A tandem colonoscopy study of adenoma miss rates during endoscopic training: a venture into uncharted territory

Risk Factors of Missed Adenoma Detected by Colonoscopic Polypectomy and Its Impact of the Endoscopic System

BACKGROUND

The adenoma detection rate is a key colonoscopy quality indicator, but the adenoma miss rate (AMR) is more strongly linked to post-colonoscopy colorectal cancer risk. While studies examined high-definition colonoscopy and AMR, no studies have assessed its impact on consecutive polypectomy.

AIM

This study aimed to identify adenomas missed in screening or surveillance colonoscopy and determine if the endoscopic system affects the miss rate.

METHODS

This retrospective study analyzed patients referred to Dong-A University Hospital for polypectomy after polyps were detected during screening or surveillance colonoscopy at 24 healthcare institutions. Endoscopic systems used in these colonoscopies were classified as FHD (FHD) or non-FHD. Consecutive polypectomies were performed by a single expert between March 2020 and February 2022 using the FHD system. The AMR was compared and analyzed for screening or surveillance colonoscopies performed using FHD endoscopic systems and those using non-FHD endoscopic systems.

RESULTS

Of 542 polyps, 186 were missed (miss rate: 25.22%). Miss rates for adenoma and advanced neoplasia were 27.34% and 14.69%. Univariate analysis identified age, adenoma count, and endoscopic system as significant factors. However, only the endoscopic system remained significant in the multivariate analysis. In screening or surveillance colonoscopy, the use of FHD endoscopic systems demonstrated a lower AMR compared to non-FHD systems (21.86% vs. 31.41%, P = 0.014).

CONCLUSION

The use of FHD endoscopic systems reduced AMR compared to non-FHD systems.

Comparison of Colon Adenoma Detection Rate Using Transparent Cap-Assisted and Conventional Colonoscopy: Result from an International Trial in Asia

INTRODUCTION

Controversy remains regarding transparent cap-assisted technique improves adenoma detection rate (ADR) in colonoscopy. We aimed to investigate the effect of transparent cap-assisted colonoscopy (CAC) on ADR and other colonoscopy performance.

METHODS

We performed subanalysis of an international, multicenter, open-label database containing colonoscopy data from 11 centers in 4 Asian countries/regions on patients who underwent colonoscopy. The patient characteristics, procedure-related characteristics, and pathological findings of all detected lesions were prospectively recorded. The patients were divided into 2 groups as receiving colonoscopy with or without transparent cap attachment. The ADR and procedure time were compared between the 2 groups. Other procedural factors related to ADR were also investigated.

RESULTS

Between November 2020 and January 2022, 3,029 who underwent colonoscopy (transparent CAC, n = 1,796; standard colonoscopy, n = 1,233) were enrolled in this study. The transparent CAC group ADR was significantly higher than the conventional colonoscopy (55.1% vs. 50.0%, p < 0.01). Transparent CAC detected a higher proportion of patients with adenoma (odd ratio [OR]: 1.59, 95% CI: 1.13-2.24, p < 0.01) and any polypoid lesion (OR: 1.49, 95% CI: 1.04-2.16, p = 0.03). Transparent CAC also reduced cecal intubation time (mean difference: -0.35 min) and total colonoscopy time (mean difference -3.4 min). In the other procedural factors, using linked-color imaging (OR: 1.75, 95% CI: 1.49-2.06, p < 0.01), patient body rotation (OR: 1.54, 95% CI: 1.12-2.13, p < 0.01), longer withdrawal time (OR: 1.12, 95% CI: 1.09-1.15, p < 0.01) were also significantly associated to adenoma detection.

CONCLUSION

In real-world practice, transparent CAC is a safe and inexpensive technology that could improve adenoma and polyp detection.

Simulation-Based Learning as a Strategy to Optimizing Efficiency of Upper Endoscopy and Colonoscopy

Gastrointestinal diseases impose a significant morbidity, mortality, and health care cost burden, affecting millions annually in the United States alone. Endoscopy plays a crucial role in managing these conditions. Despite technological advancements in endoscopy, ensuring efficient, high-quality care remains challenging. A critical need to standardize high-quality endoscopy is for education reform in the training of endoscopists. Traditional apprenticeship-based training methods are dependent on the trainer as well as the patient case mix. Simulation-based mastery learning (SBML) emerges as a promising strategy to improve endoscopy training. This review discusses the current state of SBML for optimizing upper endoscopy and colonoscopy efficiency.

Linked color imaging improves colorectal lesion detection especially for low performance endoscopists: An international trial in Asia

BACKGROUND AND AIM

Linked color imaging (LCI) is an image-enhanced endoscopy technique that accentuates the color difference between red and white, potentially improving the adenoma detection rate (ADR). However, it remains unclear whether LCI performance in detecting colorectal lesions differs based on endoscopists' experience levels. We aimed to evaluate the differences in LCI efficacy based on the experience levels of endoscopists by conducting an exploratory analysis.

METHODS

In this post hoc analysis of an international randomized controlled trial comparing the detection of adenoma and other lesions using colonoscopy with LCI and high-definition white light imaging (WLI), we included patients from 11 institutions across four countries/regions: Japan, Thailand, Taiwan, and Singapore. We retrospectively reviewed differences in the lesion detection of LCI according to endoscopists' colonoscopy history or ADR.

RESULTS

We included 1692 and 1138 patients who underwent colonoscopies performed by 54 experts (experience of ≥ 5000 colonoscopies) and by 43 non-experts (experience of < 5000 colonoscopies), respectively. Both expert and non-expert groups showed a significant improvement in ADR with LCI compared to WLI (expert, 61.7% vs 46.4%; P < 0.001; non-expert, 56.6% vs 46.4%; P < 0.001). LCI had no effect on sessile serrated lesion detection rate in non-experts (3.1% vs 2.5%; P = 0.518). LCI significantly improved detection rates in endoscopists with relatively low detection performance, defined as an ADR < 50%.

CONCLUSIONS

This exploratory study analyzed data from a previous trial and revealed that LCI is useful for both experts and non-experts and is even more beneficial for endoscopists with relatively low detection performance using WLI.

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).

Effect of artificial intelligence on novice-performed colonoscopy: a multicenter randomized controlled tandem study

BACKGROUND AND AIMS

The efficacy and safety of colonoscopy performed by artificial intelligence (AI)-assisted novices remain unknown. The aim of this study was to compare the lesion detection capability of novices, AI-assisted novices, and experts.

METHODS

This multicenter, randomized, noninferiority tandem study was conducted across 3 hospitals in China from May 1, 2022, to November 11, 2022. Eligible patients were randomized into 1 of 3 groups: the CN group (control novice group, withdrawal performed by a novice independently), the AN group (AI-assisted novice group, withdrawal performed by a novice with AI assistance), or the CE group (control expert group, withdrawal performed by an expert independently). Participants underwent a repeat colonoscopy conducted by an AI-assisted expert to evaluate the lesion miss rate and ensure lesion detection. The primary outcome was the adenoma miss rate (AMR).

RESULTS

A total of 685 eligible patients were analyzed: 229 in the CN group, 227 in the AN group, and 229 in the CE group. Both AMR and polyp miss rate were lower in the AN group than in the CN group (18.82% vs 43.69% [P < .001] and 21.23% vs 35.38% [P < .001], respectively). The noninferiority margin was met between the AN and CE groups of both AMR and polyp miss rate (18.82% vs 26.97% [P = .202] and 21.23% vs 24.10% [P < .249]).

CONCLUSIONS

AI-assisted colonoscopy lowered the AMR of novices, making them noninferior to experts. The withdrawal technique of new endoscopists can be enhanced by AI-assisted colonoscopy. (Clinical trial registration number: NCT05323279.).

Efficacy of image-enhanced endoscopy for colorectal adenoma detection: A multicenter, randomized trial

BACKGROUND

Improved adenoma detection at colonoscopy has decreased the risk of developing colorectal cancer. However, whether image-enhanced endoscopy (IEE) further improves the adenoma detection rate (ADR) is controversial.

AIM

To compare IEE with white-light imaging (WLI) endoscopy for the detection and identification of colorectal adenoma.

METHODS

This was a multicenter, randomized, controlled trial. Participants were enrolled between September 2019 to April 2021 from 4 hospital in China. Patients were randomly assigned to an IEE group with WLI on entry and IEE on withdrawal (n = 2113) or a WLI group with WLI on both entry and withdrawal (n = 2098). The primary outcome was the ADR. The secondary endpoints were the polyp detection rate (PDR), adenomas per colonoscopy, adenomas per positive colonoscopy, and factors related to adenoma detection.

RESULTS

A total of 4211 patients (966 adenomas) were included in the analysis (mean age, 56.7 years, 47.1% male). There were 2113 patients (508 adenomas) in the IEE group and 2098 patients (458 adenomas) in the WLI group. The ADR in two group were not significantly different [24.0% vs 21.8%, 1.10, 95% confidence interval (CI): 0.99-1.23, P = 0.09]. The PDR was higher with IEE group (41.7%) than with WLI group (36.1%, 1.16, 95%CI: 1.07-1.25, P = 0.01). Differences in mean withdrawal time (7.90 ± 3.42 min vs 7.85 ± 3.47 min, P = 0.30) and adenomas per colonoscopy (0.33 ± 0.68 vs 0.28 ± 0.62, P = 0.06) were not significant. Subgroup analysis found that with narrow-band imaging (NBI), between-group differences in the ADR, were not significant (23.7% vs 21.8%, 1.09, 95%CI: 0.97-1.22, P = 0.15), but were greater with linked color imaging (30.9% vs 21.8%, 1.42, 95%CI: 1.04-1.93, P = 0.04). the second-generation NBI (2G-NBI) had an advantage of ADR than both WLI and the first-generation NBI (27.0% vs 21.8%, P = 0.01; 27.0% vs 21.2.0%, P = 0.01).

CONCLUSION

This prospective study confirmed that, among Chinese, IEE didn't increase the ADR compared with WLI, but 2G-NBI increase the ADR.

Correlation between Surrogate Quality Indicators for Adenoma Detection Rate and Adenoma Miss Rate in Qualified Colonoscopy, CORE Study: KASID Multicenter Study

BACKGROUND/AIMS

The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested. This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy.

METHODS

We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR.

RESULTS

A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001).

CONCLUSIONS

The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy.

Key factors for improving adenoma detection rate

INTRODUCTION

Colonoscopy is a fundamental tool in colorectal cancer (CRC) prevention. Nevertheless, one-fourth of colorectal neoplasms are still missed during colonoscopy, potentially being the main reason for post-colonoscopy colorectal cancer (PCCRC). Adenoma detection rate (ADR) is currently known as the best quality indicator correlating with PCCRC incidence.

AREAS COVERED

We performed a literature review in order to summarize evidences investigating key factors affecting ADR: endoscopists education and training, patient management, endoscopic techniques, improved navigation (exposition defect), and enhanced lesions recognition (vision defect) were considered.

EXPERT OPINION

'Traditional' factors, such as split dose bowel preparation, adequate withdrawal time, and right colon second view, held a significant impact on ADR. Several devices and technologies have been developed to promote high-quality colonoscopy, however artificial intelligence may be considered the most promising tool for ADR improvement, provided that endoscopists education and recording are guaranteed.

Adenoma detection rate using narrow-band imaging is inferior to high-definition white light colonoscopy in screening and surveillance colonoscopies in daily clinical care: A randomized controlled trial

BACKGROUND

Despite recent advances in endoscopic technology adenoma miss rate still is up to 20% contributing to interval cancers. Improved imaging modalities have been introduced to increase adenoma detection rate (ADR). Recently, narrow-band imaging (NBI) (Exera II series, Olympus Corporation) was not significantly better than high-definition white light colonoscopy (HD-WLC). An improved second generation of NBI (190-NBI) is characterized by better illumination of the bowel lumen and may be associated with a higher ADR.

METHODS

We performed a prospective randomized study on patients referred to the Jena University Hospital for screening or surveillance colonoscopy between January 2015 and April 2017. Participating endoscopists were divided into 2 subgroups depending on their individual experience. Colonoscopy was performed by use of HD-WLC or 190-NBI upon withdrawal.

RESULTS

Five hundred fifty-three patients participated in the study. Eighty patients were excluded (insufficient bowel cleansing [n = 34], anticoagulation precluding polypectomy [n=15], partial colonic resection [n=9], other reasons [n = 22]). Mean age was 66.9 years (standard deviation 10.3 years), and 253 patients were male (53.5%). Bowel preparation and withdrawal time were not different. ADR among all subgroups was 39.4% using HD-WLC, but only 29.1% were using 190-NBI (P = .02). Number of polyps per patient was lower using 190-NBI than with HD-WLC (0.58 vs 0.86; P = .02). Subgroup analysis revealed that 190-NBI was inferior to HD-WLC only in unexperienced endoscopists.

CONCLUSION

In our stud,y ADR was lower by use of 190-NBI. These differences persisted only in unexperienced investigators. 190-NBI seems to be more challenging regarding ADR, requiring more intensive training prior to implementing this technology in daily clinical care.

REGISTRATION

ClinicalTrials.gov (identifier: NCT03081975).

Detecting colon polyps in endoscopic images using artificial intelligence constructed with automated collection of annotated images from an endoscopy reporting system

BACKGROUND

Artificial intelligence (AI) has made considerable progress in image recognition, especially in the analysis of endoscopic images. The availability of large-scale annotated datasets has contributed to the recent progress in this field. Datasets of high-quality annotated endoscopic images are widely available, particularly in Japan. A system for collecting annotated data reported daily could aid in accumulating a significant number of high-quality annotated datasets.

AIM

We assessed the validity of using daily annotated endoscopic images in a constructed reporting system for a prototype AI model for polyp detection.

METHODS

We constructed an automated collection system for daily annotated datasets from an endoscopy reporting system. The key images were selected and annotated for each case only during daily practice, not to be performed retrospectively. We automatically extracted annotated endoscopic images of diminutive colon polyps that had been diagnosed (study period March-September 2018) using the keywords of diagnostic information, and additionally collect the normal colon images. The collected dataset was devised into training and validation to build and evaluate the AI system. The detection model was developed using a deep learning algorithm, RetinaNet.

RESULTS

The automated system collected endoscopic images (47,391) from colonoscopies (745), and extracted key colon polyp images (1356) with localized annotations. The sensitivity, specificity, and accuracy of our AI model were 97.0%, 97.7%, and 97.3% (n = 300), respectively.

CONCLUSION

The automated system enabled the development of a high-performance colon polyp detector using images in endoscopy reporting system without the efforts of retrospective annotation works.

Real-time, computer-aided, detection-assisted colonoscopy eliminates differences in adenoma detection rate between trainee and experienced endoscopists

Background and study aims  Adenoma detection rate (ADR) is a well-accepted quality indicator of screening colonoscopy. In recent years, the added value of artificial intelligence (AI) has been demonstrated in terms of ADR and adenoma miss rate (AMR). To date, there are no studies evaluating the impact of AI on the performance of trainee endoscopists (TEs). This study aimed to assess whether AI might eliminate any difference in ADR or AMR between TEs and experienced endoscopists (EEs). Patients and methods  We performed a prospective observational study in 45 subjects referred for screening colonoscopy. A same-day tandem examination was carried out for each patient by a TE with the AI assistance and subsequently by an EE unaware of the lesions detected by the TE. Besides ADR and AMR, we also calculated for each subgroup of endoscopists the adenoma per colonoscopy (APC), polyp detection rate (PDR), polyp per colonoscopy (PPC) and polyp miss rate (PMR). Subgroup analyses according to size, morphology, and site were also performed. Results  ADR, APC, PDR, and PPC of AI-supported TEs were 38 %, 0.93, 62 %, 1.93, respectively. The corresponding parameters for EEs were 40 %, 1.07, 58 %, 2.22. No significant difference was found for each analysis between the two groups ( P  > 0.05). AMR and PMR for AI-assisted TEs were 12.5 % and 13 %, respectively. Sub-analyses did not show any significant difference ( P  > 0.05) between the two categories of operators. Conclusions  In this single-center prospective study, the possible impact of AI on endoscopist quality training was demonstrated. In the future, this could result in better efficacy of screening colonoscopy by reducing the incidence of interval or missed cancers.

Effect of water exchange method on adenoma miss rate of patients undergoing selective polypectomy: A randomized controlled trial

BACKGROUND

Adenomas may be missed in up to 40% of screening colonoscopies. Although the water exchange (WE) method can improve ADR, as shown in several RCTs, it remains uncertain whether it can increase the detection of missing adenomas compared with standard air-insufflated (AI) colonoscopy.

METHODS

Patients aged 18-80 years who underwent selective polypectomy were randomly allocated to the WE or AI group. The primary endpoint was the adenoma miss rate (AMR), defined as the number of patients with one or more additional adenomas during the polypectomy procedure divided by the total number of patients in each group.

RESULTS

A total of 450 patients were enrolled, with 225 in each group. The overall AMRs were 45.8% (103/225) in the WE group and 35.6% (80/225) in the AI group (p = 0.035). More patients in the WE group had at least one missed adenoma in the proximal colon (38.2% vs 24.4%, p = 0.002). The adenoma-level miss rate was also higher in the WE group than in the AI group (35.1% vs 29.0%, p = 0.036). Subgroup analysis showed that patients in the WE group had more missed adenomas located in the proximal colon or with flat shapes.

CONCLUSIONS

This study confirmed that substantial adenomas were missed in patients undergoing selective polypectomy. The WE method significantly improved the detection of missed adenomas, especially those located in the proximal colon or with flat shapes. (ClnicalTrials.gov number: NCT02880748).

Impact of fellow participation on colon adenoma detection rates: a multicenter randomized trial

BACKGROUND AND AIMS

There are limited and conflicting data on the impact of fellow participation in improving the colon adenoma detection rate. We performed a multicenter randomized controlled trial to evaluate whether fellow involvement might have a beneficial effect on adenoma detection rate.

METHODS

The trial was conducted at 4 tertiary hospitals between April and December 2019. Eight hundred twelve patients were randomized to undergo colonoscopy performed by a fellow under the supervision of a staff endoscopist or by an attending physician alone.

RESULTS

No significant differences in demographic or adenoma risk factors were detected between the 2 groups. The adenoma detection rate in the intervention group was 44.8% versus 37.1% in the control arm (P = .02). The mean number of adenomas per colonoscopy was significantly higher in the intervention group (0.65 ± 0.3 vs 0.53 ± 0.2 in the control arm, P < .001). The polyp detection rate was 69.7% in the intervention group and 62.5% in the control arm (P = .03), whereas rates of advanced and sessile/serrated adenoma detection were not different between the trial arms (P = .50 and .42, respectively). In the subgroup of more experienced fellows, the adenoma detection rate and polyp detection rate were 49.5% and 75.7%, respectively. No difference was observed between less-experienced fellows and attending physicians alone (P = .53 and 0.86, respectively). The level of bowel preparation and fellow involvement were significant predictors of increased adenoma detection rate in a multivariate analysis.

CONCLUSIONS

Our multicenter trial represents the first prospective validation of the beneficial role of fellow involvement in colonoscopy procedures. (Clinical trial registration number: NCT03908229.).

Curriculum for optical diagnosis training in Europe: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement

This manuscript represents an official Position Statement of the European Society of Gastrointestinal Endoscopy (ESGE) aiming to guide general gastroenterologists to develop and maintain skills in optical diagnosis during endoscopy. In general, this requires additional training beyond the core curriculum currently provided in each country. In this context, ESGE have developed a European core curriculum for optical diagnosis practice across Europe for high quality optical diagnosis training. 1:  ESGE suggests that every endoscopist should have achieved general competence in upper and/or lower gastrointestinal (UGI/LGI) endoscopy before commencing training in optical diagnosis of the UGI/LGI tract, meaning personal experience of at least 300 UGI and/or 300 LGI endoscopies and meeting the ESGE quality measures for UGI/LGI endoscopy. ESGE suggests that every endoscopist should be able and competent to perform UGI/LGI endoscopy with high definition white light combined with virtual and/or dye-based chromoendoscopy before commencing training in optical diagnosis. 2:  ESGE suggests competency in optical diagnosis can be learned by attending a validated optical diagnosis training course based on a validated classification, and self-learning with a minimum number of lesions. If no validated training course is available, optical diagnosis can only be learned by attending a non-validated onsite training course and self-learning with a minimum number of lesions. 3:  ESGE suggests endoscopists are competent in optical diagnosis after meeting the pre-adoption and learning criteria, and meeting competence thresholds by assessing a minimum number of lesions prospectively during real-time endoscopy. ESGE suggests ongoing in vivo practice by endoscopists to maintain competence in optical diagnosis. If a competent endoscopist does not perform in vivo optical diagnosis on a regular basis, ESGE suggests repeating the learning and competence phases to maintain competence.Key areas of interest were optical diagnosis training in Barrett's esophagus, esophageal squamous cell carcinoma, early gastric cancer, diminutive colorectal lesions, early colorectal cancer, and neoplasia in inflammatory bowel disease. Condition-specific recommendations are provided in the main document.

Quality of Preoperative Colonoscopy Affects Missed Postoperative Adenoma Detection in Colorectal Cancer Patients

BACKGROUND

Despite thorough preoperative screening, 19-30% of synchronous polyps or adenomas are detected after colon cancer surgery. Remnant synchronous lesions require additional colonoscopy procedures or surgery.

AIM

To investigate factors of preoperative colonoscopy potentially affecting the detection of missed lesions in patients subjected to colorectal cancer surgery.

METHODS

Of 1147 colorectal cancer patients subjected to curative open or laparoscopic colectomy and colonoscopy at the Chungnam National University Hospital from January 2012 to December 2016, 518 patients underwent pre- and postoperative colonoscopy. The index colonoscopy was defined as the last preoperative endoscopy performed. We analyzed pre- and postoperative medical charts for colonoscopy and pathological data. The effects of patient, procedure, and tumor factors on the postoperative adenoma detection rate, advanced adenoma detection rate, and adenoma miss rate (AMR) were analyzed.

RESULTS

The overall AMR was 25.7% (95% confidence interval, 22.2-29.8%). Comparing optimal and non-optimal bowel preparation groups, the latter had greater postoperative polyp missed rate (PMR), AMR (p < 0.01), and AAMR (p = 0.272). The optimal preparation group allowed identification of more synchronous adenomas than in the fair (OR 5.72) and poor (OR 11.39) preparation groups. On univariate analysis, patient age and left-sided colectomy (p < 0.01) influenced AMR. Multivariate analysis showed that age, preoperative bowel preparation, and left colon resection influenced postoperative AMR.

CONCLUSION

A better quality of index colonoscopy had a positive effect on lowering the detection rate of postoperative adenoma. Older age and suboptimal bowel preparation at the index colonoscopy and left-sided colectomy had negative effects on lowering the postoperative AMR.

Adenoma miss rate of polypectomy-referring hospitals is high in Korea

BACKGROUND/AIMS

We evaluated the miss rates of polyps, adenomas, and advanced neoplasia of polypectomy-referring hospitals and risk factors for missed adenomas.

METHODS

We compared medical records and electronic images of initial colonoscopies from polypectomy-referring hospitals with those of corresponding therapeutic colonoscopies from Seoul St. Mary's Hospital obtained from May 2014 to February 2016.

RESULTS

A total of 147 patients (56.6 ± 12.1 years, 37 females) were included. The mean number of polyps and adenomas detected on initial colonoscopy was 2.4 ± 1.7 and 1.7 ± 1.4, respectively. The mean number of additionally detected polyps and adenomas per patient during therapeutic colonoscopy was 1.4 ± 1.8 and 1.0 ± 1.5, respectively. Pooled miss rate for polyps, adenomas, and advanced neoplasia was 36%, 37%, and 11%, respectively. Pooled miss rate for adenomas was significantly higher for right-sided, non-pedunculated, and small (< 1 cm) adenomas (p = 0.031, p = 0.000, and p = 0.000, respectively). The miss rate of polyps, adenomas, and advanced neoplasia per patient was 60%, 49%, and 7%, respectively. Multivariate analysis revealed age and number of adenoma on initial colonoscopy were significantly related with risk for adenoma-missing (p = 0.005 and p = 0.023, respectively).

CONCLUSION

Among patients referred for polypectomy, adenoma is missed in one of two patients and advanced neoplasm is missed in one of 13. Patients with advanced age or multiple adenoma on initial colonoscopy have a higher possibility of missed adenoma. Total colon exploration should be performed carefully during therapeutic colonoscopy.

Multicolor fluorescence imaging using a single RGB-IR CMOS sensor for cancer detection with smURFP-labeled probiotics

A multicolor fluorescence imaging device was recently developed for image-guided surgery. However, conventional systems are typically bulky and function with two cameras. To overcome these issues, we developed an economical home-built fluorescence imaging device based on a single RGB-IR sensor that can acquire both color and fluorescence images simultaneously. The technical feasibility of RGB-IR imaging was verified ex vivo in chicken breast tissue using fluorescein isothiocyanate (FITC), cyanine 5 (Cy5), and indocyanine green (ICG) as fluorescent agents. The minimum sensitivities for FITC, Cy5, and ICG were 0.200 µM, 0.130 µM, and 0.065 µM, respectively. In addition, we validated the fluorescence imaging of this device in vitro during a minimally invasive procedure using smURFP-labeled probiotics, which emit a spectrum similar to that of Cy5. Our preliminary study of the ex vivo tissue suggests that Cy5 and ICG are good candidates for deep tissue imaging. In addition, the tumor-specific amplification process was visualized using cancer cells incubated with probiotics that had been labeled with a fluorescent protein. Our approach indicates the potential for in vivo screening of tumors in rodent tumor models.

Endocuff-Assisted versus Cap-Assisted Colonoscopy Performed by Trainees: A Retrospective Study

Background/Aims

The adenoma detection rate (ADR) of screening colonoscopies performed by trainees is often lower than that of colonoscopies performed by experts. The effcacy of cap-assisted colonoscopy (CAC) in adenoma detection is well documented, especially that of CACs performed by trainees. Endocuff, a new endoscopic cap, is reportedly useful for adenoma detection; however, no trials have compared the effcacy of Endocuff-assisted colonoscopy (EAC) and CAC conducted by trainees. Therefore, the present study retrospectively compared the effcacy between EAC and CAC in trainees.

Methods

This was a single-center, retrospective study involving 305 patients who underwent either EAC or CAC performed by three trainees between January and December 2018. We evaluated the ADR, mean number of adenomas detected per patient (MAP), cecal intubation rate, cecal intubation time, and occurrence of complications between the EAC and CAC groups.

Results

The ADR was significantly higher in the EAC group than in the CAC group (54.3% vs. 37.3%, p=0.019), as was the MAP (1.36 vs. 0.74, p=0.003). No significant differences were found between the groups with respect to the cecal intubation rate or cecal intubation time. No major complications occurred in either group.

Conclusions

Our results suggest that EAC exhibits increased ADR and MAP compared to CAC when performed by trainees.

Linked color imaging versus narrow-band imaging for colorectal polyp detection: a prospective randomized tandem colonoscopy study

BACKGROUND AND AIMS

Linked color imaging (LCI) is a newly available image-enhanced endoscopy (IEE) system that emphasizes the red mucosal color. No study has yet compared LCI with other available IEE systems. Our aim was to investigate polyp detection rates using LCI compared with narrow-band imaging (NBI).

METHODS

This is a prospective randomized tandem colonoscopy study. Eligible patients who underwent colonoscopy for symptoms or screening/surveillance were randomized in a 1:1 ratio to receive tandem colonoscopy with both colonoscope withdrawals using LCI or NBI. The primary outcome was the polyp detection rate.

RESULTS

Two hundred seventy-two patients were randomized (mean age, 62 years; 48.2% male; colonoscopy for symptoms, 72.8%) with 136 in each arm. During the first colonoscopy, the polyp detection rate (71.3% vs 55.9%; P = .008), serrated lesion detection rate (34.6% vs 22.1%; P = .02), and mean number of polyps detected (2.04 vs 1.35; P = .02) were significantly higher in the NBI group than in the LCI group. There was also a trend of higher adenoma detection rate in the NBI group compared with the LCI group (51.5% vs 39.7%, respectively; P = .05). Multivariable analysis confirmed that use of NBI (adjusted odds ratio, 1.99; 95% confidence interval, 1.09-3.68) and withdrawal time >8 minutes (adjusted odds ratio, 5.11; 95% confidence interval, 2.79-9.67) were associated with polyp detection. Overall, 20.5% of polyps and 18.1% of adenomas were missed by the first colonoscopy, but there was no significant difference in the miss rates between the 2 groups.

CONCLUSION

NBI was significantly better than LCI for colorectal polyp detection. However, both LCI and NBI missed 20.5% of polyps. (Clinical trial registration number: NCT03336359.).

Training interventions to improve adenoma detection rates during colonoscopy: a systematic review and meta-analysis

BACKGROUND

Colonoscopies are effective means of detecting and removing precancerous adenomatous polyps. The adenoma detection rate (ADR) is a marker of colonoscopy quality and an independent predictor of colorectal cancer incidence. Focused training interventions may improve an endoscopist's ADR, but the supporting research is limited. This systematic review and meta-analysis identified, critically appraised, and meta-analyzed data from randomized trials (RCTs) evaluating the effect of training interventions on ADRs.

METHODS

Ovid Medline, EMBASE, CENTRAL, Eric, CINAHL, Scopus, Web of Science, and ClinicalTrials.gov were searched for RCTs investigating the effect of an educational intervention on ADRs. Two reviewers independently screened, identified, and extracted trial-level data. Internal validity was assessed in duplicate using the Risk of Bias tool. Our primary outcome was the ADR. Secondary outcomes were advanced ADR, adenocarcinoma detection rate, polyp detection rate, and withdrawal times. Safety outcomes were post-polypectomy bleeding rate and colonoscopy-related perforation rate.

RESULTS

From 2837 screened citations, we identified 3 trials (119 endoscopists) meeting our inclusion criteria. Training interventions were associated with a trend toward increased ADRs (odds ratio 1.16, 95% confidence interval (CI) 1.00-1.34; I² 83%; 3 trials; 119 endoscopists). When limited to screening colonoscopies, the odds ratio for ADRs associated with training interventions was 1.17 (95% CI 1.00-1.36; I² 80%; 3 trials; 119 endoscopists). There was a high level of heterogeneity between the trials' training interventions. Training intervention improved the advanced ADR, adenocarcinoma detection rate, polyp detection rate, and withdrawal times. Safety outcomes were not reported.

CONCLUSIONS

A focused training intervention was associated with a strong trend toward increased ADRs among certified endoscopists. While the described training interventions definitely show promise, further efforts around continuing professional developments activities are needed to more consistently improve ADRS among certified endoscopists.

Effect of fellow involvement on colonoscopy outcomes: A systematic review and meta-analysis

BACKGROUND AND AIMS

The effect of fellow involvement on colonoscopy outcomes is controversial. Thus, we evaluated this effect on adenoma detection rate (ADR) and on other colonoscopy quality indicators.

METHODS

MEDLINE and Cochrane central register of controlled trials were searched up to September 2018 for studies evaluating fellow-involved colonoscopies vs. attending physicians-only examinations in terms of colonoscopy outcomes. Primary outcome was ADR, while advanced ADR (AADR), mean number of adenomas per colonoscopy (MAC), cecum intubation rate (CIR) and adverse events rate comprised the secondary outcomes. The effect size on study outcomes was calculated using random-effects model and it is presented as Odds Ratio (OR) or Mean Difference (MD) with 95% confidence interval (CI).

RESULTS

Nineteen observational studies involving 34,059 patients (fellow-involved 16,875, attending physician-only 17,184) were included. Compared to the attending physician-only group, fellow involvement marginally increased ADR [OR (95%CI) = 1.12 (1.00-1.26); p = 0.06, I2 = 76%]. Attending physicians with low-to-moderate ADR (<35%) benefited most from fellow's participation [OR (95%CI): 1.26 (1.13-1.40) vs. 1.12 (1.00-1.26); p = 0.03 when ADR < 35% and OR (95%CI): 1.29 (1.13-1.46) vs. 0.95 (0.78-1.16); p = 0.01 when ADR < 30%, respectively]. Moreover, fellow-involved group had higher MAC compared to attending-only group [MD (95%CI) = 0.12 (0.04-0.20); p = 0.002, I2 = 53%]. No benefit from fellow involvement was detected either for AADR, CIR or adverse events rate.

CONCLUSIONS

Fellow involvement during colonoscopy is associated with more adenomas detected per procedure and with higher ADR when the attending physician-only group ADR is less than 35%.

Factors associated with oesophagogastric cancers missed by gastroscopy: a case-control study

INTRODUCTION

There is increasing demand for gastroscopy in the United Kingdom. In around 10% of patients, gastroscopy is presumed to have missed oesophagogastric (OG) cancer prior to diagnosis. We examine patient, endoscopist and service level factors that may affect rates of missed OG cancers.

METHODS

Gastroscopies presumed to have missed OG cancers performed up to 3 years prior to diagnosis were identified over 6 years in Sheffield, UK. Factors related to the patient, endoscopist and endoscopy lists were examined in a case-control study. Procedures which missed cancer were compared with two procedure controls: the procedures which subsequently diagnosed cancer in the same patient, and second, endoscopist matched procedures diagnostic of small benign focal lesions.

RESULTS

We identified 48 (7.7%) cases of missed OG cancer. Endoscopy lists on which OG cancer diagnoses were missed contained a greater number of total procedures compared with lists on which diagnoses were subsequently made (OR 1.42 95% CI 1.13 to 1.78) and when compared with lists during which matched endoscopists diagnosed benign small focal lesions (OR 1.25, 95% CI 1.02 to 1.52). The use of sedation, endoscopist profession and experience, or time of procedure were not associated with a missed cancer.

CONCLUSION

7.7% of patients diagnosed with OG cancer could have been diagnosed and treated earlier. Our study suggests that endoscopy lists with greater numbers of procedures may be associated with missed OG cancers. The use of sedation, endoscopist background or time of procedure did not increase the risk of missed cancer procedures.

Improved adenoma detection with Endocuff Vision: the ADENOMA randomised controlled trial

OBJECTIVE

Low adenoma detection rates (ADR) are linked to increased postcolonoscopy colorectal cancer rates and reduced cancer survival. Devices to enhance mucosal visualisation such as Endocuff Vision (EV) may improve ADR. This multicentre randomised controlled trial compared ADR between EV-assisted colonoscopy (EAC) and standard colonoscopy (SC).

DESIGN

Patients referred because of symptoms, surveillance or following a positive faecal occult blood test (FOBt) as part of the Bowel Cancer Screening Programme were recruited from seven hospitals. ADR, mean adenomas per procedure, size and location of adenomas, sessile serrated polyps, EV removal rate, caecal intubation rate, procedural time, patient experience, effect of EV on workload and adverse events were measured.

RESULTS

1772 patients (57% male, mean age 62 years) were recruited over 16 months with 45% recruited through screening. EAC increased ADR globally from 36.2% to 40.9% (P=0.02). The increase was driven by a 10.8% increase in FOBt-positive screening patients (50.9% SC vs 61.7% EAC, P<0.001). EV patients had higher detection of mean adenomas per procedure, sessile serrated polyps, left-sided, diminutive, small adenomas and cancers (cancer 4.1% vs 2.3%, P=0.02). EV removal rate was 4.1%. Median intubation was a minute quicker with EAC (P=0.001), with no difference in caecal intubation rate or withdrawal time. EAC was well tolerated but caused a minor increase in discomfort on anal intubation in patients undergoing colonoscopy with no or minimal sedation. There were no significant EV adverse events.

CONCLUSION

EV significantly improved ADR in bowel cancer screening patients and should be used to improve colonoscopic detection.

TRIAL REGISTRATION NUMBER

NCT02552017, Results; ISRCTN11821044, Results.

New-generation full-spectrum endoscopy versus standard forward-viewing colonoscopy: a multicenter, randomized, tandem colonoscopy trial (J-FUSE Study)

BACKGROUND AND AIMS

Although colonoscopy is the criterion standard for detection of colorectal adenomas, some adenomas are missed. Full-spectrum endoscopy (FUSE) allows for observation with a 330-degree angle of view, which is expected to decrease the miss rate. However, no consensus has been reached regarding the superiority of FUSE over standard forward-viewing colonoscopy (SFVC) for detection of adenomas; we therefore compared new-generation FUSE and SFVC regarding colorectal adenoma miss rate (AMR) in this, the first reported randomized control trial using new-generation FUSE.

METHODS

We enrolled individuals aged 40 to 75 years who had been referred for screening, surveillance, fecal occult blood test positivity, or symptoms in a prospective randomized trial of tandem colonoscopy in 8 institutions. Patients were randomly assigned (1:1) via computer-generated stratified randomization. Neither the endoscopists nor patients were blinded to the allocation. The primary endpoint was AMR per patient (AMR-PP).

RESULTS

We enrolled 345 patients and included 319 in the per-protocol analyses. AMR-PP was significantly lower with FUSE (11.7%; 95% confidence interval [CI], 8.0%-15.4%) than with SFVC (22.9%; 95% CI, 17.5%-28.3%; P < .001). AMR-PP for lesions ≤5 mm in size was significantly lower with FUSE (10.4%; 95% CI, 6.5%-14.3%) than with SFVC (20.0%; 95% CI, 14.4%-25.6%; P = .0057). Furthermore, AMR-PP in the ascending colon was significantly lower with FUSE (4.3%; 95% CI, 1.4%-7.2%) than with SFVC (10.6%; 95% CI, 6.1%-15.1%; P = .0212).

CONCLUSIONS

FUSE is superior to SFVC regarding both AMR-PP and AMR; additionally, AMR-PP is both significantly lower with FUSE than SFVC for lesions ≤5 mm in size and in the ascending colon. (Clinical trial registration number: UMIN000020448.).

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.

Impact of fellowship training level on colonoscopy quality and efficiency metrics

BACKGROUND AND AIMS

Previous studies have described variable effects of fellow involvement on the adenoma detection rate (ADR), but few have stratified this effect by level of training. We aimed to evaluate the "fellow effect" on multiple procedural metrics including a newly defined adenoma management efficiency index, which may have a role in documenting colonoscopy proficiency for trainees. We also describe the impact of level of training on moderate sedation use.

METHODS

We performed a retrospective review of 2024 patients (mean age, 60.9 ± 10 years; 94% men) who underwent outpatient colonoscopy between June 2012 and December 2014 at our Veterans Affairs Medical Center. Colonoscopies were divided into 5 groups. The first 2 groups were first-year fellows in the first 6 months and last 6 months of the training year. Second- and third-year fellows and attending-only procedures accounted for 1 group each. We collected data on doses of sedatives used, frequency of adjunctive agent use, procedural times, and location, size, and histology of polyps. We defined the adenoma management efficiency index as average time required per adenoma resected during withdrawal.

RESULTS

Of the colonoscopies performed, 1675 involved a fellow and 349 were performed by the attending alone. There was no difference in ADR between fellows according to level of training (P = .8) or between fellows compared with attending-only procedures (P = .67). Procedural times decreased consistently during training and declined further for attending-only procedures. This translated into improvement in the adenoma management efficiency index (fellow groups by ascending level of training: 23.5 minutes vs 18.3 minutes vs 13.7 minutes vs 13.4 minutes vs attending group 11.7 minutes; P < .001). There was no difference in the average doses of midazolam and fentanyl used among fellow groups (P = .16 and P = .1, respectively). Compared with attending-only procedures, fellow involvement was associated with higher doses of fentanyl and midazolam and more frequent use of diphenhydramine and glucagon (P < .0001, P = .0002, P < .0001, and P = .01, respectively).

CONCLUSIONS

ADR was similar at different stages of fellowship training and comparable with the attending group. Efficiency of detecting and resecting polyps improved throughout training without reaching the attending level. Fellow involvement led to a greater use of moderate sedation, which may relate to a longer procedure duration and an evolving experience in endoscopic technique.

The B-ADENOMA Study: Bowelscope - Accuracy of Detection using Endocuff Optimisation of Mucosal Abnormalities: Study Protocol for randomised controlled trial

BACKGROUND AND STUDY AIMS

 UK Bowel Cancer Screening flexible sigmoidoscopy (BowelScope) currently offers patients aged 55 a one-off flexible sigmoidoscopy for adenoma clearance to decrease colorectal cancer incidence by interrupting the adenoma-carcinoma sequence. Recent evidence has shown maximum benefit in increasing adenoma detection rate (ADR) using the Endocuff Vision device in the left side of the colon and in screening patients. Currently, ADR is low and shows unacceptable variation in BowelScope. ADR is a quality indicator in screening sigmoidoscopy and higher rates have been shown to reduce colorectal cancer incidence.

PATIENTS AND METHODS

 This will be a prospective, multicenter, UK-based randomized controlled trial (RCT) comparing ADR in Endocuff-assisted versus standard bowel cancer screening flexible sigmoidoscopy (BowelScope). All patients aged 55 to 61 years invited to BowelScope screening and able to give informed consent will be eligible for recruitment. Exclusion criteria include absolute contraindications to flexible sigmoidoscopy, known or suspected large bowel obstruction or pseudo-obstruction, colonic strictures or polyposis syndromes, known severe diverticular segment, active colitis, inability to give informed consent, anticoagulation precluding polypectomy and pregnancy. Patients will be randomized on the day of procedure to Endocuff-assisted flexible sigmoidoscopy or standard flexible sigmoidoscopy, stratified by age group and sex. Baseline, endoscopy and polyp data were collected as well as nurse and patient assessment of comfort. Polyp histology was collected when available. Patients will be asked to return a comfort questionnaire the following day and were followed up for 14 days for complications.

RESULTS

 The ADENOMA trial will be designed to demonstrate a significant improvement in ADR with maximal effect in the left colon and in fecal occult blood test-positive screening patients. This trial will be the first RCT to look at Endocuff Vision in bowel cancer screening flexible sigmoidoscopy. We will aim to establish whether Endocuff vision improves ADR in this population.

Differences with experienced nurse assistance during colonoscopy in detecting polyp and adenoma: a randomized clinical trial

OBJECTIVES

This study aims to evaluate whether the participation of an experienced endoscopy nurse in colonoscopy increases the polyp detection rate (PDR) and adenoma detection rate (ADR) of experienced colonoscopists.

METHODS

This study was a randomized controlled trial. Patients were randomly assigned to the experienced colonoscopist alone (single observer) group, or experienced nurse participation (dual observer) group. The primary outcome was the PDR and ADR. The advanced lesion detection rate was also recorded.

RESULTS

A total of 587 patients were included in the analysis. Among these patients, 291 patients were assigned to the single observer group, while 296 patients were assigned to the dual observer group. The PDR was 33% in the single observer group and 41.9% in the dual observer group (P = 0.026), while the ADR was 23.0% in the single observer group and 30.4% in the dual observer group (P = 0.043). No significant difference was found for advanced lesions between groups.

CONCLUSIONS

The present data demonstrated that experienced nurse observation during colonoscopy can improve polyp and adenoma detection rates, even if the colonoscopist is experienced.

TRIAL REGISTRATION

Clinicaltrials.gov No. NCT02292563. https://clinicaltrials.gov/ct2/results?cond=&term=NCT02292563&cntry=&state=&city=&dist=.

Can technology increase adenoma detection rate?

Colorectal cancer is the third most common cancer worldwide and the second most common cause of cancer-related death in Europe and North America. Colonoscopy is the gold standard investigation for the colon but is not perfect, and small or flat adenomas can be missed which increases the risk of patients subsequently developing colorectal cancer. Adenoma detection rate is the most widely used marker of quality, and low rates are associated with increased rates of post-colonoscopy colorectal cancer. Standards of colonoscopy and adenoma detection vary widely between different endoscopists. Interventions to improve adenoma detection rate are therefore required. Many devices have been purported to increase adenoma detection rate. This review looks at current available evidence for device technology to improve adenoma detection rate during colonoscopy.

Colonoscopy procedural volume increases adenoma and polyp detection rates in gastroenterologytrainees

AIM

To investigate changes in polyp detection throughout fellowship training, and estimate colonoscopy volume required to achieve the adenoma detection rate (ADRs) and polyp detection rate (PDRs) of attending gastroenterologists.

METHODS

We reviewed colonoscopies from July 1, 2009 to June 30, 2014. Fellows’ procedural logs were used to retrieve colonoscopy procedural volumes, and these were treated as the time variable. Findings from screening colonoscopies were used to calculate colonoscopy outcomes for each fellow for the prior 50 colonoscopies at each time point. ADR and PDR were plotted against colonoscopy procedural volumes to produce individual longitudinal graphs. Repeated measures linear mixed effects models were used to study the change of ADR and PDR with increasing procedural volume.

RESULTS

During the study period, 12 fellows completed full three years of training and were included in the analysis. The average ADR and PDR were, respectively, 31.5% and 41.9% for all fellows, and 28.9% and 38.2% for attendings alone. There was a statistically significant increase in ADR with increasing procedural volume (1.8%/100 colonoscopies, P = 0.002). Similarly, PDR increased 2.8%/100 colonoscopies (P = 0.0001), while there was no significant change in advanced ADR (0.04%/100 colonoscopies, P = 0.92). The ADR increase was limited to the right side of the colon, while the PDR increased in both the right and left colon. The adenoma per colon and polyp per colon also increased throughout training. Fellows reached the attendings’ ADR and PDR after 265 and 292 colonoscopies, respectively.

CONCLUSION

We found that the ADR and PDR increase with increasing colonoscopy volume throughout fellowship. Our findings support recent recommendations of ≥ 275 colonoscopies for colonoscopy credentialing.

Who Performs Colonoscopy? Workforce Trends Over Space and Time

PURPOSE

With the increased availability of colonoscopy to average risk persons due to insurance coverage benefit changes, we sought to identify changes in the colonoscopy workforce. We used outpatient discharge records from South Carolina between 2001 and 2010 to examine shifts over time and in urban versus rural areas in the types of medical providers who perform colonoscopy, and the practice settings in which they occur, and to explore variation in colonoscopy volume across facility and provider types.

METHODS

Using an all-payer outpatient discharge records database from South Carolina, we conducted a retrospective analysis of all colonoscopy procedures performed between 2001 and 2010.

FINDINGS

We identified a major shift in the type of facilities performing colonoscopy in South Carolina since 2001, with substantial gains in ambulatory surgery settings (2001: 15, 2010: 34, +127%) versus hospitals (2001: 58, 2010: 59, +2%), particularly in urban areas (2001: 12, 2010: 27, +125%). The number of internists (2001: 46, 2010: 76) and family physicians (2001: 34, 2010: 106) performing colonoscopies also increased (+65% and +212%, respectively), while their annual procedures volumes stayed fairly constant. Significant variation in annual colonoscopy volume was observed across medical specialties (P < .001), with nongastroenterologists having lower volumes versus gastroenterologists and colon and rectal surgeons.

CONCLUSIONS

There have been substantial changes over time in the number of facilities and physicians performing colonoscopy in South Carolina since 2001, particularly in urban counties. Findings suggest nongastroenterologists are meeting a need for colonoscopies in rural areas.

Comparison of linked color imaging and white-light colonoscopy for detection of colorectal polyps: a multicenter, randomized, crossover trial

BACKGROUND AND AIMS

Linked color imaging (LCI), a recently developed technology, uses a laser endoscopic system to enhance the color separation of red color to depict red and white colors more vividly. The benefits of LCI in the detection of colorectal polyps remain unknown. The aim of this study was to assess the ability of LCI to improve the detection of colorectal polyps compared with white-light (WL) endoscopy.

METHODS

We performed a multicenter, crossover, prospective, randomized controlled trial in 3 hospitals in China. All patients underwent crossover colonoscopies with LCI and WL endoscopy in a randomized order. All lesions were removed during the second endoscopic procedure. The primary outcome measure was the difference in sensitivity between LCI and WL endoscopy for the detection of colorectal polyps. The secondary outcome measures were the adenoma detection rate per patient in the 2 groups and the factors associated with polyp miss rates.

RESULTS

A total of 152 patients were randomized, and 141 were included in the analysis. The overall polyp detection rate increased significantly by 24% for LCI colonoscopy, corresponding to a higher sensitivity with LCI than with WL endoscopy (91% vs 73%, P < .0001). Furthermore, LCI identified significantly more patients (32%) with polyps. The per-patient adenoma detection rate was significantly higher for LCI than for WL endoscopy (37% vs 28%; 95% confidence interval, 2.39%-19.41%).

CONCLUSIONS

LCI improves the detection of colorectal polyps and adenomas during colonoscopy. (Clinical trial registration number: NCT02724397.).

Correlation between adenoma detection rate and novel quality indicators for screening colonoscopy. A proposal for quality measures tool kit

BACKGROUND AND AIMS

Adenoma detection rate (ADR) is the most validated quality indicator for colonoscopy. Calculating ADR may not yield information in regards to advanced adenoma detection rate (advanced ADR). In addition, calculating ADR for individual endoscopists cannot distinguish between those who find only one versus more than one adenoma per colonoscopy. Several novel quality indictors were recently proposed to ensure adequate assessment of quality during colonoscopy. Our study aims to determine the correlation between ADR and novel quality indicators.

METHODS

A retrospective cohort study of patients undergoing screening colonoscopy in a university hospital setting. Patient characteristics and colonoscopy findings were combined and analyzed to calculate the correlation of ADR with novel quality indicators using Spearman's rank-order correlation were used.

RESULTS

A total of 1433 patients out of 2116 patients met the inclusion criteria. There was a significant positive correlation between ADR correlated with [advanced-ADR-2, nonadvanced-ADR, adenoma per colonoscopy, Multiplicity detection rate and ADR-Plus] r = (0.82, 0.99, 0.99, 0.07 and 0.85), respectively. However, ADR did not correlate with advanced-ADR and adenomas per positive participant.

CONCLUSION

Adding advanced-ADR and adenomas per positive participant to ADR may create a more comprehensive quality indicators tool kit, which is sensitive and difficult to game. Future studies are needed to investigate the impact of the tool kit on the interval cancers and adenoma missing rate.

Detectability of colorectal neoplastic lesions using a novel endoscopic system with blue laser imaging: a multicenter randomized controlled trial

BACKGROUND AND AIMS

Most studies have not reported an improvement in the detection of adenomas with the use of image-enhanced colonoscopy methods, possibly because of the darkness of the images. To overcome this limitation, a new-generation endoscopic system has been developed. This system has 2 blue-laser imaging (BLI) observation modes. The BLI observation was set to BLI-bright mode to detect lesions. We aimed to evaluate the efficacy of BLI in detecting lesions.

METHODS

This study was designed as a randomized controlled trial with participants from 8 institutions. We enrolled patients aged ≥40 years. The participants were randomly assigned to 2 groups: observation by using white-light imaging (WLI) with a conventional xenon light source (WLI group) or observation by using BLI-bright mode with a laser light source (BLI group). All of the detected lesions were resected or had a biopsy taken for histopathologic analysis. The primary outcome was the mean number of adenomas per patient (MAP) that were detected per procedure.

RESULTS

The WLI and BLI groups consisted of 474 and 489 patients, respectively. The MAP was significantly higher in the BLI group than in the WLI group (mean ± standard deviation [SD] WLI 1.01 ± 1.36, BLI 1.27 ± 1.73; P = .008). Adenoma detection rate in the BLI group was not significantly higher than in the WLI group. Observation times differed significantly, with BLI (9.48 minutes) being longer than WLI (8.42; P < .001). The mean (± SD) number of polyps per patient was significantly higher in the BLI group compared with the WLI group (WLI 1.43 ± 1.64, BLI 1.84 ± 2.09; P = .001).

CONCLUSIONS

A newly developed system that uses BLI improves the detection of adenomatous lesions compared with WLI. (Clinical trial registration number: UMIN 000014555.).

A Longitudinal Study of Adenoma Detection Rate in Gastroenterology Fellowship Training

BACKGROUND

Current guidelines suggest that a gastroenterology fellow in training needs to perform 140 colonoscopies to achieve competency. Data are limited regarding adenoma detection rate (ADR) in fellowship.

AIMS

To assess how fellow ADR correlates with number of colonoscopies performed.

METHODS

We performed a retrospective study examining consecutive colonoscopies performed by gastroenterology fellows. Fellow ADR before and after the 140 procedure benchmark was compared to colonoscopies performed by attending only with whom these fellows trained. A threshold for ideal procedure count was performed using ROC analysis.

RESULTS

We analyzed 2021 average-risk colonoscopies performed by 10 gastroenterology fellows under the supervision of an attending physician. When fellows had performed <140 colonoscopies, the ADR was 27 % compared with an ADR of 36 % when fellows had performed >140 colonoscopies under attending supervision (p = 0.02). The ADR of fellows who had performed >140 colonoscopies under attending supervision was greater than that of attending-only colonoscopies (36 vs. 25 %, p < 0.0001). A threshold of >325 (male patients) and 539 (female patients) colonoscopies was determined to be ideal for achieving adequate ADR based on ROC analysis.

CONCLUSIONS

Our data suggest that ADR increases after fellows perform >140 colonoscopies under attending supervision, and thereafter surpasses the ADR of attending-only colonoscopies. Some of the differences may be driven by detection of small adenomas. The findings of this study suggest that a higher threshold for number of colonoscopies performed under attending supervision may be needed to achieve adequate ADR during fellowship prior to independent practice.

Learning curve for endoscopy training: Is it all about numbers?

Endoscopy training is an important component of postgraduate gastroenterology and general surgery programs. Proficiency in endoscopy requires the development of several tangible and intangible skills. Much attention has traditionally been paid to establishing a threshold, or minimum procedural volume during the training period, which is necessary for a trainee to achieve competence in endoscopy by the conclusion of his or her program. However, despite several attempts to characterize this target, it has become clear in recent years that training programs need to consider other factors rather than relying on this measure as the sole marker of trainee competency. Here, we present a review of general concepts in endoscopy skills acquisition that affect the learning curve, the evolving definition of competency as it relates to procedural volume, the role of simulation in endoscopy training, and the concept of massed versus spaced delivery of endoscopy training.

The Secondary Quality Indicator to Improve Prediction of Adenoma Miss Rate Apart from Adenoma Detection Rate

OBJECTIVES

Adenoma detection rate (ADR) cannot distinguish between endoscopists who detect one adenoma and those who detect ≥2 adenomas. Hypothetically, adenoma miss rate (AMR) may be significant for endoscopists with high ADRs who examine the rest of colon with less care after detecting first polyp. Our objective was to evaluate other quality indicators plus ADR vs. ADR alone in prediction of AMR.

METHODS

We conducted a cross-sectional study of asymptomatic participants aged 50-75 years who underwent back-to-back screening colonoscopies by four faculty endoscopists. Each round of colonoscopy was performed by two of the endoscopists in a randomized order. During each round of colonoscopy, all detected polyps were removed. The second endoscopist was blinded to the results of the first. The total number of adenomas per positive participant (APP), the total number of adenomas per colonoscopy (APC), the additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and ADR were calculated for prediction of AMR.

RESULTS

In all, 200 participants underwent back-to-back colonoscopies. There were no significant differences in ADRs of four endoscopists (44, 50, 54, and 46%). APPs were 1.91, 2.12, 2.19, and 2.43. APCs were 0.84, 1.06, 1.18, and 1.12. ADR-Plus were 0.40, 0.56, 0.64, and 0.66, respectively. AMRs differed significantly between the endoscopists (36, 27, 21, and 13%; P=0.01). There was no correlation between ADR and AMR (r=-0.25; P=0.75). Whereas APP exhibited a strong inverse correlation with AMRs (r=-0.99; P<0.01). APC and ADR-Plus appeared to be inversely correlated with AMR, however this was not statistically significant (r=-0.82; P=0.18 and r=-0.93; P=0.07, respectively).

CONCLUSIONS

Among high-ADR endoscopists, AMRs still varied. APP may be a promising secondary indicator for distinguishing between the one-and-done polyp endoscopist and the meticulous endoscopist. The evaluation of influence of new metrics on colorectal cancer (CRC) prevention requires a larger population-based study.

A novel quality scoring system for the evaluation of individual colonoscopy: A multicenter retrospective study

BACKGROUND AND AIM

It is essential to develop a novel evaluation system for the quality of individual colonoscopy and provide guidelines on whether and when to follow up the patient after the initial colonoscopy. This study aimed to establish and validate a scoring system for the quality of individual colonoscopy in terms of the adenoma miss rate (AMR).

METHODS

Patients undergoing two consecutive colonoscopies within 90 days between 2009 and 2011 from different levels of hospitals in China were enrolled into this study. Potential risk factors for adenoma miss at the individual colonoscopy in a cohort of patients were evaluated in univariate and multivariate analyses. Corresponding scores for the procedure-related factors were generated based on their weights, and a scoring system was established and then validated by correlating the system with AMR.

RESULTS

A total of 2093 patients were enrolled. Procedure-related factors at the individual colonoscopy (including bowel preparation and imaging methods), doctor experience, retroflexion, and withdrawal time were identified to be independent risk factors, and each of these factors was scored from 0 to 3. Then, a novel scoring system for the quality of individual colonoscopy (ranging from 0 to 9) was established, which was closely correlated with the AMRs in the establishment (adjusted R(2) = 0.845) and validation databases (adjusted R(2) = 0.733).

CONCLUSIONS

The developed and validated evaluation system, consisting of procedure-related independent factors, successfully assesses the quality of individual colonoscopy in terms of AMRs.

Achieving competence in colonoscopy: Milestones and the need for a new endoscopic curriculum in gastroenterology training

Colonoscopy is considered to be the most effective tool for reducing colorectal cancer (CRC) morbidity and mortality. As a result, certifying trainee competence in the performance of colonoscopy is critical to maximizing CRC screening and prevention efforts. Guidelines on training and accreditation around the world have been revised to emphasize the attainment of milestones in the technical and cognitive skills necessary to perform the procedure. To meet this challenge, new evaluation systems have been developed to measure trainee competence through all aspects of colonoscopy training. These changes stem from increased recognition that procedural numbers alone do not necessarily guarantee trainees’ proficiency in the performance of colonoscopy. Variability in endoscopic practice and in CRC screening outcomes also point to deficiencies in the current approach towards colonoscopy instruction. However, technological innovations hold great promise in training endoscopists to perform high quality colonoscopy. Furthermore, potential advances in the use of feedback as a training tool provide new avenues for research. This review summarizes the latest evidence on the effort to define, evaluate and promote the achievement of competence in colonoscopy among trainees.

Linear-array EUS improves detection of pancreatic lesions in high-risk individuals: a randomized tandem study

BACKGROUND

Studies comparing linear and radial EUS for the detection of pancreatic lesions in an asymptomatic population with increased risk for pancreatic cancer are lacking.

OBJECTIVES

To compare pancreatic lesion detection rates between radial and linear EUS and to determine the incremental diagnostic yield of a second EUS examination.

DESIGN

Randomized controlled tandem study.

SETTING

Five academic centers in the United States.

PATIENTS

Asymptomatic high-risk individuals (HRIs) for pancreatic cancer undergoing screening EUS.

INTERVENTIONS

Linear and radial EUS performed in randomized order.

MAIN OUTCOME MEASUREMENTS

Pancreatic lesion detection rate by type of EUS, miss rate of 1 EUS examination, and incremental diagnostic yield of a second EUS examination (second-pass effect).

RESULTS

Two hundred seventy-eight HRIs were enrolled, mean age 56 years (43.2%), and 90% were familial pancreatic cancer relatives. Two hundred twenty-four HRIs underwent tandem radial and linear EUS. When we used per-patient analysis, the overall prevalence of any pancreatic lesion was 45%. Overall, 16 of 224 HRIs (7.1%) had lesions missed during the initial EUS that were detected by the second EUS examination. The per-patient lesion miss rate was significantly greater for radial followed by linear EUS (9.8%) than for linear followed by radial EUS (4.5%) (P = .03). When we used per-lesion analysis, 73 of 109 lesions (67%) were detected by radial EUS and 99 of 120 lesions (82%) were detected by linear EUS (P < .001) during the first examination. The overall miss rate for a pancreatic lesion after 1 EUS examination was 47 of 229 (25%). The miss rate was significantly lower for linear EUS compared with radial EUS (17.5% vs 33.0%, P = .007).

LIMITATIONS

Most detected pancreatic lesions were not confirmed by pathology.

CONCLUSION

Linear EUS detects more pancreatic lesions than radial EUS. There was a "second-pass effect" with additional lesions detected with a second EUS examination. This effect was significantly greater when linear EUS was used after an initial radial EUS examination.

Adenoma detection rate varies greatly during colonoscopy training

BACKGROUND

The adenoma detection rate (ADR) is considered the most important quality indicator for colonoscopy and varies widely among colonoscopists. It is unknown whether the ADR of gastroenterology consultants can already be predicted during their colonoscopy training.

OBJECTIVE

To evaluate the ADR of fellows in gastroenterology and evaluate whether this predicts their ADR as gastroenterology consultants.

DESIGN

Retrospective observational study.

SETTING

Academic and regional centers.

PATIENTS

Symptomatic patients undergoing colonoscopy.

MAIN OUTCOME MEASUREMENTS

The variance in ADR among 7 gastroenterology fellows during their training (between May 2004 and March 2012) and of the same fellows after they registered as consultants (between October 2011 and April 2014) was evaluated. Multivariate logistic regression was performed to compare the highest detector (endoscopist with highest ADR) with the individual fellows and to evaluate whether an ADR of 20% or higher during the training was predictive of a high ADR as a consultant.

RESULTS

During training, ADRs ranged from 14% to 36% (P < .001). Compared with the highest detector, the OR for detecting an adenoma ranged from 0.64 (95% CI, 0.40-1.03) to 0.29 (95% CI, 0.17-0.48). After registration, ADR ranged from 19.8% to 40.2% (P = .066). Compared with the highest detector during consultancy, the OR ranged from 0.64 (95% CI, 0.34-1.21) to 0.26 (95% CI, 0.13-0.52). Only 2 fellows significantly improved their ADR after completing their training. An ADR lower than 20% during training was associated with a lower ADR as a consultant (OR 0.51; 95% CI, 0.30-0.87).

LIMITATIONS

Retrospective study.

CONCLUSIONS

Variance in ADR is already present during the endoscopy training of gastroenterology fellows. Most fellows do not improve their ADR after completing their training. These findings suggest that the ADR can be predicted during colonoscopy training, and we suggest that feedback and benchmarking should be implemented early during training of fellows in an effort to improve ADR in future daily practice as a consultant.

Trainee colonoscopists fulfil quality standards for the detection of adenomatous polyps

BACKGROUND

The detection of adenomatous lesions is a major indicator for quality and competence in colonoscopy. Little is known about adenoma detection rates (ADR) of endoscopy trainees. The aim of our study was to investigate the performance of trainee colonoscopists in detecting adenomas and to depict the shape of adenoma detection learning curves during apprenticeship.

METHODS

We retrospectively investigated a prospectively maintained database of a single tertiary referral center to reveal colonoscopies performed by trainee endoscopists during 2001 and 2013. Colonoscopy reports were chronologically retrieved and separately analyzed for each trainee. Using cumulative curves, courses of trainee's Adenoma detection rates (ADR) during apprenticeship were displayed. Additionally, procedural data including cecal intubation rate and occurrence of complications were assessed.

RESULTS

We retrospectively analyzed 4354 colonoscopies conducted by 10 trainee endoscopists (TE). A median number of 371 investigations were performed by each apprentice. Group ADR was 23%. No significant difference between aggregated ADRs at the beginning (23%) and at the end (22%) of apprenticeship could be determined (p = 0.70). However, individual learning curves showed considerable different slopes. Personal ADR values ranged between 17% and 31%. Overall cecum intubation rate was 99.0 %. Complication rates were low and fulfilled quality requirements recommended in guidelines.

CONCLUSION

From the beginning of education, trainee colonoscopists are capable to provide high-quality investigations considering the detection of adenomas as a benchmark quality indicator. Nevertheless, performance differs markedly between investigators. Therefore, individual detection rates should be reviewed regularly to reveal further need for training.

Risk factors associated with missed colorectal flat adenoma: A multicenter retrospective tandem colonoscopy study

AIM: To determine the miss rate for colorectal flat adenomas during colonoscopy and the risk factors.

METHODS: Flat adenomas are frequently missed during colonoscopy. However, the risk factors that influence their miss rates are unclear. This was a multicenter, retrospective study in which patients diagnosed with colorectal adenomas at a diagnostic colonoscopy and followed within 3 mo by a second therapeutic colonoscopy were pooled out from the established database. The “per-patient” and “per-adenoma” adenoma miss rates (AMR) for overall adenomas and flat adenomas, and patient-, adenoma-, and procedure-related risk factors potentially associated with the “per-adenoma” AMR for flat adenomas were determined.

RESULTS: Chromoscopy and high-definition colonoscopy were not taken under consideration in the study. Among 2093 patients with colorectal adenomas, 691 (33.0%) were diagnosed with flat adenomas, 514 with concomitant protruding adenomas and 177 without. The “per-patient” AMR for flat adenomas was 43.3% (299/691); the rates were 54.3% and 11.3%, respectively, for those with protruding adenomas and those without (OR = 9.320, 95%CI: 5.672-15.314, χ² = 99.084, P < 0.001). The “per-adenoma” AMR for flat adenomas was 44.3% (406/916). In multivariate analysis, older age, presence of concomitant protruding adenomas, poor bowel preparation, smaller adenoma size, location at the right colon, insufficient experience of the colonoscopist, and withdrawal time < 6 min were associated with an increased “per-adenoma” AMR for flat adenomas. The AMR for flat adenomas was moderately correlated with that for overall adenomas (r = 0.516, P < 0.0001). The AMR for flat adenomas during colonoscopy was high.

CONCLUSION: Patient’s age, concomitant protruding adenomas, bowel preparation, size and location of adenomas, proficiency of the colonoscopist, and withdrawal time are factors affecting the “per-adenoma” AMR for flat adenomas.

Does hyoscine butylbromide really improve polyp detection during colonoscopy? A meta-analysis of randomized controlled trials

AIM: To investigate the benefits of hyoscine butylbromide in polyp detection during colonoscopy by a meta-analysis of available randomized controlled trials (RCTs).

METHODS: Databases, including PubMed, EMBASE, the Cochrane Library, and the Science Citation Index up to September 2013, were searched. The primary outcome was polyp detection rate, and the secondary outcome was adenoma detection rate. The meta-analysis was performed using the free software Review Manager. Differences observed between the treated and the control groups were expressed as odds ratio (OR) with a 95% confidence interval (CI). A fixed-effects model was used to pool data when statistical heterogeneity was absent. If statistical heterogeneity was present (P < 0.05), a random-effects model was used.

RESULTS: The initial search identified nine articles. After screening, five RCTs with a total of 1998 patients were included in this meta-analysis. Of the five studies, all described a comparison of baseline patient characteristics and showed that there was no statistically significant difference between the two groups. Among the 1998 patients, 1006 received hyoscine butylbromide and 992 were allocated to the control group, and the polyp detection rate was reported. There were no significant differences between the treated and the control group (OR = 1.09, 95%CI: 0.91-1.31, P = 0.33). Four RCTs included 1882 patients, of whom 948 received hyoscine butylbromide, and the adenoma detection rate was reported. There were no significant differences between the treated and the control group (OR = 1.13, 95%CI: 0.92-1.38, P = 0.24).

CONCLUSION: The use of hyoscine butylbromide did not significantly improve the polyp detection rate during colonoscopy.

Intravital imaging of mouse colonic adenoma using MMP-based molecular probes with multi-channel fluorescence endoscopy

Intravital imaging has provided molecular, cellular and anatomical insight into the study of tumor. Early detection and treatment of gastrointestinal (GI) diseases can be enhanced with specific molecular markers and endoscopic imaging modalities. We present a wide-field multi-channel fluorescence endoscope to screen GI tract for colon cancer using multiple molecular probes targeting matrix metalloproteinases (MMP) conjugated with quantum dots (QD) in AOM/DSS mouse model. MMP9 and MMP14 antibody (Ab)-QD conjugates demonstrate specific binding to colonic adenoma. The average target-to-background (T/B) ratios are 2.10 ± 0.28 and 1.78 ± 0.18 for MMP14 Ab-QD and MMP9 Ab-QD, respectively. The overlap between the two molecular probes is 67.7 ± 8.4%. The presence of false negative indicates that even more number of targeting could increase the sensitivity of overall detection given heterogeneous molecular expression in tumors. Our approach indicates potential for the screening of small or flat lesions that are precancerous.