Computer-aided diagnosis for the resect-and-discard strategy for colorectal polyps: a systematic review and meta-analysis.

BACKGROUND: The resect-and-discard strategy allows endoscopists to replace post-polypectomy pathology with real-time prediction of polyp histology during colonoscopy (optical diagnosis). We aimed to investigate the benefits and harms of implementing computer-aided diagnosis (CADx) for polyp pathology into the resect-and-discard strategy. METHODS: In this systematic review and meta-analysis, we searched MEDLINE, Embase, and Scopus from database inception to June 5, 2024, without language restrictions, for diagnostic accuracy studies that assessed the performance of real-time CADx systems, compared with histology, for the optical diagnosis of diminutive polyps (≤5 mm) in the entire colon. We synthesised data for three strategies: CADx-alone, CADx-unassisted, and CADx-assisted; when the endoscopist was involved in the optical diagnosis, we synthesised data exclusively from diagnoses for which confidence in the prediction was reported as high. The primary outcomes were the proportion of polyps that would have avoided pathological assessment (ie, the proportion optically diagnosed with high confidence; main benefit) and the proportion of polyps incorrectly predicted due to false positives and false negatives (main harm), directly compared between CADx-assisted and CADx-unassisted strategies. We used DerSimonian and Laird's random-effects model to calculate all outcomes. We used Higgins I2 to assess heterogeneity, the Grading of Recommendations, Assessment, Development, and Evaluation approach to rate certainty, and funnel plots and Egger's test to examine publication bias. This study is registered with PROSPERO, CRD42024508440. FINDINGS: We found 1019 studies, of which 11 (7400 diminutive polyps, 3769 patients, and 185 endoscopists) were included in the final meta-analysis. Three studies (1817 patients and 4086 polyps [2148 neoplastic and 1938 non-neoplastic]) provided data to directly compare the primary outcome measures between the CADx-unassisted and CADx-assisted strategies. We found no significant difference between the CADx-assisted and CADx-unassisted strategies for the proportion of polyps that would have avoided pathological assessment (90% [88-93], 3653 [89·4%] of 4086 polyps diagnosed with high confidence vs 90% [95% CI 85-94], 3588 [87·8%] of 4086 polyps diagnosed with high confidence; risk ratio 1·01 [95% CI 0·99-1·04; I2=53·49%; low-certainty evidence; Egger's test p=0·18). The proportion of incorrectly predicted polyps was lower with the CADx-assisted strategy than with the CADx-unassisted strategy (12% [95% CI 7-17], 523 [14·3%] of 3653 polyps incorrectly predicted with a CADx-assisted strategy vs 13% [6-20], 582 [16·2%] of 3588 polyps incorrectly diagnosed with a CADx-unassisted strategy; risk ratio 0·88 [95% CI 0·79-0·98]; I2=0·00%; low-certainty evidence; Egger's test p=0·18). INTERPRETATION: CADx did not produce benefit nor harm for the resect-and-discard strategy, questioning its value in clinical practice. Improving the accuracy and explainability of CADx is desired. FUNDING: European Commission (Horizon Europe), the Japan Society of Promotion of Science, and Associazione Italiana per la Ricerca sul Cancro.

The Derivation and External Validation of a Fibrosis Risk Model for Colorectal Tumours Undergoing Endoscopic Submucosal Dissection.

Background: Endoscopic submucosal dissection (ESD) is an advanced technique that can become more challenging in the presence of submucosal fibrosis. Predicting the grade of fibrosis is important in order to identify technically difficult ESD. Aims and Methods: Our study aimed to derive and validate a prediction model to determine the preoperative degree of submucosal fibrosis in colorectal tumours undergoing ESD. A predictive model was developed to derive the probability of an increasing submucosal fibrosis in the derivation cohort and then externally validated. Results: 309 patients (age: 68 ± 10.9 years) underwent colorectal ESD between January 2016 and June 2020. F0, F1, and F2 fibroses were reported in 196 (63.4%), 70 (22.6%), and 43 (13.9%) cases, respectively. R0 resection was found in 266 (87%) lesions. At multivariable analysis in the derivation cohort, lesion morphology (OR = 0.37 and CI = 0.14-0.97 for LST-NG vs. 0-Is; OR = 0.29 and CI = 0.1-0.87 for the LST mixed type vs. 0-Is; and OR = 0.32 and CI = 0.1-1.03 for LST-G vs. 0-Is) and increasing size (OR = 1.02 and CI = 1.01-1.04 for a 1 mm increase) were significantly associated with an increasing degree of fibrosis. The model had fair discriminating ability in the derivation group (AUROC = 0.61 and CI = 0.52-0.69 for F1-F2 vs. F0 fibroses; AUROC = 0.61 and CI = 0.45-0.77 for F2 vs. F0-F1 fibroses) and in the validation group (AUROC = 0.71 and CI = 0.59-0.83 for F1-F2 vs. F0 fibroses; AUROC = 0.65 and CI = 0.52-0.77 for F2 vs. F0-F1 fibroses). Conclusions: Our findings introduce a new tool for the stratification of ESD technical difficulty based on lesion size and morphological characteristics which could become crucial during the procedure's planning process.

Accuracy of Computer-aided Diagnosis in Colonoscopy Varies according to Polyp Location. A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Computer-Aided Diagnosis (CADx) assists endoscopists in differentiating between neoplastic and non-neoplastic polyps during colonoscopy. This study aimed to evaluate the impact of polyp location (proximal vs. distal colon) on the diagnostic performance of CADx for ≤5mm polyps. METHODS: We searched for studies evaluating the performance of real-time CADx alone (i.e., independently of endoscopist judgement) for predicting the histology of colorectal polyps ≤5mm. The primary endpoints were CADx sensitivity and specificity in the proximal and distal colon. Secondary outcomes were the negative predictive value (NPV), positive predictive value (PPV), and the accuracy of the CADx alone. Distal colon was limited to the rectum and sigmoid. RESULTS: We included 11 studies for analysis with a total of 7,782 <5mm polyps. CADx specificity was significantly lower in the proximal colon compared to the distal colon (62% versus 85%; Risk ratio (RR): 0.74 [95% CI: 0.72-0.84]). Conversely, sensitivity was similar (89% vs 87% (EC-1); RR: 1.00 [95% CI: 0.97-1.03]. The NPV (64% versus 93%; RR: 0.71 [95% CI: 0.64-0.79]) and accuracy (81% vs 86%; RR: 0.95 [95% CI: 0.91-0.99]) were significantly lower in the proximal than distal colon, while PPV was higher in the proximal colon (87% vs 76%; RR: 1.11 [95% CI: 1.06-1.17]). CONCLUSION: The diagnostic performance of CADx for polyps in the proximal colon is inadequate, exhibiting significantly lower specificity compared to its performance for distal polyps. While current CADx systems are suitable for use in the distal colon, they should not be employed for proximal polyps until more performant systems are developed specifically for these lesions.

Per oral endoscopic myotomy for achalasia.

Achalasia, characterized by impaired lower esophageal sphincter (LES) relaxation and failed peristalsis, stands out as the most widely recognized primary esophageal motility disorder. It manifests with dysphagia to solid and liquid foods, chest pain, regurgitation, and weight loss, leading to significant morbidity and healthcare burden. Traditionally, surgical Heller myotomy and pneumatic dilation were the primary therapeutic approaches for achalasia. However, in 2009, Inoue and colleagues introduced a groundbreaking endoscopic technique called peroral endoscopic myotomy (POEM), revolutionizing the management of this condition. This review aims to comprehensively examine the recent advancements in the POEM technique for patients diagnosed with achalasia, delving into critical aspects, such as the tailoring of the myotomy, the prevention of intraprocedural adverse events (AEs), the evaluation of long-term outcomes, and the feasibility of retreatment in cases of therapeutic failure.

Effectiveness and safety of newly introduced endoscopic submucosal dissection in a Western center: a real-life study.

OBJECTIVES: Endoscopic submucosal dissection (ESD) is a minimally invasive technique for the resection of superficial gastrointestinal lesions, providing high rates of 'en bloc' and R0 resection. East-West differences in ESD quality indicators have been reported. This study aims to assess feasibility, effectiveness, and safety of ESD for the treatment of superficial gastrointestinal (GI) lesions in a Western cohort. METHODS: Consecutive patients undergoing ESD at one Italian endoscopic referral center from September 2018 to March 2020 were included in this prospective study. Primary outcomes were technical success, R0 resection rate, curative resection rate, and adverse events (AEs). RESULTS: In total 111 patients (111 lesions) undergoing ESD were included. Anatomic site of the lesions was rectum in 56.8%, colon in 13.5%, stomach in 24.3%, and esophagus in 5.4% of cases, respectively. For upper GI procedures, technical success was 100%, and R0 and curative resection rates were 84.8% and 78.8%, respectively. For colorectal procedures, technical success was 98.7%, R0 and curative resection rates were 88.5% and 84.6%, respectively. Major AEs were reported in 12 cases (10.8%). CONCLUSION: The introduction of ESD in a Tertiary Center is feasible, effective, and safe, and should be taken into consideration for the treatment of superficial GI lesions requiring 'en bloc' resection.

Outcome of Endoscopic Resection of Rectal Neuroendocrine Tumors ≤ 10 mm.

BACKGROUND AND AIM: Guidelines suggest endoscopic resection for rectal neuroendocrine tumors (rNETs) < 10 mm, but the most appropriate resection technique is unclear. In real-life clinical practice, the endoscopic removal of unrecognized rNETs can take place with "simple" techniques and without preliminary staging. The aim of the current study is to report our own experience at a referral center for both neuroendocrine neoplasms and endoscopy. METHODS: Retrospective analyses of polypectomies were performed at the Humanitas Research Hospital for rNETs (already diagnosed or previously unrecognized). RESULTS: A total of 19 patients were included, with a median lesion size of 5 mm (range 3-10 mm). Only five lesions were suspected as NETs before removal and underwent endoscopic ultrasound (EUS) before resection, being removed with advanced endoscopic techniques. Unsuspected rNETs were removed by cold polypectomy in eleven cases, EMR in two, and biopsy forceps in one. When described, the margins were negative in four cases, positive in four (R1), and indeterminate in one. The median follow-up was 40 months. A 10 mm polypoid lesion removed with cold snare polypectomy (G2 R1) needed subsequent surgery. Eighteen patients underwent EUS after a median time of 6.5 months from resection. The EUS identified local recurrence after 14 months in a 7 mm polypoid lesion removed with cold snare polypectomy (G1 R1); the lesion was treated with cap-assisted EMR. For all the other lesions, the follow-up was negative. CONCLUSIONS: When rNETs are improperly removed without prior staging, caution must be exercised. The data from our cohort suggest that even if inappropriate resection had happened, patients may be safely managed with early EUS evaluation.

Artificial Intelligence to Predict the Risk of Lymph Node Metastasis in T2 Colorectal Cancer.

OBJECTIVE: To develop and externally validate an updated artificial intelligence (AI) prediction system for stratifying the risk of lymph node metastasis (LNM) in T2 colorectal cancer (CRC). SUMMARY BACKGROUND DATA: Recent technical advances allow complete local excision of T2 CRC, traditionally treated with surgical resection. Yet, the widespread adoption of this approach is hampered by the inability to stratify the risk of LNM. METHODS: Data from pT2 CRC patients undergoing surgical resection between April 2000 and May 2022 at one Japanese and one Italian center were analyzed. Primary goal was AI system development for accurate LNM prediction. Predictors encompassed seven variables: age, sex, tumor size and location, lympho-vascular invasion, histological differentiation, and carcinoembryonic antigen level. The tool's discriminating power was assessed via Area Under the Curve (AUC), sensitivity, and specificity. RESULTS: Out of 735 initial patients, 692 were eligible. Training and validation cohorts comprised of 492 and 200 patients, respectively. The AI model displayed an AUC of 0.75 in the combined validation dataset. Sensitivity for LNM prediction was 97.8% and specificity was 15.6%. The Positive and the Negative Predictive Value were 25.7% and 96% respectively. The False Negative (FN) rate was 2.2%, the False Positive was 84.4%. CONCLUSIONS: Our AI model, based on easily accessible clinical and pathological variables, moderately predicts LNM in T2 CRC. However, the risk of FN needs to be considered. The training of the model including more patients across Western and Eastern centers -differentiating between colon and rectal cancers- may improve its performance and accuracy.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study.

OBJECTIVES: There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices. METHODS: Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale. RESULTS: Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care. CONCLUSIONS: An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

Is there a best choice of equipment for colorectal endoscopic submucosal dissection?

INTRODUCTION: Endoscopic submucosal dissection (ESD) is a widely used technique to remove early neoplastic lesions. It was primarily used in the initial days to treat gastric lesions, but recently, the horizon of this endoscopic procedure has expanded, which has allowed us to manage other technically more complex locations, such as the colorectum. AREAS COVERED: There has been an exponential growth regarding the wide range of devices available in the market for performing colorectal ESD. As a result, the aim of this review is to highlight the indication of this endoscopic technique, which device is best suited for which indication, as well as future trajectories in this field. EXPERT OPINION: Although some devices have proven to be more advantageous than others in this area, very often the choice is still subjective, which is commonly attributed to individual preferences and experience. However, an accurate knowledge of the available tools and their functioning, with their pros and cons, is fundamental for any endoscopist venturing into the field of third space endoscopy. In this way, one can choose which device best suits a particular situation, along with simultaneously having the wealth of knowledge related to therapeutic armamentarium at our disposal in the endoscopy suite.

Management of perforations during endoscopic resection.

Despite the evolution in tools and techniques, perforation is still one of the most pernicious adverse events of therapeutic endoscopy with potentially huge consequences. As advanced endoscopic resection techniques are worldwide spreading, endoscopists must be ready to manage intraprocedural perforations. In fact, immediate endoscopic closure through a prompt diagnosis represents the first-line option, saving patients from surgery, long hospitalizations and worse outcomes. Traditional and novel endoscopic closure modalities, including clips, suturing devices, stents and vacuum therapy, are increasingly expanding the therapeutic armamentarium for closing these defects. Nevertheless, available literature on this topic is currently limited. In this review our goal is to give an overview on the management of perforations occurring during endoscopic resections, with particular attention to characteristics, advantages, disadvantages and new horizons of endoscopic closure tools.

Endoscopic Resection for Duodenal Neuroendocrine Neoplasms between 10 and 20 mm-A Systematic Review and Meta-Analysis.

Background. The optimal management of duodenal neuroendocrine neoplasms (dNENs) sized 10-20 mm remains controversial and although endoscopic resection is increasingly performed instead of surgery, the therapeutic approach in this setting is not fully standardized. We performed a systematic review of the literature and a meta-analysis to clarify the outcomes of endoscopic resection for 10-20 mm dNENs in terms of efficacy (i.e., recurrence rate) and safety. Methods. A computerized literature search was performed using relevant keywords to identify pertinent articles published until January 2023. Results. Seven retrospective studies were included in this systematic review. The overall recurrence rate was 14.6% (95%CI 5.4-27.4) in 65 patients analyzed, without significant heterogeneity. When considering studies specifically focused on endoscopic mucosal resection, the recurrence rate was 20.5% (95%CI 10.7-32.4), without significant heterogeneity. The ability to obtain the free margin after endoscopic resection ranged between 36% and 100%. No complications were observed in the four studies reporting this information. Conclusions. Endoscopic resection could be the first treatment option in patients with dNENs sized 10-20 mm and without evidence of metastatic disease. Further studies are needed to draw more solid conclusions, particularly in terms of superiority among the available endoscopic techniques.

American Society for Gastrointestinal Endoscopy-European Society of Gastrointestinal Endoscopy guideline on primary endoscopic bariatric and metabolic therapies for adults with obesity.

This joint ASGE-ESGE guideline provides an evidence-based summary and recommendations regarding the role of endoscopic bariatric and metabolic therapies (EBMTs) in the management of obesity. The document was developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. It evaluates the efficacy and safety of EBMT devices and procedures that currently have CE mark or FDA-clearance/approval, or that had been approved within five years of document development. The guideline suggests the use of EBMTs plus lifestyle modification in patients with a BMI of ≥ 30 kg/m2, or with a BMI of 27.0-29.9 kg/m2 with at least 1 obesity-related comorbidity. Furthermore, it suggests the utilization of intragastric balloons and devices for endoscopic gastric remodeling (EGR) in conjunction with lifestyle modification for this patient population.

American Society for Gastrointestinal Endoscopy-European Society of Gastrointestinal Endoscopy guideline on primary endoscopic bariatric and metabolic therapies for adults with obesity.

This joint ASGE-ESGE guideline provides an evidence-based summary and recommendations regarding the role of endoscopic bariatric and metabolic therapies (EBMTs) in the management of obesity. The document was developed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework. It evaluates the efficacy and safety of EBMT devices and procedures that currently have CE mark or FDA-clearance/approval, or that had been approved within five years of document development. The guideline suggests the use of EBMTs plus lifestyle modification in patients with a BMI of ≥30 kg/m2, or with a BMI of 27.0-29.9 kg/m2 with at least 1 obesity-related comorbidity. Furthermore, it suggests the utilization of intragastric balloons and devices for endoscopic gastric remodeling (EGR) in conjunction with lifestyle modification for this patient population.

Women in Gastroenterology: What Is the Current Situation? Results of an Italian National Survey.

BACKGROUND: Many women grow up dreaming of becoming doctors, preferring specialties that allow more focus on time outside the hospital and on family life. Nowadays, specialties, like gastroenterology, have still a significant gender gap. METHODS: Based on this known discrepancy, a web-based questionnaire was designed by the Young Component of the Scientific Committee of the Federation of Italian Scientific Societies of Digestive Diseases 2023 (FISMAD) to examine the current situation of female gastroenterologists in Italy. The survey, designed specifically for this study, was sent by email to all female gastroenterologists and residents gastroenterologists, members of the three major Italian societies of Gastroenterology. RESULTS: A total of 423 female physicians responded to the survey: 325 (76.8%) had full-time employment, and only a few had an academic career (7.2%). The main occupations were outpatient clinics (n = 288, 68%) and diagnostic endoscopy (n = 289, 68.3%); only 175 (41.3%) performed interventional endoscopy. One hundred and forty-seven (34.7%) had the chance to attend a master in advanced or interventional endoscopy, while 133 (31.4%) faced disadvantages that enabled them to attend. Of the 244 (58%) who reported feeling underappreciated, 194 (79.5%) said it was due to gender bias. We found that women doctors considered themselves disadvantaged compared with men doctors due to career opportunities (n = 338), salary negotiations (n = 64), and training opportunities (n = 144). CONCLUSIONS: In conclusion, gastroenterology still has a long way to go before approaching greater gender parity.

Artificial Intelligence-assisted colonoscopy and colorectal cancer screening: Where are we going?

Colorectal cancer is a significant global health concern, necessitating effective screening strategies to reduce its incidence and mortality rates. Colonoscopy plays a crucial role in the detection and removal of colorectal neoplastic precursors. However, there are limitations and variations in the performance of endoscopists, leading to missed lesions and suboptimal outcomes. The emergence of artificial intelligence (AI) in endoscopy offers promising opportunities to improve the quality and efficacy of screening colonoscopies. In particular, AI applications, including computer-aided detection (CADe) and computer-aided characterization (CADx), have demonstrated the potential to enhance adenoma detection and optical diagnosis accuracy. Additionally, AI-assisted quality control systems aim to standardize the endoscopic examination process. This narrative review provides an overview of AI principles and discusses the current knowledge on AI-assisted endoscopy in the context of screening colonoscopies. It highlights the significant role of AI in improving lesion detection, characterization, and quality assurance during colonoscopy. However, further well-designed studies are needed to validate the clinical impact and cost-effectiveness of AI-assisted colonoscopy before its widespread implementation.

Saline-immersion peroral endoscopic septotomy: a case report.

Video 1Saline-immersion peroral endoscopic septotomy.