Full-spectrum versus standard colonoscopy for improving polyp detection rate: A systematic review and meta-analysis

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Endocuff-assisted versus standard colonoscopy for improving adenoma detection rate: meta-analysis of randomized controlled trials

BACKGROUND

The effect of Endocuff-assisted colonoscopy compared with standard colonoscopy is conflicting in terms of the adenoma detection rate. The aim of this meta-analysis was to compare the efficacy of Endocuff-assisted colonoscopy for adenoma detection.

METHODS

PubMed, Embase, Google Scholar and Cochrane Library were searched up to the end of June 8, 2021. All randomized controlled trials (RCTs) comparing Endocuff-assisted colonoscopy with standard colonoscopy were included. Dichotomous data were pooled to obtain the relative risk with a 95% CI, whereas continuous data were pooled using a mean difference with 95% CI.

RESULTS

A total of 23 RCTs involving 17,999 patients were included. Compared with standard colonoscopy, use of the Endocuff was associated with a significant improvement in the adenoma detection rate (RR = 1.16, 95% CI 1.08-1.24), polyp detection rate (RR = 1.17, 95% CI 1.09-1.25), sessile serrated lesion detection rate (RR = 1.23, 95% CI 1.05-1.43), left-side lesion detection rate (RR = 1.24, 95% CI 1.08-1.43), and mean number of adenomas per patient (MD = 0.17, 95% CI 0.08-0.26). There were no significant differences between the and groups in detection of advanced adenomas, mean number of polyps per patient, right-side lesion detection rate, cecal intubation rate, cecal intubation time and withdrawal time.

CONCLUSIONS

The pooled evidence suggests a significant improvement in the adenoma detection rate, and polyp detection rate using the Endocuff. On the other hand, no significant effect on the detection of advanced adenomas and mean number of polyps per patient was noted.

Measuring and Improving Quality of Colonoscopy for Colorectal Cancer Screening

Colorectal cancer (CRC) is largely preventable, yet it remains a major public health issue as it is the third most common and deadly malignancy in the United States. While there are many ways to screen for CRC, colonoscopy remains the gold standard as it is the only test that is both cancer-detecting and cancer-preventing through removal of precancerous polyps. Through identifying and removing neoplastic lesions, colonoscopy reduces CRC incidence by 31%-91% and CRC mortality by 65%-88%. However, colonoscopy is not an infallible test-there is a chance for missed lesions during the exam and there is substantial variation in outcomes among endoscopists. To enhance the quality of colonoscopic exams, and ultimately to improve CRC outcomes, quality indicators have been developed for measuring endoscopists' performance. In this review, we describe the colonoscopic quality indicators and benchmarks recommended by the American Society for Gastrointestinal Endoscopy/American College of Gastroenterology Task Force on Quality in Endoscopy for screening colonoscopies in average-risk individuals. Measuring and monitoring endoscopists' performance on these measures are critical first steps in striving toward conducting high quality exams. We also review the evidence for interventions that aim to improve critical measures including adenoma detection rate, withdrawal time, cecal intubation, and bowel preparation quality. Finally, we provide a preview of the forthcoming Advancing Care for Appropriate Colon Health Merit-Based Incentive Payment System Value Pathway by the Centers for Medicare & Medicaid Services and its potential impact on clinical practice.

Enhancing polyp detection: technological advances in colonoscopy imaging

The detection and removal of polyps at colonoscopy is core to the current colorectal cancer (CRC) prevention strategy. However, colonoscopy is flawed with a well described miss rate and variability in detection rates associated with incomplete protection from CRC. Consequently, there is significant interest in techniques and technologies which increase polyp detection with the aim to remedy colonoscopy's ills. Technologic advances in colonoscope imaging are numerous and include; increased definition of imaging, widening field of view, virtual technologies to supplant conventional chromocolonoscopy (CC) and now computer assisted detection. However, despite nearly two decades of technologic advances, data on gains in detection from individual technologies have been modest at best and heterogenous and conflicted as a rule. This state of detection technology science is exacerbated by use of relatively blunt metrics of improvement without consensus, the myopic search for gains over single generations of technology improvement and an unhealthy focus on adenomatous lesions. Yet there remains cause for optimism as detection gains from new technology, while small, may still improve CRC prevention. The technologies are also readily available in current generation colonoscopes and have roles beyond simply detection such as lesion characterization, further improving their worth. Coupled with the imminent expansion of computer assisted detection the detection future from colonoscope imaging advances looks bright. This review aims to cover the major imaging advances and evidence for improvement in polyp detection.

Panoramic colonoscopy in colorectal cancer screening - a randomized controlled trial

Introduction

Colonoscopy is considered the gold standard for colorectal cancer screening. Panoramic colonoscopy offers better visualization to decrease the adenoma miss rate.

Aim

To assess the influence of 330° panoramic view colonoscopy on adenoma and polyp detection rate, cecal intubation time, and examiner’s comfort.

Material and methods

The study enrolled 421 patients aged 18–80 years who were eligible for colonoscopy screening. Patients with prior abdominal surgery, inflammatory bowel disease or after colorectal resections were excluded from the study. Patients were randomized to either standard frontal view (SFV) (Olympus Evis Exera III 190 CF-HQ190L) or the panoramic view colonoscopy (PVC) (FUSE CDVL slim c38). The study was approved by the local bioethics committee and registered at ClinicalTrial.gov (NCT02929381).

Results

There were 214 patients examined with SFV and 207 with PVC. The mean age of patients was 64 ±12.26 years. The two groups were comparable. The median cecal intubation time was 234 s with SFV vs. 311 s with PVC (p < 0.001). There were no significant differences in CIR or withdrawal time. PVC made it possible to discover more diverticula in the ascending colon (p = 0.009). PDR with SFV was 34.6% and 40.1% with PVC (p = 0.242). A higher number of polyps was found in the transverse colon in the PVC group (p = 0.006). ADR and advanced ADR (aADR) in both groups were similar (26.4% vs. 27.1% and 14, 2% vs. 13.9%).

Conclusions

Colonoscopy with wide-angle endoscopes lasts longer and allows for the detection of more polyps and diverticula without affecting ADR and aADR. Our study did not reveal the superiority of wide-angle colonoscopy in colorectal cancer screening

Impact of EndoRings on colon adenoma detection rate: A meta-analysis of randomized trials

BACKGROUND AND AIM

Evidence of a superior efficacy of EndoRings over standard colonoscopy in improving colon adenoma detection rate is lacking. We aimed to compare EndoRings and standard colonoscopy through a pairwise meta-analysis of randomized trials.

METHODS

We searched the PubMed/Medline and Embase database through July 2020 and identified five randomized controlled trials (recruiting 2751 patients). The primary outcome was adenoma detection rate; secondary outcomes included advanced and sessile serrated adenoma detection rate, mean adenoma per colonoscopy, cecal intubation rate, and time. We performed pairwise meta-analysis through a random-effects model and expressed data as risk ratio and 95% confidence interval.

RESULTS

Overall, pooled adenoma detection rate was 53.9% (49-58.8%) with EndoRings and 49.1% (42-56.1%) with standard colonoscopy (risk ratio 1.05, 0.95-1.17). Advanced adenoma detection (risk ratio 0.91, 0.74-1.12), sessile serrated detection rate (risk ratio 1.10, 0.81-1.50), and polyp detection rate (risk ratio 1.06, 0.98-1.15) were similar between the two groups. Likewise, mean adenoma per colonoscopy (mean difference 0.17, -0.09 to 0.43), cecal intubation rate (risk ratio 1.00, 0.99-1.01), and cecal intubation time (mean difference 0.20 min, -0.34 to 0.74) did not differ between the two add-on devices. No serious adverse event was observed.

CONCLUSION

EndoRings did not seem to significantly improve the diagnostic performance of colonoscopy. Further trials are needed to confirm these results.

Detection of colorectal adenomas with a real-time computer-aided system (ENDOANGEL): a randomised controlled study

BACKGROUND

Colonoscopy performance varies among endoscopists, impairing the discovery of colorectal cancers and precursor lesions. We aimed to construct a real-time quality improvement system (ENDOANGEL) to monitor real-time withdrawal speed and colonoscopy withdrawal time and to remind endoscopists of blind spots caused by endoscope slipping. We also aimed to evaluate the effectiveness of this system for improving adenoma yield of everyday colonoscopy.

METHODS

The ENDOANGEL system was developed using deep neural networks and perceptual hash algorithms. We recruited consecutive patients aged 18-75 years from Renmin Hospital of Wuhan University in China who provided written informed consent. We randomly assigned patients (1:1) using computer-generated random numbers and block randomisation (block size of four) to either colonoscopy with the ENDOANGEL system or unassisted colonoscopy (control). Endoscopists were not masked to the random assignment but analysts and patients were unaware of random assignments. The primary endpoint was the adenoma detection rate (ADR), which is the proportion of patients having one or more adenomas detected at colonoscopy. The primary analysis was done per protocol (ie, in all patients having colonoscopy done in accordance with the assigned intervention) and by intention to treat (ie, in all randomised patients). This trial is registered with http://www.chictr.org.cn, ChiCTR1900021984.

FINDINGS

Between June 18, 2019, and Sept 6, 2019, 704 patients were randomly allocated colonoscopy with the ENDOANGEL system (n=355) or unassisted (control) colonoscopy (n=349). In the intention-to-treat population, ADR was significantly greater in the ENDOANGEL group than in the control group, with 58 (16%) of 355 patients allocated ENDOANGEL-assisted colonoscopy having one or more adenomas detected, compared with 27 (8%) of 349 allocated control colonoscopy (odds ratio [OR] 2·30, 95% CI 1·40-3·77; p=0·0010). In the per-protocol analysis, findings were similar, with 54 (17%) of 324 patients assigned ENDOANGEL-assisted colonoscopy and 26 (8%) of 318 patients assigned control colonoscopy having one or more adenomas detected (OR 2·18, 95% CI 1·31-3·62; p=0·0026). No adverse events were reported.

INTERPRETATION

The ENDOANGEL system significantly improved the adenoma yield during colonoscopy and seems to be effective and safe for use during routine colonoscopy.

FUNDING

Hubei Provincial Clinical Research Center for Digestive Disease Minimally Invasive Incision, Hubei Province Major Science and Technology Innovation Project, and the National Natural Science Foundation of China.

Compared Abilities of Endoscopic Techniques to Increase Colon Adenoma Detection Rates: A Network Meta-analysis

BACKGROUND AND AIMS

Adenoma detection rate (ADR) is a quality metric for colorectal cancer screening. We performed a systematic review and network meta-analysis to assess the overall and comparative efficacies of different endoscopic techniques in adenoma detection.

METHODS

We performed a systematic review of published articles and abstracts, through March 15, 2018, to identify randomized controlled trials of adults undergoing colonoscopy that compared the efficacy of different devices in detection of adenomas. Our final analysis included 74 2-arm trials that comprised 44948 patients. These studies compared efficacies of add-on devices (cap, endocuff, endo-rings, G-EYE), enhanced imaging techniques (chromoendoscopy, narrow-band imaging, flexible spectral imaging color enhancement, blue laser imaging), new scopes (full-spectrum endoscopy, extra-wide-angle-view colonoscopy, dual focus), and low-cost optimizing existing resources (water-aided colonoscopy, second observer, dynamic position change), alone or in combination with high-definition colonoscopy or each other. Primary outcome was increase in ADR. We performed pairwise and network meta-analyses, and appraised quality of evidence using GRADE.

RESULTS

Low-cost optimizing existing resources (odds ratio [OR], 1.29; 95% CI,1.17-1.43), enhanced imaging techniques (OR,1.21; 95% CI, 1.09-1.35), and add-on devices (OR,1.18; 95% CI, 1.07-1.29) were associated with a moderate increase in ADR compared with high-definition colonoscopy; there was low to moderate confidence in estimates. Use of newer scopes was not associated with significant increases in ADR compared with high-definition colonoscopy (OR, 0.98; 95% CI, 0.79-1.21). In our comparative efficacy analysis, no specific technology for increasing ADR was superior to others. We did not find significant differences between technologies in detection of advanced ADR, polyp detection rate, or mean number of adenomas/patient.

CONCLUSIONS

In a network meta-analysis of published trials, we found that low-cost optimization of existing resources to be as effective as enhanced endoscopic imaging, or add-on devices, in increasing ADR during high-definition colonoscopy.

Meta-analysis indicates that add-on devices and new endoscopes reduce colonoscopy adenoma miss rate

INTRODUCTION

A variety of add-on devices and new-generation endoscopes have the potential to detect lesions 'hidden' behind colonic folds. We measured the effect of these new modalities on colonoscopy's lesions miss rates by a meta-analysis of data from individual studies.

MATERIALS AND METHODS

We performed literature searches in Medline and Cochrane Library for back-to-back randomized-controlled trials evaluating colonoscope add-on devices and new endoscopes in terms of lesions miss rates. The effect size on study outcomes is shown as relative risk (95% confidence interval).

RESULTS

We identified nine tandem studies with 1594 patients: seven evaluating add-on devices (one with cap, two with Endocuff, one with Endorings, one with Third-Eye Retroscope, two with G-EYE endoscope) and two evaluating the full-spectrum endoscopy system (FUSE) in comparison with conventional colonoscopy (CC). Overall, adenoma miss rate (AMR) was significantly lower with add-on devices/FUSE [0.33 (0.22-0.50), P<0.00001] compared with CC, the effect being similar among the add-on devices [0.35 (0.22-0.57), P<0.0001] and the FUSE [0.26 (0.15-0.46), P<0.00001] studies, respectively. Advanced AMR and polyp miss rate (PMR) were also significantly lower using add-on devices/FUSE [0.30 (0.21-0.44), P<0.0001 and 0.31 (0.13-0.79), P=0.01, respectively]. Use of add-on devices/FUSE scope was associated with significantly lower AMR and PMR in the proximal colon and it was associated with shortening of the colonoscopy surveillance interval.

CONCLUSION

Our meta-analysis provides evidence that AMR, advanced AMR, and PMR are significantly lower using add-on to colonoscope devices and the full-spectrum endoscopy systems compared with CC. Heterogeneity among the included studies and the small number of detected advanced adenomas call for cautious interpretation of the results.

Comparative Efficacy of Colonoscope Distal Attachment Devices in Increasing Rates of Adenoma Detection: A Network Meta-analysis

BACKGROUND & AIMS

Several add-on devices have been developed to increase rates of colon adenoma detection (ADR). We assessed their overall and comparative efficacy, and estimated absolute magnitude of benefit through a network meta-analysis.

METHODS

We searched the PubMed/Medline and Embase database through March 2017 and identified 25 randomized controlled trials (comprising 16,103 patients) that compared the efficacy of add-on devices (cap; Endocuff; Arc Medical Design Ltd, Leeds, UK, and Endorings; Us Endoscopy, Mentor, OH) with each other or with standard colonoscopy. The primary outcome was ADR; secondary outcomes included rate of polyp detection, and rate of and time to cecal intubation. We performed pairwise and network meta-analyses, and appraised quality of evidence using Grading of Recommendations Assessment, Development and Evaluation. We estimated the magnitude of increase in ADR by low-performing endoscopists (baseline ADR, 10%) and high-performing endoscopists (baseline ADR, 40%) with use of these devices.

RESULTS

Overall, distal attachment devices increased ADR compared with standard colonoscopy (relative risk [RR], 1.13; 95% CI, 1.03-1.23; low-quality evidence), with potential absolute increases in ADR to 11.3% for low-performing endoscopists and to 45.2% for high-performing endoscopists. In a comparative evaluation, we found low-quality evidence that Endocuff increases ADR compared with standard colonoscopy (RR, 1.21; 95% CI, 1.03-1.41), with anticipated increases in ADR to 12% for low-performing endoscopists and to 48% for high-performing endoscopists. We found very low quality evidence to support the use of Endorings (RR, 1.70; 95% CI, 0.86-3.36) or caps (RR, 1.07; 95% CI, 0.96-1.19) vs standard colonoscopy for increasing ADR. The benefit of one distal attachment device over another was uncertain due to very low quality evidence.

CONCLUSIONS

Based on network meta-analysis, we anticipate only modest improvement in ADRs with use of distal attachment devices, especially in low-performing endoscopists.

Is there a difference in adenoma detection rates between gastroenterologists and surgeons?

AIM

To compare the adenoma detection rate (ADR) between gastroenterologists and colorectal surgeons at Box Hill Hospital, Melbourne, Australia.

METHODS

A total of 300 colonoscopies performed by gastroenterologists and colorectal surgeons at Box Hill Hospital were retrospectively reviewed from May 2016 to June 2017. Exclusion criteria were: Patients ≤ 50 years old, colonoscopies with failure of caecal intubation, patients who previously had colon cancer and/or a colonic resection, history of polyposis syndromes or inflammatory bowel disease, or a colonoscopy within the last 10 years. Patient demographics, indications, symptoms and procedural-related outcomes were measured.

RESULTS

The ADR was not significantly different between gastroenterologists and colorectal surgeons (34% vs 34.67%; P = 0.90). The adjusted odds ratio correcting for gender, age, 1^st degree relative with colorectal cancer, previous colonoscopy, trainee involvement and caecal or terminal ileum intubation rate was 1.19 (0.69-2.05).

CONCLUSION

Both specialties at our institution exceed benchmark standards suggested by published Australian and American guidelines. An association between endoscopist specialty and ADR was not observed.