Improved colorectal adenoma detection with a transparent retractable extension device

Cap-assisted colonoscopy can increase the rate of sessile serrated lesion detection at the left lateral decubitus position: A retrospective case-control study

We investigated the effectiveness of cap-assisted colonoscopy conducted with the patient in the left lateral decubitus position at both the colonoscope's insertion and withdrawal timepoints compared to the effectiveness of colonoscopy without a cap conducted in the supine position at withdrawal. This was a case-control study, based on historical comparisons of patients over 2 time periods. The first group of patients underwent colonoscopies with a transparent cap and the patient was in the left lateral decubitus position at both the insertion and withdrawal timepoints from April to June 2019. The subsequent group underwent colonoscopies without a cap and with the patient in the supine position at withdrawal from July to September 2019. The rates of successful intubation, cecal intubation time, and number, size, shape, and location of the detected adenomas and sessile serrated lesions were compared between the 2 groups. Data from 644 colonoscopies (cap-assisted colonoscopy + left lateral decubitus position, n=320; other colonoscopies, n=324) were analyzed. The demographic characteristics and technical performances were similar. The SSL detection rate was significantly higher with cap-assisted colonoscopy and the left lateral decubitus position than with other colonoscopies (3.4% vs 0.93%, P=.029). The adenoma detection rates in the 2 groups were similar (31% and 28%, respectively, P=.43).Cap-assisted colonoscopy in the left lateral decubitus position may increase the detection rate of sessile serrated lesions compared to colonoscopy without a cap and supine position at withdrawal.

Multicenter propensity score-matched analysis comparing short versus long cap-assisted colonoscopy for acute hematochezia

BACKGROUND AND AIM

While short and long attachment caps are available for colonoscopy, it is unclear which type is more appropriate for stigmata of recent hemorrhage (SRH) identification in acute hematochezia. This study aimed to compare the performance of short versus long caps in acute hematochezia diagnoses and outcomes.

METHODS

We selected 6460 patients who underwent colonoscopy with attachment caps from 10 342 acute hematochezia cases in the CODE BLUE-J study. We performed propensity score matching (PSM) to balance baseline characteristics between short and long cap users. Then, the proportion of definitive or presumptive bleeding etiologies found on the initial colonoscopy and SRH identification rates were compared. We also evaluated rates of blood transfusions, interventional radiology, or surgery, as well as the rate of rebleeding and mortality within 30 days after the initial colonoscopy.

RESULTS

A total of 3098 patients with acute hematochezia (1549 short cap and 1549 long cap users) were selected for PSM. The rate of colonic diverticular bleeding (CDB) diagnosis was significantly higher in long cap users (P = 0.006). While the two groups had similar rates of the other bleeding etiologies, the frequency of unknown etiologies was significantly lower in long cap users (P < 0.001). The rate of SRH with active bleeding was significantly higher in long cap users (P < 0.001). Other clinical outcomes did not differ significantly.

CONCLUSION

Compared to that with short caps, long cap-assisted colonoscopy is superior for the diagnosis of acute hematochezia, especially CDB, and the identification of active bleeding.

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.

Comparative Efficacy of Endoscopic Assist Devices on Colonic Adenoma Detection: A Systematic Review With Network Meta-analysis

BACKGROUND AND AIMS

Numerous endoscopic assist devices exist, yet data surrounding their comparative efficacy is lacking. We conducted a systematic review with network meta-analysis to determine the comparative efficacy of endoscopic assist devices on colonic adenoma detection.

METHODS

A systematic search was performed using multiple electronic databases through July 2020, to identify all randomized controlled trials and dual-arm observational studies compared with either other endoscopic assist devices and/or standard colonoscopy. The primary outcome was adenoma detection rate (ADR). Secondary outcomes included polyp detection rate (PDR), serrated adenoma detection rate (SADR), right-sided adenoma detection rate (RADR), and proximal adenoma detection rate (PADR).

RESULTS

Fifty-seven studies (31,051 patients) met inclusion criteria and were analyzed. Network meta-analysis identified an enhanced ADR among (clear) cap [odds ratio (OR): 2.69, 95% confidence interval (CI): 1.45-4.99], endocuff, (OR: 4.95, 95% CI: 3.15-7.78), and endoring (OR: 3.68, 95% CI: 1.47-9.20)-with no significant difference amongst any particular device. Similar findings for PDR were also seen. Enhanced SADR was identified for endocuff (OR: 9.43) and endoring (OR: 4.06) compared with standard colonoscopy. Enhanced RADR (OR: 5.36) and PADR (OR: 3.78) were only identified for endocuff. Endocuff comparatively demonstrated the greatest ADR, PDR, and SADR, but this was not significant when compared with the other assist devices. Subgroup analysis of randomized controlled trials identified enhanced PDR and ADR for both cap and endocuff.

CONCLUSIONS

Endoscopic assist devices displayed increased ADR and PDR as compared with standard colonoscopy and thus should be widely adopted. A nonsignificant trend was seen toward higher efficacy for the endocuff device.

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.

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.

Indications and outcomes of endoscopic resection for non-pedunculated colorectal lesions: A narrative review

In the last years, endoscopic techniques gained a crucial role in the treatment of colorectal flat lesions. At the same time, the importance of a reliable assessment of such lesions to predict the malignancy and the depth of invasion of the colonic wall emerged. The current unsolved dilemma about the endoscopic excision techniques concerns the necessity of a reliable submucosal invasive cancer assessment system that can stratify the risk of the post-procedural need for surgery. Accordingly, this narrative literature review aims to compare the available diagnostic strategies in predicting malignancy and to give a guide about the best techniques to employ. We performed a literature search using electronic databases (MEDLINE/PubMed, EMBASE, and Cochrane Library). We collected all articles about endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) registering the outcomes. Moreover, we analyzed all meta-analyses comparing EMR vs ESD outcomes for colorectal sessile or non-polypoid lesions of any size, preoperatively estimated as non-invasive. Seven meta-analysis studies, mainly Eastern, were included in the analysis comparing 124 studies and overall 22954 patients who underwent EMR and ESD procedures. Of these, eighty-two were retrospective, twenty-four perspective, nine case-control, and six cohorts, while three were randomized clinical trials. A total of 18118 EMR and 10379 ESD were completed for a whole of 28497 colorectal sessile or non-polypoid lesions > 5-10 mm in size. In conclusion, it is crucial to enhance the preoperative diagnostic workup, especially in deciding the most suitable endoscopic method for radical resection of flat colorectal lesions at risk of underlying malignancy. Additionally, the ESD necessitates further improvement because of the excessively time-consuming as well as the intraprocedural technical hindrances and related complications. We found a higher rate of en bloc resections and R0 for ESD than EMR for non-pedunculated colorectal lesions. Nevertheless, despite the lower local recurrence rates, ESD had greater perforation rates and needed lengthier procedural times. The prevailing risk for additional surgery in ESD rather than EMR for complications or oncologic reasons is still uncertain.

Endoscopic cuff-assisted colonoscopy versus cap-assisted colonoscopy in adenoma detection: randomized tandem study-DEtection in Tandem Endocuff Cap Trial (DETECT)

BACKGROUND AND AIMS

Adenoma miss rate during colonoscopy is directly linked to risk of postcolonoscopy colorectal cancer. One of the reasons for missed adenomas is poor visualization of proximal folds during standard colonoscopy withdrawal. Disposable distal attachments such as the plastic cap and Endocuff (Arc Medical Design, Leeds, UK) that hold back folds appear to improve adenoma detection. The primary aim of this study was to compare adenoma detection rates between Endocuff-assisted colonoscopy (EAC) and cap-assisted colonoscopy (CAC).

METHODS

This is a randomized, single-center, tandem colonoscopy trial performed by the same endoscopists on the same day, first with Endocuff Vision (Arc Medical Design, Leeds, UK) followed by cap or vice versa. All procedures were performed by 3 experienced gastroenterology fellows.

RESULTS

One hundred fifty-four patients were recruited. Seventy-eight (50.6%) had CAC as their first procedure. Mean patient age was 61 years (male-to-female ratio, 1:1). Adenoma detection rate was significantly higher for EAC when compared to CAC (53% vs 26%, P = .001). Polyp miss rate was significantly lower in EAC (8.4%) compared with CAC (26.1%, P < .001) as was adenoma miss rate (EAC vs CAC, 6%, vs 19%; P = .002) and diminutive adenoma (<5 mm) miss rate in the EAC group (1.8% vs 19.6%, P < .001). However, there was no significant differences in the miss rates for small adenomas (5-9 mm) (3.7% vs 2.9%, P = .69) or adenomas 10 mm or larger (1.6% vs 2.6%, P = .98 ). The mean number of adenomas per procedure was significantly higher with EAC compared with CAC (1.5 vs .8, P < .001). Cecal intubation time was significantly shorter with EAC than CAC (median 6 vs 7 minutes, P = .01). Conversely, withdrawal time (median 10 vs 8 minutes, P = .01) was significantly longer in EAC.

CONCLUSIONS

This randomized, tandem study demonstrates that EAC has a significantly higher adenoma detection rate and lower adenoma miss rate than CAC. Although insertion times were shorter with EAC, procedures were slightly more uncomfortable, and the cuff had to be removed in a small number of cases. (Clinical trial registration number: NCT03254498.).

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.

Standards of diagnostic colonoscopy for early-stage neoplasia: Recommendations by an Asian private group

BACKGROUND AND AIM

In recent years, the incidence of colorectal cancer has been increasing, and it is now becoming the major cause of cancer death in Asian countries. The aim of the present study was to develop Asian expert-based consensus to standardize the preparation, detection and characterization for the diagnosis of early-stage colorectal neoplasia.

METHODS

A professional group was formed by 36 experts of the Asian Novel Bio-Imaging and Intervention Group (ANBI2 G) members. Representatives from 12 Asia-Pacific countries participated in the meeting. The group organized three consensus meetings focusing on diagnostic endoscopy for gastrointestinal neoplasia. The Delphi method was used to develop the consensus statements.

RESULTS

Through the three consensus meetings with debating, reviewing the literature and regional data, a consensus was reached at third meeting in 2016. The consensus was reached on a total of 10 statements. Summary of statements is as follows: (i) Adequate bowel preparation for high-quality colonoscopy; (ii) Antispasmodic agents for lesion detection; (iii) Image-enhanced endoscopy (IEE) for polyp detection; (iv) Adenoma detection rate for quality indicators; (v) Good documentation of colonoscopy findings; (vi) Complication rates; (vii) Cecal intubation rate; (viii) Cap-assisted colonoscopy (CAC) for polyp detection; (ix) Macroscopic classification using indigocarmine spray for characterization of colorectal lesions; and (x) IEE and/or magnifying endoscopy for prediction of histology.

CONCLUSION

This consensus provides guidance for carrying out endoscopic diagnosis and characterization for early-stage colorectal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early-stage colorectal neoplasia.

To cap/cuff or ring: do distal attachment devices improve the adenoma detection?

Colonoscopy reduces the risk of colorectal cancer, by interrupting the adenoma-carcinoma sequence enabling the detection and removal of adenomas before they turn into colorectal cancer. Colonoscopy has its limitations as adenoma miss rates as high as 25% have been reported. The reasons for missed pathology are complicated and multi-factorial. The recent drive to improve adenoma detection rates has led to a plethora of new technologies. Areas covered: An increasing number of advanced endoscopes and distal attachment devices have appeared in the market. Advanced endoscopes aim to improve mucosal visualization by widening the field of view. Distal attachment devices aim to increase adenoma detection behind folds by flattening folds on withdrawal. In this review article, we discuss the three following distal attachment devices: the transparent cap, the Endocuff, and the Endoring. Expert commentary: The authors believe that the distal attachment devices will have a greater benefit for endoscopists with low baseline adenoma detection rates.

Colonoscopy attachments for the detection of precancerous lesions during colonoscopy: A review of the literature

Although colonoscopy has been proven effective in reducing the incidence of colorectal cancer through the detection and removal of precancerous lesions, it remains an imperfect examination, as it can fail in detecting up to almost one fourth of existing adenomas. Among reasons accounting for such failures, is the inability to meticulously visualize the colonic mucosa located either proximal to haustral folds or anatomic curves, including the hepatic and splenic flexures. In order to overcome these limitations, various colonoscope attachments aiming to improve mucosal visualization have been developed. All of them - transparent cap, Endocuff, Endocuff Vision and Endorings - are simply mounted onto the distal tip of the scope. In this review article, we introduce the rationale of their development, present their mode of action and discuss in detail the effect of their implementation in the detection of lesions during colonoscopy.

Cap-assisted colonoscopy: a meta-analysis of high-quality randomized controlled trials

Background and study aims  Standard colonoscopy (SC) is the preferred modality for screening for colon cancer; however, it carries a significant polyp/adenoma miss rate. Cap-assisted colonoscopy (CC) has been shown to improve polyp/adenoma detection rate, decrease cecal intubation time and increase cecal intubation rate when compared to standard colonoscopy (SC). However, data on adenoma detection rate (ADR) are conflicting. The aim of this meta-analysis was to compare the performance of CC with SC for ADR among high-quality randomized controlled trials. Patients and methods  We performed an extensive literature search using MEDLINE, EMBASE, Scopus, Cochrane and Web of Science databases and abstracts published at national meetings. Only comparative studies between CC and SC were included if they reported ADR, adenoma per person (APP), cecal intubation rate, and cecal intubation time. The exclusion criterion for comparing ADR was studies with Jadad score ≤ 2. The odds ratio (OR) was calculated using Mantel-Haenszel method. I ² test was used to measure heterogeneity among studies. Results  Analysis of high-quality studies (Jadad score ≥ 3, total of 7 studies) showed that use of cap improved the ADR with the results being statistically significant (OR 1.18, 95 % CI 1.03 - 1.33) and detection of 0.16 (0.02 - 0.30) additional APP. The cecal intubation rate in the CC group was 96.3 % compared to 94.5 % with SC (total of 17 studies). Use of cap improved cecal intubation (OR 1.61, 95 % CI 1.33 - 1.95) when compared to SC ( P value < 0.001). Use of cap decreased cecal intubation time by an average of 0.88 minutes (95 % CI 0.37 - 1.39) or 53 seconds. Conclusions  Meta-analysis of high-quality studies showed that CC improved the ADR compared to SC.

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.

Cecal intubation time between cap-assisted water exchange and water exchange colonoscopy: a randomized-controlled trial

BACKGROUND AND AIM

The water exchange (WE) method can decrease the discomfort of the patients undergoing colonoscopy. It also provides salvage cleansing and improves adenoma detection, but a longer intubation time is required. Cap-assisted colonoscopy leads to a significant reduction in cecal intubation time compared with traditional colonoscopy with air insufflation. The aim of this study was to investigate whether combined cap-assisted colonoscopy and water exchange (CWE) could decrease the cecal intubation time compared with WE.

PATIENTS AND METHODS

A total of 120 patients undergoing fully sedated colonoscopy at a regional hospital in southern Taiwan were randomized to colonoscopy with either CWE (n=59) or WE (n=61). The primary endpoint was cecal intubation time.

RESULTS

The mean cecal intubation time was significantly shorter in CWE (12.0 min) compared with WE (14.8 min) (P=0.004). The volume of infused water during insertion was lower in CWE (840 ml) compared with WE (1044 ml) (P=0.003). The adenoma detection rate was 50.8 and 47.5% for CWE and WE, respectively (P=0.472). The Boston Bowel Preparation Scale scores were comparable in the two groups. Results from the multiple linear regression analysis indicated that WE with a cap, a higher degree of endoscopist's experience, a higher Boston Bowel Preparation Scale score, and a lower volume of water infused during insertion, without abdominal compression, without change of position, and without chronic laxative use, were significantly associated with a shorter cecal intubation time.

CONCLUSION

In comparison with WE, CWE could shorten the cecal intubation time and required lower volume of water infusion during insertion without compromising the cleansing effect of WE.

Cap-assisted colonoscopy versus standard colonoscopy: is the cap beneficial? A meta-analysis of randomized controlled trials

Background:

In an effort to improve visualization during colonoscopy, a transparent plastic cap or hood may be placed on the end of the colonoscope. Cap-assisted colonoscopy (CAC) has been studied and is thought to improve polyp detection. Numerous studies have been conducted comparing pertinent clinical outcomes between CAC and standard colonoscopy (SC) with inconsistent results.

Methods:

Numerous databases were searched in November 2016. Only randomized controlled trials (RCTs) involving adult subjects that compared CAC to SC were included. Outcomes of total colonoscopy time, time to cecum, cecal intubation rate, terminal ileum intubation rate, polyp detection rate (PDR), and adenoma detection rate (ADR) were analyzed in terms of odds ratio (OR) or mean difference (MD) with fixed effect and random effects models.

Results:

Five hundred eighty-nine articles and abstracts were discovered. Of these, 23 RCTs (n=12,947) were included in the analysis. CAC showed statistically significant superiority in total colonoscopy time (MD -1.51 min; 95% confidence interval [CI] -2.67 to -0.34; P<0.01) and time to cecum (MD -0.82 min; 95%CI -1.20 to -0.44; P<0.01) compared to SC. CAC also showed better PDR (OR 1.17; 95%CI 1.06-1.29; P<0.01) but not ADR (OR 1.11; 95%CI 0.95-1.30; P=0.20). In contrast, on sensitivity analysis, ADR was better with CAC. Terminal ileum intubation and cecal intubation rates demonstrated no significant difference between the two groups (P=0.11 and P=0.73, respectively).

Conclusions:

The use of a transparent cap during colonoscopy improves PDR while reducing procedure times. ADR may improve in cap-assisted colonoscopy but further studies are required to confirm this.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM: To evaluate the efficacy of cap-assisted colonoscopy (CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.

METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy (SC), and all of the procedures were performed by 11 endoscopists (8 trainees and 3 experts). All procedures were performed with high-definition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mm-long transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate (PDR), and the number of adenomas and adenoma detection rate (ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.

RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon (48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon (35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon (1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon (0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon (46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon (34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon (42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020).

CONCLUSION: CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.

Novel endocuff-assisted colonoscopy significantly increases the polyp detection rate: a randomized controlled trial

GOALS AND BACKGROUND

Screening colonoscopy for colorectal cancer has proven to reduce mortality rates. Recently the Endocuff (EC), an attachment to the distal tip of the colonoscope, was introduced. The aim of our study was to compare EC-assisted colonoscopies with standard colonoscopies for the detection of colonic polyps.

STUDY

This study is a randomized prospective 2-center trial. The study was conducted at 2 tertiary care centers.

PARTICIPANTS

A total of 498 patients [249 males; median age 67 y; interquartile range (IQR), 56-75 y] for colon adenoma screening purposes were included. All patients underwent standard colonoscopy with or without the use of EC. Overall polyp detection rate, the number of colonic polyps, and the polyp distribution in the colon were measured. Difference in recognition of polyps with or without the use of EC was assessed. Statistical analysis was applied.

RESULTS

In the EC group, the number of polyps detected per patient was 63% higher [2.00 (IQR, 1.00-4.00) vs. 1.00 (IQR, 1.00-2.25), P<0.0001]. The polyp detection rate in patients increased by 14% with the use of EC (56% vs. 42%, P=0.001). For polyp detection, superiority by use of EC could be observed in the sigmoid (P=0.001) and cecum (P=0.002) for polyps <1 cm in diameter. In the EC group, the number of adenomas detected per patient significantly increased by 86% (P=0.002). No major complications occurred in both groups.

CONCLUSIONS

The use of the EC is feasible and safe with significantly higher polyp detection rates, especially for those located in the sigmoid region. The cuff system has the potential to improve the accuracy of screening colonoscopies.

Cap-assisted endoscopic mucosal resection of a granulosa cell tumor of the upper esophagus

A 28-year-old woman was admitted for pain in the upper abdomen accompanied with dysphagia. Endoscopic ultrasonography showed submucosal protrusion measuring 0.5 cm × 0.6 cm in the posterior wall of the esophagus 20 cm away from incisor teeth. Scanning of the esophagus with an ultrasonic probe shows that the lesion was located in the muscularis mucosa with a section size of 2.5 mm × 3.2 mm. Heterogeneous hypoecho was noted inside the tumor, while the submucosa and muscularis propria were clear and complete. The tumor was excised by cap-assisted endoscopic mucosal resection (EMRC). Postoperative pathological analysis demonstrated that the tumor was excised completely. The clinical course was uneventful, and gastroscopy showed that the tumor was excised completely 6 wk after surgery. Submucosal excision by EMR has been proposed in current therapy of granulose cell tumors. Since the view of tumors in the upper esophagus is not good, throat edema, operation failure and other complications may easily occur. Therefore, adjunctive therapy by EMRC for granulose cell tumors of the upper esophagus is much effective and safe.

Improving quality measures in colonoscopy and its therapeutic intervention

Colonoscopy with polypectomy has been shown to reduce the risk of colon cancer. The critical element in the quality of colonoscopy in terms of polyp detection and removal continues to be the performance of the endoscopist, independent of patient-related factors. Improved results in terms of polyp detection and complete removal have implications regarding the development of screening and surveillance intervals and the reduction of interval cancers after negative colonoscopy. Advances in colonoscopy techniques such as high-definition colonoscopy, hood-assisted colonoscopy and dye-based chromoendoscopy have improved the detection of small and flat-type colorectal polyps. Virtual chromoendoscopy has not proven to improve polyp detection but may be useful to predict polyp pathology. The majority of polyps can be removed endoscopically. Available polypectomy techniques include cold forceps polypectomy, cold snare polypectomy, conventional polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection. The preferred choice depends on the polyp size and characteristics. Other useful techniques include colonoscopic hemostasis for acute colonic diverticular bleeding, endoscopic decompression using colonoscopic stenting, and transanal tube placement for colorectal obstruction. Here we review the current knowledge concerning the improvement of quality measures in colonoscopy and colonoscopy-related therapeutic interventions.

Image-enhanced, chromo, and cap-assisted colonoscopy for improving adenoma/neoplasia detection rate: a systematic review and meta-analysis

OBJECTIVE

The effectiveness of narrow band imaging (NBI), chromoendoscopy (CE), and cap-assisted colonoscopy (CAC) on adenoma detection rate (ADR) has been investigated in previous meta-analyses; however, there have been no meta-analyses of autofluorescence imaging (AFI) or flexible spectral imaging color enhancement (FICE) or i-scan. The aim of this study was to determine whether AFI and FICE/i-scan was more effective than standard/high-definition white light endoscopy to improve ADR and to update previous meta-analyses of NBI, CE, and CAC.

DESIGN

A systematic review and meta-analysis was conducted. Four investigators selected appropriate randomized controlled trials (RCT) using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline. All RCTs in which colonoscopy were performed with AFI, FICE, i-scan, NBI, CE, and CAC were included. The risk ratios (RRs) calculated from adenoma/neoplasia detection rate were used as the main outcome measurement.

RESULTS

A total of 42 studies were included in the analysis. Pooled estimates of RR (95%confidence interval [CI]) using AFI, FICE/i-scan, NBI, CE, and CAC were 1.04 (95% CI: 0.87-1.24) (I² = 0%) (fixed effects model [FEM]); 1.09 (95% CI: 0.97-1.23) (I² = 5%) (FEM); 1.03 (95% CI: 0.96-1.11) (I² = 0%) (FEM); 1.36 (95% CI: 1.23-1.51) (I² = 16%) (FEM); and 1.03 (95% CI: 0.93-1.14) (I² = 48%) (random effects model [REM]), respectively. The pooled estimate of RR (95%CI) using indigo carmine in non-ulcerative colitis (UC) patients and methylene blue in UC patients was 1.33 (95% CI: 1.20-1.48) (I² = 14%) (FEM) and 2.39 (95% CI: 1.18-4.84) (I² = 0%) (FEM), respectively.

CONCLUSION

In contrast to AFI, FICE/i-scan, NBI, and CAC, only CE improves ADR. CE with methylene blue, though not NBI, is effective for surveillance of neoplasia in chronic UC patients.

Cap-assisted colonoscopy

Cap-assisted colonoscopy is a simple, practical, and inexpensive technique that serves several useful purposes in enhancing the performance of colonoscopy. It helps improve polyp detection by its ability to visualize otherwise blind mucosal areas on the proximal aspects of folds and flexures, although its effect on adenoma detection is inconsistent. By helping navigate the colon more efficiently, it facilitates intubation of the cecum faster, with lesser patient discomfort. Cap-assisted colonoscopy can be tried as a salvage procedure in cases of failed cecal intubation with regular colonoscopy and can be of assistance during polypectomy, especially for polyps located on the proximal aspects of folds.

Transparent cap colonoscopy versus standard colonoscopy: a systematic review and meta-analysis

Due to the increasing demand for colonoscopy, devices to advance examination techniques are highly sought after. Several studies have examined the use of a transparent cap attached to the tip of the colonoscope, but the data are inconsistent. The aim of our study was to establish whether transparent cap colonoscopy is beneficial in the improvement of caecal intubation rate, time and polyp detection. We undertook a systematic review and meta-analysis in the form of a Cochrane review to evaluate these outcomes. We included fourteen randomised controlled trials that have been published to date. Transparent cap colonoscopy demonstrates a significant reduction in caecal intubation time, by an average of 48 s, when compared to standard colonoscopy. There was no significant difference in caecal intubation rate or polyp detection between the two groups. Despite a significant difference in caecal intubation time, the clinical significance of the transparent cap remains to be seen. We believe further research is needed to investigate this adjunct.

Benefits and limitations of cap-fitted colonoscopy in screening colonoscopy

BACKGROUND

Colonoscopy is widely used to detect colorectal cancer and to remove precancerous lesions to reduce the risk of colonic cancer.

AIMS

To examine the benefits and limitations of cap-fitted colonoscopy compared to conventional colonoscopy in terms of technical performance and colorectal adenoma detection rate.

METHODS

Screening colonoscopies performed from 2009 to 2010 with or without a transparent cap were retrospectively examined to compare the rate of successful intubation, cecal intubation time, and number, size, shape, and location of adenomas detected. An inclusion criterion was visualization of >95 % of the right colon.

RESULTS

Data from 2,301 colonoscopies (1,165 with cap-fitted colonoscopy, 1,136 without the transparent cap) were retrospectively analyzed. Procedures were performed by four experienced endoscopists. The subjects' demographic characteristics and technical performances were similar between the two methods. The only significant difference in the technical performance between the two techniques was a shorter cecal intubation time with cap-fitted colonoscopy (5.3 vs. 6.6 min; p = 0.045) by one endoscopist. The total number of adenomas detected was significantly higher with cap-fitted colonoscopy than without the cap (586 vs. 484, respectively; p < 0.0001). Adenoma detection with cap-fitted endoscopy was significantly higher in the right colon than in the left colon (19 vs. 12 %, respectively; p = 0.0001).

CONCLUSION

Cap-fitted colonoscopy did not improve the technical aspects of colonoscopy but significantly increased adenoma detection, especially in the right colon. It did not increase the detection rate of flat or depressed adenomas.

Transparent cap colonoscopy versus standard colonoscopy to improve caecal intubation

BACKGROUND

Colonoscopy is considered the gold-standard investigation for screening and diagnosis of colorectal cancer. It is also becoming increasingly desirable for assessment, management, diagnosis and follow-up of other colorectal diseases, such as inflammatory bowel diseases and acute diverticulitis. Hence, due to the increasing demand for colonoscopy, devices to advance examination techniques are highly sought-after and the colonoscope with the transparent cap could be one of these.

OBJECTIVES

To identify and review all relevant data in order to determine whether colonoscopy with a transparent cap is a more effective diagnostic tool than colonoscopy.

SEARCH METHODS

We searched the MEDLINE, EMBASE and CINAHL databases, and the Cochrane Central Register of Controlled Trials for all randomised controlled trials (RCTs) comparing the use of colonoscopy with a transparent cap with standard colonoscopy.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials which compared the use of colonoscopy with a transparent cap with standard colonoscopy.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, interventions used and outcomes measured was extracted from each study. Data was entered into the Cochrane Review Manager software (RevMan 5.0, 2008) and analysed using Cochrane MetaView.

MAIN RESULTS

In the present meta-analysis, we considered 14 randomised controlled trials so far published. The findings of our work indicate that colonoscopy with transparent cap has a faster caecal intubation time when compared with standard colonoscopy. Reviewing studies individually would also seem to favour colonoscopy with transparent cap for polyp detection rate and pain during procedure but due to lack of comparable data meta-analysis was not feasible.

AUTHORS' CONCLUSIONS

This review suggests that a transparent cap on the end of the colonoscope may give a marginally faster caecal intubation time compared with standard colonoscopy. It also suggests that there is a better polyp detection rate and less pain with the cap. However, the authors feel that further randomised controlled trials in this area would provide more clinically significant information on this adjunct to colonoscopy.

Endoscopic techniques for improving colorectal adenoma detection: Recent progress

Colorectal cancer (CRC) is one of the most common malignant neoplasms worldwide and develops mostly from precancerous lesions such as colorectal adenomas. Therefore, early detection and resection of colorectal adenomas is key to preventing CRC. At present, colonoscopy is acknowledged as the gold standard for the diagnosis and treatment of colorectal lesions; however, conventional colonoscopy is still associated with a certain rate of missed lesions. It is reported that the missed detection rate is 6% when adenomas are more than 1 cm, 13% for adenomas 6-9 mm, and 27% for adenomas less than 5 mm. The missed detection rate for right colonic adenomas is higher than that for left colonic adenomas. The missed diagnosis of colorectal adenomas or malignant tumors invariably increases surgical rate and mortality. Currently, great efforts have been made to improve the detection rate of colorectal adenomas. This paper will briefly review recent advances in endoscopic techniques for improving the detection rate of colorectal adenomas.

Hood colonoscopy in trainees: a useful adjunct to improve the performance

BACKGROUND

The use of a transparent hood to improve colonoscopic performance has recently been proposed.

AIMS

The purpose of this study was to evaluate whether using the hood might improve the cecal intubation rate, cecal intubation time, number of attempts needed to intubate the ileo-cecal valve, and polyp detection rate in trainees.

METHODS

Patients undergoing colonoscopy (n = 378) were randomized in two groups, one studied with hood colonoscopy (n = 179) and the other (n = 199) with standard examination.

RESULTS

No differences were found between hood and standard colonoscopy with respect to cecal intubation rate (95 vs 92 %), whereas hood colonoscopy significantly shortened the cecal intubation time, the number of attempts needed to intubate the ileo-cecal valve, and the overall polyp detection rate (p < 0.01 for all these variables).

CONCLUSIONS

Hood colonoscopy might represent a useful adjunct to standard colonoscopy, especially improving the performance of endoscopic trainees.

Invasive colorectal cancer within 5 years of negative colonoscopy in a Japanese population

AIM

Colonoscopy provides imperfect protection against colorectal cancer (CRC). In an attempt to improve cancer detection we evaluated the clinical features of invasive CRC detected within 5 years of a negative colonoscopy.

METHOD

The details of colonoscopies performed in a rural hospital in Japan were prospectively recorded at the time of the examination. The patients were followed over 5 years for the subsequent occurrence of cancer.

RESULTS

In a 5-year period, 10148 patients underwent colonoscopy and 202 without previous colonoscopy were diagnosed with invasive CRC. Of 3212 patients with a colonoscopy negative for cancer, nine developed invasive cancer within 5 years. The ratios for invasive CRC detected without/with previous colonoscopy were 60:1 in the rectum, 54:1 in the sigmoid colon, 15:1 in the descending colon, 28:0 in the transverse colon, 31:5 in the ascending colon and 14:1 in the caecum (P=0.041). The ratio between left- and right-sided colonic cancer was also significantly different (129:3 and 45:6, P=0.0078). Six (67%) of the invasive CRCs were in the ascending colon or caecum. Five of six patients with invasive CRC in the ascending colon and caecum had right-sided small adenomas at prior colonoscopy.

CONCLUSION

The majority of early/missed CRCs were right-sided and associated with prior right-sided colonic adenomas. Repeated colonoscopy of patients with right-sided adenomas at a shorter surveillance interval deserves consideration.

The efficacy of cap-assisted colonoscopy in polyp detection and cecal intubation: a meta-analysis of randomized controlled trials

OBJECTIVES

The role of cap-assisted colonoscopy (CAC) in polyp detection and cecal intubation is unclear. We conducted a meta-analysis to compare the efficacy of CAC vs. standard colonoscopy (SC).

METHODS

Publications in English and non-English literatures (OVID, MEDLINE, and EMBASE) and abstracts in major international conferences were searched for controlled trials comparing CAC and SC. Outcome measures included the proportion of patients with polyps or adenomas detected, cecal intubation rate, cecal intubation time, and total colonoscopy time. The statistical heterogeneity of trials was examined and the effects were pooled by random-effects model. The risk of bias was evaluated by the assessment tool from the Cochrane Handbook. Subgroup analyses were performed for possible clinical and methodological heterogeneities.

RESULTS

From 2,358 citations, 16 randomized controlled clinical trials were included consisting of 8,991 subjects (CAC: 4,501; SC: 4,490). Mean age of subjects was 61.0 years old and 60% were males. CAC detected a higher proportion of patients with polyp(s) (relative risk (RR): 1.08; 95% confidence interval (CI): 1.00-1.17) and reduced the cecal intubation time (mean difference: -0.64 min; 95% CI: -1.19 to -0.10). Cecal intubation rate (RR: 1.00; 95% CI: 0.99-1.02) and total colonoscopy time (mean difference: -0.97 min; 95% CI: -2.33 to 0.40) were comparable between the two groups. In subgroup analyses, a short cap (≤4 mm) was associated with improved polyp detection, whereas a long cap (≥7 mm) was associated with a shorter cecal intubation time.

CONCLUSIONS

CAC demonstrated marginal benefit over SC for polyp detection and shortened the cecal intubation time.

Transparent cap-assisted colonoscopy versus standard adult colonoscopy: a systematic review and meta-analysis

BACKGROUND

Cap-assisted colonoscopy uses a transparent plastic hood attached to the tip of the colonoscope to flatten the semilunar folds and improve mucosal exposure. Several studies have examined the effect of cap-assisted colonoscopy on polyp detection, but the data are inconsistent.

OBJECTIVE

This study aimed to evaluate whether cap-assisted colonoscopy improves the yield of colorectal neoplasia detected compared with standard colonoscopy.

DATA SOURCES

A systematic search of the PubMed, MEDLINE, Embase, and Cochrane databases identified 12 studies that met the inclusion criteria for data extraction.

STUDY SELECTION

Publications that compared cap-assisted colonoscopy vs standard colonoscopy in adults in a prospective randomized controlled study were selected for review.

MAIN OUTCOME MEASURES

The primary outcomes used for meta-analysis were cecal intubation rate, cecal intubation time, and polyp detection rate. The analysis was performed using a fixed-effect model. Outcomes were calculated as odds ratios or standardized mean differences with 95% confidence intervals. The average polyp miss rate determined by tandem colonoscopy was also calculated.

RESULTS

The outcomes of 6185 patients were studied. Cap-assisted colonoscopy detected significantly more patients with polyps (OR 1.13; p = 0.030) and had a lower average polyp miss rate (12.2% vs 28.6%) than standard colonoscopy. Cap-assisted colonoscopy had a significantly higher cecal intubation rate than standard colonoscopy (OR 1.36; p = 0.020), whereas the time to cecal intubation (standard mean difference, 0.04 min; p = 0.280) was similar for the 2 colonoscope types.

CONCLUSIONS

Cap-assisted colonoscopy is associated with improved detection of colorectal neoplasia and higher cecal intubation rates than standard adult colonoscopy.

Participation by experienced endoscopy nurses increases the detection rate of colon polyps during a screening colonoscopy: a multicenter, prospective, randomized study

BACKGROUND

No reported prospective, randomized study has evaluated the impact of an endoscopy nurse participating as a second observer during colonoscopy.

OBJECTIVE

To determine whether the participation of an endoscopy nurse enhanced the polyp detection rate (PDR) and adenoma detection rate (ADR) during screening colonoscopy.

DESIGN

Multicenter, prospective, randomized study.

SETTING

Academic hospitals.

PATIENTS

A total of 844 consecutive patients undergoing screening colonoscopy.

INTERVENTIONS

Single observation by colonoscopist or dual observation by colonoscopist and endoscopy nurse during colonoscope withdrawal.

MAIN OUTCOME MEASUREMENTS

PDR and ADR.

RESULTS

No significant difference in patient demographic data, adequacy of bowel preparation, or mean withdrawal time was observed between the 2 groups. In total, 1153 polyps, including 762 adenomas, were detected in 791 patients. Seven nonpolypoid, depressed neoplastic lesions (0-IIc or combined types) were only detected in the dual observation group. A multivariate analysis revealed that experienced (≥ 2 years) endoscopy nurse participation significantly increased the PDR and ADR compared with those in the single observation group by a colonoscopist alone (adjusted odds ratio [OR] 1.58 [95% CI, 1.07-2.32]; adjusted OR 1.47 [95% CI, 1.01-2.12], respectively). Additionally, the PDR was significantly higher in the dual-observation group with fellows (<500 colonoscopies) and an experienced endoscopy nurse versus that in the single observation group (adjusted OR 2.07 [95% CI, 1.15-3.74]). There was no significant benefit of experienced nurse participation in the subgroup with experienced colonoscopists.

LIMITATIONS

Absence of colonoscopist blinding.

CONCLUSIONS

Experienced endoscopy nurse participation increased the PDR and ADR during screening colonoscopy. However, the benefit of participation by experienced nurses appears to be exclusively with inexperienced colonoscopists.

Usefulness of cap-assisted colonoscopy during colonoscopic EMR: a randomized, controlled trial

BACKGROUND

Clinical demand for total colonoscopy is increasing. Several articles have reported on the usefulness of a cap for faster cecal intubation and reduced patient discomfort, but results for polyp and adenoma detection have been inconsistent.

OBJECTIVE

To assess the efficacy of a cap attached to the tip of a colonoscope for detection and resection of polyps by experienced colonoscopists.

DESIGN

Prospective, randomized, controlled trial.

SETTING

A tertiary referral center.

PATIENTS AND INTERVENTION

A total of 329 patients who underwent colonoscopic EMR were randomized to cap-assisted colonoscopy (CAC) (CAC group, n = 166) or regular colonoscopy (RC) (RC group, n = 163).

MAIN OUTCOME MEASUREMENTS

Cecal intubation time, total procedure time, required time for colonoscopic EMR of each polyp, and missing polyp rate.

RESULTS

The cecal intubation time in the CAC group and RC group was 5.3 ± 3.3 minutes and 5.8 ± 3.7 minutes, respectively (P = .170). The total procedure time in the CAC group and RC group was 23.0 ± 15.5 minutes and 29.2 ± 13.4 minutes, respectively (P = .626). The time required for colonoscopic EMR of each polyp in the CAC group and RC group was 3.5 ± 4.5 minutes and 4.2 ± 5.1 minutes, respectively (P = .010). The number of polyps during the initial colonoscopy in the CAC group and RC group was 2.2 ± 1.7 and 2.0 ± 1.8, respectively (P = .221). The number of detected polyps during colonoscopic EMR in the CAC group and RC group was 3.4 ± 2.7 and 2.7 ± 1.9 (P = .003). The number of missed polyps in the CAC group and RC group was 1.1 ± 1.5 and 0.8 ± 0.9 (P = .024).

LIMITATION

Single-center experience.

CONCLUSIONS

CAC may reduce the time required for colonoscopic EMR of each polyp and may also improve the polyp detection rate.

Evolving techniques in colonoscopy

PURPOSE OF REVIEW

This review summarizes recent clinical studies of colonoscopy technique and new technologies.

RECENT FINDINGS

Water immersion reduces pain and sedation doses in unsedated and lightly sedated colonoscopy. Cap-fitted colonoscopy makes insertion faster and improves detection of lesions behind folds, but the latter effect is operator-dependent. A single controlled trial showed improved detection with the Third Eye Retroscope, but the two arms of the study were not controlled for withdrawal time. Chromoendoscopy increases detection of diminutive adenomas, but adds time to the colonoscopy procedure. Electronic chromoendoscopy methods (narrow band imaging, Fujinon Intelligent ChromoEndoscopy, i-scan, and autofluorescence) have been either unsuccessful in improving detection or require more study. However, these methods and several other methods (chromoendoscopy with magnification, confocal laser microscopy, and endocytoscopy) allow accurate real time determination of polyp histology.

SUMMARY

Water immersion is a clear advance in unsedated colonoscopy. Cap-fitted colonoscopy is a promising method for both practical and effective visualization of the proximal sides of haustral folds. Electronic chromoendoscopy has been largely ineffective at improving polyp detection, but is effective (as are confocal laser microscopy and endocytoscopy) for diagnosis of polyp histology.

Magnifying gastroscopy using a soft black hood for difficult colonoscopy

BACKGROUND

Various methods are reported as aids to cecal intubation for cases in which colonoscopy is difficult. This study aimed to investigate prospectively whether a gastroscope with magnification function, narrow-band imaging (NBI), and a soft black hood can aid insertion in cases of difficult colonoscopy and facilitate both accurate diagnosis and safe treatment.

METHODS

This prospective study recruited 177 patients. All were examined with a magnifying gastroscope. A commercially available soft black hood was attached to the gastroscope during insertion and magnification. Difficult colonoscopy was anticipated before colonoscopy in cases of patients with at least one of the following factors: low BMI (<20 kg/m(2)), adhesion due to previous surgery, or previous colonoscopy that could not reach to the cecum. The success rate and duration of cecal intubation then were assessed. All detected lesions were evaluated by magnifying NBI and then classified as non-neoplastic or neoplastic for endoscopic diagnosis. Subsequently, all the lesions were removed and examined histologically for comparison.

RESULTS

The overall success rate of cecal intubation was 100% (177/177), and the mean time taken to reach the cecum was 5.9 min. A total of 156 lesions were detected endoscopically, and the overall diagnostic accuracy of NBI with magnification was 98.7%. No associated complications occurred.

CONCLUSION

Magnifying gastroscopy using a soft black hood and NBI is useful for cecal intubation in cases wherein colonoscopy is difficult, facilitating accurate diagnosis and safe treatment.

Transparent Cap Colonoscopy versus Standard Colonoscopy for Investigation of Gastrointestinal Tract Conditions

BACKGROUND

Colonoscopy is considered the gold-standard investigation for screening and diagnosis of colorectal cancer. It is also becoming increasingly desirable for assessment, management, diagnosis and follow-up of other colorectal diseases, such as inflammatory bowel diseases and acute diverticulitis. Hence, due to the increasing demand for colonoscopy, devices to advance examination techniques are highly sought-after and the colonoscope with the transparent cap could be one of these.

OBJECTIVES

To identify and review all relevant data in order to determine whether colonoscopy with a transparent cap is a more effective diagnostic tool than colonoscopy.

SEARCH STRATEGY

We searched the MEDLINE, EMBASE and CINAHL databases, and the Cochrane Central Register of Controlled Trials for all randomised controlled trials (RCTs) comparing the use of colonoscopy with a transparent cap with standard colonoscopy.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials which compared the use of colonoscopy with a transparent cap with standard colonoscopy.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, interventions used and outcomes measured was extracted from each study. Data was entered into the Cochrane Review Manager software (RevMan 5.0, 2008) and analysed using Cochrane MetaView.

MAIN RESULTS

In the present meta-analysis, we considered for the first time all five randomised controlled trials so far performed. The findings of our work indicate that colonoscopy with transparent cap has a faster caecal intubation time when compared with standard colonoscopy. Reviewing studies individually would also seem to favour colonoscopy with transparent cap for polyp detection rate and pain during procedure but due to lack of comparable data meta-analysis was not feasible.

AUTHORS' CONCLUSIONS

This review suggests that a transparent cap on the end of the colonoscope may give a marginally faster caecal intubation time compared with standard colonoscopy. It also suggests that there is a better polyp detection rate and less pain with the cap. However, the authors feel that further randomised controlled trials in this area would provide more clinically significant information on this adjunct to colonoscopy.

Wide view and retroview during colonoscopy

Colonoscopy is the best imaging device currently available for the detection of lesions in the large bowel, but may be an imperfect tool against colon cancer. Because recent guidelines for colorectal cancer screening and surveillance depend on whether polyps are found on colonoscopy and on their size, the need to identify all the neoplasia in the colon has assumed greater importance. This article reviews and assesses the latest developments in colonoscopy including wide-angle optics, endoscope caps and hoods, retroflexion and the use of the third eye retroscope.

Transparent cap improves patients' tolerance of colonoscopy and shortens examination time by inexperienced endoscopists

OBJECTIVE

Up to 10% of colonoscopy procedures cannot be completed and polyps may be missed because of patients' discomfort and the endoscopists' technique. The aim of this study was to test the feasibility and safety of attaching a transparent cap to improve the outcome, especially for inexperienced endoscopists.

METHODS

A total of 250 patients were randomized to undergoing either a cap-fitted colonoscopy (CCF) or a normal colonoscopy without a cap (NCCF). The procedures were performed by an experienced or inexperienced endoscopist, and the time to reach the cecum, the total colonoscopy time and the polyp detection rate were recorded. Visual analogue scales (VAS) assessing the severity of abdominal pain and distension were obtained.

RESULTS

For the experienced endoscopist there was no difference between CCF and NCCF on the time to reach the cecum and the time for the whole procedure. But for the inexperienced endoscopist, both times were significantly shorter in the CCF group than in the NCCF group (9.48 min vs. 12.45 min; 18.50 min vs. 21.89 min, respectively, P < 0.05). No complication was observed except some abdominal pain and distension. The VAS scores of abdominal pain and distension were significantly lower in CCF group than those in the NCCF group for the two endoscopists. There was no significant difference in the number of polyps found between the two groups.

CONCLUSION

A cap-fitted colonoscopy can shorten the examination time for inexperienced endoscopists. It can also reduce the patients' discomfort during the procedure.

Cap-fitted colonoscopy: a randomized, tandem colonoscopy study of adenoma miss rates

BACKGROUND

Failures of adenoma detection diminish the effectiveness of colonoscopy.

OBJECTIVE

This study investigated the impact of cap-fitted colonoscopy (CFC) on the adenoma miss rate at colonoscopy.

DESIGN

Randomized, tandem colonoscopy study.

SETTING

University hospital.

PATIENTS

This study involved patients undergoing elective screening or surveillance colonoscopy.

INTERVENTION

Patients were randomized to undergo cap-fitted (n = 52) or regular, high-definition (n = 48) colonoscopy before undergoing a second colonoscopy by the alternate method. During CFC, a plastic cap or hood was attached to the tip of the colonoscope, which was used to flatten haustral folds and improve mucosal exposure.

MAIN OUTCOME MEASUREMENTS

The primary outcome measure was the miss rate for adenomas between patients who underwent CFC first and patients who underwent regular colonoscopy first.

RESULTS

A total of 238 adenomas were detected in 67 patients (67%), with a combined overall miss rate of 27.7%, comprising 66 missed adenomas in 38 patients. Patients undergoing initial CFC had a significantly lower miss rate for all adenomas compared with that of patients undergoing regular colonoscopy (21% vs 33%, P = .039). Miss rates with CFC were significantly lower for adenomas of ≤5 mm (22% vs 35%; P = .037). There was no significant difference in per-patient miss rates between the initial CFC group (51%, n = 18) and the initial regular colonoscopy group (63%, n = 20, P = .36).

LIMITATIONS

Single-center study with two endoscopists.

CONCLUSION

CFC reduces miss rates for all adenomas and specifically for small adenomas. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT00577083).

Prospective randomized controlled trial evaluating cap-assisted colonoscopy vs standard colonoscopy

AIM: To study the significance of cap-fitted colonoscopy in improving cecal intubation time and polyp detection rate.

METHODS: This study was a prospective randomized controlled trial conducted from March 2008 to February 2009 in a tertiary referral hospital at Sydney. The primary end point was cecal intubation time and the secondary endpoint was polyp detection rate. Consecutive cases of total colonoscopy over a 1-year period were recruited. Randomization into either standard colonoscopy (SC) or cap-assisted colonoscopy (CAC) was performed after consent was obtained. For cases randomized to CAC, one of the three sizes of cap was used: D-201-15004 (with a diameter of 15.3 mm), D-201-14304 (14.6 mm) and D-201-12704 (13.0 mm). All of these caps were produced by Olympus Medical Systems, Japan. Independent predictors for faster cecal time and better polyp detection rate were also determined from this study.

RESULTS: There were 200 cases in each group. There was no significant difference in terms of demographic characteristics between the two groups. CAC, when compared to the SC group, had no significant difference in terms of cecal intubation rate (96.0% vs 97.0%, P = 0.40) and time (9.94 ± 7.05 min vs 10.34 ± 6.82 min, P = 0.21), or polyp detection rate (32.8% vs 31.3%, P = 0.75). On the subgroup analysis, there was no significant difference in terms of cecal intubation time by trainees (88.1% vs 84.8%, P = 0.40), ileal intubation rate (82.5% vs 79.0%, P = 0.38) or total colonoscopy time (23.24 ± 13.95 min vs 22.56 ± 9.94 min, P = 0.88). On multivariate analysis, the independent determinants of faster cecal time were consultant-performed procedures (P < 0.001), male patients (P < 0.001), non-usage of hyoscine (P < 0.001) and better bowel preparation (P = 0.01). The determinants of better polyp detection rate were older age (P < 0.001), no history of previous abdominal surgery (P = 0.04), patients not having esophagogastroduodenoscopy in the same setting (P = 0.003), trainee-performed procedures (P = 0.01), usage of hyoscine (P = 0.01) and procedures performed for polyp follow-up (P = 0.01). The limitations of the study were that it was a single-center experience, no blinding was possible, and there were a large number of endoscopists.

CONCLUSION: CAC did not significantly different from SC in term of cecal intubation time and polyp detection rate.

Performance improvements of imaging-based screening tests

Endoscopic and radiologic tests appear to be more accurate than stool-tests in detecting advanced neoplasia because of direct visualisation of colorectal mucosa. Further technological advances are expected to improve the performance and acceptability of these tests. Several attempts at increasing the adenoma detection rate of colonoscopy have been tested, and in vivo histologic differentiation between neoplastic and hyperplastic polyps may lead to substantial saving in economic and medical resources. Low-volume and non-cathartic bowel preparations may improve CT colonography acceptability, whilst computer-aided detection and low-dose protocols may result in a higher accuracy and safety of this procedure. Despite the lack of ionising radiation, significant drawbacks will likely to limit the role of MR colonography in screening programs. Colon capsule endoscopy appears to be a safe and technically feasible procedure. The suboptimal accuracy of the first generation seems to be substantially improved by the second generation of this device.

Hood-assisted colonoscopy is more effective in detection of colorectal adenomas than narrow-band imaging

BACKGROUND & AIMS

Colonoscopy, using either a transparent retractable extension device or narrow band imaging, is thought to improve colon adenoma detection. We compared the abilities of a transparent retractable extension device and narrow band imaging to detect colorectal adenomas.

METHODS

One hundred and seven patients with colonic adenomas that were detected by traditional colonoscopy were randomly assigned to groups that underwent a second colonoscopy that used either a transparent retractable extension or narrow band imaging; adenomas were removed. The principal outcome parameters were the number, size, shape, and location of adenomas detected. The patients' demographic characteristics, indications for colonoscopy, and cecal intubation times were similar between groups.

RESULTS

Use of the transparent retractable extension resulted in detection of 31% more adenomas than the initial procedure (P < .0001). The majority of newly discovered adenomas were sessile (79%; 26/33) and less than 5 mm in size (73%; 24/33). There was no significant increase in adenoma detection (5%) between first colonoscopy and second colonoscopy using narrow band imaging. Additional adenomas were found in 40.7% of patients that were examined using the transparent hood (22/54) versus 13.2% of those examined using narrow band imaging (7/53) (P = .0028).

CONCLUSIONS

Colonoscopy with a transparent retractable extension significantly improved the adenoma detection rate compared with repeat colonoscopy using narrow band imaging.