Quality indicators for colonoscopy and the risk of interval cancer

Elevated Adenomatous Polyp Detection Rate Among Alaska Native and American Indian People in Interior Alaska, 2018-2022

OBJECTIVES

Colorectal cancer (CRC) incidence and mortality are twice as high among Alaska Native people as among non-Hispanic White people in the United States; as such, colonoscopy is a recommended screening test for Alaska Native people. Adenoma detection rate (ADR) is measured in patients at average risk of CRC undergoing initial screening colonoscopy and reflects the prevalence of precancerous polyps in a screened population. We evaluated the ADR among Alaska Native people living in Interior Alaska.

METHODS

This project evaluated the ADR among Alaska Native and American Indian adults aged ≥40 years (N = 460) living in Interior Alaska, using a retrospective medical record review of patients referred for screening colonoscopy from February 1, 2018, through March 31, 2022. The main outcome measure was ADR, stratified by age and sex.

RESULTS

The ADR was 45.0% overall: 43.0% among women and 47.1% among men. Among patients aged ≥50 years, the ADR was 67.1%: 62.7% among women and 70.7% among men. Among patients aged 40-49 years, the ADR was 34.4%: 35.3% among women and 33.3% among men.

CONCLUSIONS

Measured ADR was high among Alaska Native men and women aged ≥50 years in Interior Alaska and in all age groups that were screened. These findings have implications for which CRC screening methods, intervals, and age to begin screening are most appropriate for Alaska Native people, as well as the need for future research on the pathology, etiology, and natural history of CRC in this population.

Long-Term Follow-Up of Colonoscopy Quality Monitoring

INTRODUCTION

High-quality colonoscopy is paramount for colorectal cancer prevention. Since 2009, endoscopists at our institution have received quarterly report cards summarizing individual colonoscopy quality indicators. We have previously shown that implementing this intervention was associated with short-term improvement in adenoma detection rate (ADR). However, the long-term effect of continued monitoring on colonoscopy quality is unclear.

METHODS

We conducted a retrospective study of prospectively administered quarterly colonoscopy quality report cards at the Roudebush Veteran's Affairs Medical Center between April 1, 2012, and August 31, 2019. The anonymized reports included individual endoscopists' ADRs, cecal intubation rates, and withdrawal times. Analyses were performed to determine slopes over time for each quality metric by physician and assess for differences based on whether ADRs were calculated quarterly or yearly.

RESULTS

Data from the report cards of 17 endoscopists who had performed 24,361 colonoscopies were included. The mean quarterly ADR (±SD) was 51.7% (±11.7%) and mean yearly ADR was 47.2% (±13.8%). There was a small increase in overall ADR based on quarterly and yearly measurements (slope + 0.6%, P = 0.02; and slope +2.7%, P < 0.001, respectively), but no significant change in individual ADRs, cecal intubation rates, or withdrawal times. Analysis of SD of ADRs showed no significant difference between yearly and quarterly measurements ( P = 0.064). Individual endoscopists' ADR SD differences between yearly and quarterly measurements ranged from -4.7% to +6.8%.

DISCUSSION

Long-term colonoscopy quality monitoring paralleled stable improvements in overall ADR. For endoscopists with baseline high ADR, frequent monitoring and reporting of colonoscopy quality metrics may not be necessary.

Measuring the observer (Hawthorne) effect on adenoma detection rates

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies. Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure. Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P =0.02) and ADRs (39.4% vs. 28.3%, P =0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05-2.17) and more than twofold (RR 2.17; 95%, CI 1.05-4.47) more likely to be higher in the index group than in the reference group. Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Retrospective comparison of G-EYE balloon-colonoscopy with standard colonoscopy for increased adenoma detection rate and reduced polyp removal time

Background and study aims  The newly introduced G-EYE colonoscope (G-EYE) employs a balloon, installed at the bending section of a standard colonoscope (SC), for increasing adenoma detection and stabilizing the colonoscope tip during intervention. This retrospective work explores the effect of introducing G-EYE into an SC endoscopy room, in terms of adenoma detection and polyp removal time. Patients and methods  This was a single-center, retrospective study. Historical data from patients who underwent colonoscopy prior to, and following, introduction of G-EYE into a particular endoscopy room were collected and analyzed to determine adenoma detection rate (ADR), adenoma per patient (APP), and polyp removal time (PRT), in each of the SC and G-EYE groups. Results  Records of 1362 patients who underwent SC and 1433 subsequent patients who underwent G-EYE colonoscopy in the same endoscopy unit by the same endoscopists were analyzed. Following G-EYE introduction, overall ADR increased by 37.5 % ( P  < 0.0001) from 39.2 % to 53.9 %, the serrated adenoma rate increased by 47.3 % from 27.9 % to 41.1 % ( P  < 0.0001), and the APP increased by 50.6 % from 0.79 to 1.19 ( P  < 0.0001). The number of advanced adenomas increased by 32.7 %, from 19.6 % to 26.0 % of all adenomas ( P  < 0.0001). With G-EYE, average PRT was reduced overall by 29.5 % ( P  < 0.0001), and particularly for endoscopic mucosal resection (EMR) by 37.5 % for polyps measuring ≥ 5 mm to ≤ 20 mm ( P  < 0.0001) and by 29.4 % for large polyps > 20 mm ( P  < 0.0001). Conclusions  Introduction of G-EYE to an SC endoscopy room yielded considerable increase in ADR and notable reduction in PRT, particularly with the EMR technique. G-EYE balloon colonoscopy might increase the effectiveness of colorectal cancer screening and surveillance colonoscopy, and can shorten the time of endoscopic intervention.

Neoplasia Diagnosis After Multi-target Stool DNA Is Enhanced Among Lowest Baseline Detectors

BACKGROUND AND AIMS

Variation in colorectal neoplasia detection limits the effectiveness of screening colonoscopy. By evaluating neoplasia detection rates of individual colonoscopists, we aimed to quantify the effects of pre-procedural knowledge of a positive (+) multi-target stool DNA (mt-sDNA) on colonoscopy quality metrics.

METHODS

We retrospectively identified physicians who performed a high volume of + mt-sDNA colonoscopies; colorectal neoplasia at post-mt-sDNA colonoscopy was recorded. These colonoscopists were stratified into quartiles based on baseline adenoma detection rates. Baseline colonoscopy adenoma detection rates and sessile serrated lesion detection rates were compared to post-mt-sDNA colonoscopy neoplasia diagnosis rates among each quartile. Withdrawal times were measured from negative exams.

RESULTS

During the study period (2014-17) the highest quartile of physicians by volume of post-mt-sDNA colonoscopies were evaluated. Among thirty-five gastroenterologists, their median screening colonoscopy adenoma detection rate was 32% (IQR, 28-39%) and serrated lesion detection rate was 13% (8-15%). After + mt-sDNA, adenoma diagnosis increased to 47% (36-56%) and serrated lesion diagnosis increased to 31% (17-42%) (both p < 0.0001). Median withdrawal time increased from 10 (7-13) to 12 (10-17) minutes (p < 0.0001) and was proportionate across quartiles. After + mt-sDNA, lower baseline detectors had disproportionately higher rates of adenoma diagnosis in female versus male patients (p = 0.048) and higher serrated neoplasia diagnosis rates among all patients (p = 0.0092).

CONCLUSIONS

Knowledge of + mt-sDNA enriches neoplasia diagnosis compared to average risk screening exams. Adenomatous and serrated lesion diagnosis was magnified among those with lower adenoma detection rates. Awareness of the mt-sDNA result may increase physician attention during colonoscopy. Pre-procedure knowledge of a positive mt-sDNA test improves neoplasia diagnosis rates among colonoscopists with lower baseline adenoma detection rates, independent of withdrawal time.

You are not lab rats at teaching hospitals: A systematic review of resident and fellow participation leads to improved colonoscopy

BACKGROUND

Participation in colonoscopies is an essential aspect of endoscopic training. The purpose of this study was to explore the impact of fellow/trainee participation on colonoscopy outcomes.

METHODS

This meta-analysis was registered on the International Prospective Register of Systematic Reviews (PROSPERO). From database inception to July 2022, studies investigating fellow involvement and colonoscopy outcomes were searched across Cochrane library, PubMed, and other databases. The random-effects model was applied to generate more conservative estimates. Sensitive analysis was conducted to explore whether the result would depend on a particular study. Egger's test and Begg's test were used to estimate the potential for publication bias.

RESULTS

Seventeen studies including 30,062 participants were included. We found that fellow/trainee involvement enhanced the overall rates of adenoma detection and polyp detection (OR = 1.26, 95% CI = 1.14-1.40, p < 0.001; OR = 1.29, 95% CI = 1.02-1.63, p = 0.020, respectively). The mean number of adenoma/polyps per colonoscopy was also higher with fellow/trainee participation (MD = 0.12, 95% CI = 0.08-0.17, p < 0.001; MD = 0.15, 95% CI = 0.02-0.28, p = 0.020, respectively).

CONCLUSION

In addition to its educational purpose, fellow or trainee involvement is associated with beneficial effects on colonoscopy outcomes.

Clinical value of sigmoid colon water exchange colonoscopy: a prospective randomized clinical trial

This prospective randomized controlled trial investigated the clinical value of sigmoid colon water exchange (SWE) colonoscopy by comparing it with air insufflation (AI) colonoscopy in terms of the patient's pain score, insertion time, and screening quality. Consecutive patients who underwent colonoscopy without sedation were randomized into an AI group (n = 267) or an SWE group (n = 255). Patient characteristics, history of abdominal or pelvic surgery, maximum pain score, insertion time, cecal intubation rate, polyp detection rate, and the need for maneuvers were recorded. There was no significant between-group difference in insertion time, cecal intubation rate, assisted maneuvers (abdominal pressure, changing patients' position), or polyp detection rate (P > 0.05). The mean maximum pain score was significantly lower in the SWE group than in the AI group. (3.57 ± 2.01 vs. 4.69 ± 1.83, P < 0.001). For patients with a history of abdominal or pelvic surgery and those who were overweight (body mass index > 24), the maximum pain scores were lower in the SWE group than in the AI group (3.67 ± 1.95 vs. 4.88 ± 1.80, P < 0.001; 3.40 ± 1.96 vs. 4.79 ± 1.97, P < 0.001, respectively). SWE colonoscopy can significantly reduce abdominal pain with non-inferior screening quality and does not increase insertion time.Trial registration number: ChiCTR2200059057 (date April 23, 2022).

Bowel cleansing effectiveness and safety of 1L PEG + Asc in the real-world setting: Observational, retrospective, multicenter study of over 13000 patients

Background and study aims Effective bowel cleansing is critical for detecting lesions during colonoscopy, highlighting the importance of bowel preparations. 1L polyethylene glycol (PEG) + ascorbate (Asc) is the only recommended 1L PEG product in Europe and the United States. Its efficacy was demonstrated in large-scale controlled trials and confirmed in smaller-scale real-world studies. However, no large-scale real-world data exist. Patients and methods This observational, retrospective, multicenter study, used outpatient follow-up data from medical records from 10 centers in Spain and two in Portugal. Outpatients aged ≥18 years using 1L PEG + Asc as bowel preparation were included. The main outcome measures were overall adequate colon cleansing (Boston Bowel Preparation Scale [BBPS] score ≥6 with BBPS score ≥2 in each segment) and high-quality cleansing of the right colon (BBPS score=3). Results Data from 13169 eligible patients were included. Overall cleansing success was achieved in 89.3% (95%CI 88.7%-89.8%) and high-quality cleansing in the right colon in 49.3% (95%CI 48.4%-50.2%) of patients. For the overnight split-dose and same-day regimens, overall adequate quality cleansing success rate was 94.7% and 86.7% ( P <0.0001) and high-quality cleansing of the right colon rate was 65.4% and 41.4% ( P <0.0001), respectively. Colonoscopy was completed in 97.3% of patients, with non-completion due to poor preparation in only 0.8%; 2.3% of patients experienced at least one adverse event (AE). Conclusions This large-scale, real-world study demonstrates the effectiveness of 1L PEG + Asc in the total and right colon, with a low percentage of patients with AEs in routine clinical practice.

Comparison of the Ability of Artificial-Intelligence-Based Computer-Aided Detection (CAD) Systems and Endoscopists to Detect Colorectal Neoplastic Lesions on Endoscopy Video

Artificial-intelligence-based computer-aided diagnosis (CAD) systems have developed remarkably in recent years. These systems can help increase the adenoma detection rate (ADR), an important quality indicator in colonoscopies. While there have been many still-image-based studies on the usefulness of CAD, few have reported on its usefulness using actual clinical videos. However, no studies have compared the CAD group and control groups using the exact same case videos. This study aimed to determine whether CAD or endoscopists were superior in identifying colorectal neoplastic lesions in videos. In this study, we examined 34 lesions from 21 cases. CAD performed better than four of the six endoscopists (three experts and three beginners), including all the beginners. The time to lesion detection with beginners and experts was 2.147 ± 1.118 s and 1.394 ± 0.805 s, respectively, with significant differences between beginners and experts (p < 0.001) and between beginners and CAD (both p < 0.001). The time to lesion detection was significantly shorter for experts and CAD than for beginners. No significant difference was found between experts and CAD (p = 1.000). CAD could be useful as a diagnostic support tool for beginners to bridge the experience gap with experts.

Evaluating colonoscopy screening intervals in patients with Lynch syndrome from a large Canadian registry

BACKGROUND

Lynch syndrome (LS) screening guidelines originally recommended colonoscopy every 1 to 2 years, beginning between the ages of 20 and 25 years. Recent studies have questioned the benefits of these short screening intervals in preventing colorectal cancer (CRC). Our goal is to determine how colonoscopy screening intervals impact CRC in patients with LS.

METHODS

We analyzed the demographics, screening practices, and outcomes of patients with LS identified through the clinic based Familial Gastrointestinal Cancer Registry at the Zane Cohen Centre, Sinai Health System, Toronto, Canada.

RESULTS

A total of 429 patients with LS were identified with median follow-up of 9.2 years; 44 developed CRC. We found a positive trend between shorter screening intervals and the number of adenomas detected during colonoscopy. Any new adenoma detected at screening decreased 10-year CRC incidence by 11.3%. For MLH1 carriers, a screening interval of 1-2 years vs 2-3 years led to a 20-year cumulative CRC risk reduction of 28% and 14% in females and males, respectively. For MSH2 carriers, this risk reduction was 29% and 17%, respectively, and for male MSH6 carriers 18%. Individuals without any adenomas detected (53.4% of LS carriers) had an increased 20-year CRC risk of 25.7% and 57.2% for women and men, respectively, compared with those diagnosed with adenomas at screening.

CONCLUSIONS

The recommended colonoscopy screening interval of 1-2 years is efficient at detecting adenomas and reducing CRC risk. The observation that 53.4% of LS patients never had an adenoma warrants further investigation about a possible adenoma-free pathway.

Variation in the rate of detection of minute and small early gastric cancers at diagnostic endoscopy may reflect the performance of individual endoscopists

OBJECTIVE

The documented variation in gastric cancer (GC) detection among endoscopists has often been dismissed as a coincidental artefact of the low incidence of gastric neoplasms; it is not considered associated with differences in physicians' performance of the esophagogastroduodenoscopy procedure. This study is to confirm whether significant variations among endoscopists in early GC detection suggest the individual performance of the upper endoscopy.

DESIGN

A retrospective observational study at a single centre in Japan assessed the results of 218 early GCs detected during 25 688 routine esophagogastroduodenoscopies by 12 endoscopists. The main outcome was the rate of early GC detection for each endoscopist under the same circumstances. Other measures included the major diameters and locations of the lesions, Helicobacter pylori infection status, and baseline patient characteristics that could affect the prevalence of GC.

RESULTS

The early GC detection rates exhibited wide variation among endoscopists (0.09%-2.87%) despite performing routine esophagogastroduodenoscopies in a population with a similar background. Endoscopists were assigned to a low-detection group (n=6; detection rate: 0.47% (range: 0.09%-0.55%)) and a high-detection group (n=5; detection rate: 0.83% (range: 0.63%-1.12%)), with the single highest detector analysed separately due to his distinct detection rate (2.87%). Endoscopists in the high-detection group had better detection rates for minute (major diameter ≤5 mm) and small (major diameter 6-10 mm) GCs than the low-detection group (0.19%/0.23% vs 0.085%/0.098%). These differences were significant (p<0.01), although there were no significant differences in detection of larger tumours (major diameter ≥11 mm; 0.40% vs 0.28%; p=0.13). The tumour location and H. pylori status were similar in the low-detection group, high-detection group and for the highest detector.

CONCLUSION

Significant variation in the detection of hard-to-find, smaller GCs may reflect individual performance of the examination.

Evaluation of the quality of colonoscopies performed by Alberta North Zone surgeons, family physicians and internists: a quality improvement initiative

BACKGROUND

In Canada, endoscopy is primarily performed by gastroenterologists and surgeons, and some studies report that colonoscopies performed by nongastroenterologists have more complications and higher rates of future colorectal cancer. Our objective was to determine whether rural-based nongastroenterologist endoscopists are achieving quality benchmarks in colonoscopy.

METHODS

This quality improvement initiative prospectively evaluated 6 key performance indicators (KPIs) (cecal intubations, polyp detection [males and females; for first-time colonoscopies on patients aged ≥ 50 yr], bowel preparations, patient comfort and withdrawal times) on consecutive colonoscopies performed by participating Alberta North Zone endoscopists. The study period was June 2018 to March 2020. Overall and individual endoscopist's KPIs were compared with standard benchmarks. Additional performance indicators included mean number of polyps per colonoscopy and an exploration of study-defined sedation-related level of consciousness.

RESULTS

Data were collected on 6212 colonoscopies performed by 16 endoscopists (9 surgeons, 5 family physicians and 2 internists) in 6 hospitals. All 6 KPI benchmarks were achieved when results were pooled over all endoscopists in the study. Overall, cecal intubation occurred in 6006 of 6209 (96.7%, 95% confidence interval 94.5%-99.0%) cases. Polyp detection was 65.9% (592/898) and 49.8% (348/699) for male and female patients, respectively, aged 50 years or older. Variability in individual endoscopist results existed, especially for the mean number of polyps per 100 colonoscopies and sedation-related level of consciousness.

INTERPRETATION

Overall, Alberta North Zone endoscopists are performing high-quality colonoscopies, collectively achieving all 6 KPIs. To understand endoscopic performance and encourage individual and group reflection on endoscopic practices, Canadian endoscopists are encouraged to participate in similar colonoscopy quality initiative studies.

Polyps are detected more often in early colonoscopies

OBJECTIVE

To examine the time variation in polyp detection for colonoscopies performed in a tertiary hospital and to explore independent factors that predict polyp detection rate (PDR).

METHODS

Data on all patients who underwent colonoscopy for the diagnostic purpose at our endoscopy center in Zhongnan Hospital of Wuhan University from January 2021 to December 2021 were reviewed. The start time of included colonoscopies for eligible patients was recorded. PDR and polyps detected per colonoscopy (PPC) were calculated. The endoscopists' schedules were classified into full-day and half-day shifts according to their participation in the morning and afternoon colonoscopies.

RESULTS

Data on a total of 12116 colonoscopies were analyzed, with a PDR of 38.03% for all the patients and 46.38% for patients ≥50 years. PDR and PPC significantly decreased as the day progressed (both p < .001). For patients ≥50 years, PDR declined below 40% at 13:00-13:59 and 16:00-16:59. The PDR in the morning was higher than that in the afternoon for both half-day (p = .019) and full-day procedures (p < .001). In multivariate analysis, start time, patient gender, age, conscious sedation, and bowel preparation quality significantly predicted PDR (p < .001).

CONCLUSIONS

The polyp detection declined as the day progressed. A continuous work schedule resulted in a subpar PDR. Colonoscopies performed in the morning had a higher PDR than that in the afternoon. Patient gender, age, conscious sedation, and bowel preparation quality were identified as the independent predictors of PDR.

Prospective study of computer-aided detection of colorectal adenomas in hospitalized patients

BACKGROUND

Adenoma detection with polypectomy during total colonoscopy reduces the incidence of colorectal cancer (CRC) and colorectal cancer-associated mortality. The adenoma detection rate (ADR) is an established quality indicator, which is associated with a decreased risk for interval cancer. An increase in ADR could be demonstrated for several artificially intelligent, real-time computer-aided detection (CADe) systems in selected patients. Most studies concentrated on outpatient colonoscopies. This sector often lacks funds for applying costly innovations like CADe. Hospitals are more likely to implement CADe and information about the impact of CADe in the distinct patient cohort of hospitalized patients is scarce.

METHODS

In this prospective, randomized-controlled study, we compared colonoscopies performed with or without computer-aided detection (CADe) system (GI Genius, Medtronic) performed at University Medical Center Schleswig-Holstein, Campus Luebeck. The primary endpoint was ADR.

RESULTS

Overall, 232 patients were randomized with n = 122 patients in the CADe arm and n = 110 patients in the control arm. Median age was 66 years (interquartile range 51-77). Indication for colonoscopy was most often workup for gastrointestinal symptoms (88.4%) followed by screening, post-polypectomy and post-CRC surveillance (each 3.9%). Withdrawal time was significantly prolonged (11 vs. 10 min, p = 0.039), without clinical relevance. Complication rate was not different between the arms (0.8% vs. 4.5%; p = 0.072). The ADR was significantly increased in the CADe arm compared to the control (33.6% vs. 18.1%, p = 0.008). ADR increase was particularly strong for the detection in elderly patients aged ≥50 years (OR 6.3, 95% CI 1.7 - 23.1, p = 0.006).

CONCLUSION

The use of CADe is safe and increases ADR in hospitalized patients.

Effectiveness and application of artificial intelligence for endoscopic screening of colorectal cancer: the future is now

INTRODUCTION

Artificial intelligence (AI) in gastrointestinal endoscopy includes systems designed to interpret medical images and increase sensitivity during examination. This may be a promising solution to human biases and may provide support during diagnostic endoscopy.

AREAS COVERED

This review aims to summarize and evaluate data supporting AI technologies in lower endoscopy, addressing their effectiveness, limitations, and future perspectives.

EXPERT OPINION

Computer-aided detection (CADe) systems have been studied with promising results, allowing for an increase in adenoma detection rate (ADR), adenoma per colonoscopy (APC), and a reduction in adenoma miss rate (AMR). This may lead to an increase in the sensitivity of endoscopic examinations and a reduction in the risk of interval-colorectal cancer. In addition, computer-aided characterization (CADx) has also been implemented, aiming to distinguish adenomatous and non-adenomatous lesions through real-time assessment using advanced endoscopic imaging techniques. Moreover, computer-aided quality (CADq) systems have been developed with the aim of standardizing quality measures in colonoscopy (e.g. withdrawal time and adequacy of bowel cleansing) both to improve the quality of examinations and set a reference standard for randomized controlled trials.

"Endoscopic" adenoma detection rate as a quality indicator of colonoscopy: First report from the J-SCOUT study

OBJECTIVES

To examine whether reasonable detection rate of endoscopically diagnosed lesions as adenoma ("endoscopic" adenoma detection rate [ADR]) could be calculated with a database generated from colonoscopy reports and whether it could be used as a surrogate colonoscopy quality indicator of "pathological" ADR.

METHODS

A lesion-by-lesion database of colonoscopies performed between 2010 and 2020 at eight Japanese endoscopy centers and corresponding pathology database were integrated. Differences in numbers of detected polyps, "endoscopic" and "pathological" adenomas, and what these differences could be attributed to were examined. Polyp detection rate (PDR), "endoscopic" and "pathological" ADRs, and correlation coefficients between "pathological" ADR and PDR or "endoscopic" ADR by each endoscopist were calculated.

RESULTS

Overall, 129,065 colonoscopy reports were analyzed. Among a total of 146,854 polyps, more "endoscopic" adenomas (n = 117,359) were observed than "pathological" adenomas (n = 70,076), primarily because adenomas were not resected on site, rather than because of a misdiagnosis. In all patients analyzed, PDR, "endoscopic" and "pathological" ADRs were 56.4% (95% confidence interval [CI] 56.2-56.7), 48.0% (95% CI 47.7-48.3), and 32.7% (95% CI 32.5-33.0), respectively. "Endoscopic" and "pathological" ADRs from each endoscopist showed a high correlation in hospitals where adenomas were usually resected at the time of examination.

CONCLUSIONS

By appropriately describing endoscopically diagnosed lesions as "adenomas" in endoscopy reports, "endoscopic" ADR might be used as a surrogate colonoscopy quality indicator of "pathological" ADR (UMIN000040690).

Recent advances in devices and technologies that might prove revolutionary for colonoscopy procedures

INTRODUCTION

Colorectal cancer (CRC) is the third most common malignancy and second leading cause of cancer-related mortality in the world. Adenoma detection rate (ADR), a quality indicator for colonoscopy, has gained prominence as it is inversely related to CRC incidence and mortality. As such, recent efforts have focused on developing novel colonoscopy devices and technologies to improve ADR.

AREAS COVERED

The main objective of this paper is to provide an overview of advancements in the fields of colonoscopy mechanical attachments, artificial intelligence-assisted colonoscopy, and colonoscopy optical enhancements with respect to ADR. We accomplished this by performing a comprehensive search of multiple electronic databases from inception to September 2023. This review is intended to be an introduction to colonoscopy devices and technologies.

EXPERT OPINION

Numerous mechanical attachments and optical enhancements have been developed that have the potential to improve ADR and AI has gone from being an inaccessible concept to a feasible means for improving ADR. While these advances are exciting and portend a change in what will be considered standard colonoscopy, they continue to require refinement. Future studies should focus on combining modalities to further improve ADR and exploring the use of these technologies in other facets of colonoscopy.

Adenoma detection rate in colonoscopy: how can it be improved?

INTRODUCTION

The introduction of widespread colonoscopy screening programs has helped in decreasing the incidence of Colorectal Cancer (CRC). However, 'back-to-back' colonoscopies revealed relevant percentage of missed adenomas. Quality indicators were created to further homogenize detection performances and decrease the incidence of post-colonoscopy CRC. Among them, the Adenoma Detection Rate (ADR), defined as the percentage obtained by dividing the number of endoscopic procedures in which at least one adenoma was resected, by the total number of procedures, was found to be inversely associated with the risks of interval colorectal cancer, advanced-stage interval cancer, and fatal interval cancer.

AREAS COVERED

In this paper, we performed a comprehensive review of the literature focusing on promising new devices and technologies, which are meant to positively affect the endoscopist performance in detecting adenomas, therefore increasing ADR.

EXPERT OPINION

Considering the current knowledge, although several devices and technologies have been proposed with this intent, the recent implementation of AI ranked over all of the other strategies and it is likely to become the new standard within few years. However, the combination of different device/technologies need to be investigated in the future aiming at even further increasing of endoscopist detection performances.

Combination of Mucosa-Exposure Device and Computer-Aided Detection for Adenoma Detection During Colonoscopy: A Randomized Trial

BACKGROUND & AIMS

Both computer-aided detection (CADe)-assisted and Endocuff-assisted colonoscopy have been found to increase adenoma detection. We investigated the performance of the combination of the 2 tools compared with CADe-assisted colonoscopy alone to detect colorectal neoplasias during colonoscopy in a multicenter randomized trial.

METHODS

Men and women undergoing colonoscopy for colorectal cancer screening, polyp surveillance, or clincial indications at 6 centers in Italy and Switzerland were enrolled. Patients were assigned (1:1) to colonoscopy with the combinations of CADe (GI-Genius; Medtronic) and a mucosal exposure device (Endocuff Vision [ECV]; Olympus) or to CADe-assisted colonoscopy alone (control group). All detected lesions were removed and sent to histopathology for diagnosis. The primary outcome was adenoma detection rate (percentage of patients with at least 1 histologically proven adenoma or carcinoma). Secondary outcomes were adenomas detected per colonoscopy, advanced adenomas and serrated lesions detection rate, the rate of unnecessary polypectomies (polyp resection without histologically proven adenomas), and withdrawal time.

RESULTS

From July 1, 2021 to May 31, 2022, there were 1316 subjects randomized and eligible for analysis; 660 to the ECV group, 656 to the control group). The adenoma detection rate was significantly higher in the ECV group (49.6%) than in the control group (44.0%) (relative risk, 1.12; 95% CI, 1.00-1.26; P = .04). Adenomas detected per colonoscopy were significantly higher in the ECV group (mean ± SD, 0.94 ± 0.54) than in the control group (0.74 ± 0.21) (incidence rate ratio, 1.26; 95% CI, 1.04-1.54; P = .02). The 2 groups did not differ in term of detection of advanced adenomas and serrated lesions. There was no significant difference between groups in mean ± SD withdrawal time (9.01 ± 2.48 seconds for the ECV group vs 8.96 ± 2.24 seconds for controls; P = .69) or proportion of subjects undergoing unnecessary polypectomies (relative risk, 0.89; 95% CI, 0.69-1.14; P = .38).

CONCLUSIONS

The combination of CADe and ECV during colonoscopy increases adenoma detection rate and adenomas detected per colonoscopy without increasing withdrawal time compared with CADe alone.

CLINICALTRIALS

gov, Number: NCT04676308.

Preclinical Evaluation of a Microwave-Based Accessory Device for Colonoscopy in an In Vivo Porcine Model with Colorectal Polyps

BACKGROUND AND AIMS

Colonoscopy is currently the most effective way of detecting colorectal cancer and removing polyps, but it has some drawbacks and can miss up to 22% of polyps. Microwave imaging has the potential to provide a 360° view of the colon and addresses some of the limitations of conventional colonoscopy. This study evaluates the feasibility of a microwave-based colonoscopy in an in vivo porcine model.

METHODS

A prototype device with microwave antennas attached to a conventional endoscope was tested on four healthy pigs and three gene-targeted pigs with mutations in the adenomatous polyposis coli gene. The first four animals were used to evaluate safety and maneuverability and compatibility with endoscopic tools. The ability to detect polyps was tested in a series of three gene-targeted pigs.

RESULTS

the microwave-based device did not affect endoscopic vision or cause any adverse events such as deep mural injuries. The microwave system was stable during the procedures, and the detection algorithm showed a maximum detection signal for adenomas compared with healthy mucosa.

CONCLUSIONS

Microwave-based colonoscopy is feasible and safe in a preclinical model, and it has the potential to improve polyp detection. Further investigations are required to assess the device's efficacy in humans.

Linked-Color Imaging Detects More Colorectal Adenoma and Serrated Lesions: An International Randomized Controlled Trial

BACKGROUND & AIMS

Effects of linked-color imaging (LCI) on colorectal lesion detection and colonoscopy quality remain controversial. This study compared the detection rates of adenoma and other precursor lesions using LCI vs white-light imaging (WLI) during screening, diagnostic, and surveillance colonoscopies.

METHODS

This randomized controlled trial was performed at 11 institutions in 4 Asian countries/regions. Patients with abdominal symptoms, a primary screening colonoscopy, positive fecal immunochemical test results, or undergoing postpolypectomy surveillance were recruited and randomly assigned in a 1:1 ratio to either the LCI or high-definition WLI group. The primary outcome was adenoma detection rate (ADR). Secondary outcomes were polyp detection rate, advanced ADR, sessile serrated lesion (SSL) detection rate, and the mean number of adenomas per colonoscopy. The recommended surveillance schedule distribution after trial colonoscopy was analyzed.

RESULTS

Between November 2020 and January 2022, there were 3050 participants (LCI, n = 1527; WLI, n = 1523) recruited. The LCI group ADR was significantly higher than the WLI group ADR using intention-to-treat (58.7% vs 46.7%; P < .01) and per-protocol analyses (59.6% vs 46.4%; P < .01). The LCI group polyp detection rates (68.6% vs 59.5%; P < .01), SSL detection rates (4.8% vs 2.8%; P < .01), and adenomas per colonoscopy (1.48 vs 1.02; P < .01) also were significantly higher. However, the advanced ADR was not significantly different (13.2% vs 11.0%; P = .06). Significantly more patients in the LCI group had shorter recommended surveillance schedules than the WLI group (P < .01).

CONCLUSIONS

Compared with WLI, LCI improved adenoma and other polyp detection rates, including SSLs, resulting in alteration of the recommended surveillance schedule after screening, diagnostic, and postpolypectomy surveillance colonoscopies.

TRIAL REGISTRATION NUMBER

UMIN000042432 (https://www.umin.ac.jp/ctr/index.htm).

Speedometer for withdrawal time monitoring during colonoscopy: a clinical implementation trial

OBJECTIVES

Meticulous inspection of the mucosa during colonoscopy, represents a lengthier withdrawal time, but has been shown to increase adenoma detection rate (ADR). We investigated if artificial intelligence-aided speed monitoring can improve suboptimal withdrawal time.

METHODS

We evaluated the implementation of a computer-aided speed monitoring device during colonoscopy at a large academic endoscopy center. After informed consent, patients ≥18 years undergoing colonoscopy between 5 March and 29 April 2021 were examined without the use of the speedometer, and with the speedometer between 29 April and 30 June 2021. All colonoscopies were recorded, and withdrawal time was assessed based on the recordings in a blinded fashion. We compared mean withdrawal time, percentage of withdrawal time ≥6 min, and ADR with and without the speedometer.

RESULTS

One hundred sixty-six patients in each group were eligible for analyses. Mean withdrawal time was 9 min and 6.6 s (95% CI: 8 min and 34.8 s to 9 min and 39 s) without the use of the speedometer, and 9 min and 9 s (95% CI: 8 min and 45 s to 9 min and 33.6 s) with the speedometer; difference 2.3 s (95% CI: -42.3-37.7, p = 0.91). The ADRs were 45.2% (95% CI: 37.6-52.8) without the speedometer as compared to 45.8% (95% CI: 38.2-53.4) with the speedometer (p = 0.91). The proportion of colonoscopies with withdrawal time ≥6 min without the speedometer was 85.5% (95% CI: 80.2-90.9) versus 86.7% (95% CI: 81.6-91.9) with the speedometer (p = 0.75).

CONCLUSIONS

Use of speed monitoring during withdrawal did not increase withdrawal time or ADR in colonoscopy.

CLINICALTRIALS.GOV IDENTIFIER

NCT04710251.

Quality in colonoscopy: time to ensure national standards are implemented?

Background

High-quality colonoscopy is crucial to ensure complete mucosal visualisation and to maximise detection of pathology. Previous audits showing variable quality have prompted national and international colonoscopy improvement programmes, including the development of quality assurance standards and key performance indicators (KPIs). The most widely used marker of mucosal visualisation is the adenoma detection rate (ADR), however, histological confirmation is required to calculate this. We explored the relationship between core colonoscopy KPIs.

Methods

Data were collected from colonoscopists in eight hospitals in North East England over a 6-month period, as part of a quality improvement study. Procedural information was collected including number of colonoscopies, caecal intubation rate (CIR), ADR and polyp detection rate (PDR). Associations between KPIs and colonoscopy performance were analysed.

Results

9265 colonoscopies performed by 118 endoscopists were included. Mean ADR and PDR per endoscopist were 16.6% (range 0-36.3, SD 7.4) and 27.2% (range 0-57.5, SD 9.3), respectively. Mean number of colonoscopies conducted in 6 months was 78.5 (range 4-334, SD 61). Mean CIR was 91.2% (range 55.5-100, SD 6.6). Total number of colonoscopies and ADR>15% were significantly associated (p=0.04). Undertaking fewer colonoscopies and using hyoscine butylbromide less frequently was significantly associated with ADR<15%. CIR, endoscopist grade, % male patients, mean patient age and CIR were not significantly related to ADR<15%. In adjusted analyses, factors which affected ADR were PDR and mean patient age.

Conclusion

Colonoscopists who perform fewer than the nationally stipulated minimum of 100 procedures per year had significantly lower ADRs. This study demonstrates that PDR can be used as a marker of ADR; providing age is also considered.

Self-supervised monocular depth estimation for gastrointestinal endoscopy

BACKGROUND AND OBJECTIVE

Gastrointestinal (GI) endoscopy represents a promising tool for GI cancer screening. However, the limited field of view and uneven skills of endoscopists make it remains difficult to accurately identify polyps and follow up on precancerous lesions under endoscopy. Estimating depth from GI endoscopic sequences is essential for a series of AI-assisted surgical techniques. Nonetheless, depth estimation algorithm of GI endoscopy is a challenging task due to the particularity of the environment and the limitation of datasets. In this paper, we propose a self-supervised monocular depth estimation method for GI endoscopy.

METHODS

A depth estimation network and a camera ego-motion estimation network are firstly constructed to obtain the depth information and pose information of the sequence respectively, and then the model is enabled to perform self-supervised training by calculating the multi-scale structural similarity with L1 norm (MS-SSIM+L1) loss function between the target frame and the reconstructed image as part of the loss of the training network. The MS-SSIM+L1 loss function is good for reserving high-frequency information and can maintain the invariance of brightness and color. Our model consists of the U-shape convolutional network with the dual-attention mechanism, which is beneficial to capture muti-scale contextual information, and greatly improves the accuracy of depth estimation. We evaluated our method qualitatively and quantitatively with different state-of-the-art methods.

RESULTS AND CONCLUSIONS

The experimental results manifest that our method has superior generality, achieving lower error metrics and higher accuracy metrics on both the UCL dataset and the Endoslam dataset. The proposed method has also been validated with clinical GI endoscopy, demonstrating the potential clinical value of the model.

Improving polyp detection at colonoscopy: Non-technological techniques

Colonoscopy and polypectomy remain the gold standard investigation for the detection and prevention of colorectal cancer. Halting the progression of colonic adenoma through adequate detection of pre-cancerous lesions interrupts the progression to carcinoma. The adenoma detection rate is a key performance indicator. Increasing adenoma detection rates are associated with reducing rates of interval colorectal cancer. Endoscopists with high baseline adenoma detection rate have a meticulous technique during colonoscopy withdrawal that improves their adenoma detection. This minireview article summarizes the evidence on the following simple operator techniques and their effects on the adenoma detection rate; minimum withdrawal times, dynamic patient position change and proximal colon retroflexion.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Image acquisition as novel colonoscopic quality indicator: a single-center retrospective study

PURPOSE

In order to reduce the incidence and mortality of colorectal cancer, improving the quality of colonoscopy is the top priority. At present, the adenoma detection rate is the most used index to evaluate the quality of colonoscopy. So, we further verified the relevant factors influencing the quality of colonoscopy and found out the novel quality indicators by studying the relationship between the influencing factors and the adenoma detection rate.

MATERIALS/METHODS

The study included 3824 cases of colonoscopy from January to December 2020. We retrospectively recorded the age and sex of the subjects; the number, size, and histological features of lesions; withdrawal time and the number of images acquired during colonoscopy. We analyzed the associated factors affecting adenoma and polyp detection, and verified their effectiveness with both univariate and multivariate logistic regression analyses.

RESULTS

Logistic regression analyses showed that gender, age, withdrawal time and the number of images acquired during colonoscopy could serve as independent predictors of adenoma/polyp detection rate. In addition, adenoma detection rate (25.36% vs. 14.29%) and polyp detection rate (53.99% vs. 34.42%) showed a marked increase when the number of images taken during colonoscopy was ≥29 (P<0.001).

CONCLUSIONS

Gender, age, withdrawal time and the number of images acquired during colonoscopy are influencing factors for the detection of colorectal adenomas and polyps. And we can gain higher adenoma/polyp detection rate when endoscopists capture more colonoscopic images.

DLGNet: A dual-branch lesion-aware network with the supervised Gaussian Mixture model for colon lesions classification in colonoscopy images

Colorectal cancer is one of the malignant tumors with the highest mortality due to the lack of obvious early symptoms. It is usually in the advanced stage when it is discovered. Thus the automatic and accurate classification of early colon lesions is of great significance for clinically estimating the status of colon lesions and formulating appropriate diagnostic programs. However, it is challenging to classify full-stage colon lesions due to the large inter-class similarities and intra-class differences of the images. In this work, we propose a novel dual-branch lesion-aware neural network (DLGNet) to classify intestinal lesions by exploring the intrinsic relationship between diseases, composed of four modules: lesion location module, dual-branch classification module, attention guidance module, and inter-class Gaussian loss function. Specifically, the elaborate dual-branch module integrates the original image and the lesion patch obtained by the lesion localization module to explore and interact with lesion-specific features from a global and local perspective. Also, the feature-guided module guides the model to pay attention to the disease-specific features by learning remote dependencies through spatial and channel attention after network feature learning. Finally, the inter-class Gaussian loss function is proposed, which assumes that each feature extracted by the network is an independent Gaussian distribution, and the inter-class clustering is more compact, thereby improving the discriminative ability of the network. The extensive experiments on the collected 2568 colonoscopy images have an average accuracy of 91.50%, and the proposed method surpasses the state-of-the-art methods. This study is the first time that colon lesions are classified at each stage and achieves promising colon disease classification performance. To motivate the community, we have made our code publicly available via https://github.com/soleilssss/DLGNet.

Identifying key mechanisms leading to visual recognition errors for missed colorectal polyps using eye-tracking technology

BACKGROUND AND AIM

Lack of visual recognition of colorectal polyps may lead to interval cancers. The mechanisms contributing to perceptual variation, particularly for subtle and advanced colorectal neoplasia, have scarcely been investigated. We aimed to evaluate visual recognition errors and provide novel mechanistic insights.

METHODS

Eleven participants (seven trainees and four medical students) evaluated images from the UCL polyp perception dataset, containing 25 polyps, using eye-tracking equipment. Gaze errors were defined as those where the lesion was not observed according to eye-tracking technology. Cognitive errors occurred when lesions were observed but not recognized as polyps by participants. A video study was also performed including 39 subtle polyps, where polyp recognition performance was compared with a convolutional neural network.

RESULTS

Cognitive errors occurred more frequently than gaze errors overall (65.6%), with a significantly higher proportion in trainees (P = 0.0264). In the video validation, the convolutional neural network detected significantly more polyps than trainees and medical students, with per-polyp sensitivities of 79.5%, 30.0%, and 15.4%, respectively.

CONCLUSIONS

Cognitive errors were the most common reason for visual recognition errors. The impact of interventions such as artificial intelligence, particularly on different types of perceptual errors, needs further investigation including potential effects on learning curves. To facilitate future research, a publicly accessible visual perception colonoscopy polyp database was created.

Post-colonoscopy cancer rate at a tertiary referral hospital in Australia: A data linkage analysis

BACKGROUND AND AIM

Colorectal cancer (CRC) diagnosed following a cancer-negative colonoscopy is termed as post-colonoscopy CRC (PCCRC). The World Endoscopy Organization has recently standardized the definition of PCCRC-3Y (CRC developing within 3 years of a cancer-negative colonoscopy). In the present study, we sought to assess PCCRC-3Y rate, perform root-cause analyses, and identify factors associated with development of PCCRC at a tertiary referral hospital in Australia.

METHODS

All patients undergoing colonoscopy from 2011 to 2018 were matched to a population-based cancer register. PCCRC-3Y rate was assessed for years 2011-2015. All PCCRC cases that developed within 6-48 months after a cancer-negative colonoscopy underwent root-cause analyses. Descriptive statistics were used to summarize data.

RESULTS

Among 17 828 patients undergoing colonoscopy, 367 CRC cases were diagnosed during the study period. This included nine PCCRC cases, which developed at a median of 14 months (range 7-34 months) after cancer-negative colonoscopy. The PCCRC-3Y rate for years 2011-2015 was 2.16% (95% CI 0.91-5.15). All nine PCCRC cases were moderately or poorly differentiated adenocarcinomas; seven of nine were early-stage CRC (stages I and II) and six of nine probably represented missed lesions at index colonoscopy despite an apparently adequate examination. History of inflammatory bowel disease (IBD) (odds ratio [OR] 21.9, 95% confidence interval [CI] 4.6-103.7, P < 0.001) and diverticulosis (OR 5.4, 95% CI 1.4-20.5, P = 0.01) were significantly associated with development of missed CRC.

CONCLUSIONS

In our tertiary referral colonoscopy cohort, PCCRC-3Y rate was 2.16% (95% CI 0.91-5.15). IBD and diverticulosis were significantly associated with risk of PCCRC. The majority of PCCRC lesions were likely missed at index colonoscopy, despite an apparently adequate examination.

Incomplete resection rates of 4- to 20-mm non-pedunculated colorectal polyps when using wide-field cold snare resection with routine submucosal injection

Background and study aims  Incomplete resection of 4- to 20-mm colorectal polyps occur frequently (> 10 %), putting patients at risk for post-colonoscopy colorectal cancer. We hypothesized that routine use of wide-field cold snare resection with submucosal injection (CSP-SI) might reduce incomplete resection rates (IRRs). Patients and methods  Patients aged 45 to 80 years undergoing elective colonoscopies were enrolled in a prospective clinical study. All 4- to 20-mm non-pedunculated polyps were resected using CSP-SI. Post-polypectomy margin biopsies were obtained to determine IRRs through histopathology assessment. The primary outcome was IRR, defined as remnant polyp tissue found on margin biopsies. Secondary outcomes included technical success and complication rates. Results  A total of 429 patients (median age 65 years, 47.1 % female, adenoma detection rate 40 %) with 204 non-pedunculated colorectal polyps 4 to 20 mm removed using CSP-SI were included in the final analysis. CSP-SI was technical successful in 97.5 % (199/204) of cases (5 conversion to hot snare polypectomy). IRR for CSP-SI was 3.8 % (7/183) (95 % confidence interval [CI] 2.7 %-5.5 %). IRR was 1.6 % (2/129), 16 % (4/25), and 3.4 % (1/29) for adenomas, serrated lesions, and hyperplastic polyps respectively. IRR was 2.3 % (2/87), 6.3 % (4/64), 4.0 % (6/151), and 3.1 % (1/32) for polyps 4 to 5 mm, 6 to 9 mm, < 10 mm, and 10 to 20 mm, respectively. There were no CSP-SI-related serious adverse events. Conclusions  Use of CSP-SI results in lower IRRs compared to what has previously been reported in the literature for hot or cold snare polypectomy when not using wide-field cold snare resection with submucosal injection. CSP-SI showed an excellent safety and efficacy profile, however comparative studies to CSP without SI are required to confirm these results.

Deep Learning Empowers Endoscopic Detection and Polyps Classification: A Multiple-Hospital Study

The present study aimed to develop an AI-based system for the detection and classification of polyps using colonoscopy images. A total of about 256,220 colonoscopy images from 5000 colorectal cancer patients were collected and processed. We used the CNN model for polyp detection and the EfficientNet-b0 model for polyp classification. Data were partitioned into training, validation and testing sets, with a 70%, 15% and 15% ratio, respectively. After the model was trained/validated/tested, to evaluate its performance rigorously, we conducted a further external validation using both prospective (n = 150) and retrospective (n = 385) approaches for data collection from 3 hospitals. The deep learning model performance with the testing set reached a state-of-the-art sensitivity and specificity of 0.9709 (95% CI: 0.9646-0.9757) and 0.9701 (95% CI: 0.9663-0.9749), respectively, for polyp detection. The polyp classification model attained an AUC of 0.9989 (95% CI: 0.9954-1.00). The external validation from 3 hospital results achieved 0.9516 (95% CI: 0.9295-0.9670) with the lesion-based sensitivity and a frame-based specificity of 0.9720 (95% CI: 0.9713-0.9726) for polyp detection. The model achieved an AUC of 0.9521 (95% CI: 0.9308-0.9734) for polyp classification. The high-performance, deep-learning-based system could be used in clinical practice to facilitate rapid, efficient and reliable decisions by physicians and endoscopists.

Polyp detection rate and cumulative incidence of post-colonoscopy colorectal cancer in Germany

Studies have shown that the quality of colonoscopy influences the incidence of post-colonoscopy colorectal cancer (PCCRC). However, data from Germany on this association are lacking. We aimed to assess cumulative incidence of PCCRC in persons undergoing colonoscopy in Germany according to the physician's polyp detection rate (PDR). Using the German Pharmacoepidemiological Research Database (GePaRD) with claims data of ~20% of the German population, we included persons with a baseline colonoscopy between 2008 and 2017 and categorized them according to the procedure at baseline (snare polypectomy, forceps polypectomy, no polypectomy). In each subgroup, we distinguished between persons examined by physicians with a PDR in the lowest quartile vs higher quartiles and described cumulative CRC incidence during follow-up. Overall, 822 715 persons examined by 1752 physicians were included. One quarter of the physicians had a PDR ≤21.8% (lowest quartile). In all subgroups, the 5-year cumulative CRC incidence was statistically significantly higher in persons examined by physicians with a PDR ≤21.8% vs >21.8%: It was 69% higher in persons with snare polypectomy (0.88% vs 0.52%), 87% higher in persons with forceps polypectomy (0.58% vs 0.31%), and 48% higher in persons without polypectomy at baseline (0.31% vs 0.21%). In conclusion, we found a substantially increased PCCRC risk in persons examined by physicians with a low PDR in Germany, irrespective of the baseline findings. Our study highlights the importance of a high-quality colonoscopy to maximize the preventive effect of colonoscopy on CRC incidence.

Impact of Artificial Intelligence on Colonoscopy Surveillance After Polyp Removal: A Pooled Analysis of Randomized Trials

BACKGROUND AND AIMS

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.

METHODS

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.

RESULTS

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]).

CONCLUSIONS

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.

Colon Cancer Screening Methods: 2023 Update

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. National screening guidelines have been implemented to identify and remove precancerous polyps before they become cancer. Routine CRC screening is advised for people with average risk starting at age 45 because it is a common and preventable malignancy. Various screening modalities are currently in use, ranging from stool-based tests (fecal occult blood test (FOBT), fecal immunochemical test (FIT), and FIT-DNA test), radiologic tests (computed tomographic colonography (CTC), double contrast barium enema), and visual endoscopic examinations (flexible sigmoidoscopy (FS), colonoscopy, and colon capsule endoscopy (CCE)) with their varying sensitivity and specificity. Biomarkers also play a vital role in assessing the recurrence of CRC. This review offers a summary of the current screening options, including biomarkers available to detect CRC, highlighting the benefits and challenges encompassing each screening modality.

Endoscopic surveillance after surgery for colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide and its global incidence is rapidly increasing among adults younger than 50 years, especially in the 20-39 age group. Once a curative resection is achieved, surveillance is mandatory. Colonoscopy has a pivotal role aimed at resecting premalignant neoplasms and detecting cancer at a curable stage. In the current review, an update on the role of surveillance colonoscopy after CRC is provided, considered the most recent international guidelines and evidence published on this issue. In particular, several questions have been answered, why, how and how often colonoscopy should be performed, whether intensive surveillance is more effective than standard surveillance, how endoscopically resected T1 cancer should be followed, the different management existing between colon and rectal cancer, and, finally, how to improve the endoscopic surveillance. In a period of resource constraints, appropriateness will be mandatory, thus understanding how to optimize the role of colonoscopy in the surveillance of patients with a history of CRC is of crucial importance. Improving the quality of colonoscopy and identifying risk factors for recurrent and new-onset CRC, will allow us to individualize the surveillance program while sparing health care cost.

Quality indicators in the endoscopic detection of gastric cancer

Gastroscopy is the reference standard for the diagnosis of gastric cancer, but it is operator-dependent and associated with missed gastric cancer. The proliferation of gastroscopic examinations, increasingly for the screening and detection of subtle premalignant lesions, has motivated scrutiny of quality in gastroscopy. The concept of a high-quality endoscopic examination for the detection of superficial gastric neoplasia has been defined by expert guidelines to improve mucosal visualization, engender a systematic examination process and detect superficial neoplasia. This review discusses the evidence supporting the components of a high-quality diagnostic gastroscopic examination in relation to the detection of gastric cancer, and their potential role as procedural quality indicators to drive a structured improvement in clinically meaningful outcomes.

PREVALENCE OF SERRATED POLYPS AND THEIR ASSOCIATION WITH SYNCHRONOUS COLORECTAL ADVANCED ADENOMAS

•This study revealed a similar prevalence of clinically significant serrated polyps and advanced adenomas among patients who underwent colonoscopy. •Multivariate analysis demonstrated an association between clinically significant serrated polyps and synchronous advanced adenomas, though the strength of this association was stronger for proximal advanced adenomas. •Large serrated polyps and sessile serrated adenomas were associated with proximal advanced adenomas. Background - Serrated lesions are the precursors of up to one-third of colorectal cancer (CRC) cases and share molecular and epidemiological features with interval CRC. Previous studies have reported wide variation in serrated polyp prevalence and diverse magnitude of its relationship with synchronous advanced adenomas.Objective - Describe the prevalence of serrated polyps and evaluate their association with synchronous advanced adenomas. Methods - The study is a retrospective analysis of 1208 colonoscopies performed in patients aged 45 to 75, predominantly for CRC screening. Data on the prevalence of serrated polyps subsets and advanced adenomas were collected, and multivariate analysis were performed to identify the association between serrated polyps and synchronous advanced adenomas. Results - The prevalence of clinically significant serrated polyps (CSSP), large serrated polyps (LSP), and sessile serrated adenomas (SSA) were 11.3%, 6%, and 3.7%. CSSP were associated with synchronous advanced adenomas (OR 2.121, 95%CI 1.321-3.406), regardless of proximal (OR 2.966, 95%CI 1.701-5.170) or distal (OR 1.945, 95%CI 1.081-3.499) location, while LSP (OR 2.872, 95%CI 1.425-5.787) and SSA (OR 5.032, 95%CI 2.395-10.576) were associated with proximal advanced adenomas. Conclusion - The prevalence of CSSP and advanced adenomas were alike. CSSP is a risk factor for advanced adenomas, and the strength of this association is stronger for proximal advanced adenomas. LSP and SSA are associated with proximal advanced adenomas.

Is There a Difference in Adenoma Detection Rates According to Indication? An Experience in a Panamanian Colorectal Cancer Screening Program

Background

The benefit of colorectal cancer screening in reducing cancer risk and related death is unclear. There are quality measure indicators and multiple factors that affect the performance of a successful colonoscopy. The main objective of our study was to identify if there is a difference in polyp detection rate (PDR) and adenoma detection rate (ADR) according to colonoscopy indication and which factors might be associated.

Methods

We conducted a retrospective review of all colonoscopies performed between January 2018 and January 2019, in a tertiary endoscopic center. All patients ≥ 50 years old scheduled for a nonurgent colonoscopy and screening colonoscopy were included. We stratified the total number of colonoscopies into two categories according to the indication: screening vs. non-screening, and then calculated PDR, ADR and serrated polyp detection rate (SDR). We also performed logistic regression model to identify factors associated with detecting polyps and adenomatous polyps.

Results

A total of 1,129 and 365 colonoscopies were performed in the non-screening and screening group, respectively. In comparison with the screening group, PDR and ADR were lower for the non-screening group (33% vs. 25%; P = 0.005 and 17% vs. 13%; P = 0.005). SDR was non-significantly lower in the non-screening group when compared with the screening group (11% vs. 9%; P = 0.53 and 22% vs. 13%; P = 0.007).

Conclusion

In conclusion, this observational study reported differences in PDR and ADR depending on screening and non-screening indication. These differences could be related to factors related to the endoscopist, time slot allotted for colonoscopy, population background, and external factors.

A NORMOCALORIC, LOW-FIBER DIET FOR COLONOSCOPY PREPARATION IS MORE ACCEPTABLE AND NON-INFERIOR TO A LIQUID, LOW-CALORIE DIET: A RANDOMIZED CONTROLLED TRIAL

•This is the first study in Brazil about diets to prepare for colonoscopy. •The normocaloric diet was not inferior to the liquid diet regarding the quality of the colonoscopy preparation. •Both diets were well tolerated, but the normocaloric diet was more accepted than the liquid diet. Background - Several publications have shown greater acceptance of less restrictive diets for colonoscopy preparation, without impairing the quality of the preparation, when compared to the clear liquid diet. Objective - To evaluate the quality, tolerance and preference regarding the colonoscopy preparation of a low-fiber, normocaloric diet compared with a hypocaloric liquid diet. Methods - This is a randomized, controlled, observer-blind study to compare two low-fiber colonoscopy preparation diets (hypocaloric liquid diet vs. normocaloric diet). The Boston Bowel Preparation Scale was used to evaluate the qua-lity of the preparations, being considered adequate BBPS ≥6 in the global assessment and ≥2 in each segment. The same laxative was used in both groups as well as the "split-dose" regimen. Results - A total of 136 individuals were enrolled in each group. Adequate preparation was achieved in 90.4% of the individuals allocated to the liquid diet group and 92.6% to the normocaloric group. There was no significant difference in the quality of preparation and tolerance between groups. A higher patient acceptance to repeat the procedure if necessary was observed in the normocaloric diet group compared with the liquid diet group (P=0.005). Conclusion - The normocaloric diet has shown to be not inferior to the liquid diet regarding the quality of the colonoscopy preparation. Patient tolerance rates were similar between both diets, but a higher accep-tance rate was observed with the normocaloric diet as compared with the liquid diet.

A Review of Colonoscopy in Intestinal Diseases

Since the development of the fiberoptic colonoscope in the late 1960s, colonoscopy has been a useful tool to diagnose and treat various intestinal diseases. This article reviews the clinical use of colonoscopy for various intestinal diseases based on present and future perspectives. Intestinal diseases include infectious diseases, inflammatory bowel disease (IBD), neoplasms, functional bowel disorders, and others. In cases of infectious diseases, colonoscopy is helpful in making the differential diagnosis, revealing endoscopic gross findings, and obtaining the specimens for pathology. Additionally, colonoscopy provides clues for distinguishing between infectious disease and IBD, and aids in the post-treatment monitoring of IBD. Colonoscopy is essential for the diagnosis of neoplasms that are diagnosed through only pathological confirmation. At present, malignant tumors are commonly being treated using endoscopy because of the advancement of endoscopic resection procedures. Moreover, the characteristics of tumors can be described in more detail by image-enhanced endoscopy and magnifying endoscopy. Colonoscopy can be helpful for the endoscopic decompression of colonic volvulus in large bowel obstruction, balloon dilatation as a treatment for benign stricture, and colon stenting as a treatment for malignant obstruction. In the diagnosis of functional bowel disorder, colonoscopy is used to investigate other organic causes of the symptom.

One-year review of real-time artificial intelligence (AI)-aided endoscopy performance

BACKGROUND

Colonoscopies have long been the gold standard for detection of pre-malignant neoplastic lesions of the colon. Our previous study tried real-time artificial intelligence (AI)-aided colonoscopy over a three-month period and found significant improvements in collective and individual endoscopist's adenoma detection rates compared to baseline. As an expansion, this study evaluates the 1-year performance of AI-aided colonoscopy in the same institution.

METHODS

A prospective cohort study was conducted in a single institution in Singapore. The AI software used was GI Genius™ Intelligent Endoscopy Module, US-DG-2000309 © 2021 Medtronic. Between July 2021 and June 2022, polypectomy rates in non-AI-aided colonoscopies and AI-aided colonoscopies were calculated and compared. Some of the AI-aided colonoscopies were recorded and video reviewed. A "hit" was defined as a sustained detection of an area by the AI. If a polypectomy was performed for a "hit," its histology was reviewed. Additional calculations for polyp detection rate (PDR), adenoma detection rate (ADR), and adenoma detection per colonoscopy (ADPC) were performed. Cost analysis was performed to determine cost effectiveness of subscription to the AI program.

RESULTS

2433 AI-aided colonoscopies were performed between July 2021 and June 2022 and compared against 1770 non-AI-aided colonoscopies. AI-aided colonoscopies yielded significantly higher rates of polypectomies (33.6%) as compared with non-AI-aided colonoscopies (28.4%) (p < 0.001). Among the AI-aided colonoscopies, 1050 were reviewed and a final 843 were included for additional analysis. The polypectomy to "hit" ratio was 57.4%, PDR = 45.6%, ADR = 32.4%, and ADPC = 2.08. Histological review showed that 25 polyps (3.13%) were sessile-serrated adenomas. Cost analysis found that the increased polypectomy rates in AI-aided colonoscopes led to an increase in revenue, which covered the subscription cost with an excess of USD 20,000.

CONCLUSION

AI-aided colonoscopy is a cost effective means of improving colonoscopy quality and may help advance colorectal cancer screening in Singapore.

Chemoresistive Nanosensors Employed to Detect Blood Tumor Markers in Patients Affected by Colorectal Cancer in a One-Year Follow Up

Colorectal cancer (CRC) represents 10% of the annual tumor diagnosis and deaths occurring worldwide. Given the lack of specific symptoms, which could determine a late diagnosis, the research for specific CRC biomarkers and for innovative low-invasive methods to detect them is crucial. Therefore, on the basis of previously published results, some volatile organic compounds (VOCs), detectable through gas sensors, resulted in particularly promising CRC biomarkers, making these sensors suitable candidates to be employed in CRC screening devices. A new device was employed here to analyze the exhalations of blood samples collected from CRC-affected patients at different stages of their pre- and post-surgery therapeutic path, in order to assess the sensor’s capability for discriminating among these samples. The stages considered were: the same day of the surgical treatment (T1); before the hospital discharge (T2); after one month and after 10–12 months from surgery (T3 and T4, respectively). This device, equipped with four different sensors based on different metal–oxide mixtures, enabled a distinction between T1 and T4 with a sensitivity and specificity of 93% and 82%, respectively, making it suitable for clinical follow-up protocols, patient health status monitoring and to detect possible post-treatment relapses.

Artificial Intelligence-Aided Endoscopy and Colorectal Cancer Screening

Colorectal cancer (CRC) is the third most common cancer worldwide, with the highest incidence reported in high-income countries. However, because of the slow progression of neoplastic precursors, along with the opportunity for their endoscopic detection and resection, a well-designed endoscopic screening program is expected to strongly decrease colorectal cancer incidence and mortality. In this regard, quality of colonoscopy has been clearly related with the risk of post-colonoscopy colorectal cancer. Recently, the development of artificial intelligence (AI) applications in the medical field has been growing in interest. Through machine learning processes, and, more recently, deep learning, if a very high numbers of learning samples are available, AI systems may automatically extract specific features from endoscopic images/videos without human intervention, helping the endoscopists in different aspects of their daily practice. The aim of this review is to summarize the current knowledge on AI-aided endoscopy, and to outline its potential role in colorectal cancer prevention.

The Effect of Serum Leptin Concentration and Leptin Receptor Expression on Colorectal Cancer

INTRODUCTION

The level of leptin in the blood shows a positive, strong correlation with the mass of adipose tissue. Being overweight and having metabolic disorders increase the risk of developing colorectal cancer.

AIM OF THE PAPER

The aim of the study was to assess the concentration of leptin in the blood serum as well as the expression of the leptin receptor in colorectal cancer cells. In addition, the effect of serum leptin concentration and leptin receptor expression on clinical and pathological parameters such as BMI, obesity, TNM, and tumor size was assessed.

METHODS

The study included 61 patients diagnosed with colorectal cancer and treated with surgery.

RESULTS

Strong leptin receptor expression and the prevalence of overweight and obesity are factors influencing the occurrence of excessive leptin concentrations.

CONCLUSION

Leptin may be involved in the development and progression of colorectal cancer. More research is needed to better elucidate the role of leptin in the development and progression of the disease.

Non-steroidal anti-inflammatory drugs and biomarkers: A new paradigm in colorectal cancer

Colorectal cancer is a sporadic, hereditary, or familial based disease in its origin, caused due to diverse set of mutations in large intestinal epithelial cells. Colorectal cancer (CRC) is a common and deadly disease that accounts for the 4th worldwide highly variable malignancy. For the early detection of CRC, the most common predictive biomarker found endogenously are KRAS and ctDNA/cfDNA along with SEPT9 methylated DNA. Early detection and screening for CRC are necessary and multiple methods can be employed to screen and perform early diagnosis of CRC. Colonoscopy, an invasive method is most prevalent for diagnosing CRC or confirming the positive result as compared to other screening methods whereas several non-invasive techniques such as molecular analysis of breath, urine, blood, and stool can also be performed for early detection. Interestingly, widely used medicines known as non-steroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation have reported chemopreventive impact on gastrointestinal malignancies, especially CRC in several epidemiological and preclinical types of research. NSAID acts by inhibiting two cyclooxygenase enzymes, thereby preventing the synthesis of prostaglandins (PGs) and causing NSAID-induced apoptosis and growth inhibition in CRC cells. This review paper majorly focuses on the diversity of natural and synthetic biomarkers and various techniques for the early detection of CRC. An approach toward current advancement in CRC detection techniques and the role of NSAIDs in CRC chemoprevention has been explored systematically. Several prominent governing mechanisms of the anti-cancer effects of NSAIDs and their synergistic effect with statins for an effective chemopreventive measure have also been discussed in this review paper.

Delphi Initiative for Early-Onset Colorectal Cancer (DIRECt) International Management Guidelines

BACKGROUND & AIMS

Patients with early-onset colorectal cancer (eoCRC) are managed according to guidelines that are not age-specific. A multidisciplinary international group (DIRECt), composed of 69 experts, was convened to develop the first evidence-based consensus recommendations for eoCRC.

METHODS

After reviewing the published literature, a Delphi methodology was used to draft and respond to clinically relevant questions. Each statement underwent 3 rounds of voting and reached a consensus level of agreement of ≥80%.

RESULTS

The DIRECt group produced 31 statements in 7 areas of interest: diagnosis, risk factors, genetics, pathology-oncology, endoscopy, therapy, and supportive care. There was strong consensus that all individuals younger than 50 should undergo CRC risk stratification and prompt symptom assessment. All newly diagnosed eoCRC patients should receive germline genetic testing, ideally before surgery. On the basis of current evidence, endoscopic, surgical, and oncologic treatment of eoCRC should not differ from later-onset CRC, except for individuals with pathogenic or likely pathogenic germline variants. The evidence on chemotherapy is not sufficient to recommend changes to established therapeutic protocols. Fertility preservation and sexual health are important to address in eoCRC survivors. The DIRECt group highlighted areas with knowledge gaps that should be prioritized in future research efforts, including age at first screening for the general population, use of fecal immunochemical tests, chemotherapy, endoscopic therapy, and post-treatment surveillance for eoCRC patients.

CONCLUSIONS

The DIRECt group produced the first consensus recommendations on eoCRC. All statements should be considered together with the accompanying comments and literature reviews. We highlighted areas where research should be prioritized. These guidelines represent a useful tool for clinicians caring for patients with eoCRC.