INTRODUCTION:The learning process for probe-based confocal laser endomicroscopy (pCLE) is challenging, and standardized training protocols are currently lacking. The main purpose of this study was to establish and evaluate a preliminary pCLE training system. METHODS:This prospective diagnostic trial was performed based on the nationwide training program. The training system included online theoretical courses and a 2-day offline training. All patients underwent pCLE and magnifying endoscopy (ME). The diagnostic performances of baseline levels, pCLE trainees, pCLE experts, and ME experts were evaluated and compared. The primary outcomes were the diagnostic accuracy, sensitivity, and specificity of gastric cancerous lesions. Linear regression analysis was adopted to explore the influence factors on the accuracy of trainees. RESULTS:A total of 150 lesions and 127 endoscopists were enrolled. All diagnostic indicators for pCLE trainees exhibited significant improvement versus baseline levels (all P < 0.001). pCLE trainees exhibited significantly lower accuracy than pCLE experts ( P = 0.036). There were no significant differences in accuracy, sensitivity, and specificity between pCLE trainees and ME experts. pCLE experts showed significantly higher accuracy ( P = 0.039) and specificity ( P = 0.022) than ME experts. Professional title, hospital level, gastroscopy experience, ME experience, and educational degree exerted no significant influence on the accuracy of pCLE trainees. DISCUSSION:Short-term systematic pCLE training demonstrated significant efficacy, and the diagnostic performance of pCLE trainees was comparable with that of mature ME technology. pCLE can serve as an effective method to promptly enhance the diagnostic proficiency of endoscopists, especially novices, for gastric cancerous lesions.

INTRODUCTION:Several studies have investigated the role of linaclotide in bowel preparation; however, dosage and timing still warrant further exploration. METHODS:This noninferiority randomized controlled study was performed in 16 medical centers. The eligible subjects were randomly assigned to 3 groups: the Lct + 3 L polyethylene glycol (PEG) group (group A), the 3 L PEG group (group B), or the Lct + 2 L PEG group (group C). The primary outcome was the adequate bowel preparation rate based on the Boston Bowel Preparation Scale. Safety was assessed based on the incidence of adverse reactions. RESULTS:A total of 1,607 eligible subjects were enrolled, and 1,545 colonoscopy videos were uploaded. In the intention-to-treat analysis, the results of the noninferiority test indicated that the adequate bowel preparation rate in group C (87.58%, 95% confidence interval [CI] 85.08%-90.62%) was neither inferior to that of group A (88.79%, 95% CI 86.11%-91.46%) nor group B (83.99%, 95% CI 80.88%-87.09%). The overall incidence of adverse reactions in group A was higher than that in group C (13.64% vs 8.19%, P = 0.012). There were no significant differences in polyp detection rate ( P = 0.089), adenoma detection rate ( P = 0.776), and bowel preparation completion rate ( P = 0.052). DISCUSSION:The adequate bowel preparation rate of the combination of 3-day linaclotide and 2 L PEG was neither inferior to the combination of 3-day linaclotide and 3 L PEG nor 3 L PEG alone in the average-risk population.

Introduction:Stool DNA testing based on methylated syndecan-2 (mSDC2) is a potential novel non-invasive screening test for colorectal cancer (CRC). This study aimed to assess its positive predictive value (PPV) in real-world practice. Methods:This study retrospectively recruited consecutive patients with positive stool DNA-based SDC2 methylation tests from 18 hospitals between November 2016 and July 2021. Included patients were classified into the average-risk equivalent or increased-risk population and the previous-negative-colonoscopy or no-previous-colonoscopy groups. Multivariate logistic regression was conducted to investigate the risk factors that affect the detection of advanced colorectal neoplasia (ACN) in patients with a positive mSDC2 test. The primary outcome was the PPV for ACN. Results:The overall PPVs for ACN, CRC, and colorectal neoplasia were 28.5%, 12.8%, and 44.6%, respectively. The PPV for ACN was higher in the no-previous-colonoscopy group than in the previous-negative-colonoscopy group (30.1% vs 18.5%, P = 0.008) and higher in the increased-risk population than in the average-risk equivalent population (41.1% vs 21.6%, P < 0.001). However, the PPV (18.5%) was still high for patients with a previous negative colonoscopy. For ACN detection in patients with a positive mSDC2 test, old age, increased risk, and smoking history were identified as independent risk factors; previous negative colonoscopy was identified as a protective factor. Conclusions:The mSDC2 test, which has a high PPV for both ACN and CRC, is expected to be an alternative CRC screening strategy. Patients with a positive mSDC2 test might require a colonoscopy as soon as possible, even if the previous colonoscopy was negative.

INTRODUCTION:Colonoscopy effectively reduces the morbidity and mortality of patients with colorectal cancer. However, incomplete resection can result in postcolonoscopy colorectal cancer. Data on the incomplete resection rate (IRR) and associated risk factors are limited; therefore, we aimed to evaluate the IRR by using data from the National Colorectal Polyp Care study. METHODS:We included patients with at least 1 polyp (1-20 mm) removed during colonoscopy. After polyp removal was completed, biopsies were obtained from the resection margins to assess the completeness of the polypectomy. The main outcome was the IRR of neoplastic polyps. Risk factors of incomplete resection were assessed by multivariate logistic regression. RESULTS:A total of 2,041 individuals (62% men) with a mean age of 55 years were included. A total of 2,453 polyps were included in the analysis, of which an IRR of 4.4% was observed for 1,944 neoplastic polyps. The overall IRR was 4.1% for endoscopists with at least 10 resections, but it broadly ranged from 0% to 36.4%, especially among endoscopists with a high level of narrow-band imaging (NBI) experience (>3,000 procedures). Multivariate logistic regression demonstrated that sessile serrated adenomas/polyps (SSA/Ps, absolute risk [AR] SSA/Ps = 0.09, AR adenomas = 0.04, difference in AR [RD] = 0.05), polyps located in the proximal colon (AR proximal colon = 0.06, AR distal colon = 0.04, RD = 0.02), and low level of NBI experience (1,000-3,000 procedures, AR low NBI experience = 0.05, AR high NBI experience = 0.03, RD = 0.02) were independent risk factors of a high IRR. DISCUSSION:The IRR of polyps varies greatly in clinical practice, even among experienced endoscopists. SSA/Ps and polyps located in the proximal colon tend to be incompletely resected, and a high level of NBI experience might help reduce the IRR.

Background and Aim: Although studies have shown that the quality of bowel preparation with low-residue diet (LRD) is as effective as that of clear fluid diet (CLD), there is currently no consensus on how long an LRD should last. The aim of this study was to compare a 1-day versus 3-day LRD on bowel preparation before colonoscopy.Methods: A systematic review search was conducted in MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane database from inception to April 2023. We identified randomized controlled trials (RCTs) that compared 1-day with 3-day LRD bowel cleansing regiments for patients undergoing colonoscopy. The rate of adequate bowel preparation, polyp detection rate, adenoma detection rate, tolerability, willingness to repeat preparation, and adverse events were estimated using odds ratios (OR) and 95% confidence interval (CI). We also performed meta-analysis to identify risk factors and predictors of inadequate preparation. Results: Four studies published between 2019 and 2023 with 1927 participants were included. The present meta-analysis suggested that 1-day LRD was comparable with 3-day LRD for adequate bowel preparation (OR 0.89; 95% CI, 0.65-1.21; P = 0.45; I-2 = 0%; P = 0.52). The polyp detection rate (OR 0.94; 95% CI, 0.77-1.14; P = 0.52; I-2 = 23%; P = 0.27) and adenoma detection rate (OR 0.87; 95% CI, 0.71-1.08; P = 0.21; I-2 = 0%; P = 0.52) were similar between the groups. There were significantly higher odds of tolerability in patients consuming 1-day LRD compared with 3-day LRD (OR 1.64; 95% CI, 1.13-2.39; P < 0.01; I-2 = 47%; P = 0.15). In addition, constipation was identified as the independent predictor of inadequate preparation (OR 1.98; 95% CI, 1.27-3.11; P < 0.01; I-2 = 0%; P = 0.46).Conclusion: The present study demonstrated that a 1-day LRD was as effective as a 3-day CLD in the quality of bowel preparation before colonoscopy and significantly improved tolerability of patients. In addition, constipation is an independent risk factor of poor bowel preparation, and the duration of LRD in patients with constipation still needs further clinical trials.

结直肠癌是全球较常见的恶性肿瘤之一，是现阶段我国消化系统发病率排名第一的恶性肿瘤，也是影响国民健康的重要公共卫生问题。早筛、早诊和早治能够有效改善结直肠肿瘤的预后。结肠镜是结直肠疾病最为准确的诊断、筛查和随访手段，但结肠镜检查的效果取决于其质控。本文主要从结直肠癌发病率、癌变途径、危险因素、诊断筛查方式和结肠镜检查质控标准等方面对该领域相关成果进行综述。

Background and aimsCompared with self-prepared LRD, a prepackaged low-residue diet (LRD) can improve patient compliance, but whether it can further improve the quality of bowel preparation is uncertain. The study aimed to compare the application of the prepackaged formula LRD with self-prepared LRD in bowel preparation for colonoscopy.MethodsA multicenter randomized controlled trial was conducted in 15 centers. The eligible subjects were randomly assigned to one of two groups: the formula LRD group and the self-prepared LRD group. On the day before the colonoscopy, subjects in the self-prepared LRD group were instructed to consume a restricted LRD prepared by themselves, while subjects in the formula LRD group were given six bags of prepackaged formula LRD and instructed to consume them according to their individual need. The primary outcome was an adequate bowel preparation rate. Secondary outcomes mainly included Boston Bowel Preparation Scale (BBPS) scores, dietary restriction compliance rate, tolerance, satisfaction, adenoma detection rate (ADR), and adverse reactions. The trial was registered at ClinicalTrials.gov under the identifier NCT03943758.ResultsA total of 550 subjects were recruited. Compared with the self-prepared LRD group, the formula LRD group showed a higher adequate bowel preparation rate (94.5 vs. 80.4%; P < 0.01), BBPS scores (7.87 ± 1.13 vs. 6.75 ± 1.47; P < 0.01), dietary compliance rate (92.4 vs. 78.9%; P < 0.01), tolerance (P < 0.01 in degree of hunger, intensity of physical strength, and negative influence on daily activities), satisfaction (8.56 ± 1.61 vs. 7.20 ± 2.02; P < 0.01), and ADR (25.6 vs. 16.0%; P < 0.01). There was no significant difference in adverse reactions.ConclusionCompared with self-prepared LRD, the formula LRD showed similar safety and higher bowel preparation quality, compliance, and tolerance in bowel preparation. More formula LRDs could be designed according to different dietary habits and ethnic populations, and further researches are warranted to confirm their effect.Clinical trial registrationhttps://register.clinicaltrials.gov, identifier: NCT03943758.

Background and Aims: Adequate bowel preparation is crucial for clear mucosal visualization during colonoscopy. We aimed to comprehensively compare oral sulfate solution (OSS) and 3-L split-dose polyethylene glycol (PEG) for bowel preparation before colonoscopy. Methods: This randomized, active-controlled, noninferiority study was performed in 10 medical centers. Eligible subjects were enrolled to receive OSS or 3-L PEG in a split-dose regimen. The quality of bowel preparation, adverse reactions, and acceptability were evaluated. The quality of bowel preparation was evaluated using the Boston Bowel Preparation Scale. Safety was evaluated by adverse reactions. The study population was divided into the full analysis set (FAS), the safety set, the modified FAS (mFAS), and the per-protocol set (PPS). Results: Three hundred forty-eight potentially eligible subjects were enrolled. Three hundred forty-four subjects were included in the FAS and safety set, 340 subjects were included in the mFAS, and 328 subjects were included in the PPS. Adequate bowel preparation of the OSS was not inferior to 3-L PEG in the mFAS (98.22% vs 97.66%) and the PPS (98.17% vs 98.78%). There was no significant difference in acceptability between the 2 groups (94.74% vs 94.80%, P = .9798). Overall adverse reactions were similar (50.88% vs 44.51%, P = .2370) between the 2 groups. Conclusions: The split-dose OSS regimen was not inferior to the split-dose 3-L PEG regimen for the quality of bowel preparation in a Chinese adult population. The safety and acceptability of the 2 groups were similar.

Conventional EUS plays an important role in identifying pancreatic cancer. However, the accuracy of EUS is strongly influenced by the operator's experience in performing EUS. Artificial intelligence (AI) is increasingly being used in various clinical diagnoses, especially in terms of image classification. This study aimed to evaluate the diagnostic test accuracy of AI for the prediction of pancreatic cancer using EUS images. We searched the Embase, PubMed, and Cochrane Library databases to identify studies that used endoscopic ultrasound images of pancreatic cancer and AI to predict the diagnostic accuracy of pancreatic cancer. Two reviewers extracted the data independently. The risk of bias of eligible studies was assessed using a Deek funnel plot. The quality of the included studies was measured by the QUDAS-2 tool. Seven studies involving 1110 participants were included: 634 participants with pancreatic cancer and 476 participants with nonpancreatic cancer. The accuracy of the AI for the prediction of pancreatic cancer (area under the curve) was 0.95 (95% confidence interval [CI], 0.93-0.97), with a corresponding pooled sensitivity of 93% (95% CI, 0.90-0.95), specificity of 90% (95% CI, 0.8-0.95), positive likelihood ratio 9.1 (95% CI 4.4-18.6), negative likelihood ratio 0.08 (95% CI 0.06-0.11), and diagnostic odds ratio 114 (95% CI 56-236). The methodological quality in each study was found to be the source of heterogeneity in the meta-regression combined model, which was statistically significant (P = 0.01). There was no evidence of publication bias. The accuracy of AI in diagnosing pancreatic cancer appears to be reliable. Further research and investment in AI could lead to substantial improvements in screening and early diagnosis.

Introduction:Colorectal adenoma can develop into colorectal cancer. Determining the risk of tumorigenesis in colorectal adenoma would be critical for avoiding the development of colorectal cancer; however, genomic features that could help predict the risk of tumorigenesis remain uncertain.Methods:In this work, DNA and RNA parallel capture sequencing data covering 519 genes from colorectal adenoma and colorectal cancer samples were collected. The somatic mutation profiles were obtained from DNA sequencing data, and the expression profiles were obtained from RNA sequencing data.Results:Despite some similarities between the adenoma samples and the cancer samples, different mutation frequencies, co-occurrences, and mutually exclusive patterns were detected in the mutation profiles of patients with colorectal adenoma and colorectal cancer. Differentially expressed genes were also detected between the two patient groups using RNA sequencing. Finally, two random forest classification models were built, one based on mutation profiles and one based on expression profiles. The models distinguished adenoma and cancer samples with accuracy levels of 81.48% and 100.00%, respectively, showing the potential of the 519-gene panel for monitoring adenoma patients in clinical practice.Conclusion:This study revealed molecular characteristics and correlations between colorectal adenoma and colorectal cancer, and it demonstrated that the 519-gene panel may be used for early monitoring of the progression of colorectal adenoma to cancer.

No fully validated risk-stratification strategies have been established in China where colonoscopies resources are limited. We aimed to develop and validate a fecal immunochemical test (FIT)-based risk-stratification model for colorectal neoplasia (CN); 10,164 individuals were recruited from 175 centers nationwide and were randomly allocated to the derivation (n = 6776) or validation cohort (n = 3388). Multivariate logistic analyses were performed to develop the National Colorectal Polyp Care (NCPC) score, which formed the risk-stratification model along with FIT. The NCPC score was developed from eight independent predicting factors and divided into three levels: low risk (LR 0-14), intermediate risk (IR 15-17), and high risk (HR 18-28). Individuals with IR or HR of NCPC score or FIT+ were classified as increased-risk individuals in the risk-stratification model and were recommended for colonoscopy. The IR/HR of NCPC score showed a higher prevalence of CNs (21.8%/32.8% vs. 11.0%, P < 0.001) and ACNs (4.3%/9.2% vs. 2.0%, P < 0.001) than LR, which was also confirmed in the validation cohort. Similar relative risks and predictive performances were demonstrated between non-specific gastrointestinal symptoms (NSGS) and asymptomatic cohort. The risk-stratification model identified 73.5% CN, 82.6% ACN, and 93.6% CRC when guiding 52.7% individuals to receive colonoscopy and identified 55.8% early-onset ACNs and 72.7% early-onset CRCs with only 25.6% young individuals receiving colonoscopy. The risk-stratification model showed a good risk-stratification ability for CN and early-onset CRCs in Chinese population, including individuals with NSGS and young age.

INTRODUCTION: Although the 9-minute mean withdrawal time (m-WT) is often reported to be associated with the optimal adenoma detection rate (ADR), no randomized trials of screening colonoscopy have confirmed the impact of a 9-minute m-WT on adenoma miss rate (AMR) and ADR. METHODS: A multicenter tandem trial was conducted in 11 centers. Seven hundred thirty-three asymptomatic participants were randomized to receive segmental tandem screening colonoscopy with a 9-minute withdrawal, followed by a 6-minute withdrawal (9-minute-first group, 9MF, n = 366) or vice versa (6-minute-first group, 6MF, n = 367). The primary outcome was the lesion-level AMR. RESULTS: The intention-to-treat analysis revealed that 9MF significantly reduced the lesion-level (14.5% vs 36.6%, P < 0.001) and participant-level AMR (10.9% vs 25.9%, P < 0.001), advanced adenoma miss rate (AAMR, 5.3% vs 46.9%, P = 0.002), multiple adenomas miss rate (20.7% vs 56.5%, P = 0.01), and high-risk adenomas miss rate (14.6% vs 39.5%, P = 0.01) of 6MF without compromising detection efficiency (P = 0.79). In addition, a lower false-negative rate for adenomas (P = 0.002) and high-risk adenomas (P < 0.05), and a lower rate of shortening surveillance schedule (P < 0.001) were also found in 9MF, accompanying with an improved ADR in the 9-minute vs 6-minute m-WT (42.3% vs 33.5%, P = 0.02). The independent inverse association between m-WT and AMR remained significant even after adjusting ADR, and meanwhile, 9-minute m-WT was identified as an independent protector for AMR and AAMR. DISCUSSION: In addition to increasing ADR, 9-minute m-WT also significantly reduces the AMR and AAMR of screening colonoscopy without compromising detection efficiency.

Background & Aims Although current quality indicators of colonoscopy recommend 6 minutes as the minimum standard for withdrawal time (WT), the impact of a WT longer than 6 minutes on neoplasia detection is unclear. Methods A multicenter randomized controlled trial involving 1027 patients was conducted from January 2018 to July 2019. Participants were randomly divided into a 9-minute (n = 514) and 6-minute (n = 513) WT group, and a timer was used to adjust the withdrawal speed. The primary outcome was the adenoma detection rate (ADR). Results Intention-to-treat analysis showed a significantly higher ADR in the 9-minute versus 6-minute WT group (36.6% vs. 27.1%, P=.001). Prolonging WT from 6 to 9 minutes significantly increased ADR of the proximal colon (21.4% vs. 11.9%, P < .001) as well as of the less experienced colonoscopists (36.8% vs. 23.5%, P=.001). Improvements were also observed in the polyp detection rate (58.0% vs. 47.8%, P < .001), and mean number of polyps and adenomas detected per colonoscopy (1.1 vs. 0.9, P=.002; 0.5 vs. 0.4, P=.008, respectively). The higher ADRs in 9-minute WT were also confirmed by the per-protocol (PP) analysis and subgroup analyses, with an increased rate of sessile serrated lesion detection in the 9-minute WT by PP analysis (4.0% vs. 1.3%, P=.04). Multivariate logistic regression demonstrated that the 9-minute WT was independently associated with increased ADR (P = .005). Conclusions Prolonging WT from 6 to 9 minutes significantly improved ADR, especially in the proximal colon and for less experienced colonoscopists. A 9-minute WT benchmark should be considered as one of the quality indicators of colonoscopy. ClinicalTrials.gov (identifier, NCT03399045)

1Department of Gastroenterology, Changhai Hospital, Naval Medical University (Second Military Medical University), Shanghai, China. Correspondence: Yu Bai, MD. E-mail: [email protected]. *Jia-Yi Ma, MD, Peng Pan, MD, and Zi-Xuan He, MD, contributed equally to this work.

目的 分析开展结肠镜检查规范化培训对结肠镜检查质量控制水平的影响.方法 本次研究吸纳国内22家带教医院及136家地县级医院参与,采用国家消化内镜质控中心牵头制定的《结肠镜检查肠道准备督导与效果评价表》作为评价依据,评价带教医院结肠镜检查质量控制水平,由22家带教医院对地县级医院采用"一对多"模式的带教培训,比较地县级医院接受培训前后结肠镜检查质量控制水平,本次研究的观察指标为前述评价表的总分及腺瘤检出率(ADR).结果 22家带教医院的前述评价表总分均在80分以上,中位总分为91.5(88.9,95.3)分.因9家地县级医院未能按照计划参加培训而无法完成完整的两轮评价,故最终纳入127家地县级医院进行分析.在开展结肠镜检查规范化培训前,评价表总分低于60分的医院占比为16.5％,接受培训后无一家医院该总分低于60分;培训后,该总分为60～80分的医院占比较培训前下降,该总分高于80分的医院占比较培训前升高.127家地县级医院培训后的前述评价表中位总分为95(88,100)分,高于接受培训前的80(66,88)分,差异有统计学意义(P<0.05).培训后,ADR低于15％的医院、ADR为15％～25％的医院占比均较培训前下降,ADR高于25％的医院占比较培训前升高.结论 通过高水平医院"以点带面"对地县级医院进行结肠镜检查规范化培训,有助于提高地县级医院结肠镜检查质量控制水平.

Objective:To investigate the current application of colonoscopy at hospitals in China.Methods:From November 2019 to January 2020, an online questionnaire survey was conducted among gastroenterologists and colonoscopists in hospitals of different levels. The contents of questionnaire survey included basic information of colonoscopy at the respondent′s hospital, protocols and patient education of bowel preparation, implementation of colonoscopy quality control, and colonoscopists′ understanding of polypectomy techniques and post-polypectomy follow-up.Results:A total of 236 valid questionnaires were collected, involving 187 hospitals, and 143 (76.5%) had an annual operation capacity of more than 5 000 cases. In terms of bowel preparation, split-dosed polyethylene glycol electrolyte powder (PEG) was the most commonly used (60.4%, 113/187) and the most common volume of PEG was 3 L (67.4%, 126/187). Verbal (90.9%, 170/187) and written (79.7%, 149/187) instructions were given more often than other methods for patient education of bowel preparation. Antifoaming agent was routinely used in 124 (66.3%) hospitals. In terms of quality control, only 11.5% (20/174) hospitals implemented all four measures. In terms of polypectomy techniques, 98.1% (203/207) colonoscopists chose hot snare polypectomy or endoscopic mucosal resection for lesions of diameter>1 cm, while options varied for lesions of diameter<1 cm. The interval of follow-up after polypectomy recommended by colonoscopists was shorter than that by guidelines.Conclusion:Several problems are found in the survey in the application of colonoscopy in China, i. e., patient education of bowel preparation is not diversified; quality control of colonoscopy still needs to be strengthened; polypectomy techniques and follow-up after polypectomy need to be further standardized.