Impact of a transparent hood on the performance of total colonoscopy: a randomized controlled trial

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.

Impact of cap-assisted colonoscopy during transendoscopic enteral tubing: A randomized controlled trial

BACKGROUND

Colonic transendoscopic enteral tubing (TET) requires double cecal intubation, raising a common concern of how to save cecal intubation time and make the tube stable. We hypothesized that cap-assisted colonoscopy (CC) might reduce the second cecal intubation time and bring potential benefits during the TET procedure.

AIM

To investigate if CC can decrease the second cecal intubation time compared with regular colonoscopy (RC).

METHODS

This prospective multicenter, randomized controlled trial was performed at four centers. Subjects ≥ 7 years needing colonic TET were recruited from August 2018 to January 2020. All subjects were randomly assigned to two groups. The primary outcome was the second cecal intubation time. Secondary outcomes included success rate, insertion pain score, single clip fixation time, purpose and retention time of TET tube, length of TET tube inserted into the colon, and all procedure-related (serious) adverse events.

RESULTS

A total of 331 subjects were randomized to the RC (n = 165) or CC (n = 166) group. The median time of the second cecal intubation was significantly shorter for CC than RC (2.2 min vs 2.8 min, P < 0.001). In patients with constipation, the median time of second cecal intubation in the CC group (n = 50) was shorter than that in the RC group (n = 43) (2.6 min vs 3.8 min, P = 0.004). However, no difference was observed in the CC (n = 42) and RC (n = 46) groups of ulcerative colitis patients (2.0 min vs 2.5 min, P = 0.152). The insertion pain score during the procedure in CC (n = 14) was lower than that in RC (n = 19) in unsedated colonoscopy (3.8 ± 1.7 vs 5.4 ± 1.9; P = 0.015). Multivariate analysis revealed that only CC (odds ratio [OR]: 2.250, 95% confidence interval [CI]: 1.161-4.360; P = 0.016) was an independent factor affecting the second cecal intubation time in difficult colonoscopy. CC did not affect the colonic TET tube’s retention time and length of the tube inserted into the colon. Moreover, multivariate analysis found that only endoscopic clip number (OR: 2.201, 95%CI: 1.541-3.143; P < 0.001) was an independent factor affecting the retention time. Multiple regression analysis showed that height (OR: 1.144, 95%CI: 1.027-1.275; P = 0.014) was the only independent factor influencing the length of TET tube inserted into the colon in adults.

CONCLUSION

CC for colonic TET procedure is a safe and less painful technique, which can reduce cecal intubation time.

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.).

Effect of dynamic position changes during colonoscope withdrawal: a meta-analysis of randomized controlled trials

BACKGROUND

Colonoscopies are considered to be the primary screening test and gold standard test for colorectal cancer. Position changes during colonoscope withdrawal are believed to be associated with an increased adenoma detection rate (ADR) and polyp detection rate (PDR). However, previous results conflicted, and this study aimed to elucidate the effectiveness of dynamic position changes during colonoscope withdrawal.

METHODS

The relevant publications were identified by searching the medical databases. The primary outcomes were the ADR and PDR, which were pooled and analyzed. The secondary outcome was the withdrawal time. The studies that supplied the ADR and PDR for different segments of the colon were separated into subgroup analyses.

RESULTS

Five randomized controlled trials were eligible for analysis. The total ADR was higher with dynamic position changes than with a static position (odds ratio, [OR] 1.34; 95% confidence interval [CI] 1.13-1.59; p < 0.001), with low evidence of between-study heterogeneity (I₂ = 0%). Although the total PDR was slightly higher with dynamic position changes than with a static position (OR 1.23; 95% CI 0.88-1.73), there difference was not statistically significant (p = 0.22). The withdrawal time was only increased by 0.47 min (95% CI - 0.11 to 1.06) with dynamic position changes, without statistical significance (p = 0.11). The subgroup analysis showed that the ADR and PDR for the transverse colon were higher with dynamic position changes, with pooled estimates of ADR (OR 1.72; 95% CI 1.02-2.88; p = 0.04) and PDR (OR 1.79; 95% CI 1.08-2.96; p = 0.02).

CONCLUSION

Dynamic position changes during colonoscope withdrawal increased the total ADR; however, no obvious increase was found in the total PDR. The withdrawal time was not significantly prolonged with dynamic position changes. Subgroup analysis showed that the ADR and PDR in the transverse colon were obviously improved with dynamic position changes.

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

Objectives and study aim  Colonoscopy prevents colorectal cancer by removing adenomatous polyps, but missed adenomas lead to interval cancers. Different devices have been used to increase adenoma detection rates (ADR). Two such devices of interest are the transparent cap (Olympus) and Endocuff (ARC Medical). Our study aimed to compare differences in ADR between Endocuff-assisted colonoscopy (EAC), cap-assisted colonoscopy (CAC) and standard colonoscopy (SC). Patients and methods  A sample size of 126 subjects was calculated to determine an effect size of 30 %. Patients undergoing screening or surveillance colonoscopy between March 2016 and January 2017 were randomized to SC, CAC or EAC groups. Three experienced endoscopists performed all colonoscopies. Patient demographics, procedure indication, Boston Bowel Prep Score (BBPS), withdrawal time, polyp size, location, histopathology, were analyzed. Results  There was no difference in ADR (52 %, 40 % and 54 %) in the SC, CAC and EAC groups respectively ( P  = 0.4). Similar findings were also observed for proximal ADR (45 %, 35 %, and 50 %, P  = 0.4) and SSA detection rate (16 %, 14 %, and 23 %, P  = 0.5). EAC detected higher mean ADR per colonoscopy compared to CAC (1.70 vs 0.76, P  = 0.01). However, there was no significant difference in mean ADR per positive colonoscopy (2.08, 1.63, and 2.59, P  = 0.21). Conclusion  In a randomized controlled trial comparing AC to CAC and SC, neither device conferred additional benefits in ADR among high detectors. When comparing each device, EAC may be better than CAC at detecting more total adenomas.

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.

Cap-assisted endoscopy: Do we have enough evidence?

So, is there enough evidence to incorporate CC in clinical practice? If we interpret the literature and the meta-analysis by Nutalapati et al., the answer for the clinically-focused endoscopist, with regard to adenoma detection rate (ADR), at present, may be "no". Significant differences do not necessarily imply clinical benefits and translation into clinical practice. The answer for the improvement of cecal intubation frequency and intubation time by the cap depends on the focus of training commitment, because these effects of the cap may be beneficial, especially for unexperienced endoscopists. It is obvious that further studies are needed. In this line, it is interesting to know, that in a recent meta-analysis of prospective studies, the length of the transparent cap had opposite effects on investigation time and polyp detection rate. Whereas, the anal to cecal time was significantly shortened by a cap length of > 7 mm and a polyp detection rate was significantly improved by a cap length of < 4 mm.

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.

Impact of cap-assisted colonoscopy on the learning curve and quality in colonoscopy: a randomized controlled trial

BACKGROUND AND AIMS

Colonoscopy competency assessment in trainees traditionally has been informal. Comprehensive metrics such as the Assessment of Competency in Endoscopy (ACE) tool suggest that competency thresholds are higher than assumed. Cap-assisted colonoscopy (CAC) may improve competency, but data regarding novice trainees are lacking. We compared CAC versus standard colonoscopy (SC) performed by novice trainees in a randomized controlled trial.

METHODS

All colonoscopies performed by 3 gastroenterology fellows without prior experience were eligible for the study. Exclusion criteria included patient age <18 or >90 years, pregnancy, prior colon resection, diverticulitis, colon obstruction, severe hematochezia, referral for EMR, or a procedure done without patient sedation. Patients were randomized to either CAC or SC in a 1:1 fashion. The primary outcome was the independent cecal intubation rate (ICIR). Secondary outcomes were cecal intubation time, polyp detection rate, polyp miss rate, adenoma detection rate, ACE tool scores, and cumulative summation learning curves.

RESULTS

A total of 203 colonoscopies were analyzed, 101 in CAC and 102 in SC. CAC resulted in a significantly higher cecal intubation rate, at 79.2% in CAC compared with 66.7% in SC (P = .04). Overall cecal intubation time was significantly shorter at 13.7 minutes for CAC versus 16.5 minutes for SC (P =.02). Cecal intubation time in the case of successful independent fellow intubation was not significantly different between CAC and SC (11.6 minutes vs 12.7 minutes; P = .29). Overall ACE tool motor and cognitive scores were higher with CAC. Learning curves for ICIR approached the competency threshold earlier with cap use but reached competency for only 1 fellow. The polyp detection rate, polyp miss rate, and adenoma detection rate were not significantly different between groups.

CONCLUSIONS

CAC resulted in significant improvement in ICIR, overall ACE tool scores, and trend toward competency on learning curves when compared with SC in colonoscopy trainees without prior colonoscopy experience. (Clinical trial registration number: NCT02472730.).

Can technology increase adenoma detection rate?

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

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.

Biliary intervention using SpyGlass DS cholangioscopy through a cap-attached variable-stiffness colonoscope in a patient following Billroth II gastrectomy

The SpyGlass DS system is currently used as a direct video cholangioscope for biliary diagnostic and therapeutic procedures. In general, the SpyGlass DS cholangioscope is passed through the working channel of a duodenoscope and inserted into a bile duct via duodenal papilla. However, the procedure has been challenging in patients with altered gastrointestinal anatomy due to the retrograde route through a potentially tortuous afferent limb. A therapeutic colonoscope with variable stiffness can offer alternative guidance for SpyGlass DS cholangioscope in patients with surgically altered gastrointestinal anatomy.

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.

The use of a transparent cap in sigmoidoscopy-A randomized controlled clinical trial on pain, time and success rate

Trials on cap-assisted colonoscopy have shown a reduction in pain, faster intubation time and a higher success rate attributed to the use of the cap. No similar studies have been published on sigmoidoscopy even though it is a common procedure associated with significant pain. Our objective was to investigate whether the use of a transparent cap for sigmoidoscopy has an impact on pain, time or success rate. To mimic the tendencies of daily clinical practice, the trainee endoscopist performed the procedures, and no analgesics or sedatives were used. We conducted a randomized, controlled clinical trial with a parallel design consisting of two groups masked for the intervention. The primary endpoint was pain, recorded on a 100-mm visual analogue scale (VAS). Our results found cap-assisted sigmoidoscopy to be significantly more painful than non-cap-assisted sigmoidoscopy (median VAS 50 vs. 38 mm; p = 0.047). We found no differences on time or success rate due to the cap. Our results suggest pain management, e.g. analgesics which is not routinely used for sigmoidoscopy, when a cap is used to gain therapeutic or diagnostic advantages. ClinicalTrials.gov Identifier: NCT02243930.

[New Colonoscopy Devices to Improve Colon Neoplasm Detection]

Early detection and removal of adenomatous polyps can prevent the development of colorectal cancer. However, it is fairly common-up to 20%-for polyps to be undetected in a colonoscopy due to poor visualization of the proximal aspect of colonic folds and anatomical flexures. To overcome these limitations, many new endoscopes and accessories have been developed. A wide-angle colonoscopy did not improve the detection of adenoma compared with the standard colonoscopy. An extra-wide angle and Retroview colonoscopies showed a significantly lower miss rate of polyps in the colon model. However, clinical trials are mandatory in the future. The recently introduced full spectrum endoscopy system showed a significantly higher adenoma detection rate than the standard forward-viewing colonoscopy. In accessories, The cap-assisted colonoscopy showed only a marginal or no benefit on the detection of polyps and adenomas. In contrast, a colonoscopy with Endocuff, EndoRings, and G-eye have showed significantly lower adenoma miss rates. The Third Eye, which provides additional retrograde viewing, has revealed a significant improvement in the detection of adenoma and polyp. However, the Third Eye Retroscope was limited by its deployment through the working channel of the scope. Recently, the Third Eye Panoramic cap, which was designed to overcome the limitation of the Third Eye Retroscope, was introduced. In the future, this would be needed to evaluate the effectiveness, efficiency and safety for these new colonoscopies and accessories.

A prospective randomized study of the use of an ultrathin colonoscope versus a pediatric colonoscope in sedation-optional colonoscopy

BACKGROUND

Ultrathin colonoscopes (UTC) reportedly produce less pain during colonoscopy than standard colonoscopes. The aim of this study was to assess the tolerability of an UTC compared with that of a pediatric colonoscope.

METHODS

A total of 270 adult patients scheduled to undergo colonoscopy were randomized, with 134 allocated to the UTC group and 136 to the pediatric colonoscope group. Pain was assessed using a visual analog scale. For all procedures, sedation was administered only if requested. Overall pain, rate and time of cecal and terminal ileum intubation, number of patients requesting sedation, adenoma detection rates (ADR), and rate of complications were measured and analyzed.

RESULTS

Among all patients, the medians of maximum pain and overall pain were significantly lower in the UTC group than in the pediatric colonoscope group (23 vs. 38, P < 0.001; 12 vs. 22, P = 0.0003, respectively). Significantly fewer patients requested sedation in the UTC group than in the pediatric colonoscope group (1.4 vs. 6.6%; P = 0.0269). No significant differences were seen in either the rate and time of successful cecal and terminal ileum intubation, or in other procedure-related outcomes, including ADR.

CONCLUSIONS

Compared with a pediatric colonoscope, the UTC was associated with reduced overall and maximum pain during colonoscopy, with no difference in ADR.

The ADENOMA Study. Accuracy of Detection using Endocuff Vision™ Optimization of Mucosal Abnormalities: study protocol for randomized controlled trial

BACKGROUND

Colonoscopy is the gold standard investigation for the diagnosis of bowel pathology and colorectal cancer screening. Adenoma detection rate is a marker of high quality colonoscopy and a high adenoma detection rate is associated with a lower incidence of interval cancers. Several technological advancements have been explored to improve adenoma detection rate. A new device called Endocuff Vision™ has been shown to improve adenoma detection rate in pilot studies.

METHODS/DESIGN

This is a prospective, multicenter, randomized controlled trial comparing the adenoma detection rate in patients undergoing Endocuff Vision™-assisted colonoscopy with standard colonoscopy. All patients above 18 years of age referred for screening, surveillance, or diagnostic colonoscopy who are able to consent are invited to the study. Patients with absolute contraindications to colonoscopy, large bowel obstruction or pseudo-obstruction, colon cancer or polyposis syndromes, colonic strictures, severe diverticular segments, active colitis, anticoagulant therapy, or pregnancy are excluded. Patients are randomized according to site, age, sex, and bowel cancer screening status to receive Endocuff Vision™-assisted colonoscopy or standard colonoscopy on the day of procedure. Baseline data, colonoscopy, and polyp data including histology are collected. Nurse assessment of patient comfort and patient comfort questionnaires are completed post procedure. Patients are followed up at 21 days and complete a patient experience questionnaire. This study will take place across seven NHS Hospital Trusts: one in London and six within the Northern Region Endoscopy Group. A maximum of 10 colonoscopists per site will recruit a total of 1772 patients, with a maximum of four bowel screening colonoscopists permitted per site.

DISCUSSION

This is the first trial to evaluate the adenoma detection rate of Endocuff Vision™ in all screening, surveillance, and diagnostic patient groups. This timely study will guide clinicians as to the role of Endocuff Vision™ in routine colonoscopy.

STUDY REGISTRATION

ISRCTN11821044.

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.

Wire assisted sigmoid intubation: An alternative approach to overcome technically difficult colonic angulations

Complete colonoscopy can sometimes prove technically challenging. Sharp colonic angulation can be one of the contributing factors. With the advancement in technology, various modalities have been employed to overcome technical difficulties. Here we describe a guidewire assisted sigmoid intubation to overcome this hurdle with limited resources.

What Influences the Quality of Prevention Colonoscopy?

Background

Colorectal cancer still has a high incidence and mortality. Although colonoscopy is considered as gold standard of colorectal cancer screening, there still exists an unsatisfactory level of adenomas missed in screening and surveillance colonoscopy. Furthermore, patients bear the burden of potentially unpleasant and painful examination and preparation procedures.

Method

A search of the literature using PubMed was carried out, supplemented by a review of the programs of the Digestive Disease Week (DDW) and the United European Gastroenterology Week (UEGW) 2011-2013.

Results

Several new approaches to colonoscopy were described: water, CO₂ and cap colonoscopy, and application of spasmolytics such as hyoscine butylbromide and glucagon. The use of these methods does not necessitate the purchase of new endoscopes. They are feasible and safe, facilitate achieving the aim of more comfort and less pain, and perhaps allow lower doses of sedatives to be used. However, a clear effect on procedure time is lacking. Furthermore, the published data do not consistently answer the question of whether these techniques have a positive impact on the most important goal, the better detection of carcinoma precursors.

Conclusion

More efforts to optimize bowel preparation have to be made to improve visualization of the mucosal surface. The most reliable criteria for the quality of screening and surveillance colonoscopy remain a minimum cecal intubation rate of >90%, a withdrawal time of at least 6 or better 9 min, and an adenoma detection rate of >20%. These results should be achieved with a complication rate lower than 1%, including polypectomy.

Compact dual-view endoscope without field obscuration

We have developed a compact dual-view endoscopic probe without field obscuration to address the need of simultaneously observing forward and backward fields of view (FOVs) in the colon. The objective is compact with the forward-view and rear-view optical paths sharing the same optical elements. The compact objective is new in that no FOV is blocked. The illumination for forward-view imaging is provided by the cylindrical light guide and backward illumination is achieved with a reflector. We have designed, prototyped, and tested the endoscope by comparing it to a standard clinical colonoscope. We will discuss the system concept, objective design, fabrication of the freeform lens, and test results.

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.

Clinical impact of endoscopy position detecting unit (UPD-3) for a non-sedated colonoscopy

AIM: To evaluate whether an endoscopy position detecting unit (UPD-3) can improve cecal intubation rates, cecal intubation times and visual analog scale (VAS) pain scores, regardless of the colonoscopist’s level of experience.

METHODS: A total of 260 patients (170 men and 90 women) who underwent a colonoscopy were divided into the UPD-3-guided group or the conventional group (no UPD-3 guidance). Colonoscopies were performed by experts (experience of more than 1000 colonoscopies) or trainees (experience of less than 100 colonoscopies). Cecal intubation rates, cecal intubation times, insertion methods (straight insertion: shortening the colonic fold through the bending technique; roping insertion: right turn shortening technique) and patient discomfort were assessed. Patient discomfort during the endoscope insertion was scored by the VAS that was divided into 6 degrees of pain.

RESULTS: The cecum intubation rates, cecal intubation times, number of cecal intubations that were performed in < 15 min and insertion methods were not significantly different between the conventional group and the UPD-3-guided group. The number of patients who experienced pain during the insertion was markedly less in the UPD-3-guided group than in the conventional group. Univariate and multivariate analysis showed that the following factors were associated with lower VAS pain scores during endoscope insertion: insertion method (straight insertion) and UPD-3 guidance in the trainee group. For the experts group, univariate analysis showed that only the insertion method (straight insertion) was associated with lower VAS pain scores.

CONCLUSION: Although UPD-3 guidance did not shorten intubation times, it resulted in less patient pain during endoscope insertion compared with conventional endoscopy for the procedures performed by trainees.

Advanced technology for the improvement of adenoma and polyp detection during colonoscopy

Early detection and removal of adenomatous polyps reduces colorectal cancer death. However, many studies have reported that up to 20% of adenomas can be missed during colonoscopy. To improve visualization and reduce the blind spot of the colonic mucosa for an increase in the adenoma detection rate, many endoscopic techniques and technologies have been developed. The benefit of the high-definition endoscope for improving adenoma and polyp detection is marginal. Wide-angle colonoscope has failed to improve adenoma detection compared to standard colonoscopy. Although the cap-assisted colonoscope can reduce cecal intubation times, it does not seem to improve adenoma and polyp detection. The diagnostic accuracy of the colon capsule endoscope is low compared to the conventional colonoscope. Third Eye(®) retroscope(®) , which provides additional retrograde viewing, has revealed significant improvement in adenoma and polyp detection compared to standard colonoscopy. However, this device increases procedural times. Recently developed full-spectrum endoscopy colonoscope and extra-wide-angle-view colonoscope have demonstrated a significantly lower miss rate of polyps. However, clinical trials are mandatory to determine the efficacy of these novel technologies for cancer screening. In addition, education and training for these novel techniques and technologies should seriously be considered to improve adenoma and polyp detection.

Water immersion colonoscopy facilitates straight passage of the colonoscope through the sigmoid colon without loop formation: randomized controlled trial

BACKGROUND AND AIM

One of the major causes of pain during colonoscopy is looping of the instrument during insertion through the sigmoid colon, which causes discomfort by stretching the mesentery. There are many studies in colonoscope techniques, but they have not been assessed objectively with respect to colonoscope passage through the sigmoid colon without loop formation. The aim of the present study was to determine whether cap-fitted colonoscopy and water immersion increase the success rate of insertion through the sigmoid without loop formation.

METHODS

A total of 1005 patients were randomized to standard colonoscopy, cap-fitted colonoscopy or water immersion technique. All examinations were carried out under a magnetic endoscope imaging device. Main outcome was the success rate of insertion without loop formation.

RESULTS

Success rate of insertion without loop formation was 37.5%, 40.0%, and 53.8% in the standard, cap, and water groups, respectively (standard vs water P = 0.00014, cap vs water P = 0.00186). There were no significant differences among the groups regarding cecal intubation rate, cecal intubation time and number of polyps ≥5 mm per patient.

CONCLUSIONS

Water immersion increases the success rate of insertion through the sigmoid colon without loop formation. This practical technique, requiring only preparation of a cap and water, is useful without compromising cecal intubation rate, cecal intubation time, or polyp detection rate.

Spatial orientation in pathway surgery

BACKGROUND

In the field of minimally invasive surgery, specifically in pathway surgery (i.e. minimal invasive procedures carried out transluminally or through instrument-created pathways), spatial disorientation is a common experience to endoscopists. In this article, two effects that may cause spatial disorientation in pathway surgery, 'control-display compatibility' and 'local disorientation', were studied.

METHOD

A custom-developed simulator Endo-PaC was developed and used for mimicking pathway surgical scenarios. In Study 1, two ways of control-display alignment, normal mapping and mirrored mapping, were tested in combination with two control devices, thumb control and wrist control, in an orienting task using Endo-PaC. In Study 2, a tethered viewpoint was added to the virtual instrument tip. It was hypothesized that the visible tip would provide a cue of orientating direction in the reference frame during the instrument navigation. In both studies, novice participants were involved, and their performance was evaluated with regard to task time, path length travelled by the virtual tip, time and number of warnings, and subjective workload and personal preference.

RESULTS

In Study 1, normal-thumb and normal-wrist mapping yielded significantly lower means than mirrored-thumb and mirrored-wrist control for all investigated objective and subjective performance measurements. Out of 24 participants, 20 participants preferred normal control mapping. In Study 2, participants performed the task in shorter time and with shorter path length when the tip was visible tip on the monitor using a tethered viewpoint, but with a lower number and time of warnings without a visible tip.

CONCLUSION

The results of our studies show that eliminating the visual-display misalignment would greatly improve novice participants' performance, reduce the training time and their cognitive workload. A visible tip on the monitor would provide strong direction cue and shorten the performance time, but might introduce collision errors to novices and therefore requires longer training time.

A simple method to improve adenoma detection rate during colonoscopy: altering patient position

BACKGROUND

Colonoscopy is currently considered to be the gold standard method for detecting and removing adenomatous polyps. However, tandem colonoscopy studies reveal a pooled polyp miss rate of 22%.

OBJECTIVE

A prospective randomized trial was conducted to assess whether alteration of patient position during colonoscopy withdrawal increases the adenoma detection rate (ADR).

METHOD

The study group included 120 patients who presented for elective colonoscopic examination. After reaching the cecum, patients were randomly assigned in a 1:1 ratio to examination in either the left lateral position or other positions (left lateral position for the cecum, ascending colon and hepatic flexure; supine for transverse colon; and supine and right lateral position for splenic flexure, descending and sigmoid colon) first. Examination of the colon was performed segment by segment. The size, morphology and location of all polyps were recorded. Polyps were removed immediately after examination of a colon segment when all positions were completed. ADR and polyp detection rates (PDR) were calculated.

RESULTS

A total of 102 patients completed the study. Examination in the left lateral position revealed 66 polyps in 31 patients (PDR 30.3%) and 42 adenomas in 24 patients (ADR 23.5%). PDR increased to 43.1% (81 polyps in 44 patients) and the ADR to 33.3% (53 adenomas in 34 patients) after the colon was examined in the additional positions (P<0.001 and P=0.002, respectively). The increase in the number of adenomas detected was statistically significant in the transverse and sigmoid colon. The addition of position changes led to a 9.8% increase in the ADR in the transverse colon, splenic flexure, and descending and sigmoid colon. The frequency of surveillance interval was shortened in nine (8.8%) patients after examination of the colon in dynamic positions.

CONCLUSION

Alteration of patient position during colonoscopy withdrawal is a simple and effective method to improve ADR.

Endoscopic innovations to increase the adenoma detection rate during colonoscopy

Up to a quarter of polyps and adenomas are missed during colonoscopy due to poor visualization behind folds and the inner curves of flexures, and the presence of flat lesions that are difficult to detect. These numbers may however be conservative because they mainly come from back-to-back studies performed with standard colonoscopes, which are unable to visualize the entire mucosal surface. In the past several years, new endoscopic techniques have been introduced to improve the detection of polyps and adenomas. The introduction of high definition colonoscopes and visual image enhancement technologies have been suggested to lead to better recognition of flat and small lesions, but the absolute increase in diagnostic yield seems limited. Cap assisted colonoscopy and water-exchange colonoscopy are methods to facilitate cecal intubation and increase patients comfort, but show only a marginal or no benefit on polyp and adenoma detection. Retroflexion is routinely used in the rectum for the inspection of the dentate line, but withdrawal in retroflexion in the colon is in general not recommended due to the risk of perforation. In contrast, colonoscopy with the Third-Eye Retroscope^® may result in considerable lower miss rates compared to standard colonoscopy, but this technique is not practical in case of polypectomy and is more time consuming. The recently introduced Full Spectrum Endoscopy™ colonoscopes maintains the technical capabilities of standard colonoscopes and provides a much wider view of 330 degrees compared to the 170 degrees with standard colonoscopes. Remarkable lower adenoma miss rates with this new technique were recently demonstrated in the first randomized study. Nonetheless, more studies are required to determine the exact additional diagnostic yield in clinical practice. Optimizing the efficacy of colorectal cancer screening and surveillance requires high definition colonoscopes with improved virtual chromoendoscopy technology that visualize the whole colon mucosa while maintaining optimal washing, suction and therapeutic capabilities, and keeping the procedural time as low and patient discomfort as optimal as possible.

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.

Advanced imaging in colonoscopy and its impact on quality

Detecting and resecting colonic polyps during endoscopy has been shown to reduce CRC. At the same time, endoscopy has faced substantial technical improvements and continues to undergo major changes. Detection of colorectal neoplasias is facilitated by using high-definition endoscopy, and characterization of lesions is more accurate by using virtual CE. High-definition endoscopy has found widespread use, whereas virtual CE is still more often used in tertiary centers and for high-risk patient groups. Endomicroscopy has opened the door for in vivo histology and functional as well as molecular imaging. Thorough training of the endoscopists is necessary, and redefined reimbursement codes may help make these techniques available in the clinical arena for high-risk patients who are most probable to benefit from the more advanced diagnostic endoscopy techniques. Over recent years, there has also been an increasing push by healthcare payors and providers to improve the quality of healthcare services. The ultimate goal of monitoring quality measures is to improve the overall health of the population and, for colon cancer screening, to reduce the incidence and mortality of colon cancer. However, the development of an appropriate quality measure and ensuring the accuracy of the data on which we base our efforts are among the first challenges that we must meet (Table 1). The continued technologic advancements in colonoscopy and endoscopic imaging may result in improvements in the quality of colonoscopy and should lead to a decrease in the incidence and mortality from colon cancer.

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.

Advanced colorectal polyp detection techniques

A long-term follow-up of the landmark National Polyp Study recently showed that colonoscopy was associated with critical clinical benefit, including reduced overall death rate, colorectal cancer (CRC) death rate, and CRC incidence Zauber et al. (N Engl J Med 366(8):687-96, 2012). This and other recent studies emphasize the need for high-quality colonoscopy to realize maximal benefit. Adenoma detection has emerged as an important predictor of quality colonoscopy. Studies from Europe have shown that individuals whose colonoscopy was performed by a physician with high adenoma detection have a much lower likelihood of interval CRC. Studies now suggest that it is possible to train endoscopists to improve their adenoma detection rate. The specific methods associated with higher quality colonoscopy include careful inspection behind folds, washing the colon surface, adequate insufflation, and recognition of subtle flat polyps. Use of high-definition white light colonoscopy, chromoendoscopy, and cap-fitted colonoscopy has also been studied as potential methods for increasing adenoma detection. We will review these methods and techniques in this article.

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.

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.

A new accessory, endoscopic cuff, improves colonoscopic access for complex polyp resection and scar assessment in the sigmoid colon (with video)

BACKGROUND

Difficult and unstable endoscopic access to large sessile/flat colon polyps in the sigmoid colon may prevent successful and complete EMR.

OBJECTIVE

We report our experience with the use of an endoscopic cuff, a new endoscopic accessory, to improve endoscopic access during endoscopic therapy and scar assessment.

DESIGN

Single-center, retrospective, feasibility case series.

SETTING

Tertiary referral academic endoscopy unit.

PATIENTS

Nonconsecutive patients referred for endoscopic resection of large flat/sessile sigmoid colon polyps or surveillance of postpolypectomy scars in the sigmoid colon.

INTERVENTIONS

When conventional methods to achieve stable access and visualization were unsuccessful, the endoscopic cuff was used to retract sigmoid colon folds.

MAIN OUTCOME MEASUREMENTS

Safety, procedural success, and complications.

RESULTS

Five patients (mean age 62 years, 3 male/2 female) underwent endoscopic cuff-assisted EMR polypectomy, and 7 patients (mean age 62 years, 2 male/5 female) underwent post-EMR scar surveillance with an endoscopic cuff-assisted flexible sigmoidoscopy. All sessile/flat polyps (mean size 29 mm) or post-EMR scar sites (mean size 15 mm) were located at acute bends in the sigmoid colon. With the endoscopic cuff placed around the tip of the colonoscope, endoscopic access improved significantly by flattening/depressing colon folds close to the lesion/scar. The entire polyp/scar surface was revealed, facilitating a complete polyp excision and a meticulous scar assessment. No immediate or delayed adverse events were seen.

LIMITATIONS

Single-center, nonrandomized case series.

CONCLUSIONS

An endoscopic cuff appears to be a safe and easily used accessory to facilitate colonoscopic access for complex polypectomy and scar assessment in the sigmoid colon.

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.

How do I overcome difficulties in insertion?

Demand for colonoscopy is increasing because it is an important tool not only for screening of colorectal neoplasm but also for resection of such lesions in early stage. Cecal intubation requires expertise on shortening of the examination time and improvement of the cecal intubation rate without causing pain to the patients. About 5% to 10% of patients still experience difficulties or failure of the cecal intubation. There are number of factors that affect the difficulty of the colonoscopy such as technical skill of the endoscopist, angulated sigmoid, redundant colon, advanced age, female gender, diverticular disease, and inadequate bowel preparation. In an effort to overcome these situations and to and aiding colonoscope insertion with reducing pain, various methods have introduced. Like this review discusses ways to approach patients with technically difficult colons for achieving the successful cecal intubation.

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.

Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup

AIM: To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized, controlled trial data.

METHODS: The Third Eye^® Retroscope^® Randomized Clinical Evaluation (TERRACE) was a randomized, controlled, multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope’s forward view. We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device. Subjects were patients scheduled for colonoscopy for screening, surveillance or diagnostic workup, and each underwent same-day tandem examinations with standard colonoscopy (SC) and Third Eye colonoscopy (TEC), randomized to SC followed by TEC or vice versa.

RESULTS: Indication for colonoscopy was screening in 176/345 subjects (51.0%), surveillance after previous polypectomy in 87 (25.2%) and diagnostic workup in 82 (23.8%). In 4 subjects no indication was specified. Previously reported overall results had shown a net additional adenoma detection rate (ADR) with TEC of 23.2% compared to SC. Relative risk (RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92 (P = 0.029). Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening, 35.7% for surveillance, 55.4% for diagnostic and 40.7% for surveillance and diagnostic combined. The RR of missing adenomas with SC vs TEC was 1.11 (P = 0.815) for screening, 3.15 (P = 0.014) for surveillance, 8.64 (P = 0.039) for diagnostic and 3.34 (P = 0.003) for surveillance and diagnostic combined. Although a multivariate Poisson regression suggested gender as a possibly significant factor, subset analysis showed that the difference between genders was not statistically significant. Age, bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC. Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm, respectively (P = NS).

CONCLUSION: TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup, but not in screening patients (ClinicalTrials.gov Identifier: NCT01044732).

Indigocarmine added to the water exchange method enhances adenoma detection - a RCT

PURPOSE

Chromoendoscopy with dye spray and the water method both increase adenoma detection.

HYPOTHESIS

Adding indigocarmine to the water method will enhance further the effectiveness of the latter in adenoma detection.

METHODS

Screening colonoscopy was performed with the water method (control) or with 0.008% indigocarmine added (study) by two endoscopists. Randomization was based on computer-generated codes contained in blocks of pre-arranged opaque sealed envelopes. High resolution colonoscopes were used. Upon insertion into the rectum, air was suctioned. With the air pump turned off, water was infused using a blunt needle adaptor connected to the scope channel and a foot pump to facilitate scope insertion until the cecum was reached. Residual stool causing cloudiness was suctioned followed by infusion of clear or colored water (water exchange) to facilitate scope passage with minimal distention of the colonic lumen. Upon seeing the appendix opening under water, water was suctioned and air was insufflated to facilitate inspection on scope withdrawal.

STATISTICS

Sample size calculation revealed 168 patients (84/group) needed to be randomized. Study was IRB-approved and registered (NCT01383265).

RESULTS

There were no significant differences in mean age, gender distribution, BMI, and family history of colon cancer. Cecal intubation success rate was 100% in both groups. The overall adenoma detection rate was 44% (water only) versus 62% (water with indigocarmine), respectively (p=0.03). One cancer was detected in each group.

CONCLUSION

In a RCT, indigocarmine at 0.008% concentration, added to the water method, significantly enhanced further the effectiveness of the latter in detecting adenomas.

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.

Benefit of "transparent soft-short-hood on the scope" for colonoscopy among experienced gastroenterologists and gastroenterologist trainee: a randomized, controlled trial

BACKGROUND

The attachment of a transparent hood to the colonoscope tip has been reported to offer some benefits, such as enabling the endoscopist to perform the colonoscopy more easily and to save time. However, there have been no randomized, controlled trials concerning these benefits, nor have any reports been published regarding the use of hoods for the purpose of training colonoscopists. Therefore, we conducted this study to evaluate the possible benefits of the transparent soft short hood when used by both experienced and trainee endoscopist groups.

METHODS

This randomized, controlled trial to assess the results of using a transparent soft short hood attached to the tip of the colonoscope was undertaken by two groups of investigators: experienced endoscopists and gastroenterologist trainees. The cecal and ileal intubation times, as well as the doses of sedative medication required, were analyzed.

RESULTS

A total of 112 patients, 65 of whom were female, underwent colonoscopy by 2 endoscopists and 5 gastroenterologist trainees. Colonoscopy was complete in 100% of the patients. The study showed significant shortening of the cecal intubation time when using the soft short hood, in both the endoscopist and gastroenterologist trainee groups (6.8/4.61 min, P = 0.006; and 9.36/7.36 min, P = 0.03). The ileal intubation time had a trend to be significantly less when using the transparent hood in the trainee group (126.4/52.9 s), although this was not statistically significant (P = 0.08). The average dose of propofol, when using the transparent hood, was significantly lower in the endoscopist group (180/120 mg, P = 0.001). No significant complications occurred in the hood or non-hood groups.

CONCLUSIONS

The transparent soft short hood shortened the cecal intubation time in both the experienced endoscopist and gastroenterologist trainee groups, as well as reducing the dose of sedative medication required in the experienced endoscopist group. Interestingly, it also reduced the trainee ileal intubation time. The attachment of this type of hood enabled both the experienced endoscopists and gastroenterological trainees to perform colonoscopy more quickly and easily, without any complications.

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.