Endoscopic innovations to increase the adenoma detection rate during colonoscopy

Effect of etomidate added to propofol target-controlled infusion in bidirectional endoscopy: A randomized clinical trial

BACKGROUND

Propofol has been widely used in bidirectional gastrointestinal endoscopy sedation; however, it frequently leads to cardiovascular adverse events and respiratory depression. Propofol target-controlled infusion (TCI) can provide safe sedation but may require higher dosages of propofol. On the contrary, etomidate offers hemodynamic stability.

AIM

To evaluate the effect of different dose etomidate added to propofol TCI sedation during same-visit bidirectional endoscopy.

METHODS

A total of 330 patients from Fujian Provincial Hospital were randomly divided into three groups: P, 0.1EP, and 0.15EP. Patients in the P group received propofol TCI only, with an initial effect-site concentration of the propofol TCI system of 3.0 mg/mL. Patients in the 0.1EP and 0.15EP groups received 0.1 and 0.15 mg/kg etomidate intravenous injection, respectively, followed by propofol TCI.

RESULTS

Patients in the 0.15EP group had higher mean blood pressure after induction than the other groups (P group: 78 mmHg, 0.1EP group: 82 mmHg, 0.15EP group: 88 mmHg; P < 0.05). Total doses of propofol consumption significantly decreased in the 0.15EP group compared with that in the other groups (P group: 260.6 mg, 0.1EP group: 228.1 mg, 0.15EP group: 201.2 mg; P < 0.05). The induction time was longer in the P group than in the other groups (P group: 1.9 ± 0.7 minutes, 0.1EP group: 1.2 ± 0.4 minutes, 0.15EP group: 1.1 ± 0.3 minutes; P < 0.01). The recovery time was shorter in the 0.15EP group than in the other groups (P group: 4.8 ± 2.1 minutes, 0.1EP group: 4.5 ± 1.6 minutes, 0.15EP group: 3.9 ± 1.4 minutes; P < 0.01). The incidence of hypotension (P group: 36.4%, 0.1EP group: 29.1%, 0.15EP group: 11.8%; P < 0.01) and injection pain was lower in the 0.15EP group than in the other groups (P < 0.05). Furthermore, the incidence of respiratory depression was lower in the 0.15EP group than in the P group (P < 0.05). Additionally, the satisfaction of the patient, endoscopist, and anesthesiologist was higher in the 0.15EP group than in the other groups (P < 0.05).

CONCLUSION

Our findings suggest that 0.15 mg/kg etomidate plus propofol TCI can significantly reduce propofol consumption, which is followed by fewer cardiovascular adverse events and respiratory depression, along with higher patient, endoscopist, and anesthesiologist satisfaction.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

The effect of position change and abdominal massage on anxiety, pain and distension after colonoscopy: A randomized clinical trial

CONTEXT

Pain, abdominal distention, and anxiety are major risk factors encountered after colonoscopy. Complementary and alternative treatments, such as abdominal massage and position change, are used to reduce the associated risk factors.

OBJECTIVE

To determine the effect of position change and abdominal massage on anxiety, pain, and distension after colonoscopy.

DESIGN

A randomized three-group experimental trial.

SETTING AND PARTICIPANTS

This study was conducted with 123 patients who underwent colonoscopy at the endoscopy unit of a hospital located in western Turkey.

METHODS

Three groups were formed: two interventional (abdominal massage and position change) and one control, each including 41 patients. Data were gathered using a personal information form, pre- and post-colonoscopy measurement form, the Visual Analog Scale (VAS), and the Spielberger State-Trait Anxiety Inventory. Pain and comfort levels, abdominal circumference values, and vital signs of the patients were measured at four evaluation times.

RESULTS

In the abdominal massage group, the VAS pain scores and abdominal circumference measurements decreased the most and the VAS comfort scores increased the most 15 min after the patients were taken to the recovery room (p<0.05). Furthermore, bowel sounds were heard, and bloating was relieved in all patients in both intervention groups 15 min after they were taken to the recovery room.

CONCLUSIONS

Abdominal massage and position change can be considered effective interventions for relieving bloating and facilitating flatulence after colonoscopy. Moreover, abdominal massage can be a powerful method for reducing pain and abdominal circumference and increasing patient comfort.

External validation and comparison of simple ultrasound activity score and international bowel ultrasound segmental activity score for Crohn's disease

BACKGROUND

Intestinal ultrasound (IUS) is a non-invasive tool for monitoring Crohn's disease (CD) activity. Recently, sonographic activity scores, including the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS) and Simple Ultrasound Activity Score for CD (SUS-CD), were developed. This study aimed to assess their clinical application value.

METHODS

This retrospective study enrolled patients with CD from March 2021 to June 2022. The diagnostic performance of the ultrasound scores was evaluated using the simplified endoscopic score for CD (SES-CD). Correlations of ultrasound scores with SES-CD, CD activity index (CDAI), and inflammatory biomarkers were assessed. Inter-rater reliability was compared.

RESULTS

In total, 140 patients were included. The IBUS-SAS for evaluating disease activity had an area under the curve (AUC) of 0.895, sensitivity of 85.4%, and specificity of 82.4% for the cut-off value of 48.7. The SUS-CD revealed an AUC of 0.835, sensitivity of 92.7%, and specificity of 64.7% for the cut-off value of 2.5. The IBUS-SAS and SUS-CD were positively correlated with SES-CD (r = 0.511 and 0.534, respectively). The scores correlated significantly with the CDAI and inflammatory biomarkers (all p < 0.01). The IBUS-SAS was more strongly correlated with CDAI (r = 0.666 vs 0.486) and C-reactive protein (r = 0.645 vs 0.434) than the SUS-CD. The intraclass correlation coefficient (ICC) of the IBUS-SAS and SUS-CD between the two sonologists was excellent (ICC = 0.96 and 0.78, respectively).

CONCLUSION

Both the IBUS-SAS and SUS-CD can evaluate disease activity in CD and exhibited a significant correlation with activity indices and inflammatory biomarkers.

CLINICAL TRIAL REGISTRATION

ChiCTR2200055221.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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.

Trial protocol for COLO-DETECT: A randomized controlled trial of lesion detection comparing colonoscopy assisted by the GI Genius™ artificial intelligence endoscopy module with standard colonoscopy

AIM

Colorectal cancer is the second commonest cause of cancer death worldwide. Colonoscopy plays a key role in the control of colorectal cancer and, in that regard, maximizing detection (and removal) of pre-cancerous adenomas at colonoscopy is imperative. GI Genius™ (Medtronic Ltd) is a computer-aided detection system that integrates with existing endoscopy systems and improves adenoma detection during colonoscopy. COLO-DETECT aims to assess the clinical and cost effectiveness of GI Genius™ in UK routine colonoscopy practice.

METHODS AND ANALYSIS

Participants will be recruited from patients attending for colonoscopy at National Health Service sites in England, for clinical symptoms, surveillance or within the national Bowel Cancer Screening Programme. Randomization will involve a 1:1 allocation ratio (GI Genius™-assisted colonoscopy:standard colonoscopy) and will be stratified by age category (<60 years, 60-<74 years, ≥74 years), sex, hospital site and indication for colonoscopy. Demographic data, procedural data, histology and post-procedure patient experience and quality of life will be recorded. COLO-DETECT is designed and powered to detect clinically meaningful differences in mean adenomas per procedure and adenoma detection rate between GI Genius™-assisted colonoscopy and standard colonoscopy groups. The study will close when 1828 participants have had a complete colonoscopy. An economic evaluation will be conducted from the perspective of the National Health Service. A patient and public representative is contributing to all stages of the trial. Registered at ClinicalTrials.gov (NCT04723758) and ISRCTN (10451355). WHAT WILL THIS TRIAL ADD TO THE LITERATURE?: COLO-DETECT will be the first multi-centre randomized controlled trial evaluating GI Genius™ in real world colonoscopy practice and will, uniquely, evaluate both clinical and cost effectiveness.

Oral IBGard™ Before Colonoscopy: A Single-Center Double-Blinded, Randomized, Placebo-Controlled Trial

BACKGROUND

Peppermint oil is well known to inhibit smooth muscle contractions, and its topical administration during colonoscopy is reported to reduce colonic spasms.

AIMS

We aimed to assess whether oral administration of IBGard™, a sustained-release peppermint oil formulation, before colonoscopy reduces spasms and improves adenoma detection rate (ADR).  METHODS: We performed a single-center randomized, double-blinded, placebo-controlled trial. Patients undergoing screening or surveillance colonoscopies were randomized to receive IBGard™ or placebo. The endoscopist graded spasms during insertion, inspection, and polypectomy. Bowel preparation, procedure time, and time of drug administration were documented. Statistical analysis was performed using the Student's t test and Wilcoxon rank-sum test.

RESULTS

There was no significant difference in baseline characteristics or dose-timing distribution between IBGard™ and placebo groups. Similarly, there was no difference in ADR (IBGard™ = 47.8%, placebo = 43.1%, p = 0.51), intubation spasm score (1.23 vs 1.2, p = 0.9), withdrawal spasm score (1.3 vs 1.23, p = 0.72), or polypectomy spasm score (0.52 vs 0.46, p = 0.69). Limiting the analysis to patients who received the drug more than 60 min prior to the start of the procedure did not produce any significant differences in these endpoints.

CONCLUSIONS

This randomized controlled trial failed to show benefit of orally administered IBGard™ prior to colonoscopy on the presence of colonic spasms or ADR. Because of its low barrier to widespread adoption, the use of appropriately formulated and timed oral peppermint oil warrants further study to determine its efficacy in reducing colonic spasms and improving colonoscopy quality.

Does self-reported symptom questionnaire play a role in nonadherence to colonoscopy for risk-increased population in the Tianjin colorectal cancer screening programme?

BACKGROUND

A colorectal cancer screening programme (CCSP) was implemented from 2012 to 2017 in Tianjin, China. Residents with a positive faecal immunochemical test (FIT) or positive self-reported symptom questionnaire (SRSQ) were recommended to undergo colonoscopy. The objective was to investigate the potential factors associated with nonadherence to colonoscopy among a risk-increased population.

METHODS

Data were obtained from the CCSP database, and 199,522 residents with positive FIT or positive SRSQ during two screening rounds (2012-2017) were included in the analysis. Logistic regression analysis was performed to assess the association between nonadherence to colonoscopy and potential predictors.

RESULTS

A total of 152,870 (76.6%) individuals did not undergo colonoscopy after positive FIT or positive SRSQ. Residents with positive SRSQ but without positive FIT were more likely not to undergo colonoscopy (negative FIT: OR, 2.35; 95% CI, 2.29-2.41, no FIT: OR, 1.27; 95% CI, 1.24-1.31). Patients without a cancer history were less likely to undergo colonoscopy even if they received risk-increased reports based on the SRSQ.

CONCLUSION

In the CCSP, seventy-seven percent of the risk-increased population did not undergo colonoscopy. FIT should be recommended since positive FIT results are related to improved adherence to colonoscopy. Residents with negative FIT but positive SRSQ should be informed of the potential cancer risk to ensure adherence to colonoscopy.

State of the Science on Quality Indicators for Colonoscopy and How to Achieve Them

Colonoscopy is a safe and effective tool, but operator dependent. Room for improvement in the quality of colonoscopy is the impetus for the development and measurement of colonoscopy quality indicators and the focus of many efforts to improve colonoscopy quality indicator prevention and control in provider practices and health systems. We present the preprocedural, intraprocedural, and postprocedural quality indicators and benchmarks for colonoscopy. Every provider and practice must make a commitment to performing high-quality colonoscopy and implement and monitor quality metrics. There are a variety of tools available to assist in improving quality indicators that range from distal attachment devices to education and feedback. Although technology can help, it is not a substitute for proper technique. The commitment also requires provider feedback through audits and report cards. The impact of these efforts on patient outcomes is an important area of further research.

Improving the quality of surveillance colonoscopy in inflammatory bowel disease

Several recommendations have addressed the topic of improving the quality of surveillance colonoscopy in inflammatory bowel disease. However, there is variation between these recommendations, in part due to the absence of well-defined quality indicators, suggesting that these quality indicators should be studied and developed. We did a systematic review of evidence related to surveillance colonoscopy in inflammatory bowel disease to look at the different variables in this practice and offer a critique of the quality control measures before, during, and after the procedure. We identified several key quality measures that could be adopted in clinical practice, including control of inflammation, optimal bowel preparation, ideal time allocation, training, sedation, detection and characterisation of lesions, therapeutic management of the lesions, and colonoscopic reports. However, further primary research and consensus reports are needed to continue developing roadmaps at a global level.

The propofol-sparing effect of intravenous lidocaine in elderly patients undergoing colonoscopy: a randomized, double-blinded, controlled study

Background

Propofol provides a prominent sedation effect in colonoscopy. However, anesthesia and sedation induced with propofol in the elderly might result in cardiopulmonary complications, especially when it is combined with opoids in the regimen. This study aimed to test the hypothesis that the addition of intravenous lidocaine to propofol-based sedation could decrease the overall propofol requirement in elderly patients during colonoscopy while the procedural sedation satisfaction and the hemodynamic stability were not compromised.

Methods

Ninety-two patients undergoing colonoscopy were randomly enrolled into lidocaine+propofol (L + P) group or normal saline+propofol (NS + P) groups. Subjects received intravenous bolus of 1.5 mg/kg lidocaine followed by 4 mg kg^− 1 h^− 1 lidocaine continuous infusion in L + P group or equivalent volumes of normal saline for boluses and infusion in NS + P group. Anesthesia was induced with 2.5 μg sufentanil followed by injection of 1.2 mg kg^− 1 propofol in all patients. A single supplemental bolus of 0.6 mg kg^− 1 propofol was administered whenever MOAA/S score > 1 or had body movement during the colonoscopy. The recorded primary endpoints included: the total amount of propofol administered during entire procedure, the supplemental amount of propofol after induction, and the frequencies of boluses of supplemental propofol.

Results

A total of 79 patients were included in the final analysis. Compared with NS + P group, the total amounts of propofol (induction plus supplemental) were no significant differences in L + P group; however, the required supplemental propofol was less (69.9 ± 39.2 mg vs. 51.5 ± 38.6 mg) (P = 0.039); the average frequencies of boluses of supplemental propofol given after induction were lower (2.1 ± 1.1 vs. 1.4 ± 0.9) (P = 0.003); the calculated “unit propofol” infusion rate was lower (0.18 ± 0.05 vs. 0.14 ± 0.04 mg kg^− 1 min^− 1) (P = 0.002).

Conclusions

The addition of intravenous lidocaine to propofol-based sedation resulted in a remarked reduction of supplemental propofol in the elderly during colonoscopy.

Trial registration

The present clinical trial was registered at http://www.chictr.org.cn on 11th March 2019 (registration No. ChiCTR1900021818).

Correlation between ultrasound consolidated score and simple endoscopic score for determining the activity of Crohn's disease

OBJECTIVES

The aim of this study was to develop an ultrasound consolidated score (UCS) in determining the activity of Crohn's disease (CD) and evaluate it with reference to simple endoscopic score (SES).

METHODS

From June 2014 to June 2017, 66 patients with CD were retrospectively enrolled in this study. Each patient underwent endoscopy and transabdominal ultrasound (US) examination. The morphological symmetry, echogenicity of bowel wall, bowel wall layer structure, echogenicity of peri-bowel fat, bowel wall thickness (BWT), and Limberg type on power Doppler US were assessed with transabdominal US, and an UCS scoring system was developed based on these characteristics. Endoscopic results were used as the reference standard and SES was calculated to determine the CD activity. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance for determining CD activity and the correlation between UCS and SES was assessed using Spearman correlation analysis.

RESULTS

330 intestinal segments in 66 patients were included. The UCS of the segments in the remission phase ranged from 3.0 to 9.0 (mean, 3.6 ± 0.9) whereas in the active phase from 3.0 to 20.0 (mean, 10.6 ± 4.0) (p < 0.001). The cut-off value of UCS was 6. The associated area under ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 0.980, 88.3%, 95.5%, 93.8%, 91.3%, and 92.3%, respectively. The correlation coefficient between UCS and SES was 0.90, which was higher than the correlation coefficient of 0.83 between BWT and SES.

CONCLUSIONS

The newly developed UCS with transabdominal US has a good performance and potentially provides an effective alternative for evaluating the activity of CD.

ADVANCES IN KNOWLEDGE

UCS is an effective method to evaluate the activity of CD because it provides comprehensive information of the disease. Therefore, it could be employed as an alternative for diagnosis of CD.

Impact of new techniques on adenoma detection rate based on meta-analysis data

The high incidence of colorectal cancer and the occurrence of interval cancers after screening colonoscopy support the need to develop methods to increase adenoma detection rate (ADR). This review focuses on the importance of ADR and the impact of new techniques on ADR based on meta-analysis data. The low-cost interventions (such as water-aided colonoscopy, second observation, and dynamic position change) were effective in increasing ADR. So were enhanced imaging techniques and add-on devices. Increase with higher cost interventions such as newer scopes is uncertain. Water exchange (WE) has the highest ADR compared with water immersion, air insufflation, and carbon dioxide insufflation. Second observation with forward or retroflexed views improved the right colon ADR. Add-on devices result in only modest improvement in ADR, of particular help in low performing endoscopists. The second-generation narrow-band imaging (NBI) provided a two-fold brighter image than the previous system. The improvement in ADR with NBI required the "best" quality bowel preparation. New endoscopic techniques incur various additional costs, nil for WE, small for tip attachments but large for the newer scopes. In conclusion, one or more of the above methods to improve ADR may be applicable in Taiwan. A comparison of these approaches to determine which is the most cost-effective is warranted.

Quantitative Analysis of Melanosis Coli Colonic Mucosa Using Textural Patterns

Melanosis coli (MC) is a disease related to long-term use of anthranoid laxative agents. Patients with clinical constipation or obesity are more likely to use these drugs for long periods. Moreover, patients with MC are more likely to develop polyps, particularly adenomatous polyps. Adenomatous polyps can transform to colorectal cancer. Recognizing multiple polyps from MC is challenging due to their heterogeneity. Therefore, this study proposed a quantitative assessment of MC colonic mucosa with texture patterns. In total, the MC colonoscopy images of 1092 person-times were included in this study. At the beginning, the correlations among carcinoembryonic antigens, polyp texture, and pathology were analyzed. Then, 181 patients with MC were extracted for further analysis while patients having unclear images were excluded. By gray-level co-occurrence matrix, texture patterns in the colorectal images were extracted. Pearson correlation analysis indicated five texture features were significantly correlated with pathological results (p < 0.001). This result should be used in the future to design an instant help software to help the physician. The information of colonoscopy and image analystic data can provide clinicians with suggestions for assessing patients with MC.

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.

Safety, Feasibility, and Efficacy of Pancolonic Retroflexed Viewing Using a Short-turn Radius Colonoscope

GOALS

The goal of this study was to evaluate the safety and feasibility of routine segmental retroflexed withdrawal viewing (RV) of the colon with the RetroView colonoscope.

MATERIALS AND METHODS

This was a prospective, single-center, 2-stage diagnostic trial. After cecal intubation, mucosal evaluation by forward viewing (FV) and RV was performed by segment (right, transverse, left, and sigmoid colon, and rectum). Lesions detected during FV were removed and/or marked before retroflexion. Safety and feasibility were measured through adverse event and technical success rates. All lesions detected and removed endoscopically were recorded.

RESULTS

Two hundred twenty-five patients underwent colonoscopy with the RetroView colonoscope. Retroflexion by segment was successful in the right, transverse, left, and sigmoid colon, and rectum in 98.9%, 100%, 100%, 82.6%, and 100% of cases, respectively. The mean total procedure time was 16.6 minutes. Ninety-four lesions were detected through retroflexion evaluation, for an increase in the lesions' detection rate of 30.7%. The per-adenoma miss rate of standard colonoscopy (FV) was 35.71%. The adenoma detection rate (ADR) for FV was 16%, whereas, when performing FV and RV, the ADR increased to 24.9%. Adverse events were recorded in 0.4% of cases. Therapeutic procedures were performed successfully through the retroflexed position in 81/225 patients.

CONCLUSIONS

Routine retroflexion evaluation of the colonic mucosa by segment using the RetroView colonoscope is safe and feasible. Retroflexion evaluation increases the detection rate of colonic lesions behind folds, including the number of adenomas per colonoscopy and ADR, offering a complete screening colonoscopy. All therapeutic procedures are feasible through retroflexion.

Impact of Electronic Chromoendoscopy on Adenoma Miss Rates During Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND

The impact of virtual chromoendoscopy such as narrow-band imaging, Fujinon intelligent chromoendoscopy, blue-light imaging, linked-color imaging, and i-SCAN on adenoma detection rate has been variable. However, adenoma miss rate (another measure suggested as a quality indicator) of electronic chromoendoscopy modalities has not been systematically evaluated.

OBJECTIVES

This study aimed to perform a systematic review and meta-analysis to examine the adenoma miss rate of white-light endoscopy compared with electronic chromoendoscopy.

DATA SOURCES

Medline, Embase, Scopus, Web of Knowledge, and Cochrane were the data sources for this study.

STUDY SELECTION

The studies selected were tandem randomized controlled trials of electronic chromoendoscopy modalities compared with white-light endoscopy.

INTERVENTIONS

Electronic chromoendoscopy compared with white light endoscopy was used to measure the adenoma miss rate.

MAIN OUTCOME MEASURES

Primary outcome was the pooled adenoma miss rate of electronic chromoendoscopy techniques compared with white-light endoscopy. Secondary outcomes were subgroup analysis, adenoma size analysis, and adenoma detection rate.

RESULTS

A total of 3507 patients were evaluated from 7 eligible tandem randomized control trials. A total of 1423 patients had white-light endoscopy as the first of the tandem examinations. The rest of the patients had electronic chromoendoscopy as the first of the tandem examination (narrow-band imaging, 988 patients; Fujinon intelligent chromoendoscopy, 728 patients; i-SCAN, 233 patients; blue-light imaging, 64 patients; and linked-color imaging, 71 patients). The pooled adenoma miss rate for electronic chromoendoscopy was not different than white-light endoscopy (17.9% vs 21%; OR, 0.72 (0.67-1.11); I 67%; p = 0.13). When only narrow-band imaging, blue-light imaging, and linked-color imaging were considered, the pooled rate was statistically significant (OR, 0.60 (0.37-0.98); p = 0.04). The pooled adenoma detection rate was not statistically different with electronic chromoendoscopy than white-light endoscopy (OR, 1.02 (0.88-1.19); p = 0.78).

LIMITATIONS

The small number of studies to assess the impact of each modality limited stratified conclusions.

CONCLUSIONS

Electronic chromoendoscopy is not associated with a significant reduction in adenoma miss rate compared with white-light colonoscopy.

Peppermint Oil to Improve Visualization in Screening Colonoscopy: A Randomized Controlled Clinical Trial

Background

Screening colonoscopy has been associated with reduced mortality from colorectal cancer by means of early detection and timely treatment. However, visualization during colonoscopy is often impaired since the colon is naturally prone to peristalsis and spasm. There is evidence to suggest benefit of topical peppermint oil in causing smooth muscle relaxation, thereby decreasing peristalsis. The aim of our study was to determine if peppermint oil helps reduce colonic spasticity so as to allow for better visualization during screening colonoscopy.

Methods

We performed a randomized controlled, double-blinded, clinical trial where patients undergoing screening colonoscopy were assigned to receive either peppermint oil or placebo. Once cecum was reached, 50 mL of either solution was directly injected via the working channel of the colonoscope. Colonic peristalsis, spasticity and bowel visibility were documented. Bowel preparation quality, withdrawal time and adenoma detection rate (ADR) were also assessed. Continuous variables were analyzed using t-test or Wilcoxon rank-sum test while categorical variables were compared using the two-way Chi-square test.

Results

Forty-eight patients were included, of whom 24 patients received peppermint oil and 24 received placebo. Mean Boston bowel preparation score (BBPS) was excellent for both groups (8 points vs. 7.9 points; P = 0.98). Both mean total colonoscopy time (17.8 min vs. 21.9 min; P = 0.07) and mean cecal intubation time (7.2 min vs. 10.3 min; P = 0.04) were shorter with peppermint oil as compared to placebo. Complete absence of bowel spasticity was observed among 58.3% patients in the peppermint oil group as compared to 45.8% patients in the placebo group (P = 0.05). More than 75% of bowel was visualized in 83% of patients in both groups (P = 0.56). Mean ADR was higher in the peppermint group as compared to the placebo group (45.8% vs. 37.5%; P = 0.56).

Conclusion

Our study suggests that topical peppermint oil reduces bowel wall spasticity, which could lead to better visualization of the bowel during screening colonoscopy. Although use of peppermint oil was associated with better ADRs, these results did not achieve statistical significance. Larger sample size and use of alternative methods of peppermint oil administration allowing for more absorption time may establish stronger results.

Tumor recognition of peanut agglutinin-immobilized fluorescent nanospheres in biopsied human tissues

We are investigating an imaging agent for early detection of colorectal cancer. The agent, named the nanobeacon, is coumarin 6-encapsulated polystyrene nanospheres whose surfaces are covered with poly(N-vinylacetamide) and peanut agglutinin that reduces non-specific interactions with the normal mucosa and exhibits high affinity for terminal sugars of the Thomsen-Friedenreich antigen, which is expressed cancer-specifically on the mucosa, respectively. We expect that cancer can be diagnosed by detecting illumination of intracolonically administered nanobeacon on the mucosal surface. In the present study, biopsied human tissues were used to evaluate the potential use of the nanobeacon in the clinic. Prior to the clinical study, diagnostic capabilities of the nanobeacon for detection of colorectal cancer were validated using 20 production batches whose characteristics were fine-tuned chemically for the purpose. Ex vivo imaging studies on 66 normal and 69 cancer tissues removed from the colons of normal and orthotopic mouse models of human colorectal cancer, respectively, demonstrated that the nanobeacon detected colorectal cancer with excellent capabilities whose rates of true and false positives were 91% and 5%, respectively. In the clinical study, normal and tumor tissues on the large intestinal mucosa were biopsied endoscopically from 11 patients with colorectal tumors. Histological evaluation revealed that 9 patients suffered from cancer and the rest had adenoma. Mean fluorescence intensities of tumor tissues treated with the nanobeacon were significantly higher than those of the corresponding normal tissues. Correlation of magnitude relation of the intensity in individuals was observed in cancer patients with a high probability (89%); however, the probability reduced to 50% in adenoma patients. There was a reasonable likelihood for diagnosis of colorectal cancer by the nanobeacon applied to the mucosa of the large intestine.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

NCT02552017, Results; ISRCTN11821044, Results.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

OBJECTIVES

Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

METHODS

We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

RESULTS

Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time.

CONCLUSIONS

The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Comparison of efficacy of colonoscopy between the morning and afternoon: A systematic review and meta-analysis

OBJECTIVE

Colonoscopy performed in the afternoon, rather than morning, has been reported to be associated with lower rates of adenoma and polyp detection (ADR and PDR) and cecal intubation (CIR). This meta-analysis evaluated the efficacy of afternoon colonoscopy relative to morning colonoscopy.

METHODS

The databases MEDLINE, Web of Science, EMBASE, and the Cochrane Library were searched to identify potential relevant studies. The primary outcome was ADR and the secondary outcomes were CIR and PDR. The outcomes were estimated by relative risk (RR) and 95% confidence interval (CI) with a random effects model.

RESULTS

Sixteen studies with 38,063 participants met the inclusion criteria. The pooled analyses indicated that ADR (RR: 1.08, 95% CI: 1.00-1.17) and CIR (RR: 1.01, 95% CI: 1.00-1.02) were stable during the whole day. In subgroup analyses, the effect of full-day block or inferior bowel preparation were more prominent, reflected by a significant reduction of ADR (RR: 1.18, 95% CI: 1.09-1.28; RR: 1.12, 95% CI: 1.01-1.24) and CIR (RR: 1.08, 95% CI: 1.02-1.13; RR: 1.02, 95% CI: 1.01-1.03) in the afternoon, respectively.

CONCLUSIONS

Colonoscopy quality, as indicated by the ADR and CIR, is not affected by the time of day for procedures performed in block shifts. However, endoscopists' working full-day blocks and inferior bowel preparation are associated with a significant decrease in ADR and CIR in the afternoon.

Perspectives, potentials and trends of ex vivo and in vivo optical molecular pathology

It is pivotal for medical applications, such as noninvasive histopathologic characterization of tissue, to realize label-free and molecule-specific representation of morphologic and biochemical composition in real-time with subcellular spatial resolution. This unmet clinical need requires new approaches for rapid and reliable real-time assessment of pathologies to complement established diagnostic tools. Photonic imaging combined with digitalization offers the potential to provide the clinician the requested information both under in vivo and ex vivo conditions. This report summarizes photonic approaches and their use in combination with image processing, machine learning and augmented virtual reality that might solve current challenges in modern medicine. Details are given for pathology, intraoperative diagnosis in head and neck cancer and endoscopic diagnosis in gastroenterology.

The Effect of Right Colon Retroflexion on Adenoma Detection: A Systematic Review and Meta-analysis

BACKGROUND

Although colonoscopy with polypectomy can prevent up to 80% of colorectal cancers, a significant adenoma miss rate still exists, particularly in the right colon. Previous studies addressing right colon retroflexion have revealed discordant evidence regarding the benefit of this maneuver on adenoma detection with concomitant concerns about safety and rates of maneuver success. In this meta-analysis, we sought to determine the effect of right colon retroflexion on improving adenoma detection compared with conventional colonoscopy without retroflexion, as well as determine the rates of retroflexion maneuver success and adverse events.

METHODS

Multiple databases including MEDLINE, Embase, and Web of Science were searched for studies on right colon retroflexion and its impact on adenoma detection compared with conventional colonoscopy. Pooled analyses of adenoma detection and retroflexion success were based on mixed-effects and random-effects models with heterogeneity analyses.

RESULTS

Eight studies met the inclusion criteria (N=3660). The primary analysis comparing colonoscopy with right-sided retroflexion versus conventional colonoscopy to determine the per-adenoma miss rate in the right colon was 16.9% (95% confidence interval, 12.5%-22.5%). The overall rate of successful retroflexion was 91.9% (95% confidence interval, 86%-95%) and rate of adverse events was 0.03%.

CONCLUSIONS

Colonoscopy with right-sided retroflexion significantly increases the detection of adenomas in the right colon compared with conventional colonoscopy with a high rate of maneuver success and small risk of adverse events. Thus, reexamination of the right colon in retroflexed view should be strongly considered in future standard of care colonoscopy guidelines for quality improvement in colon cancer prevention.

Missed adenomas with behind-folds visualizing colonoscopy technologies compared with standard colonoscopy: a pooled analysis of 3 randomized back-to-back tandem colonoscopy studies

BACKGROUND AND AIMS

The Third Eye Retroscope, Full Spectrum Endoscope (FUSE), and EndoRings devices have been shown to reduce overall adenoma miss rates. We evaluated the characteristics of adenomas and patient subgroups for which these behind-folds visualizing technologies mostly reduce adenoma miss rates.

METHODS

Data of 3 multicenter randomized trials (NCT01044732, NCT01549535, NCT01955122) were combined. Patients underwent same-day, back-to-back tandem examinations with standard colonoscopy and Third Eye Retroscope, FUSE, or EndoRings colonoscopy, respectively. Adenoma miss rates were stratified by adenoma characteristics and patient subgroups.

RESULTS

A total of 650 patients (60% male, mean age 57.5 years, standard deviation 9.7 years) were included; 330 patients underwent behind-folds visualizing colonoscopy first, and 320 patients underwent standard colonoscopy first. Regarding adenoma characteristics, adenoma miss rates were significantly (P < .001) lower with behind-folds visualizing technologies compared with standard colonoscopy for proximal (14% vs 38%) and distal (15% vs 35%), ≤5 mm (17% vs 38%), 6 to 9 mm (8% vs 44%), sessile (16% vs 37%), flat (9% vs 52%; P = .014), and tubular (15% vs 38%) adenomas and sessile serrated polyps (7% vs 50%; P = .039) but were not statistically significantly (P > .05) different for ≥10 mm, pedunculated, (tubulo-)villous, and advanced adenomas. Regarding patient subgroups, adenoma miss rates were significantly (P ≤ .020) lower with behind-folds visualizing technologies for patients ≥50 years, both sexes, and all indications.

CONCLUSIONS

Behind-folds visualizing colonoscopy reduces miss rates for 1 to 9 mm adenomas in the entire colon, whereas no advantage was found for ≥10 mm and advanced adenomas. Whether increased detection and removal of <10 mm adenomas also reduces colorectal cancer incidence and mortality remains to be determined. Future research is needed to determine which colonoscopy technology would be most beneficial for which patient or endoscopist.

Endocuff assisted colonoscopy significantly increases sessile serrated adenoma detection in veterans

BACKGROUND

Colorectal cancer (CRC) is the second most common cause of cancer related deaths in the United States. Colonoscopy is the gold standard for the detection of CRC. There are many colonoscopy quality measures and among these the adenoma detection rate (ADR) has demonstrated a significant impact in reducing mortality from CRC. The primary aim of our study was to compare ADR and distribution of polyp type in patients undergoing Endocuff-assisted colonoscopy (EAC) versus standard colonoscopy (SC) in a VA system.

METHODS

Retrospective data was collected from 496 patients who underwent routine screening, surveillance and diagnostic colonoscopies either via SC from January 6, 2014 through March 12, 2014 or EAC from September 24, 2014 through February 19, 2015. A total of 54 patients were excluded based on a personal history of CRC and prior resection, incomplete colonoscopy due to poor bowel preparation, and removal or loss of Endocuff (EC). Primary outcomes measured and compared were ADR and types of polyps found.

RESULTS

The overall ADR in the EAC group was higher at 59.91% versus 50.66% for SC, accounting for a 9% increase (P=0.0508). EAC was able to detect a total of 59 sessile serrated adenoma/polyps (SSA/Ps) compared to SC only detecting 8 (P≤0.0001). There was a significant increase in the SSA/P detection rate with EAC at 15% versus 3% in the SC group (P≤0.0001).

CONCLUSIONS

EAC significantly increases the detection of SSA/P and has shown a trend in improving ADR in our veteran population.

Risk factors of missed colorectal lesions after colonoscopy

Several studies have reported a significant rate of missed colorectal polyps during colonoscopy. This study aimed to determine the variables that affect the miss rate of colorectal polyps.We performed a retrospective observational study of patients who, between January 2007 and December 2014, had undergone a second colonoscopy within 6 months of their first. In all patients, the first colonoscopy constituted a screening or surveillance colonoscopy as part of a health check-up, and the patients were referred to the endoscopic clinic if there were meaningful polyps. The miss rate of colorectal polyps was evaluated, as were the variables related to these missed lesions.Among 659 patients (535 men), the miss rate of colorectal polyps was 17.24% (372/2158 polyps), and 38.69% of patients (255/659 patients) had at least 1 missed polyp. The most common site for missed polyps was the ascending colon (29.8%), followed by the sigmoid colon (27.8%). The miss rate of polyps was higher in men [odds ratio (OR) = 1.611, 95% confidence interval (95% CI) = 1.024-2.536], patients with multiple polyps at their first colonoscopy (OR = 1.463, 95% CI = 0.992-2.157), and patients who had a history of polyps (OR = 23.783, 95% CI = 3.079-183.694). Multiple missed polyps were more frequently located in the right colon (OR = 2.605, 95% CI = 1.458-4.657), and the risk of sessile serrated adenoma/polyp was greater in the right colon (OR = 10.418, 95% CI = 2.073-52.353).Endoscopists should pay careful attention in patients who have multiple polyps and in those who have a history of polyps, because such patients are at a high risk of missed polyps in colonoscopy.

Enhanced flat adenoma detection rate with high definition colonoscopy plus i-scan for average-risk colorectal cancer screening

BACKGROUND AND AIM

The usefulness of high definition colonoscopy plus i-scan (HD+i-SCAN) for average-risk colorectal cancer screening has not been fully assessed. The detection rate of adenomas and other measurements such as the number of adenomas per colonoscopy and the flat adenoma detection rate have been recognized as markers of colonoscopy quality. The aim of the present study was to compare the diagnostic performance of an HD+i-SCAN with that of standard resolution white-light colonoscope.

METHODS

This is a retrospective analysis of a prospectively collected screening colonoscopy database. A comparative analysis of the diagnostic yield of an HD+i-SCAN or standard resolution colonoscopy for average-risk colorectal screening was conducted.

RESULTS

During the period of study, 155/163 (95.1%) patients met the inclusion criteria. The mean age was 56.9 years. Sixty of 155 (39%) colonoscopies were performed using a HD+i-SCAN. Adenoma-detection-rates during the withdrawal of the standard resolution versus HD+i-SCAN colonoscopies were 29.5% and 30% (p = n.s.). Adenoma/colonoscopy values for standard resolution versus HD+i-SCAN colonoscopies were 0.46 (SD = 0.9) and 0.72 (SD = 1.3) (p = n.s.). A greater number of flat adenomas were detected in the HD+i-SCAN group (6/60 versus 2/95) (p < .05). Likewise, serrated adenomas/polyps per colonoscopy were also higher in the HD+i-SCAN group.

CONCLUSIONS

A HD+i-SCAN colonoscopy increases the flat adenoma detection rate and serrated adenomas/polyps per colonoscopy compared to a standard colonoscopy in average-risk screening population. HD+i-SCAN is a simple, available procedure that can be helpful, even for experienced providers. The performance of HD+i-SCAN and substantial prevalence of flat lesions in our average-risk screening cohort support its usefulness in improving the efficacy of screening colonoscopies.

Colonoscopy: Advanced and Emerging Techniques-A Review of Colonoscopic Approaches to Colorectal Conditions

A complete colonoscopy is key in the diagnostic and therapeutic approaches to a variety of colorectal diseases. Major challenges are incomplete polyp removal and missed polyps, particularly in the setting of a difficult colonoscopy. There are a variety of both well-established and newer techniques that have been developed to optimize polyp detection, perform complete polypectomy, and endoscopically treat various complications and conditions such as strictures and perforations. The objective of this article is to familiarize the colorectal surgeon with techniques utilized by advanced endoscopists.

Strategies to Increase Adenoma Detection Rates

OPINION STATEMENT

The adenoma detection rate (ADR), i.e., the proportion of average risk patients with at least one adenoma detected during screening colonoscopy, is inversely associated with the development of interval colorectal cancer. Increasing the ADR is therefore an important proxy for increase in quality and efficacy of (screening) colonoscopy. Several potentially modifiable factors, such as, procedural and technological factors, and quality improvement programs, and their effect on the ADR will be reviewed. Procedural factors, such as, bowel preparation, withdrawal time, and position changes of the patient are associated with the ADR. While the relation of others, such as inspection during insertion, use of antispasmodic agents, and second inspection in the proximal colon, with the ADR is not completely clear. Many new colonoscopy technologies have been evaluated over recent years and are still under evaluation, but no unequivocal positive effect on the ADR has been observed in randomized trials that have mostly been performed by experienced endoscopists with high baseline ADRs. Several quality improvement programs have been evaluated and seem to have a positive effect on endoscopists' ADR. Increase in ADR is important for the protective benefit of colonoscopy. There are now extensive methods to measure, benchmark, and improve ADR but increased awareness of these is critical. We have provided an overview of potential factors that can be used to increase personal ADRs in every day practice.

[Additional polyp detection rate using colonoscopic retroflexion in right colon]

BACKGROUND/AIMS

There have been several studies showing that retroflexion (RF) in the right colon (RC) could reduce the polyp miss rate of proximal colon during colonoscopy. This study was conducted to evaluate the additional benefit of RF technique in the RC.

METHODS

Patients who underwent colonoscopy from May 2008 to April 2011 were enrolled in the study. Data were obtained by retrospectively reviewing the medical records. RF was attempted in every patients undergoing colonoscopy since May 2008 except in cases of small RC vault, co-morbidity, severe diverticulosis, failed RF despite two trials, complaints of severe abdominal pain, or time burden. At first, RC was examined under direct vision. It was then examined by RF to detect missed polyps during the initial observation. Finally, the RC was re-examined with direct view.

RESULTS

The cumulative RF success rate in the RC was 78.84% (1,805 of 2,319). The RF success rate increased with the number of cases (50% at 160 cases, 70% at 400 cases, and reached near 90% over 1,000 cases). Few polyps (4.88%) were detected only with RF and the additional adenoma detection rate was 3.32%. The additional polyp/adenoma detection rates were higher in the old age group (p<0.01). There were no RF associated perforation or severe complication.

CONCLUSIONS

Using RF examination, additional 4.88% of polyps could be detected in the RC. This technique could be a useful and safe method to detect hidden polyp during colonoscopy.

Measuring gaze patterns during colonoscopy: a useful tool to evaluate colon inspection?

BACKGROUND AND OBJECTIVE

Considerable variation in adenoma detection has been shown between endoscopists, which may be explained by differences in colon inspection. Eye-tracking technology is an objective tool that detects differences in viewing patterns. We investigated the feasibility of eye-tracking technology during real-time, self-performed colonoscopies.

METHODS

In this pilot study, 10 endoscopists performed two colonoscopies each. A mobile eye-tracking system to register the right eye position was used to determine the gaze across four areas of interest of the endoscopy monitor (upper, lower, left, and right quadrant). The measured gaze across the endoscopy monitor was correlated with the gaze across the endoscopically visualized colonic surface.

RESULTS

Gaze patterns were measured successfully in 18 of 20 procedures. Significant differences in the time spent per area of interest were observed between endoscopists. The measured total gaze time per area of interest correlated strongly with the time spent on the corresponding area of the colonic surface (Pearson correlation coefficients ranging between 0.91 and 0.97). Endoscopists with more years of colonoscopy experience showed significantly higher percentages of overlap between the measured gaze position in the different areas of interest and the actual inspected area of the colonic surface (r=0.65, P=0.02). More experienced endoscopists had nonsignificantly longer mean gaze times per area of interest (r=0.52, P=0.06).

CONCLUSION

Eye-tracking technology to measure gaze patterns of endoscopists during real-time, self-performed colonoscopies is feasible and may be used to evaluate and compare viewing behavior across the colonic surface of experienced endoscopists.

Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Background/Aims

The efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.

Methods

Among patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.

Results

Overall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.

Conclusions

Cautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy.

What Can We Do to Optimize Colonoscopy and How Effective Can We Be?

In the USA, colorectal cancer is the third most common cancer and third leading cause of cancer death among both men and women. Declining rates of colon cancer in the past decade have been attributed in part to screening and removal of precancerous polyps via colonoscopy. Recent emphasis has been placed on measures to increase the quality and effectiveness of colonoscopy. These have been divided into pre-procedure quality metrics (bowel preparation), procedural quality metrics (cecal intubation, withdrawal time, and adenoma detection rate), post-procedure metrics (surveillance interval), and other quality metrics (patient satisfaction and willingness to repeat the procedure). The purpose of this article is to review the data and controversies surrounding each of these and identify ways to optimize the performance of colonoscopy.

Procedure Delays and Time of Day Are Not Associated With Reductions in Quality of Screening Colonoscopies

BACKGROUND & AIMS

There have been conflicting results from studies to determine whether factors unrelated to endoscopist skill, such as fatigue, affect the quality of screening colonoscopy. We studied the effects of human and system factors on screening colonoscopy withdrawal time and likelihood of detecting an adenoma in a large cohort of patients.

METHODS

We performed a retrospective analysis of operation and quality improvement data in colonoscopies performed at single academic medical center from November 2012 through February 2014. We collected data from the Northwestern Medicine Enterprise Data Warehouse on endoscopy procedure reports, patient demographics, and pathology reports of all patients undergoing endoscopy. We identified all screening colonoscopies during the study period and determined whether an adenoma was identified in each screening colonoscopy procedure. Our study included data from 7004 screening colonoscopies of patients 50-75 years old performed by endoscopists who performed at least 100 screening colonoscopies during the study period (n = 18).

RESULTS

Approximately 27% of procedures began on time; the median colonoscope insertion time was 5.9 minutes (interquartile range, 4.0-8.6). In multivariable logistic regression analysis adjusting for covariates and endoscopist-level clustering, adenoma detection was not associated with procedure delay (P = .48), hour of day (P = .40), or performing the second of 2 colonoscopy blocks in 1 day (P = .88). Adenoma detection was associated with insertion time overall (P = .006), but there was no consistent directional relationship across insertion quintiles.

CONCLUSIONS

Procedure delays and measured factors associated with fatigue, including time of day and multiple procedure blocks, do not reduce the odds of detecting an adenoma. Adenoma detection varies widely among providers, so efforts to improve adenoma detection should focus mainly on optimizing physician skill.

Effective colonoscopy training techniques: strategies to improve patient outcomes

Colonoscopy has substantially evolved during the last 20 years and many different training techniques have been developed in order to improve the performance of endoscopists. The most known are mechanical simulators, virtual reality simulators, computer-simulating endoscopy, magnetic endoscopic imaging, and composite and explanted animal organ simulators. Current literature generally indicates that the use of simulators improves performance of endoscopists and enhances safety of patients, especially during the initial phase of training. Moreover, newer endoscopes and imaging techniques such as high-definition colonoscopes, chromocolonoscopy with dyes spraying, and third-eye retroscope have been incorporated in everyday practice, offering better visualization of the colon and detection of polyps. Despite the abundance of these different technological features, training devices are not widely used and no official guideline or specified training algorithm or technique for lower gastrointestinal endoscopy has been evolved. In this review, we present the most important training methods currently available and evaluate these using existing literature. We also try to propose a training algorithm for novice endoscopists.

Magnitude of Missed Esophageal Adenocarcinoma After Barrett's Esophagus Diagnosis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

A proportion of patients with Barrett's esophagus (BE) are diagnosed with esophageal adenocarcinoma (EAC) within 1 year of an endoscopic examination that produced negative findings. These cases of missed cancers have not been well studied, despite current surveillance strategies for BE. We performed a systematic review and meta-analysis to determine the magnitude of missed EAC in cohorts of patients with BE.

METHODS

We searched MEDLINE, EMBASE, and Web of Science from their inception to May 31, 2015 to identify cohort studies of adults with BE (baseline nondysplastic BE ± BE with low-grade dysplasia) and at least a 3-year follow-up period, providing data on missed and incident EACs (diagnosed within 1 year and diagnosed more than 1 year after the initial endoscopy in which BE was diagnosed, respectively). The main outcome measure was pooled proportion of missed and incident EACs (of all EACs detected after initial endoscopy) among BE cohorts, using a random effects model.

RESULTS

In a meta-analysis of 24 studies reporting on 820 missed and incident EACs, 25.3% were classified as missed (95% confidence interval: 16.4%-36.8%) and 74.7% as incident EACs (95% CI: 63.2%-83.6%), although there was substantial heterogeneity among studies (I2 = 74%). When the analysis was restricted to nondysplastic BE cohorts (15 studies), 23.9% of EACs were classified as missed (95% confidence interval: 15.3%-35.4%; I2 = 0%). In a meta-analysis of 10 studies with follow-up periods of ≥5 years (a total of 239 EACs), 22.0% were classified as missed (95% confidence interval: 8.7%-45.5%), with substantial heterogeneity (I2 = 68%).

CONCLUSIONS

Among adults with nondysplastic BE (or BE with low-grade dysplasia) at their index endoscopy and at least a 3-year follow-up period, 25% of EACs are diagnosed within 1 year after the index endoscopy. Additional resources should be allocated to detect missed EAC.

Cap-assisted retrograde single-balloon enteroscopy results in high terminal ileal intubation rate

BACKGROUND AND STUDY AIMS

Retrograde single-balloon enteroscopy (RSBE) facilitates evaluation of the distal small bowel and provision of appropriate therapy when necessary. Intubation of the terminal ileum (TI) is a major rate-limiting step, with failure rates as high as 30 %. Cap-assisted endoscopy has proven beneficial in other aspects of endoscopy. We have noticed that it similarly aids in TI intubation during RSBE by facilitating opening of the ileocecal valve (ICV). The primary aim of this study was to measure the TI intubation rate using cap-assisted RSBE. Other procedural details and outcomes were also measured.

PATIENTS AND METHODS

A total of 36 consecutive RSBEs performed between July 2011 and May 2014 at the Medical University of South Carolina were retrospectively reviewed. All procedures were performed or supervised by our center's small bowel endoscopist (ASB). Outcomes measured included TI intubation rate, procedure time, depth of maximal insertion (DMI), diagnostic yield (DY), therapeutic yield (TY), and complications.

RESULTS

The TI intubation rate was 97 % (35 /36). The one failure was due to stool completely obscuring the cecum. Median procedure time was 54 minutes, with a mean DMI of 68 cm beyond the ICV. The technical success rate was 86 %, whereas DY and TY were 61 % and 25 %, respectively. There were no complications. The study was limited in that it involved a single endoscopist at a single center.

CONCLUSIONS

Cap-assisted RSBE results in a high TI intubation rate, without compromise to safety or procedural yield.

Usefulness of oil lubrication during colonoscopy: A comparative study with the conventional technique

BACKGROUND

The different forms of lubrication are among the most simple, accessible, and economic techniques that have been implemented for improving the diagnostic performance of colonoscopy.

AIM

To determine whether the use of oil improved the number of complete colonoscopies, facilitated the procedure, reduced pain, or improved the study's diagnostic performance, compared with the conventional lubrication technique.

PATIENTS AND METHODS

One hundred and seventy-five patients referred for colonoscopy were alternately allocated to receive treatment with the standard lubrication method with chlorhexidine gel (group 1) or lubrication with corn oil administered through the working channel (group II). The number of complete colonoscopies, the length of time needed to reach the cecum, the degree of difficulty estimated by the endoscopist and the assistant, the level of pain at the end of the study estimated by the patient, and the endoscopic findings were all determined.

RESULTS

Eighty-eight patients made up group I and 87 made up group II. No statistically significant differences were found between the two groups in relation to general characteristics, the number of complete colonoscopies (93 vs. 97%, respectively), the time needed to reach the cecum (8:00 vs. 8:41min, respectively), the level of pain at the end of the study, or the detection of polyps. The degree of difficulty was slightly lower in group II, but with no statistical significance.

CONCLUSIONS

Lubrication with oil during colonoscopy did not improve the number of complete colonoscopies, did not facilitate the study, nor did it reduce pain or increase the diagnostic performance of the study, when compared with the conventional technique.