Comparison of colon adenoma detection rates using cap-assisted and Endocuff-assisted colonoscopy: a randomized controlled trial

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.

Variability in adenoma detection rate in control groups of randomized colonoscopy trials: a systematic review and meta-analysis

BACKGROUND AND AIMS

Adenoma detection rate (ADR) is still the main surrogate outcome parameter of screening colonoscopy, but most studies include mixed indications, and basic ADR is quite variable. We therefore looked at the control groups in randomized ADR trials using advanced imaging or mechanical methods to find out whether indications or other factors influence ADR levels.

METHODS

Patients in the control groups of randomized controlled trials (RCTs) on ADR increase using various methods were collected based on a systematic review; this control group had to use high-definition white-light endoscopy performed between 2008 and 2021. Random-effects meta-analysis was used to pool ADR in control groups and its 95% confidence interval (CI) according to clinical (indication and demographic), study setting (tandem/parallel, number of centers, sample size), and technical (type of intervention, withdrawal time) parameters. Interstudy heterogeneity was reported with the I² statistic. Multivariable mixed-effects meta-regression was performed for potentially relevant variables.

RESULTS

From 80 studies, 25,304 patients in the respective control groups were included. ADR in control arms varied between 8.2% and 68.1% with a high degree of heterogeneity (I² = 95.1%; random-effect pooled value, 37.5%; 95% CI, 34.6‒40.5). There was no difference in ADR levels between primary colonoscopy screening (12 RCTs, 15%) and mixed indications including screening/surveillance and diagnostic colonoscopy; however, fecal immunochemical testing as an indication for colonoscopy was an independent predictor of ADR (odds ratio [OR], 1.6; 95% CI, 1.1-2.4). Other well-known parameters were confirmed by our analysis such as age (OR, 1.038; 95% CI, 1.004-1.074), sex (male sex: OR, 1.02; 95% CI, 1.01-1.03), and withdrawal time (OR, 1.1; 95% CI, 1.0-1.1). The type of intervention (imaging vs mechanical) had no influence, but methodologic factors did: More recent year of publication and smaller sample size were associated with higher ADR.

CONCLUSIONS

A high level of variability was found in the level of ADR in the control groups of RCTs. With regards to indications, only fecal immunochemical test-based colonoscopy studies influenced basic ADR, and primary colonoscopy screening appeared to be similar to other indications. Standardization for variables related to clinical, methodologic, and technical parameters is required to achieve generalizability and reproducibility.

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.

Second-generation distal attachment cuff for adenoma detection in screening colonoscopy: a randomized multicenter study

BACKGROUND AND AIMS

Randomized studies have demonstrated that a distal attachment cap with rubber side arms, the Endocuff Vision (ECV; Olympus America, Center Valley, Pa, USA), increased colonoscopic adenoma detection rate (ADR) in various mixed patient collectives. This is the first study to evaluate its use in a primary colonoscopic screening program.

METHODS

Patients over age 55 years undergoing screening colonoscopy in 9 German private offices in Berlin and Hamburg were randomized to either the study group using ECV or the control group using high-definition colonoscopies (standard of care). The main outcome parameter was ADR, whereas secondary outcomes were detection rates of all adenomas per colonoscopy (APCs), of adenoma subgroups, and of hyperplastic polyps.

RESULTS

Of 1416 patients (mean age, 61.1 years; 51.8% women), with a median of 41 examinations per examiner (n = 23; interquartile range, 12-81), 700 were examined with ECV and 716 without. Adjusting for the effects of the colonoscopies, ADR was 39.5% (95% confidence interval [CI], 32.6%-46.3%) in the ECV group versus 32.2% (95% CI, 25.9%-38.6%) in the control group, which resulted in an increase of 7.2% (95% CI, 2.3%-12.2%; P = .004). The increase in ADR was mainly because of small polyps, with adjusted ADRs for adenomas <10 mm of 33.3% (95% CI, 26.5%-40.2%) for study patients versus 24.0% (95% CI, 18.2%-29.8%) for control patients (P < .001). APC was also significantly increased (.57 ECV vs .51 control subjects, P = .045).

CONCLUSIONS

A distal attachment cap with side arms significantly increased the ADR in patients undergoing primary colonoscopic screening. Because of the correlation of ADR and interval cancer, its use should be encouraged, especially in this setting. (Clinical trial registration number: NCT03442738.).

The effect of the endoscopic device Endocuff™/Endocuff vision™ on quality standards in colonoscopy: A systematic review and meta-analysis of randomized trials

AIM

The adenoma detection rate (ADR) is an important quality measure, with a high ADR reflecting high-quality colonoscopy. This systematic review and meta-analysis aimed to assess the effects of Endocuff™/Endocuff Vision™-assisted colonoscopy (EAC) versus standard colonoscopy (SC) on ADR and other clinical, patient and resource-use outcomes.

METHOD

MEDLINE, EMBASE, Web of Science, Scopus and the Cochrane Central Register of Controlled Trials were searched for full papers reporting randomized studies comparing EAC with SC. The primary outcome was ADR. Secondary outcomes comprised key polyp/adenoma detection, procedure-related, patient-related and health economic measures. Random effects meta-analyses provided pooled estimates of outcomes [risk ratio (RR) or mean difference (MD), with 95% confidence intervals (CI)].

RESULTS

Twelve parallel-group randomized controlled trials (RCTs) and three crossover RCTs with data on 9140 patients were included. EAC significantly increased the ADR (RR 1.18, 95% CI 1.09-1.29), mean adenomas per procedure (MAP) (MD 0.19, 95% CI 0.06-0.33), polyp detection rate (PDR) (RR 1.20, 95% CI 1.10-1.30) and mean polyps per procedure (MPP) (MD 0.39, 95% CI 0.14-0.63) versus SC. EAC significantly increased segmental PDR versus SC in the sigmoid (RR 2.02, 95% CI 1.64-2.49), transverse (RR 1.63, 95% CI 1.09-2.42), ascending (RR 1.74, 95% CI 1.26-2.41) and caecal segments (RR 1.91, 95% CI 1.29-2.82). Procedure-related variables did not differ between arms. There were insufficient data for meta-analysis of health economic or patient-centred outcomes.

CONCLUSIONS

EAC increased ADR, MAP, PDR and MPP versus SC without detrimental effects on procedure measures. Cost-effectiveness and patient experience data are lacking and would be valuable to inform practice recommendations.

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.

Endocuff Vision to Improve Adenoma Vision: A Brief Overview

Colorectal cancer (CRC)-related mortality can be reduced through screening and early detection. The aim of any CRC screening program is to detect as many adenomas/polyps in the early stage as possible and hence, adenoma detection rate (ADR) is a key quality indicator of colonoscopy. Various methods and techniques have been studied and developed over the years to improve the quality of colonoscopy and thereby increase ADR. This ranges from use of various regimens to improve bowel preparation, defining an optimum colonoscope withdrawal time for the operator, distal attachment caps, use of different wavelength of light, colonoscope with increased degree of view to the use of modern-day artificial intelligence to improve ADR. Of all the various measures, use of distal attachment device seems an easy, cheap and readily usable technique to increase real-time ADR. A variety of such devices have been evaluated over time starting from simple transparent caps, EndoRings, Endocuff to Endocuff Vision for their effectiveness. In this review, we have provided a brief description of the various available distal attachment devices and a detailed technical overview of Endocuff and its modification the Endocuff Vision.

High-Definition Colonoscopy Compared With Cuff- and Cap-Assisted Colonoscopy: Results From a Multicenter, Prospective, Randomized Controlled Trial

BACKGROUND AND AIMS

Mucosal exposure devices including distal attachments such as the cuff and cap have shown variable results in improving adenoma detection rate (ADR) compared with high-definition white light colonoscopy (HDWLE).

METHODS

We performed a prospective, multicenter randomized controlled trial in patients undergoing screening or surveillance colonoscopy comparing HDWLE to 2 different types of distal attachments: cuff (CF) (Endocuff Vision) or cap (CP) (Reveal). The primary outcome was ADR. Secondary outcomes included adenomas per colonoscopy, advanced adenoma and sessile serrated lesion detection rate, right-sided ADR, withdrawal time, and adverse events. Continuous variables were compared using Student's t test and categorical variables were compared using chi-square or Fisher's exact test using statistical software Stata version16. A P value <.05 was considered significant.

RESULTS

A total of 1203 subjects were randomized to either HDWLE (n = 384; mean 62 years of age; 81.3% males), CF (n = 379; mean 62.7 years of age; 79.9% males) or CP (n = 379; mean age 62.1 years of age; 80.5% males). No significant differences were found among 3 groups for ADR (57.3%, 59.1%, and 55.7%; P = .6), adenomas per colonoscopy (1.4 ± 1.9, 1.6 ± 2.4, and 1.4 ± 2; P = .3), advanced adenoma (7.6%, 9.2%, and 8.2%; P = .7), sessile serrated lesion (6.8%, 6.3%, and 5.5%; P = .8), or right ADR (48.2%, 49.3%, and 46.2%; P = .7). The number of polyps per colonoscopy were significantly higher in the CF group compared with HDWLE and CP group (2.7 ± 3.4, 2.3 ± 2.5, and 2.2 ± 2.3; P = .013). In a multivariable model, after adjusting for age, sex, body mass index, withdrawal time, and Boston Bowel Preparation Scale score, there was no impact of device type on the primary outcome of ADR (P = .77). In screening patients, CF resulted in more neoplasms per colonoscopy (CF: 1.7 ± 2.6, HDWLE: 1.3 ± 1.7, and CP: 1.2 ± 1.8; P = .047) with a shorter withdrawal time.

CONCLUSIONS

Results from this multicenter randomized controlled trial do not show any significant benefit of using either distal attachment devices (CF or CP) over HDWLE, at least in high-detector endoscopists. The Endocuff may have an advantage in the screening population. (ClinicalTrials.gov, Number: NCT03952611).

Sessile serrated adenoma/polyp detection rate of water exchange, Endocuff, and cap colonoscopy: A network meta-analysis

BACKGROUND AND AIM

Sessile serrated adenoma/polyp (SSA/P) may contribute to interval cancer. In a recent meta-analysis, water exchange (WE) was shown to be superior to Endocuff and cap colonoscopy at adenoma and advanced adenoma detection. The strong positive correlation between adenoma detection rate (ADR), advanced adenoma detection rate (AADR), and sessile serrated adenoma/polyp detection rate (SSA/PDR) prompted us to hypothesize that WE could significantly improve SSA/PDR compared with Endocuff and cap colonoscopy.

METHODS

The literature was searched for all randomized controlled trials (RCTs) that reported SSA/PDR as an outcome and included the keywords colonoscopy, and water exchange, Endocuff, or cap. We performed traditional network meta-analyses with random effect models comparing SSA/PDR of each method using air insufflation as the control and reported the odds ratios (ORs) with 95% confidence interval (CI). Performances were ranked based on P-score.

RESULTS

A total of 531 articles resulted from initial keywords search. Eleven RCTs were included in the analysis. A total of 7856 patients underwent air insufflation, WE, Endocuff, or cap colonoscopy. WE significantly increased SSA/PDR (OR 2.04; 95% CI 1.33-3.13). Endocuff (OR 1.15; 95% CI 0.94-1.41) and cap (OR 1.08; 95% CI 0.42-2.74) did not significantly impact SSA/P detection. P-scores for WE (0.96), Endocuff (0.49), cap (0.37), and air insufflation (0.17) suggested that WE had the highest SSA/PDR. The results did not change after adjusting for mean withdrawal time and indication for colonoscopy.

CONCLUSION

Water exchange significantly increases SSA/PDR and is superior to Endocuff and cap colonoscopy at detecting SSA/P.

Computer-aided detection versus advanced imaging for detection of colorectal neoplasia: a systematic review and network meta-analysis

BACKGROUND

Computer-aided detection (CADe) techniques based on artificial intelligence algorithms can assist endoscopists in detecting colorectal neoplasia. CADe has been associated with an increased adenoma detection rate, a key quality indicator, but the utility of CADe compared with existing advanced imaging techniques and distal attachment devices is unclear.

METHODS

For this systematic review and network meta-analysis, we did a comprehensive search of PubMed/Medline, Embase, and Scopus databases from inception to Nov 30, 2020, for randomised controlled trials investigating the effectiveness of the following endoscopic techniques in detecting colorectal neoplasia: CADe, high definition (HD) white-light endoscopy, chromoendoscopy, or add-on devices (ie, systems that increase mucosal visualisation, such as full spectrum endoscopy [FUSE] or G-EYE balloon endoscopy). We collected data on adenoma detection rates, sessile serrated lesion detection rates, the proportion of large adenomas detected per colonoscopy, and withdrawal times. A frequentist framework, random-effects network meta-analysis was done to compare artificial intelligence with chromoendoscopy, increased mucosal visualisation systems, and HD white-light endoscopy (the control group). We estimated odds ratios (ORs) for the adenoma detection rate, sessile serrated lesion detection rate, and proportion of large adenomas detected per colonoscopy, and calculated mean differences for withdrawal time, with 95% CIs. Risk of bias and certainty of evidence were assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

FINDINGS

50 randomised controlled trials, comprising 34 445 participants, were included in our main analysis (six trials of CADe, 18 of chromoendoscopy, and 26 of increased mucosal visualisation systems). HD white-light endoscopy was the control technique in all 50 studies. Compared with the control technique, the adenoma detection rate was 7·4% higher with CADe (OR 1·78 [95% CI 1·44-2·18]), 4·4% higher with chromoendoscopy (1·22 [1·08-1·39]), and 4·1% higher with increased mucosal visualisation systems (1·16 [1·04-1·28]). CADe ranked as the superior technique for adenoma detection (with moderate confidence in hierarchical ranking); cross-comparisons of CADe with other imaging techniques showed a significant increase in the adenoma detection rate with CADe versus increased mucosal visualisation systems (OR 1·54 [95% CI 1·22-1·94]; low certainty of evidence) and with CADe versus chromoendoscopy (1·45 [1·14-1·85]; moderate certainty of evidence). When focusing on large adenomas (≥10 mm) there was a significant increase in the detection of large adenomas only with CADe (OR 1·69 [95% CI 1·10-2·60], moderate certainty of evidence) when compared to HD white-light endoscopy; CADe ranked as the superior strategy for detection of large adenomas. CADe also seemed to be the superior strategy for detection of sessile serrated lesions (with moderate confidence in hierarchical ranking), although no significant increase in the sessile serrated lesion detection rate was shown (OR 1·37 [95% CI 0·65-2·88]). No significant difference in withdrawal time was reported for CADe compared with the other techniques.

INTERPRETATION

Based on the published literature, detection rates of colorectal neoplasia are higher with CADe than with other techniques such as chromoendoscopy or tools that increase mucosal visualisation, supporting wider incorporation of CADe strategies into community endoscopy services.

FUNDING

None.

Increased Sessile Serrated Adenoma Detection Rate With Mechanical New Technology Devices: A Systematic Review and Meta-Analysis

GOAL

This meta-analysis aims to compare the sessile-serrated adenoma detection rate (SSADR) of currently available mechanical new technology devices (NTDs) to conventional colonoscopy (CC).

BACKGROUND

NTDs including Endocuff, EndoRing, G-Eye, and AmplifEYE were developed with the aim of improving adenoma detection rate by enhancing colonic mucosal visualization. Increasing awareness of the risk of sessile-serrated adenoma progression to malignancy has ushered a need to increase the detection of these characteristically flat lesions.

STUDY

Embase and PubMed/Medline databases were searched from inception through January 2019 for published manuscripts or major conference abstracts reporting SSADR with Endocuff, EndoRing, G-Eye, AmplifEYE, and CC. Randomized controlled trials, high-quality case-control, cohort, and observational studies in adults with >10 subjects were included. The primary outcome was pooled SSADR odds ratio (ORs) with 95% confidence interval (95% CI) comparing CC with the NTDs. In addition, an analysis comparing each device to CC was performed.

RESULTS

Of 207 citations identified, a total of 14 studies with 12,655 subjects were included in our analysis (5931 subjects with NTDs and 6724 with CC). There were 12 studies with Endocuff, 2 with EndoRing, 1 with G-EYE, and 1 with AmplifEYE. The mean age was 62.4 years and 57.5% were males. Pooled SSADR with NTDs was 12.3% as compared with 6.4% with CC, with an OR of 1.81 (95% CI: 1.6-2.0, I2: 77%). Analysis of Endocuff alone yielded an OR 1.81 (95% CI: 1.6-2.1, I2: 79%).

CONCLUSION

Mechanical NTDs, notably Endocuff, are a safe and effective tool to increase the SSADR.

EndoCuff-Assisted Colonoscopy Versus Standard Colonoscopy in Colonic Polyp Detection-Experience from a Single Tertiary Centre

Background. Standard colonoscopy fails to visualize the entire colon mucosa and consequently a significant amount of polyps are still being missed. New device, such as EndoCuff, have been developed to improve mucosal visualisation, hence the quality in colonoscopy. The aim of this study was to assess the diagnostic yield of EndoCuff-assisted colonoscopy in comparison with standard colonoscopy by taking into consideration several quality indicators. Methods. In this study, 965 adults ≥ 18 years referred for colonoscopy were randomly divided into two groups. The main statistical investigation compared the difference between EndoCuff-assisted colonoscopy (EC) vs. standard colonoscopy (SC) in the detection of colonic polyps and adenoma detection rate (ADR). The second inquiry sought to compare experienced vs. recently trained and female vs. male operators. Results. The ADR was higher for EC than for SC (37.50% vs. 26.64%). Regarding the mean number of detected polyps per procedure (MPP), the result was statistically significant when generally comparing the EC vs. SC (p=0.0009). There were no differences in MPP between EC and SC for recently trained endoscopists (p=0.7446), while a significant difference for experienced doctors (p=0,0020) was noted. A significant difference was observed between female doctors and male doctors only when using SC. EC was more helpful for female doctors when assessing MPP (p=0.0118). No serious adverse events related to EndoCuff-assisted colonoscopy was noted. Conclusions. EndoCuff-assisted colonoscopy seems to be safe and may bring benefits for improving the polyp/adenoma detection rates in regard to missed lesions, usually located in blind areas.

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

BACKGROUND AND AIMS

Add-on devices have been widely used in clinical practice. The aim of this meta-analysis was to compare the adenoma detection rate between Endocuff-assisted colonoscopy (EAC) and cap-assisted colonoscopy (CAC).

METHODS

PubMed, EMBASE, SCOPUS, and Cochrane databases were searched. Outcomes included adenoma detection rate, cecal intubation rate, cecal intubation time, and withdrawal time. Dichotomous data were pooled to obtain the odds ratio or risk ratio. Continuous data were pooled using the mean difference.

RESULTS

Of the 240 articles reviewed, six randomized controlled trials were included, with a total of 1994 patients. In the meta-analysis, no statistical difference in adenoma detection rate was detected between EAC and CAC (47.0% vs 45.1%; P = 0.33). EAC significantly improved detection rate of diminutive adenomas/polyps compared with CAC (P = 0.01). Cecal intubation was achieved in 96.5% in EAC group and 97.9% in CAC group (P = 0.04). Besides, no statistical difference was found in cecal intubation time (P = 0.86), withdrawal time (P = 0.88), small adenomas/polyps (P = 0.60), or large adenomas/polyps (P = 0.95).

CONCLUSION

EAC and CAC have their respective merits. EAC significantly improve the detection of diminutive adenomas/polyps. CAC was better in cecal intubation rate.