and prioritization of vaccination.

Background and aimsArtificial intelligence has been shown to increase adenoma detection rate (ADR) as the main surrogate outcome parameter of colonoscopy quality. To which extent this effect may be related to physician experience is not known. We performed a randomised trial with colonoscopists in their qualification period (AID-2) and compared these data with a previously published randomised trial in expert endoscopists (AID-1).MethodsIn this prospective, randomised controlled non-inferiority trial (AID-2), 10 non-expert endoscopists (ResultsIn 660 patients (62.3±10 years; men/women: 330/330) with equal distribution of study parameters, overall ADR was higher in the CADe than in the control group (53.3% vs 44.5%; relative risk (RR): 1.22; 95% CI: 1.04 to 1.40; pConclusionsIn less experienced examiners, CADe assistance during colonoscopy increased ADR and a number of related polyp parameters as compared with the control group. Experience appears to play a minor role as determining factor for ADR.Trial registration numberNCT:04260321.

Background and aims: Adequate bowel cleansing is critical to ensure quality and safety of a colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) regimen was previously validated against low-volume regimens but was never compared with high-volume regimens. Methods: In a phase IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen (4L-PEG) in 5 Italian centers. Preparation was assessed with the Boston Bowel Preparation Scale (BBPS) by local endoscopists and centralized reading, both blinded to the randomization arm. The primary endpoint was noninferiority of 1L-PEG+ASC in colon cleansing. Secondary endpoints were superiority of 1L-PEG+ASC, patient compliance, segmental colon cleansing, adenoma detection rate, tolerability, and safety. Results: Three hundred eighty-eight patients (median age, 59.8 years) were randomized between January 2019 and October 2019: 195 to 1L-PEG+ASC and 193 to 4L-PEG. Noninferiority of 1L-PEG+ASC was demonstrated for cleansing in both the entire colon (BBPS≥ 6: 97.9% vs 93%; relative risk [RR], 1.03; 95% confidence interval [CI], 1.001-1.04; P superiority= .027) and in the right-sided colon segment (98.4% vs 96.0%; RR, 1.02; 95% CI, .99-1.02; P noninferiority= .013). Compliance was higher with 1L-PEG+ASC than with 4L-PEG (178/192 [92.7%] vs 154/190 patients [81.1%]; RR, 1.10; 95% CI, 1.05-1.12), whereas no difference was found regarding safety (moderate/severe side effects: 20.8% vs 25.8%; P= .253). No difference in adenoma detection rate (38.8% vs 43.0%) was found. Conclusions: One-liter PEG+ASC showed noninferiority compared with 4L-PEG in achieving adequate colon cleansing and provided a higher patient compliance. No differences in tolerability and safety were detected. (Clinical trial registration number: NCT03742232.).

Background Thermal damage to the muscle layer during mucosal application of argon plasma coagulation (APC) may be avoided by creating a fluid cushion within the submucosal layer, but the minimum injection volume needed or the ideal injection fluid are yet to be established. We conducted a systematic ex vivo study with this aim. Methods All experiments were performed in an ex vivo porcine gastrointestinal tract model. Five different fluids (saline, Glyceol, Gelafundin, Voluven, and Eleview) of different volumes were injected into the submucosa of different parts of the gastrointestinal tract. APC was applied to the mucosa at different power settings. Immediately after APC treatment, the temperature was measured through a thermocouple placed inside the fluid cushion, just on top of the muscle layer. The minimum volume of fluid needed to protect the muscle layer from thermal damage was determined. Results There was no difference in the temperature measured among the different injection fluids at the surface of the muscle, in all the locations, at equal injection volumes and power settings. The minimum amounts of fluid needed to protect the muscle layer were 2 and 3 mL for power settings of 30-90 W and 90-120 W, respectively. Conclusions Normal saline and 4 commercially available submucosal injection fluids possess similar thermal protective effects. To reduce the likelihood of thermal damage to deeper layers when APC is applied, a minimum injection volume of 3 mL is recommended if less than 90 W power will be utilized over 3 sec.

INTRODUCTION: Delayed bleeding (DB) is the most common major complication of endoscopic mucosal resection (EMR). Two randomized clinical trials recently demonstrated that clip closure after EMR of large nonpedunculated colorectal polyps (LNPCPs) reduces the risk of DB. We analyzed the cost-effectiveness of this prophylactic measure. METHODS: EMRs of LNCPCPs were consecutively registered in the ongoing prospective multicenter database of the Spanish EMR Group from May 2013 until July 2017. Patients were classified according to the Spanish Endoscopy Society EMR group (GSEED-RE2) DB risk score. Cost-effectiveness analysis was performed for both Spanish and US economic contexts. The average incremental cost-effectiveness ratio (ICER) thresholds were set at 54,000 euro or $100,000 per quality-adjusted life year, respectively. RESULTS: We registered 2,263 EMRs in 2,130 patients. Applying their respective DB relative risk reductions after clip closure (51% and 59%), the DB rate decreased from 4.5% to 2.2% in the total cohort and from 13.7% to 5.7% in the high risk of the DB GSEED-RE2 subgroup. The ICERs for the universal clipping strategy in Spain and the United States, 469,706 euro and $1,258,641, respectively, were not cost effective. By contrast, selective clipping in the high-risk of DB GSEED-RE2 subgroup was cost saving, with a negative ICER of -2,194 euro in the Spanish context and cost effective with an ICER of $87,796 in the United States. DISCUSSION: Clip closure after EMR of large colorectal lesions is cost effective in patients with a high risk of bleeding. The GSEED-RE2 DB risk score may be a useful tool to identify that high-risk population.

Colonoscopy remains the standard strategy for screening for colorectal cancer around the world due to its efficacy in both detecting adenomatous or pre-cancerous lesions and the capacity to remove them intra-procedurally. Computer-aided detection and diagnosis (CAD), thanks to the brand new developed innovations of artificial intelligence, and especially deep-learning techniques, leads to a promising solution to human biases in performance by guarantying decision support during colonoscopy. The application of CAD on real-time colonoscopy helps increasing the adenoma detection rate, and therefore contributes to reduce the incidence of interval cancers improving the effectiveness of colonoscopy screening on critical outcome such as colorectal cancer related mortality. Furthermore, a significant reduction in costs is also expected. In addition, the assistance of the machine will lead to a reduction of the examination time and therefore an optimization of the endoscopic schedule. The aim of this opinion review is to analyze the clinical applications of CAD and artificial intelligence in colonoscopy, as it is reported in literature, addressing evidence, limitations, and future prospects.

Background and aims Granular mixed laterally spreading tumors (GM-LSTs) have an intermediate level of risk for submucosal invasive cancer (SMICs) without clear signs of invasion (covert); the optimal resection method is uncertain. We aimed to determine the risk of covert SMIC in GM-LSTs based on clinical and endoscopic factors. Methods We collected data from 693 patients (50.6% male; median age, 69 years) with colorectal GM-LSTs, without signs of invasion, who underwent endoscopic resection (74.2%) or endoscopic submucosal dissection (25.2%) at 7 centers in Italy from 2016 through 2019. We performed multivariate and univariate analyses to identify demographic and endoscopic factors associated with risk of SMIC. We developed a multivariate model to calculate the number needed to treat (NNT) to detect 1 SMIC. Results Based on pathology analysis, 66 patients (9.5%) had covert SMIC. In multivariate analyses, increased risk of covert SMIC were independently associated with increasing lesion size (odds ratio per mm increase, 1.02, 95% CI, 1.01–1.03; P = .003) and rectal location (odds ratio, 3.08; 95% CI, 1.62-5.83; P = .004). A logistic regression model based on lesion size (with a cutoff of 40 mm) and rectal location identified patients with covert SMIC with 47.0% sensitivity, 82.6% specificity, and an area under the curve of 0.69. The NNT to identify 1 patient with a nonrectal SMIC smaller than 4 cm was 20; the NNT to identify 1 patient with a rectal SMIC of 4 cm or more was 5. Conclusions In an analysis of data from 693 patients, we found the risk of covert SMIC in patients with GM-LSTs to be approximately 10%. GM-LSTs of 4 cm or more and a rectal location are high risk and should be treated by en-bloc resection. ClinicalTrials.gov , Number: NCT03836131.

BACKGROUND & AIMS: Efficacy of bowel preparation is an important determinant of outcomes of colonoscopy. It is not clear whether approved low-volume polyethylene glycol (PEG) and non-PEG regimens are as effective as high-volume PEG regimens when taken in a split dose. METHODS: In a systematic review of multiple electronic databases through January 31, 2019 with a registered protocol (PROSPERO: CRD42019128067), we identified randomized controlled trials that compared low- vs high-volume bowel cleansing regimens, administered in a split dose, for colonoscopy. The primary efficacy outcome was rate of adequate bowel cleansing, and the secondary efficacy outcome was adenoma detection rate. Primary tolerability outcomes were compliance, tolerability, and willingness to repeat. We calculated relative risk (RR) and 95% CI values and assessed heterogeneity among studies by using the I2 statistic. The overall quality of evidence was assessed using the GRADE framework. RESULTS: In an analysis of data from 17 randomized controlled trials, comprising 7528 patients, we found no significant differences in adequacy of bowel cleansing between the low- vs high-volume split-dose regimens (86.1% vs 87.4%; RR, 1.00; 95% CI, 0.98-1.02) and there was minimal heterogeneity (I2 = 17%). There was no significant difference in adenoma detection rate (RR, 0.96; 95% CI, 0.87-1.08) among 4 randomized controlled trials. Compared with high-volume, split-dose regimens, low-volume split-dose regimens had higher odds for compliance or completion (RR, 1.06; 95% CI, 1.02-1.10), tolerability (RR, 1.39; 95% CI, 1.12-1.74), and willingness to repeat bowel preparation (RR, 1.41; 95% CI, 1.20-1.66). The overall quality of evidence was moderate. CONCLUSIONS: Based on a systematic review of 17 randomized controlled trials, low-volume, split-dose regimens appear to be as effective as high-volume, split-dose regimens in bowel cleansing and are better tolerated, with superior compliance. ispartof: CLINICAL GASTROENTEROLOGY AND HEPATOLOGY vol:18 issue:7 pages:1454-+ ispartof: location:United States status: published

Background and Aims One-fourth of colorectal neoplasia are missed at screening colonoscopy, representing the main cause of interval colorectal cancer. Deep learning systems with real-time computer-aided polyp detection (CADe) showed high accuracy in artificial settings, and preliminary randomized controlled trials (RCTs) reported favorable outcomes in the clinical setting. The aim of this meta-analysis was to summarize available RCTs on the performance of CADe systems in colorectal neoplasia detection. Methods We searched MEDLINE, EMBASE, and Cochrane Central databases until March 2020 for RCTs reporting diagnostic accuracy of CADe systems in the detection of colorectal neoplasia. The primary outcome was pooled adenoma detection rate (ADR), and secondary outcomes were adenoma per colonoscopy (APC) according to size, morphology, and location; advanced APC; polyp detection rate; polyps per colonoscopy; and sessile serrated lesions per colonoscopy. We calculated risk ratios (RRs), performed subgroup and sensitivity analyses, and assessed heterogeneity and publication bias. Results Overall, 5 randomized controlled trials (4354 patients) were included in the final analysis. Pooled ADR was significantly higher in the CADe group than in the control group (791/2163 [36.6%] vs 558/2191 [25.2%]; RR, 1.44; 95% confidence interval [CI], 1.27-1.62; P Conclusions According to available evidence, the incorporation of artificial intelligence as aid for detection of colorectal neoplasia results in a significant increase in the detection of colorectal neoplasia, and such effect is independent from main adenoma characteristics.

Multiple randomized controlled trials (RCTs) using the second-generation distal attachment cuff device (Endocuff Vision; Olympus America, Center Valley, Pa, USA) have reported conflicting results in improving adenoma detection rate (ADR) compared with standard high-definition colonoscopy without the distal attachment. We conducted a systematic review and meta-analysis of RCTs to compare outcomes between second-generation cuff colonoscopy (CC) versus colonoscopy without the distal attachment (standard colonoscopy [SC]).An electronic literature search was performed using PubMed, Google Scholar, Embase, and Cochrane Library through May 2020. The primary outcome was reporting of ADR, and secondary outcomes were polyp detection rate (PDR), mean withdrawal time, mean adenomas per colonoscopy (APC), sessile serrated lesion detection rate, and adverse events. Pooled rates and risk ratios (RRs) with 95% confidence intervals were reported.Eight RCTs with 5695 patients were included in the final analysis, with 2862 patients (mean age, 62.8 years; 52.9% men) in the CC group and 2833 patients (mean age, 62.6 years; 54.2% men) in the SC group. Compared with SC, use of CC was associated with a significant improvement in ADR (49.8% vs 45.6%, respectively; RR, 1.12; P = .02), PDR (58.1% vs 53%, respectively; RR, 1.12; P = .009), and APC (P .01). Furthermore, use of CC had a .93-minute lower mean withdrawal time (P .01) when compared with SC. The difference in ADR was larger in the screening/surveillance population (6.5%, P = .02) and when used by endoscopists with ADRs 30% (9.4%, P = .03).The results of this meta-analysis of randomized trials show a significant improvement in ADR and APC with shorter withdrawal times using the second-generation cuff device compared with SC.

Importance Treatment options for Severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) are limited with no clarity on the efficacy and safety profiles. Objective To assess if the effect estimate of any intervention improves the outcomes and safety profile. Data sources PubMed, Embase, Cochrane Central were searched from December 1, 2019 to May 11, 2020. Study selection Any prospective/retrospective clinical study on SARS-CoV-2 patients ≥18 years of age with report on therapeutic interventions. Data synthesis and extraction Data was screened and extracted by two independent investigators. Main outcomes and measures The primary outcome was all-cause in-hospital mortality. The secondary outcomes were rates of mechanical ventilation, viral clearance, adverse events, discharge, progression to severe disease, median time for clinical recovery and anti-viral clearance. Pooled rates and odds ratios (OR) were calculated. Results A total of 29 studies with 5207 participants were included in the analysis. The pooled all-cause in-hospital mortality rate was 12.8% (95%CI: 8.1%-17.4%) in intervention arm. There was no significant difference in mortality between both arms overall (OR: 1.36, 95% CI: 0.97-1.89). The mortality was significantly higher in the Hydroxychloroquine (HCQ) group compared to control: (1.86, 95% CI: 1.38 – 2.50). The need for mechanical ventilation in patients with mild-moderate disease was 13.5% vs 9.8% in intervention and control groups, with no significant difference (OR: 1.58, 95% CI: 0.60 – 4.15).The median duration for viral clearance in the intervention arm was 6.1 (IQR: 4.3 – 8.8) days and control arm was 9 (IQR: 4.5 – 14) days, with no significant difference between the groups (p = 0.37). There was no significant difference between pooled adverse event rates in intervention and control groups: 34% vs 29.5% (OR: 1.44, 95% CI: 0.70 – 2.94), respectively. However, incidence of adverse events was significantly higher in HCQ sub-group (OR: 3.88, 95% CI: 1.60 – 9.45, I2 = 0%). There was no significant difference in other secondary outcomes. Conclusion and relevance The use of hydroxychloroquine was associated with increased mortality and adverse event rates. No other therapeutic intervention including Lopinavir/Ritonavir, Remdesivir or Tocilizumab seem to alter the natural course of the disease. There is a further need for well-designed randomized clinical trials. Article summary line The use of hydroxychloroquine was associated with increased mortality and adverse event rates in Severe acute respiratory syndrome-related coronavirus-2 infection and other therapeutic interventions did not show any difference in outcomes

Background & Aims The risk of metachronous colorectal cancer (CRC) among patients with no adenomas, low-risk adenomas (LRAs), or high-risk adenomas (HRAs), detected at index colonoscopy, is unclear. We performed a systematic review and meta-analysis to compare incidence rates of metachronous CRC and CRC-related mortality after a baseline colonoscopy for each group. Methods We searched the PubMed, Embase, Google Scholar, and Cochrane databases for studies that reported the incidence of CRC and adenoma characteristics after colonoscopy. The primary outcome was odds of metachronous CRC and CRC-related mortality per 10,000 person-years of follow-up after baseline colonoscopy for all the groups. Results Our final analysis included 12 studies with 510,019 patients (mean age, 59.2 ± 2.6 years; 55% male; mean duration of follow up, 8.5 ± 3.3 years). The incidence of CRC per 10,000 person-years was marginally higher for patients with LRAs compared to those with no adenomas (4.5 vs 3.4; odds ratio [OR], 1.26; 95% CI, 1.06–1.51; I2=0), but significantly higher for patients with HRAs compared to those with no adenoma ( 13.8 vs 3.4; odds ratio [OR], 2.92; 95% CI, 2.31–3.69; I2=0 ) and patients with HRAs compared to LRAs (13.81 vs 4.5; OR, 2.35; 95% CI, 1.72–3.20; I2=55%). However, the CRC-related mortality per 10,000 person-years did not differ significantly for patients with LRAs compared to no adenomas (OR, 1.15; 95% CI, 0.76–1.74; I2=0) but was significantly higher in persons with HRAs compared with LRAs (OR, 2.48; 95% CI, 1.30–4.75; I2=38%) and no adenomas (OR, 2.69; 95% CI, 1.87–3.87; I2=0). Conclusions The results of this systematic review and meta-analysis demonstrate that the risk of metachronous CRC and mortality is significantly higher for patients with HRAs, but this risk is very low in patients with LRAs, comparable to patients with no adenomas. Follow-up of patients with LRAs detected at index colonoscopy should be the same as for persons with no adenomas.