Adenoma miss rates associated with a 3-minute versus 6-minute colonoscopy withdrawal time: a prospective, randomized trial

Effect of Real-Time Computer-Aided Polyp Detection System (ENDO-AID) on Adenoma Detection in Endoscopists-in-Training: A Randomized Trial

BACKGROUND

The effect of computer-aided polyp detection (CADe) on adenoma detection rate (ADR) among endoscopists-in-training remains unknown.

METHODS

We performed a single-blind, parallel-group, randomized controlled trial in Hong Kong between April 2021 and July 2022 (NCT04838951). Eligible subjects undergoing screening/surveillance/diagnostic colonoscopies were randomized 1:1 to receive colonoscopies with CADe (ENDO-AID[OIP-1]) or not (control) during withdrawal. Procedures were performed by endoscopists-in-training with <500 procedures and <3 years' experience. Randomization was stratified by patient age, sex, and endoscopist experience (beginner vs intermediate level, <200 vs 200-500 procedures). Image enhancement and distal attachment devices were disallowed. Subjects with incomplete colonoscopies or inadequate bowel preparation were excluded. Treatment allocation was blinded to outcome assessors. The primary outcome was ADR. Secondary outcomes were ADR for different adenoma sizes and locations, mean number of adenomas, and non-neoplastic resection rate.

RESULTS

A total of 386 and 380 subjects were randomized to CADe and control groups, respectively. The overall ADR was significantly higher in the CADe group than in the control group (57.5% vs 44.5%; adjusted relative risk, 1.41; 95% CI, 1.17-1.72; P < .001). The ADRs for <5 mm (40.4% vs 25.0%) and 5- to 10-mm adenomas (36.8% vs 29.2%) were higher in the CADe group. The ADRs were higher in the CADe group in both the right colon (42.0% vs 30.8%) and left colon (34.5% vs 27.6%), but there was no significant difference in advanced ADR. The ADRs were higher in the CADe group among beginner (60.0% vs 41.9%) and intermediate-level (56.5% vs 45.5%) endoscopists. Mean number of adenomas (1.48 vs 0.86) and non-neoplastic resection rate (52.1% vs 35.0%) were higher in the CADe group.

CONCLUSIONS

Among endoscopists-in-training, the use of CADe during colonoscopies was associated with increased overall ADR. (ClinicalTrials.gov, Number: NCT04838951).

What are the priority quality indicators for colonoscopy in real-world clinical practice?

Colonoscopy is widely used as a colorectal cancer (CRC) screening tool. The effectiveness of a screening colonoscopy is associated with a decreased risk of CRC. However, colonoscopy is an operator-dependent procedure, and endoscopists' quality performance varies widely. This article reviewed the priority metrics and practices that contribute to high-quality screening colonoscopy in real-world clinical practice. With growing evidence, quality indicators have been subject to intense research and associated with reducing postcolonoscopy CRC incidence and mortality. Some quality metrics can reflect an endoscopy unit-based practice (i.e. quality of bowel preparation and withdrawal time). Other quality indicators primarily reflect individuals' skill and knowledge (i.e. cecal intubation rate, adenoma detection rate, and appropriately assigned follow-up colonoscopy interval). Measurement and improvement of priority quality indicators for colonoscopy should be made at both the endoscopist and unit levels. Substantial evidence supports the impact of high-quality colonoscopy in reducing the incidence of postcolonoscopy CRC.

Clinical and endoscopic characteristics and management of 220 cases with serrated polyps

BACKGROUND

Serrated polyps are considered the precursor lesions of colorectal cancer through the serrated pathway. In the present study, we aimed to evaluate and discuss the clinical and endoscopic characteristics and management of serrated polyps.

METHODS

The data of 220 cases with serrated polyps between September 2018 and November 2021 in Shenzhen People's Hospital were retrospectively analyzed.

RESULTS

Of all these cases, 32 were hyperplastic polyps, 36 were traditional serrated adenomas, 126 were sessile serrated lesions, 25 were SSLs with dysplasia, and one was an unclassified serrated adenoma. Although most patients were males aged ≥50 years and most serrated polyps were located in the distal colon and rectum with a size of 6-10 mm and the shape of type 0-Is, there was no significant difference (P > 0.05). Serrated polyps of ≤5 mm in size and type 0-IIa were mostly removed by cold biopsy forceps. Cold snare polypectomy was primarily used for those of 6-10 mm in size. Endoscopic mucosal resection was used for those of 6-20 mm, and endoscopic submucosal dissection was used for those of ≥20 mm (P < 0.05). All complications occurred in SSL patients with or without dysplasia (P < 0.05).

CONCLUSIONS

Clinical and endoscopic characteristics were beneficial for distinguishing and diagnosing serrated polyps. In addition, management options were crucial to prevent recurrence and progression. However, the detection rate of serrated polyps was relatively low. Therefore, prospective multicenter studies with large samples are necessary to better assess colorectal serrated polyps.

Effectiveness of switching endoscopists for repeat surveillance colonoscopy: a retrospective study

BACKGROUND

Surveillance colonoscopy decreases colorectal cancer mortality; however, lesions are occasionally missed. Although an appropriate surveillance interval is indicated, variations may occur in the methods used, such as scope manipulation or observation. Therefore, individual endoscopists may miss certain areas. This study aimed to verify the effectiveness of performing repeat colonoscopies with a different endoscopist from the initial procedure.

METHODS

We retrospectively reviewed a database of 8093 consecutive colonoscopies performed in the Omori Red Cross Hospital from January 1st 2018 to June 30th 2021. Data from repeat total colonoscopies performed within three months were collected to assess missed lesions. The patients were divided into two groups according to whether the two examinations were performed by different endoscopists (group D) or the same endoscopist (group S). The primary outcome in both groups was the missed lesion detection rate (MLDR).

RESULTS

Overall, 205 eligible patients were analyzed. In total, 102 and 103 patients were enrolled in groups D and S, respectively. The MLDR was significantly higher in group D (61.8% vs. 31.1%, P < 0.0001). Multivariate logistic regression analysis for the detection of missed lesions identified performance by the different endoscopists (odds ratio, 3.38; 95% CI, 1.81-6.30), and sufficient withdrawal time (> 6 min) (odds ratio, 3.10; 95% CI, 1.12-8.61) as significant variables.

CONCLUSIONS

Overall, our study showed a significant improvement in the detection of missed lesions when performed by different endoscopists. When performing repeat colonoscopy, it is desirable that a different endoscopist perform the second colonoscopy.

TRIAL REGISTRATION

This study was approved by the Institutional Review Board of the Omori Red Cross Hospital on November 28, 2022 (approval number:22-43).

Sedation Is Associated with Higher Polyp and Adenoma Detection Rates during Colonoscopy: A Retrospective Cohort Study

Background and Aims

Currently sedation is a common practice in colonoscopy to reduce pain of patients and improve the operator satisfaction, whereas its impact on examination quality, especially adenoma detection rate (ADR) is still controversial. Thus, we aimed to investigate the association of sedation with ADR.

Methods

Consecutive patients receiving colonoscopy between January 2017 and January 2020 at the Nanjing Drum Tower Hospital, Nanjing, China, were collected. Univariate and multivariate logistic regression models were performed to investigate the association between sedation and ADR. Subgroup analysis and propensity score matching (PSM) analysis, as sensitivity analysis, were performed to validate the independent effect.

Results

The ADR was significantly higher in cases with sedation (ADR: 36.9% vs. 29.1%, odds ratio [OR]: 1.42, 95% confidence interval [CI]: 1.31-1.55, P < 0.001). Multivariate analysis showed that the sedation was an independent factor associated with ADR (OR: 1.49, 95% CI: 1.35-1.65, P < 0.001). The effect was consistent in subgroup analyses (P > 0.05) and PSM analysis (ADR: 37.6% vs. 29.1%, OR: 1.47, 95% CI: 1.33-1.63, P < 0.001).

Conclusion

Sedation was associated with a higher polyp and ADR s during colonoscopy, which can promote the quality of colonoscopy.

Factors Associated with Difficulty Maintaining Insufflation of the Colon During Endoscopy

BACKGROUND

Insufflation of the colon allows for adequate visualization of the mucosal tissue and advancement of the endoscope during colonoscopy. Most colonoscopies are performed with sedation to mitigate discomfort and enhance the colonoscopy experience for both the patient and the endoscopist.

AIM

We aimed to evaluate factors associated with difficulty maintaining insufflation.

METHODS

A cross-sectional study of individuals undergoing colonoscopy at the Oklahoma City Veterans Affairs Medical Center was performed. Experiencing difficulty maintaining air insufflation during colonoscopy was assessed with a questionnaire completed by the performing endoscopist at the end of procedure. Information regarding procedure times, sedation used, demographics, comorbidities, surgical history, and medications used was extracted from the medical record. A multivariate regression analysis was performed to identify factors associated with difficulty maintaining air insufflation. A P value < 0.05 was considered significant.

RESULTS

996 Patients were included for the analysis. Difficulty with insufflation was reported in 240 (24%) colonoscopies; mean age of 63.8 ± 10.4 years old and 13% were female. Fellow trainees were involved in 669 (67%) colonoscopies. Older age (OR 1.02, P 0.03, CI [1.00-1.04]), diabetes (OR 1.5, 95% CI [1.03, 2.05]), fellow's involvement (OR 2.6. (95% CI [1.68, 4.09]), total procedure time (OR 1.02, 95% CI [1.00, 1.03]), mean number of adenomas (OR 1.05, 95% CI [1.00, 1.09]), and MAC use (OR 2.6, 95% CI [1.80, 3.85]) were independent predictors for difficulty in maintaining air insufflation.

CONCLUSION

Our findings suggest that endoscopists should be cognizant of colon insufflation issues in older, diabetic patients undergoing colonoscopies under deep sedation, particularly if prolonged procedure is anticipated or encountered.

Automated Detection of Bowel Preparation Scoring and Adequacy With Deep Convolutional Neural Networks

INTRODUCTION

Adequate bowel preparation is integral to effective colonoscopy. Inadequate bowel preparation has been associated with reduced adenoma detection rate and increased post-colonoscopy colorectal cancer (PCCRC). As a result, the USMSTF recommends early interval reevaluation for colonoscopies with inadequate bowel preparation. However, bowel preparation documentation is highly variable with subjective interpretation. In this study, we developed deep convolutional neural networks (DCNN) to objectively ascertain bowel preparation.

METHODS

Bowel preparation scores were assigned using the Boston Bowel Preparation Scale (BBPS). Bowel preparation adequacy and inadequacy were defined as BBPS ≥2 and BBPS <2, respectively. A total of 38523 images were extracted from 28 colonoscopy videos and split into 26966 images for training, 7704 for validation, and 3853 for testing. Two DCNNs were created using a Densenet-169 backbone in PyTorch library evaluating BBPS score and bowel preparation adequacy. We used Adam optimiser with an initial learning rate of 3 × 10-4 and a scheduler to decay the learning rate of each parameter group by 0.1 every 7 epochs along with focal loss as our criterion for both classifiers.

RESULTS

The overall accuracy for BBPS subclassification and determination of adequacy was 91% and 98%, respectively. The accuracy for BBPS 0, BBPS 1, BBPS 2, and BBPS 3 was 84%, 91%, 85%, and 96%, respectively.

CONCLUSION

We developed DCCNs capable of assessing bowel preparation adequacy and scoring with a high degree of accuracy. However, this algorithm will require further research to assess its efficacy in real-time colonoscopy.

Reduced Adenoma Miss Rate With 9-Minute vs 6-Minute Withdrawal Times for Screening Colonoscopy: A Multicenter Randomized Tandem Trial

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.

Establishment and evaluation of a nomogram predicting risks of missed diagnoses of colorectal polyps

Background

A missed diagnosis of colorectal polyps during colonoscopy may be associated with the occurrence of interval colorectal cancer. The risk factors for a missed diagnosis or a method to predict the risk of a missed diagnosis of colorectal polyps during colonoscopy remain unidentified.

Methods

The clinical data of patients who underwent two colonoscopies within three months at the Affiliated Hospital of North Sichuan Medical College between February 2017 and August 2019 were retrospectively reviewed. Independent risk factors for missed diagnoses were identified, and a nomogram was established to predict the risk of missed diagnoses. The prediction performance of the nomogram was evaluated using C-index and calibration curves, and its clinical application value was assessed using the Youden index and decision curve analysis.

Results

Independent influencing factors for missed diagnoses included age, endoscopist experience, bowel preparation, retroflected view, withdrawal time, number of polyps in the right colon, and number of polyps ≥ 6 mm. The C-index of the nomogram in the training and validation cohorts was 0.763 (95% confidence interval [CI]: 0.724 − 0.807) and 0.726 (95%CI: 0.657 − 0.794), respectively. The optimal cut-off value of the nomogram calculated using the Youden index was 152.2 points. Under the cut-off value, the sensitivity, specificity, positive predictive value, and negative predictive value were 67.1%, 75.7%, 45.8%, and 88.2%, respectively, in the training cohort, and 57.1%, 79.9%, 53.3%, and 82.3%, respectively, in the validation cohort.

Conclusions

The nomogram provides a reference value for clinicians to analyse the risk of a missed diagnosis of colorectal polyps in individuals, identify high-risk groups, and formulate appropriate follow-up strategies.

Detection of colorectal lesions during colonoscopy

Owing to its high mortality rate, the prevention of colorectal cancer is of particular importance. The resection of colorectal polyps is reported to drastically reduce colorectal cancer mortality, and examination by endoscopists who had a high adenoma detection rate was found to lower the risk of colorectal cancer, highlighting the importance of identifying lesions. Various devices, imaging techniques, and diagnostic tools aimed at reducing the rate of missed lesions have therefore been developed to improve detection. The distal attachments and devices for improving the endoscopic view angle are intended to help avoid missing blind spots such as folds and flexures in the colon, whereas the imaging techniques represented by image‐enhanced endoscopy contribute to improving lesion visibility. Recent advances in artificial intelligence‐supported detection systems are expected to supplement an endoscopist's eye through the instant diagnosis of the lesions displayed on the monitor. In this review, we provide an outline of each tool and assess its impact on the reduction in the incidence of missed colorectal polyps by summarizing previous clinical research and meta‐analyses. Although useful, the many devices, image‐enhanced endoscopy, and artificial intelligence tools exhibited various limitations. Integrating these tools can improve their shortcomings. Combining artificial intelligence‐based diagnoses with wide‐angle image‐enhanced endoscopy may be particularly useful. Thus, we hope that such tools will be available in the near future.

Factors Associated with Withdrawal Time in European Colonoscopy Practice: Findings of the European Colonoscopy Quality Investigation (ECQI) Group

The European Colonoscopy Quality Investigation (ECQI) Group aims to raise awareness for improvement in colonoscopy standards across Europe. We analyzed data collected on a sample of procedures conducted across Europe to evaluate the achievement of the European Society of Gastrointestinal Endoscopy (ESGE) mean withdrawal time (WT) target. We also investigated factors associated with WT, in the hope of establishing areas that could lead to a quality improvement. Methods: 6445 form completions from 12 countries between 2 June 2016 and 30 April 2018 were considered for this analysis. We performed an exploratory analysis looking at WT according to the ESGE definition. Stepwise multivariable logistic regression analysis was conducted to determine the most influential associated factors after adjusting for the other pre-specified variables. Results: In 1150 qualifying colonoscopies, the mean WT was 7.8 min. Stepwise analysis, including 587 procedures where all inputs were known, found that the variables most associated with mean WT were a previous total colonoscopy in the last five years (p = 0.0011) and the time of day the colonoscopy was performed (p = 0.0192). The main factor associated with a WT < 6 min was the time of day that a colonoscopy was performed. Use of sedation was the main factor associated with a higher proportion of WT > 10 min, along with a previous colonoscopy. Conclusions: On average, the sample of European practice captured by the ECQI survey met the minimum standard set by the ESGE. However, there was variation and potential for improvement.

Impact of 9-Minute Withdrawal Time on the Adenoma Detection Rate: A Multicenter Randomized Controlled Trial

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).

A comparison of 9-min colonoscopy withdrawal time and 6-min colonoscopy withdrawal time: A systematic review and meta-analysis

INTRODUCTION

The optimal colonoscopy withdrawal time is still a controversial topic. While several studies demonstrate that longer withdrawal time improves adenoma detection rate, others have contradicted these findings.

METHODS

Three independent reviewers performed a comprehensive review of all original articles published from inception to January 2021 and included studies reporting comparison of the two cohorts-(i) ≥ 6 but less than 9 min of colonoscopy withdrawal time (CWT) and (ii) ≥ 9 min of CWT. The outcome measures were the following: (i) adenoma detection rate (ADR), (ii) advanced ADR, and (iii) sessile serrated adenoma detection rate (SDR). The meta-analysis was performed, and the statistics were two-tailed.

RESULTS

A total of seven studies met the inclusion criteria after a thorough search of the literature was completed. The analysis revealed that ≥ 9 min of CWT had significantly higher odds of adenoma detection as compared with 6-9 min of CWT (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.30-1.82; I²  = 93.7). Additionally, a significantly higher odds of sessile serrated adenoma detection (OR 1.68, 95% CI 1.28-2.22; I²  = 0) and a trend towards higher odds of advanced adenoma detection (OR 1.38, 95% CI 0.98-1.95, I²  = 90) were seen with CWT of at least 9 min when compared with 6-9 min of CWT.

CONCLUSION

This systematic review and meta-analysis analysis provides further evidence that at least 9 min of CWT cohort had significantly higher ADR and SDR as compared with the at least 6 min but less than 9 min of cohort.

Comparison of Right Colon Adenoma Miss Rates Between Water Exchange and Carbon Dioxide Insufflation: A Prospective Randomized Controlled Trial

GOALS

To test the hypothesis that water exchange (WE), when compared with carbon dioxide (CO2) insufflation, significantly reduces the right colon adenoma miss rate (rAMR) in a blinded randomized controlled trial with cap-assisted colonoscopy.

BACKGROUND

The unblinded consecutive group observational data showed that WE significantly decreased rAMR. The unblinded data are limited by potential bias.

STUDY

Consecutive patients aged 45 years or more were randomized to undergo insertion with WE or CO2. Withdrawal and polypectomy were performed with CO2 in both groups to the hepatic flexure. The colonoscope was reinserted to the cecum. A second colonoscopist re-examined the right colon. The second colonoscopist was unaware, but made a guess, of the initial insertion method. The number of additional adenomas divided by the total number detected in both examinations equaled rAMR.

RESULTS

Among 262 patients (131/group), demographic variables were similar. The body mass index was significantly higher in the WE group. Compared with CO2, WE significantly decreased rAMR [18.0% (33/183) vs. 34.6% (62/179), P=0.0025] and right colon serrated polyp miss rate [17.4% (27/155) vs. 39.3% (33/84), P=0.002]. Multivariate logistic regression analysis showed that WE was an independent predictor of rAMR (odds ratio, 0.42; 95% confidence interval, 0.21-0.86), and so was ≥2 adenomas in the right colon (odds ratio, 2.35; 95% confidence interval, 1.17-4.76). Whether the second colonoscopist guessed the insertion method correctly or not, and demographic and procedure variables were not associated with rAMR.

CONCLUSIONS

The randomized controlled trial validated unblinded observational data showing that WE significantly decreased rAMR and right colon serrated polyp miss rate (clinical trial registration number: NCT03845933).

A New Dawn for the Use of Artificial Intelligence in Gastroenterology, Hepatology and Pancreatology

Artificial intelligence (AI) is rapidly becoming an essential tool in the medical field as well as in daily life. Recent developments in deep learning, a subfield of AI, have brought remarkable advances in image recognition, which facilitates improvement in the early detection of cancer by endoscopy, ultrasonography, and computed tomography. In addition, AI-assisted big data analysis represents a great step forward for precision medicine. This review provides an overview of AI technology, particularly for gastroenterology, hepatology, and pancreatology, to help clinicians utilize AI in the near future.

Surveillance of Colorectal Cancer (CRC) in Cystic Fibrosis (CF) Patients

Cystic Fibrosis (CF) is the commonest inherited genetic disorder in Caucasians due to a mutation in the gene CFTR (Cystic Fibrosis Transmembrane Conductance Regulator), and it should be considered as an Inherited Colorectal Cancer (CRC) Syndrome. In the United States, physicians of CF Foundation established the “Developing Innovative Gastroenterology Speciality Training Program” to increase the research on CF in gastrointestinal and hepatobiliary diseases. The risk to develop a CRC is 5–10 times higher in CF patients than in the general population and even greater in CF patients receiving immunosuppressive therapy due to organ transplantation (30-fold increased risk relative to the general population). Colonoscopy should be considered the best screening for CRC in CF patients. The screening colonoscopy should be started at the age of 40 in CF patients and, if negative, a new colonoscopy should be performed every 5 years and every 3 years if adenomas are detected. For transplanted CF patients, the screening colonoscopy could be started at the age of 35, in transplanted patients at the age of 30 and, if before, at the age of 30. CF transplanted patients, between the age of 35 and 55, must repeat colonoscopy every 3 years. Our review draws attention towards the clinically relevant development of CRC in CF patients, and it may pave the way for further screenings and studies.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Real-time use of a computer-aided system for polyp detection during colonoscopy, an ambispective study

OBJECTIVE

This study aimed to evaluate ambispectively the effectiveness of a real-time computer-aided detection (CADe) system on the number of polyp (PPC) or adenoma per colonoscopy (APC), and polyp (PDR) or adenoma detection rate (ADR).

METHODS

Eight-five videos marked using the CADe system, together with the unmarked videos, were reviewed by two senior endoscopists. Polyps detected in the marked and unmarked videos were recounted in parallel. Additionally, 128 consecutive patients were enrolled for a prospective evaluation using a standard colonoscopy or the CADe monitor alternately every 2 weeks. The PC, APC, PDR and ADR were compared between the two groups.

RESULTS

The total number of polyps reported in the unmarked and marked videos were 73 and 88, respectively (mean PPC 0.86 vs 1.04, P = 0.001). The proportion of polyps detected per colonoscopy increased by 20.5%. Of the 128 prospectively enrolled patients, 186 polyps were detected. The mean PPC was higher in the CADe colonoscopy than in the standard colonoscopy (1.66 vs 1.13, P = 0.039). The PDR using the CADe colonoscopy was significantly higher than that of the standard colonoscopy (78.1% vs 56.3%, P = 0.008).

CONCLUSION

Real-time CADe system significantly increases the PDR and PPC under the situation of a high rate of polyp detection.

New polyp image classification technique using transfer learning of network-in-network structure in endoscopic images

While colorectal cancer is known to occur in the gastrointestinal tract. It is the third most common form of cancer of 27 major types of cancer in South Korea and worldwide. Colorectal polyps are known to increase the potential of developing colorectal cancer. Detected polyps need to be resected to reduce the risk of developing cancer. This research improved the performance of polyp classification through the fine-tuning of Network-in-Network (NIN) after applying a pre-trained model of the ImageNet database. Random shuffling is performed 20 times on 1000 colonoscopy images. Each set of data are divided into 800 images of training data and 200 images of test data. An accuracy evaluation is performed on 200 images of test data in 20 experiments. Three compared methods were constructed from AlexNet by transferring the weights trained by three different state-of-the-art databases. A normal AlexNet based method without transfer learning was also compared. The accuracy of the proposed method was higher in statistical significance than the accuracy of four other state-of-the-art methods, and showed an 18.9% improvement over the normal AlexNet based method. The area under the curve was approximately 0.930 ± 0.020, and the recall rate was 0.929 ± 0.029. An automatic algorithm can assist endoscopists in identifying polyps that are adenomatous by considering a high recall rate and accuracy. This system can enable the timely resection of polyps at an early stage.

Segmental Withdrawal During Screening Colonoscopy Does Not Increase Adenoma Detection Rate

OBJECTIVES

The aim of this study was to compare a standard versus segmental withdrawal during screening colonoscopy and its effect on the adenoma detection rate (ADR).

METHODS

We performed a single-center clinical trial of average-risk patients 50 years of age and older undergoing screening colonoscopy. Patients were randomized into four groups: a standard withdrawal of at least 6 or 8 minutes and a segmental withdrawal, in which ≥3 or ≥4 minutes were dedicated to the right side of the colon, with a minimum withdrawal time of at least 6 or 8 minutes, respectively.

RESULTS

There were 311 patients in the study. There was no difference in ADR between the standard and segmental groups (relative ratio [RR] 0.91, P = 0.50), even after stratifying for right-sided adenomas. During standard withdrawal, an increased continuous withdrawal time was associated with a higher ADR (RR 1.08, P <0.001) and total adenomas per patient (RR 1.12, P < 0.001). A binary analysis of ≥8 minutes or <8 minutes withdrawal was associated with an increased adenomas per colonoscopy (RR 1.86, P = 0.04). These differences were not observed in the segmental group.

CONCLUSIONS

Overall, there was no benefit from a segmental withdrawal protocol on ADR, but this may have been the result of the inherent limitations in the study design. After sensitivity analysis, a segmental withdrawal protocol led to an improvement in the detection of adenomas per colonoscopy and polyps per colonoscopy. A larger sample size is needed to confirm these findings.

Artificial intelligence in gastrointestinal endoscopy. VideoGIE. 2020;5:598-613. [PMID: 33319126 PMCID: PMC7732722 DOI: 10.1016/j.vgie.2020.08.013]

Background and Aims

Artificial intelligence (AI)-based applications have transformed several industries and are widely used in various consumer products and services. In medicine, AI is primarily being used for image classification and natural language processing and has great potential to affect image-based specialties such as radiology, pathology, and gastroenterology (GE). This document reviews the reported applications of AI in GE, focusing on endoscopic image analysis.

Methods

The MEDLINE database was searched through May 2020 for relevant articles by using key words such as machine learning, deep learning, artificial intelligence, computer-aided diagnosis, convolutional neural networks, GI endoscopy, and endoscopic image analysis. References and citations of the retrieved articles were also evaluated to identify pertinent studies. The manuscript was drafted by 2 authors and reviewed in person by members of the American Society for Gastrointestinal Endoscopy Technology Committee and subsequently by the American Society for Gastrointestinal Endoscopy Governing Board.

Results

Deep learning techniques such as convolutional neural networks have been used in several areas of GI endoscopy, including colorectal polyp detection and classification, analysis of endoscopic images for diagnosis of Helicobacter pylori infection, detection and depth assessment of early gastric cancer, dysplasia in Barrett’s esophagus, and detection of various abnormalities in wireless capsule endoscopy images.

Conclusions

The implementation of AI technologies across multiple GI endoscopic applications has the potential to transform clinical practice favorably and improve the efficiency and accuracy of current diagnostic methods.

Relationship between serrated polyps and synchronous and metachronous advanced neoplasia: A retrospective study

OBJECTIVE

Serrated polyps (SP) are regarded as precursor lesions of colorectal cancer (CRC). We conducted this single-center study aiming to investigate the relationship between SP and synchronous and metachronous advanced neoplasia in the Chinese population.

METHODS

The data for this retrospective study were collected from the Endoscopy Center and Department of Gastroenterology of Renji Hospital, School of Medicine, Shanghai Jiao Tong University between May 2012 and May 2019. Altogether 2205 patients were pathologically confirmed with colorectal SP.

RESULTS

The detection rate of SP among all polyps has gradually increased since 2014 and reached 8.74% by 2019. Among all the SP cases, 1540 (69.84%) were confirmed as having hyperplasic polyps (HP), 486 (22.04%) were having sessile serrated lesions (SSL), and 171 (7.76%) had traditional serrated adenomas (TSA). Compared with HP (2.14%), SSL and TSA were larger and more likely to be accompanied by synchronous and metachronous advanced neoplasia (6.79% and 6.08%). We next found that large SP (diameter ≥10 mm) (odds ratio [OR] 2.52, 95% confidence interval [CI] 1.40-4.55, P = 0.002) and SSL with high-grade intraepithelial neoplasia (OR 13.85, 95% CI 3.28-58.56, P < 0.001) were associated with an increased risk of synchronous advanced neoplasia. However, we failed to find a relationship between SP and metachronous advanced neoplasia because few patients had developed metachronous advanced neoplasia.

CONCLUSION

Large SP and SSL with high-grade intraepithelial neoplasia are associated with synchronous advanced neoplasia and require timely surveillance.

Review of computational methods for the detection and classification of polyps in colonoscopy imaging

Computer-aided diagnosis (CAD) is a tool with great potential to help endoscopists in the tasks of detecting and histologically classifying colorectal polyps. In recent years, different technologies have been described and their potential utility has been increasingly evidenced, which has generated great expectations among scientific societies. However, most of these works are retrospective and use images of different quality and characteristics which are analysed off line. This review aims to familiarise gastroenterologists with computational methods and the particularities of endoscopic imaging, which have an impact on image processing analysis. Finally, the publicly available image databases, needed to compare and confirm the results obtained with different methods, are presented.

Quality indicators in colonoscopy: an evolving paradigm

The year 1969 marked a revolution in the diagnosis of colorectal cancer (CRC). It is when Dr Wolff developed the colonoscope and quickly realized its potential in both diagnosis and treatment of colonic neoplasms. Over the past 50 years there has been exponential increase in utilization of colonoscopy with over 1 million colonoscopies performed annually throughout Australasia. Endoscopic removal of pre-malignant lesions has been proven to reduce the incidence and mortality of colorectal. Although timing and frequency of surveillance colonoscopy plays a crucial role in risk reduction of CRC, this is dependent upon the findings of the index colonoscopy. The goal of screening colonoscopy is to detect CRC and identify and remove pre-malignant neoplasms that risk progression to CRC. With increasing uptake of bowel screening throughout Australasia, there is increasing pressure to ensure all endoscopists and endoscopy units perform at a universal high-quality. All too often high demand and constant delays compromise colonoscopy quality. Without clear and concise quality indicators with transparent measurement and audit, these flaws can quickly jeopardize screening goals and patient outcomes. This review aims to explore six key quality indicators and explore the evidence behind the current recommended standards. These key indicators include; rate of adequate bowel preparation, caecal intubation rate, adenoma detection rate, withdrawal time, complication rates and surveillance intervals.

Berberine versus placebo for the prevention of recurrence of colorectal adenoma: a multicentre, double-blinded, randomised controlled study

BACKGROUND

Chemoprevention of colorectal adenoma and colorectal cancer remains an important public health goal. The present study aimed to investigate the clinical potential and safety of berberine for prevention of colorectal adenoma recurrence.

METHODS

This double-blind, randomised, placebo-controlled trial was done in seven hospital centres across six provinces in China. Individuals aged 18-75 years who had at least one but no more than six histologically confirmed colorectal adenomas that had undergone complete polypectomy within the 6 months before recruitment were recruited and randomly assigned (1:1) to receive berberine (0·3 g twice daily) or placebo tablets via block randomisation (block size of six). Participants were to undergo a first follow-up colonoscopy 1 year after enrolment, and if no colorectal adenomas were detected, a second follow-up colonoscopy at 2 years was planned. The study continued until the last enrolled participant reached the 2-year follow-up point. All participants, investigators, endoscopists, and pathologists were blinded to treatment assignment. The primary efficacy endpoint was the recurrence of adenomas at any follow-up colonoscopy. Analysis was based on modified intention-to-treat, with the full analysis set including all randomised participants who received at least one dose of study medication and who had available efficacy data. The study is registered with ClinicalTrials.gov, number NCT02226185; the trial has ended and this report represents the final analysis.

FINDINGS

Between Nov 14, 2014, and Dec 30, 2016, 553 participants were randomly assigned to the berberine group and 555 to the placebo group. The full analysis set consisted of 429 participants in the berberine group and 462 in the placebo group. 155 (36%) participants in the berberine group and 216 (47%) in the placebo group were found to have recurrent adenoma during follow-up (unadjusted relative risk ratio for recurrence 0·77, 95% CI 0·66-0·91; p=0·001). No colorectal cancers were detected during follow-up. The most common adverse event was constipation (six [1%] of 446 patients in the berberine group vs one [<0·5%] of 478 in the placebo group). No serious adverse events were reported.

INTERPRETATION

Berberine 0·3 g twice daily was safe and effective in reducing the risk of recurrence of colorectal adenoma and could be an option for chemoprevention after polypectomy.

FUNDING

National Natural Science Foundation of China.

INCREASED RISK OF SYNCHRONOUS COLORECTAL LESIONS IN PATIENTS REFERRED FOR ENDOSCOPIC MUCOSAL RESECTION OF LATERAL SPREADING TUMORS

BACKGROUND

Endoscopic mucosal resection is one of the most frequent therapeutic alternatives for large colorectal lateral spreading tumors. There are few data on the prevalence of synchronous lesions on these patients.

OBJECTIVE

To describe the prevalence of synchronous colorectal lesions in patients referred for endoscopic mucosal resection of lateral spreading tumors >20 mm.

METHODS

We reviewed the endoscopic database of our Department and identified adult patients who were referred for the resection of a colorectal lateral spreading tumor >20 mm and had a diagnostic colonoscopy performed up to six months before. The proportion of patients with at least one synchronous lesion was estimated. The following features were compared between patients with and without synchronous lesions: age, gender, bowel preparation quality and cecal intubation on index colonoscopy and therapeutic colonoscopy, serrated adenoma as index lesion.

RESULTS

From December 2016 to November 2017, we identified 70 patients who fulfilled inclusion criteria. Median size of lesions was 25 mm (20-45). Eighty percent were located in the right colon and 35.71% were serrated adenomas. Synchronous lesion rate was 38.57%. Bowel preparation quality was similar in both groups when comparing both index and therapeutic colonoscopies. Patients with synchronous lesions had a higher proportion of serrated adenoma as index lesion than patients without synchronous lesions [51.85% vs 25.58%, OR 3.13 (1.13-8.68), P=0.03].

CONCLUSION

We found a high prevalence of synchronous lesions among patients with a large colorectal lateral spreading tumor. This risk seems to be increased if index lesions are serrated adenomas.

Impact of Electronic Chromoendoscopy on Adenoma Miss Rates During Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND

The impact of virtual chromoendoscopy such as narrow-band imaging, Fujinon intelligent chromoendoscopy, blue-light imaging, linked-color imaging, and i-SCAN on adenoma detection rate has been variable. However, adenoma miss rate (another measure suggested as a quality indicator) of electronic chromoendoscopy modalities has not been systematically evaluated.

OBJECTIVES

This study aimed to perform a systematic review and meta-analysis to examine the adenoma miss rate of white-light endoscopy compared with electronic chromoendoscopy.

DATA SOURCES

Medline, Embase, Scopus, Web of Knowledge, and Cochrane were the data sources for this study.

STUDY SELECTION

The studies selected were tandem randomized controlled trials of electronic chromoendoscopy modalities compared with white-light endoscopy.

INTERVENTIONS

Electronic chromoendoscopy compared with white light endoscopy was used to measure the adenoma miss rate.

MAIN OUTCOME MEASURES

Primary outcome was the pooled adenoma miss rate of electronic chromoendoscopy techniques compared with white-light endoscopy. Secondary outcomes were subgroup analysis, adenoma size analysis, and adenoma detection rate.

RESULTS

A total of 3507 patients were evaluated from 7 eligible tandem randomized control trials. A total of 1423 patients had white-light endoscopy as the first of the tandem examinations. The rest of the patients had electronic chromoendoscopy as the first of the tandem examination (narrow-band imaging, 988 patients; Fujinon intelligent chromoendoscopy, 728 patients; i-SCAN, 233 patients; blue-light imaging, 64 patients; and linked-color imaging, 71 patients). The pooled adenoma miss rate for electronic chromoendoscopy was not different than white-light endoscopy (17.9% vs 21%; OR, 0.72 (0.67-1.11); I 67%; p = 0.13). When only narrow-band imaging, blue-light imaging, and linked-color imaging were considered, the pooled rate was statistically significant (OR, 0.60 (0.37-0.98); p = 0.04). The pooled adenoma detection rate was not statistically different with electronic chromoendoscopy than white-light endoscopy (OR, 1.02 (0.88-1.19); p = 0.78).

LIMITATIONS

The small number of studies to assess the impact of each modality limited stratified conclusions.

CONCLUSIONS

Electronic chromoendoscopy is not associated with a significant reduction in adenoma miss rate compared with white-light colonoscopy.

Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

BACKGROUND & AIMS

Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors.

METHODS

We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness.

RESULTS

Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75-1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6-9 mm was 0.62 (95% CI, 0.44-0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33-0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16-2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49-4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34-1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47-1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21-1.33) than women (0.86; 95% CI, 0.80-0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57-0.94).

CONCLUSIONS

In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men.

Determination of withdrawal times in individualized opportunistic screening colonoscopies

To investigate effects of bowel preparation, experience level of colonoscopists, and colonoscopy withdrawal time (CWT) on the quality of an individual opportunistic screening colonoscopy, according to adenoma detection rate (ADR).Data were retrospectively analyzed from opportunistic screening colonoscopies (n = 16,951) at 4 hospitals of various care levels in China.The ADR positively correlated with the experience level of the colonoscopist. The individualized CWT varied, depending on the quality of bowel preparation and the number of colonoscopies performed previously by the colonoscopist. In a setting of adequate bowel preparation, the mean CWT decreased with the increased experience of the colonoscopist. With poor and inadequate bowel preparation, no colonoscopist at any level of experience could obtain a satisfactory ADR.For adequately prepared colonoscopies, minimum CWTs have been determined. Repeat colonoscopy is strongly recommended for patients with poor bowel preparation, regardless of the colonoscopist's experience.

Case report of synchronous post-lung transplant colon cancers in the era of colorectal cancer screening recommendations in cystic fibrosis: screening "too early" before it's too late

BACKGROUND

The increasing life expectancy of individuals with Cystic Fibrosis (CF) is likely to be associated with new age-related challenges, colorectal cancer (CRC) most notably; recent consensus recommendations for CRC screening published in 2018 represent an important early step in addressing the emerging awareness of CF as a gastrointestinal cancer syndrome. These recommendations, however, need to be further refined based on more systematic data. We discuss an illustrative first-ever case of synchronous CRC arising in a post-lung transplant individual with CF within the recommended surveillance interval after a well-documented prior normal colonoscopy.

CASE PRESENTATION

A 51-year-old female individual with homozygous F508del CF, presents to clinic with abdominal discomfort and intermittent blood in stools. She had previously undergone bilateral lung transplantation 18 years earlier, as well as two kidney transplants related to immunosuppression-related nephrotoxicity. A diagnostic colonoscopy was performed which revealed the presence of two separate synchronous colon cancers in the cecum and transverse colon; she had undergone a colonoscopy three years prior to this exam which was structurally normal. Endoscopic quality indicators, including a good quality bowel preparation, colonoscopic withdrawal time > 12 min, and quarterly Adenoma Detection Rate (ADR) ranging from 50 to 70% for both male and female patients for the endoscopist from both colonoscopic exams, as well as secondary retrospective comparative review of the pertinent case images, diminish the risk for a "missed" cancer or advanced lesion on the index exam. These cancers did not demonstrate any immunohistochemical features suggestive of Lynch Syndrome, though the rapid progression to cancer within the surveillance interval (possibly non-polypoid in nature) is similar. This cancer presentation within the newly-established recommended colon cancer screening interval warrants concern.

CONCLUSIONS

This case prompts serious discussion regarding the length of surveillance intervals in the post-transplant CF population (a population at 20-30 times greater risk for CRC compared to the general non-CF population), as well as the importance of documenting endoscopic quality benchmarks, particularly if a narrative of interval CRC development continues to develop with further prospective monitoring and multi-center experience.

Adenoma detection rates in colonoscopies for positive fecal immunochemical tests versus direct screening colonoscopies

BACKGROUND AND AIMS

Recent guidelines propose higher adenoma detection rate (ADR) benchmarks for colonoscopies performed for positive results for fecal immunochemical tests (FIT), but this is based on low-quality evidence. We aimed to compare ADR, advanced ADR (AADR), and number of adenomas per colonoscopy (APC) in direct screening colonoscopy (DSC) versus FIT-positive colonoscopy (FITC) in a multicenter Asia-Pacific cohort to justify differential targets.

METHODS

Asymptomatic average-risk patients ≥50 years of age who underwent screening colonoscopy directly or as follow-up for positive OC-Sensor FIT results were identified from 8 sites across the Asia-Pacific region. Overall, sex-specific ADR, overall AADR, and overall APC were compared between the 2 screening methods. Multivariable logistic regression was performed to adjust for confounding by differences in patient characteristics. Linear regression was used to correlate ADR with APC and to propose APC benchmarks.

RESULTS

A total of 2901 (mean age, 60.1 years; 57% men) individuals had DSC, and 2485 (mean age, 62.8 years; 57% men) underwent FITC. Overall ADR (53.6% vs 37.5%; odds ratio [OR], 1.93; P < .001), male-specific ADR (61.6% vs 44.6%; OR, 2; P < .001), female-specific ADR (43.2% vs 28.2%; OR, 1.94; P < .001) and overall AADR (29.9% vs 4.9%; OR, 8.2; P < .001) in FITC were significantly higher than the corresponding values for DSC. Differences remained significant after adjustment for patient characteristics. ADR was strongly and positively correlated to APC, with an ADR of 45% and 35% correlating to an APC of ∼1 and ∼0.65.

CONCLUSIONS

Results from this international multicenter cohort study provide early evidence that newly proposed higher ADR targets are justified as quality indicators for FITC.

Adenoma miss rate determined by very shortly repeated colonoscopy: Retrospective analysis of data from a single tertiary medical center in China

Adenoma miss rate (AMR) has been calculated in several tandem colonoscopy studies, but it costs overmuch to carry out a clinical trial.We aimed to put forward AMR by taking advantage of retrospective data, and to judge the comparability between AMRs from prospective and retrospective data.Data of the patients accepting repeated colonoscopies during January to September 2016 was retrospectively collected and analyzed. Information was recorded, including bowel preparation quality of the first colonoscopy, size, location, histology and whether missed within the first colonoscopy of each single adenoma. AMR was compared by different risk factors through χ test and multivariable logistic regression.Around 267 adenomas were detected during 309 pairs of repeated colonoscopies, of which 66 were missed during the first colonoscopies. AMRs of the lesions small in size, nonadvanced in histology, in poor bowel preparation context and located in the proximal colon, were significantly higher than the opposite ones, and old age and male were related to adenoma missing (P < .05). In multivariable logistic regression analysis, adenoma-related factors (diminutive in size, poor bowel preparation and located in ascending colon, transverse colon or sigmoid colon), and patient-related factors (older than 60 years, male and poor bowel preparation) were found to be independently associated with missing adenomas (P < .05).AMR of retrospective data is comparable to that of tandem studies. Several risk factors influence AMR dramatically, which should be paid attention to.

Colonoscopic withdrawal time and adenoma detection in the right colon

Shorter colonoscopic withdrawal time (CWT) has been associated with lower adenoma detection rate (ADR), which can increase the risk of interval colorectal cancer (ICC) that commonly arises in the right colon (RC). Therefore, a better ADR in the RC could decrease the incidence of ICC. We analyzed the relationship between CWT and ADR in the RC and entire colon.We retrospectively reviewed the patients who had undergone screening colonoscopy at Chungnam National University Hospital between March 2015 and February 2016. We enrolled 5370 patients in whom colonoscopies were performed by 7 gastroenterologists. We categorized patients into 4 groups in the RC and 6 groups in the entire colon by CWT. Multivariable analysis was used for detection of adenoma in the RC and entire colon.In the RC, the odds ratio (OR) of CWT longer than 3 minutes was 3.70, compared to CWT of <2 minutes [3.06-4.85, 95% confidence interval (CI), P < .001]. In the entire colon, the OR of CWT between 9 to 10 minutes and longer than 10 minutes was 3.34 [2.61-4.27, 95% CI, P < .001] and 3.49 [2.80-4.33, 95% CI, P < .001] compared to CWT of <6 minutes.Based on our result, we suggest that the optimum CWT in the RC should exceed 3 minutes, and considering the "ceiling effect," the optimum CWT in the entire colon should exceed 9 minutes.

Is It Necessary to Intubate the Cecum to Examine the Whole Colorectum During Endoscopic Polypectomy?

Background

The official guidelines are unclear about whether endoscopic polypectomy should intubate the whole cecum or just intubate the location of the endoscopy inspection. Therefore, the objective of this study was to provide a new perspective of assisting endoscopists make better decisions and decrease the missing detection rate in clinical practice.

Material/Methods

We retrospectively reviewed records of 8923 patients who underwent endoscopic polypectomy, and 394 participants were included after screening by inclusion and exclusion criteria. We collected and analyzed data on the size, shape, and location of polyps and the clinical experience level of endoscopists in this retrospective study.

Results

Among the 394 cases, 152 (38.6%) had additional lesions detected through the second endoscopic polypectomy after the first colonoscopy was performed, showing statistically significant differences between the missing group and non-missing group on actual polys (P<0.05). No significant differences were detected between the 2 groups (P>0.05) in age, sex, withdrawal time, and examination period. Regarding the location, 50.4% of the missing lesions were found on the relatively proximal colon of the detected polyps in the first colonoscopy. In addition, the level of experience of endoscopists was significantly different between the missing group and the non-missing group (P<0.05).

Conclusions

The characteristics of polyps and the level of endoscopist experience play important roles in the detection of polyps in the colorectum. Moreover, it may be necessary to intubate the cecum to examine the whole colorectum during endoscopic polypectomy.

Reassessing the value of gastroscopy for the investigation of dyspepsia

OBJECTIVE

To evaluate the diagnostic yield of investigating dyspepsia with oesophagogastroduodenoscopy (OGD) with or without mucosal biopsy.

DESIGN

Retrospective service evaluation study.

SETTING

Two teaching hospitals: The Royal Hallamshire Hospital and Northern General Hospital, Sheffield Teaching Hospitals NHS Foundation Trust, UK.

PATIENTS

500 patients, 55 years of age and over, who underwent OGD to investigate dyspepsia were included. The study period included a 3-month window. All OGDs were performed on an outpatient basis.

INTERVENTIONS

Data were extracted from electronic OGD records within the study period.

MAIN OUTCOME MEASURES

Diagnostic yield provided by endoscopic examination and histological assessment.

RESULTS

378 patients (75.6%) were reported to have some form of endoscopic abnormality, and 417 patients (83.4%) had biopsies taken. The most common findings at OGD were gastritis (47.2%) and oesophagitis (24.4%). Oesophagogastric malignancy was seen in 1%. Diagnoses made endoscopically or histologically that would not have been appropriately managed by empirical therapies were seen in 16.2%.

CONCLUSION

OGD in dyspepsia influences patient management in approximately one-sixth of cases. However, the majority of patients are sufficiently managed with Helicobacter pylori testing and eradication and/or a trial of proton pump inhibitor therapy. Further non-invasive approaches are needed to identify patients who need endoscopy for biopsy or therapy.

Evaluation of a fecal immunochemistry test prior to colonoscopy for outpatients with various indications

BACKGROUND

Stool tests can predict advanced neoplasms prior to colonoscopy. Results of immunochemical stool tests to predict findings at colonoscopy for various indications are less often reported. We compared pre-colonoscopy stool tests with findings in patients undergoing colonoscopy for different indications.

PATIENTS AND METHODS

Charts of patients undergoing elective or semi-urgent colonoscopy were reviewed. Comparison of adenoma detection rates and pathological findings was made between prescreened and non-prescreened, and between stool-positive and stool-negative cases. Demographics, quality of colonoscopy, and pathological findings were recorded. Odds ratios (ORs) and 95% confidence intervals (CIs) were assessed. Statistical significance was accepted at p≤0.05.

RESULTS

Charts of 325 patients were reviewed. Among them, stool tests were done on 144 patients: 114 were negative and 30 were positive. Findings were similar in the pretest and non-pretest groups. Detection of advanced adenomas per patient was higher in the stool-positive group compared to the stool-negative group (23.4% vs 3.5%, p=0.0016, OR =7.6 [95% CI: 2-29.3]). Five advanced adenomas (without high-grade dysplasia or adenocarcinoma) and several cases of multiple adenomas were missed in the negative group. Sensitivity and specificity for advanced polyps was 63.6% and 82.7%, respectively. The negative predictive value was 96.5%. Male gender was independently predictive of any adenoma.

CONCLUSION

The stool immunochemical test best predicted advanced neoplasms and had a high negative predictive value in this small cohort. Whether this test can be applied to determine the need for colonoscopy in groups other than average risk would require more studies.

Accredited residents perform colonoscopy to the same high standards as consultants

BACKGROUND

Endoscopy remains a critical component of General Surgery and Gastroenterology training. Whilst residents need to gain experience, the quality of endoscopy which patients receive cannot be compromised. We conducted this study to compare quality indicators between consultants and residents with regards to colonoscopy.

METHODS

A review of colonoscopies from a prospectively collected database was performed from September 2011 to February 2016. Quality indicators such as caecum intubation rate, adenoma detection rate, adherence to a 6-min withdrawal rule, mean number of polyps detected per colonoscope, and complications were collected and compared between the two groups.

RESULTS

In total, out of 25,749 colonoscopies that were performed, 14,168 (55.0%) were performed by Consultants. Consultants achieved a better caecum intubation rate compared with residents (96.0% vs 94.9%, p < 0.001), and were more compliant to the 6-min withdrawal rule (74.7% vs 68.6%, p < 0.001). There were, however, no statistically significant differences in the adenoma detection rate (33.5% vs 34.5%, p = 0.098). Bleeding was a rare complication that was encountered more frequently in colonoscopies performed by consultants than for residents (0.002% vs 0.00008%, p < 0.001). There were only three (%) perforations in the entire series, and all were from colonoscopies performed by Consultants.

CONCLUSION

Given the proper training, residents are able to perform colonoscopy with the same level of competence as consultants. Whilst colonoscopic related complications are often tied to the difficulty of the procedures, the adherence to the 6-min withdrawal rule must be reinforced and continually educated to both residents and consultants.

Impact of feedback and monitoring on colonoscopy withdrawal times and polyp detection rates

Background

Previous studies have shown colonoscopy withdrawal time (WT) to be a reliable surrogate indicator for polyp detection rate (PDR) and adenoma detection rate (ADR) in colonoscopy. Our aim was to assess the impact of feedback and monitoring of WT on PDR in routine colonoscopies with long-term follow-up.

Materials and methods

A total of 307 colonoscopies were performed in three separate clinical scenarios. First, PDR and WT were recorded without the staff being aware of the specific objective of the study. Before the second scenario, the staff was given interventional information and feedback on WTs and PDRs from the first scenario and was encouraged to aim for a minimum WT of 8 min. Retention of knowledge gained was reassessed in the third scenario 1 year later.

Results

The PDR in the first two scenarios differed significantly (p<0.01), with a more than 90% increase in PDR after intervention from 22% to 42% (95% CI 1.44 to 4.95), although the mean WT did not change (6.8 vs 7.2 min; p>0.05). The increase in PDR between the first and second scenarios was retained in the third follow-up scenario 1 year later where the WT of both polyp-positive and polyp-negative colonoscopies was found to be longer.

Conclusions

PDR almost doubled from the first to the second scenario of a real-life colonoscopy setting, indicating that awareness of WT is crucial. The knowledge gained from this intervention in routine practice was even retained after a year.