Water infusion versus air insufflation for colonoscopy

Delivering a high-quality colonoscopy service fit for the 21st century

Colorectal cancer (CRC) is the third most prevalent cancer globally. There is a concerning increase in its incidence among younger individuals. Colonoscopy remains the gold standard for CRC diagnosis. With the introduction of population-based bowel screening and increased public awareness, there has been a significant rise in referrals for colonoscopy. Healthcare providers worldwide will need to strategically evaluate how to allocate resources to adequately train the next generation of colonoscopists who will need to provide accurate endoscopic assessment and treatment for premalignant polyps and early CRC. This review outlines the current workload challenges faced by colonoscopists whilst exploring emerging technologies such as artificial intelligence for adenoma detection. Additionally, advanced endoscopic surgical techniques like endoscopic submucosal dissection are discussed.

Effectiveness of Water-Assisted Colonoscopy without Sedation in Patients with Ulcerative Colitis

BACKGROUND

Studies have found that water-assisted colonoscopy (WAC) including water immersion colonoscopy (WIC) and water exchange colonoscopy (WEC) is superior to air insufflation colonoscopy (AIC) in terms of the cecal intubation rate. However, the application of WAC in ulcerative colitis (UC) has rarely been reported. This study aimed to explore the effectiveness of WAC without sedation in patients with UC.

METHODS

One hundred and seventy-two UC patients were randomly divided into the AIC group (n = 56), WIC group (n = 58), and WEC group (n = 58). The cecal intubation rate, abdominal pain score, operator difficulty, bowel cleanliness, insertion, and total time were compared.

RESULTS

The cecal intubation rate was higher in the WIC (91.4% vs. 75.0%; mean difference = 16.4%; 95% CI: 3.0-29.8%) and WEC (93.1% vs. 75.0%; mean difference = 18.1%; 95% CI: 5.0-31.2%) compared to the AIC group, while there was no difference between the WIC and WEC groups. The abdominal pain score and operator difficulty were lower in the WIC and WEC groups than in the AIC group, while there was no difference between the WIC and WEC groups. The bowel cleanliness during withdrawal was higher in the WIC and WEC groups than in the AIC group, while the WEC was superior to WIC. Compared with the AIC and WIC groups, the insertion time and total time were longer in the WEC group, and there was no difference in the AIC group and WIC group.

CONCLUSION

In comparison with AIC, WAC can increase the cecal intubation rate, reduce abdominal pain scores and improve bowel cleanliness in patients with UC.

JAG consensus statements for training and certification in colonoscopy

Introduction

In the UK, endoscopy certification is awarded when trainees attain minimum competency standards for independent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for colonoscopy training and certification.

Methods

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted between 2019 and 2020 with multisociety expert representation. Following literature review and Grading of Recommendations, Assessment, Development and Evaluations appraisal, recommendation statements on colonoscopy training and certification were formulated and subjected to anonymous voting to obtain consensus. Accepted statements were peer reviewed by JAG and relevant stakeholders for incorporation into the updated colonoscopy certification pathway.

Results

In total, 45 recommendation statements were generated under the domains of: definition of competence (13), acquisition of competence (20), assessment of competence (8) and postcertification support (4). The consensus process led to revised criteria for colonoscopy certification, comprising: (1) achieving key performance indicators defined within British Society of Gastroenterology standards (ie, unassisted caecal intubation rate >90%, rectal retroversion >90%, polyp detection rate >15%+, polyp retrieval rate >90%, patient comfort <10% with moderate–severe discomfort); (2) minimum procedure count 280+; (3) performing 15+ procedures over the preceding 3 months; (4) attendance of the JAG Basic Skills in Colonoscopy course; (5) terminal ileal intubation rates of 60%+ in inflammatory bowel disease; (6) satisfying requirements for formative direct observation of procedure skills (DOPS) and direct observation of polypectomy skills (Size, Morphology, Site, Access (SMSA) level 2); (7) evidence of reflective practice as documented on the JAG Endoscopy Training System reflection tool; (8) successful performance in summative DOPS.

Conclusion

The UK standards for training and certification in colonoscopy have been updated, culminating in a single-stage certification process with emphasis on polypectomy competency (SMSA Level 2+). These standards are intended to support training, improve standards of colonoscopy and polypectomy, and provide support to the newly independent practitioner.

Impact of an Abdominal Compression Bandage on the Completion of Colonoscopy for Obese Adults: A Prospective Randomized Controlled Trial

METHODS

Eligible patients were randomly allocated into the abdominal bandage and conventional groups during a routine colonoscopy. The primary outcome was CCR.

RESULTS

A total of 250 eligible patients were randomly assigned to the abdominal bandage and conventional groups from January 2021 to April 2021. Eleven patients (five in the abdominal bandage group and six in the conventional group) were excluded due to schedule cancellation after randomization, and 239 patients were eventually included in the final analysis. There were no significant differences between the two groups regarding baseline characteristics (P > 0.05). Furthermore, no significant differences were observed in terms of advanced adenoma detection rate (AADR), polyp detection rate (PDR), bowel preparation scale (BBPS), bubble scale (BS), and withdrawal time between the two groups (P > 0.05). However, compared with the conventional group, the cecal insertion time (CIT) of the abdominal bandage group was significantly shortened (279.00 (234.50-305.75) vs. 421.00 (327.00-485.00), P < 0.001), and the CCR (96.7% vs. 88.2%, P = 0.01) and adenoma detection rate (ADR) (47.5% vs. 32.8%, P < 0.001) were improved. Besides, logistic regression analysis showed that body mass index (BMI) and abdominal compression bandage were associated with CCR.

CONCLUSIONS

Abdominal compression bandages could effectively shorten CIT and improve CCR and ADR for obese patients during a routine colonoscopy. This trial is registered with the Chinese Clinical Trial Registry (No. ChiCTR2100043556).

Colonoscopy skills improvement training improves patient comfort during colonoscopy

INTRODUCTION

We aimed to assess the effect of Colonoscopy Skills Improvement (CSI) training on patient comfort and sedation-related complications during colonoscopy.

METHODS

This retrospective cohort study was performed on 19 endoscopists practicing in a Canadian tertiary care center who completed CSI training between October 2014 and May 2016. Data from 50 procedures immediately prior to, immediately after, and eight months following CSI training were included for each endoscopist. The primary outcome variable was intraprocedural comfort, and secondary outcomes included intraprocedural hypotension and hypoxia. Data were extracted from an electronic medical record and analyzed using SPSS version 20.0. Univariate analysis and stepwise multivariable logistic regression were performed to determine if there was an association between patient comfort and CSI training. Predictors of these outcomes including patient age, gender, sedation use and dosing, procedure completion, quality of bowel preparation, endoscopist experience, and specialty were included in the analysis.

RESULTS

2533 colonoscopies were included in the study. The mean dose of sedatives was reduced immediately following CSI training and at 8 months for both Fentanyl (75.4 mcg v. 67.8 mcg v. 65.9 mcg, p < 0.001) and Midazolam (2.57 mg v. 2.27 mg v. 2.19 mg, p < 0.001). The percentage of patients deemed to have a comfortable exam improved following endoscopist participation in CSI training and remained improved at 8 months (55.1% v. 70.2% v. 69.8%, p < 0.001). No significant change in rates of intraprocedural hypoxia or hypotension were noted following CSI training.

CONCLUSION

CSI training is associated with improved patient comfort and reduced sedation requirements during colonoscopy.

Screening colonoscopy: The present and the future

In the United States, colorectal cancer (CRC) is the second leading cause of mortality in men and women. We are now seeing an increasing number of patients with advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age, which requires earlier screening. With the increasing need for CRC screening through colonoscopy, and thus endoscopists, easier and simpler techniques are needed to train proficient endoscopists. The most widely used approach by endoscopists is air insufflation colonoscopy, where air distends the colon to allow visualization of the colonic mucosa. This technique is un-comfortable for patients and requires an anesthetist to administer sedation. In addition, patients commonly complain about discomfort post-op as air escapes into the small bowel and cannot be adequately removed. Current research into the use of water insufflation colonoscopies has proved promising in reducing the need for sedation, decreasing discomfort, and increasing the visibility of the colonic mucosa. Future direction into water insufflation colonoscopies which have shown to be simpler and easier to teach may increase the number of proficient endoscopists in training to serve our aging population.

Efficacy and safety of the starting position during colonoscopy: a systematic review and meta-analysis

Background and study aims  We aimed to assess the efficacy and safety of the starting position during colonoscopy. Patients and methods  We searched CENTRAL, MEDLINE, EMBASE, and the WHO International Clinical Trials Registry Platform through February 2019 to identify studies reporting the comparison between the right/supine/prone/tilt-down and left lateral starting position during colonoscopy. The primary outcomes were mean cecal insertion time and adverse events requiring medication. Two reviewers performed study selection and risk of bias assessment. We determined the quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation method. This study was registered in PROSPERO (CRD42019124360). Results  We identified 10 randomized controlled trials (RCTs) (2083 participants), including three trials on right/tilt-down versus left, two trials on supine/prone versus left, respectively. Mean difference in mean cecal insertion time in supine versus left was -41.0 s (95 % confidence interval [CI] -57.3 to -24.7) in one study and in tilt-down versus left was - 37.3 s (95 % CI -72.1 to -2.4; I ²  = 58 %) in three studies; however, there were no statistically significant differences in prone/right versus left position (very low certainty of evidence). Four of eight studies noted adverse effects requiring medication (moderate certainty of evidence). One RCT applying the tilt-down position was terminated because of increased occurrence of oxygen desaturation. Conclusion  We could not conclusively determine the efficacy and safety of the starting position during colonoscopy because of low certainty of evidence. Further studies are needed to confirm the efficacy and safety of the starting potion during colonoscopy.

Frontiers of Robotic Colonoscopy: A Comprehensive Review of Robotic Colonoscopes and Technologies

Flexible colonoscopy remains the prime mean of screening for colorectal cancer (CRC) and the gold standard of all population-based screening pathways around the world. Almost 60% of CRC deaths could be prevented with screening. However, colonoscopy attendance rates are affected by discomfort, fear of pain and embarrassment or loss of control during the procedure. Moreover, the emergence and global thread of new communicable diseases might seriously affect the functioning of contemporary centres performing gastrointestinal endoscopy. Innovative solutions are needed: artificial intelligence (AI) and physical robotics will drastically contribute for the future of the healthcare services. The translation of robotic technologies from traditional surgery to minimally invasive endoscopic interventions is an emerging field, mainly challenged by the tough requirements for miniaturization. Pioneering approaches for robotic colonoscopy have been reported in the nineties, with the appearance of inchworm-like devices. Since then, robotic colonoscopes with assistive functionalities have become commercially available. Research prototypes promise enhanced accessibility and flexibility for future therapeutic interventions, even via autonomous or robotic-assisted agents, such as robotic capsules. Furthermore, the pairing of such endoscopic systems with AI-enabled image analysis and recognition methods promises enhanced diagnostic yield. By assembling a multidisciplinary team of engineers and endoscopists, the paper aims to provide a contemporary and highly-pictorial critical review for robotic colonoscopes, hence providing clinicians and researchers with a glimpse of the major changes and challenges that lie ahead.

A randomized controlled trial comparing right and left lateral decubitus starting position on outcomes in colonoscopy

BACKGROUND

Patient positioning in colonoscopy has been proposed as a simple and inexpensive technique to increase luminal distention and improve navigation through the large bowel. We sought to determine if the right lateral (RL) starting position compared to the standard left lateral (LL) starting position could improve outcomes in colonoscopy.

METHODS

We conducted a randomized controlled trial of 185 patients who were undergoing an elective colonoscopy. Patients were randomized to either a right lateral decubitus starting position or a left lateral decubitus starting position and the primary outcome measure was cecal intubation time. Secondary outcome measures included cecal intubation rate, patient discomfort, and sedation dosage. All colonoscopists who had successfully completed a colonoscopy skills improvement course were included in the trial. A sample size was calculated prior to the start of the study and outcomes were analyzed using univariate and multiple regression analyses.

RESULTS

A total of 94 patients were randomized to RL starting position and 91 patients were randomized to LL starting position. No difference was found in time to cecal intubation comparing the RL starting position (542.6 s, SD 360.7 s) to LL starting position (497.85 s, SD 288.3 s) (p = 0.354). Variables associated with prolonged cecal intubation time included female gender, General Surgery specialty, less than 5 years of endoscopist experience, a high patient discomfort score, amount of water used, and number of position changes required to reach the cecum. There was no difference in any of the secondary outcome measures aside from the amount of midazolam used, with more midazolam used for patients starting in the right lateral decubitus position.

CONCLUSION

This study failed to show an association between cecal intubation time and patient position comparing right and left lateral starting position.

Practice recommendations for the use of sedation in routine hospital-based colonoscopy

Objective

Although sedation improves patient experience during colonoscopy, there is great jurisdictional variability in sedative practices. The objective of this study was to develop practice recommendations for the use of moderate and deep sedation in routine hospital-based colonoscopy to facilitate standardisation of practice.

Design

We recruited 32 multidisciplinary panellists to participate in a modified Delphi process to establish consensus-based recommendations for the use of sedation in colonoscopy. Panel members participated in a values assessment survey followed by two rounds of anonymous online voting on preliminary practice recommendations. An inperson meeting was held between voting rounds to facilitate consensus-building. Consensus was defined as >60% agreement/disagreement with recommendation statements; >80% agreement/disagreement was considered indicative of strong consensus.

Results

Twenty-nine panellists participated in the values assessment survey. Panellists ranked all factors presented as important to the development of practice recommendations. The factor considered most important was patient safety. Patient satisfaction, procedural efficiency, and cost were considered less important. Strong consensus was achieved for all nine practice recommendations presented to the panel. These recommendations included that all endoscopists be able to perform colonoscopy with moderate sedation, that an endoscopist and a single trained nurse are sufficient for performing colonoscopy with moderate sedation, and that anaesthesia-provided deep sedation be used for select patients.

Conclusion

The recommendations presented in this study were agreed on by a multidisciplinary group and provide guidance for the use of sedation in routine hospital-based colonoscopy. Standardised sedation practices will promote safe, effective, and efficient colonoscopy for all patients.

The WASh Trial: water-assisted sigmoidoscopy in the English Bowel Scope Screening Programme: study protocol for a randomized multicenter trial

Background and study aims  The English National Bowel Scope Screening Programme (BSSP) invites 55-year-olds for a one-off, unsedated flexible sigmoidoscopy (FSIG). Data from BSSP participant-reported experience studies shows 1 in 3 participants report moderate or severe discomfort. Water-assisted colonoscopy (WAS) may improve participants' comfort. The primary objective of this study is to ascertain if post-procedural participant-assessed pain is reduced in WAS compared with carbon dioxide (CO 2 ) insufflation, in invitees undergoing FSIG in BSSP. Patients and methods  This is a multicenter, prospective, randomized, two-arm, single-blinded trial designed to evaluate the performance of WAS versus CO 2 insufflation in BSSP. Participants will be randomized to either CO 2 or WAS and will be asked to rate pain post-procedure. Key procedure-related data will be analyzed, including adenoma detection rates (ADR) and degree of sigmoid looping. A cost-effectiveness analysis of WAS versus CO 2 and a discrete choice experiment exploring preferences of participants for attributes of sigmoidoscopy will also be performed. Discussion  This is the first trial in the United Kingdom (UK) to investigate the effects of WAS in a screening setting. If the trial shows WAS either reduces pain or increases ADR, this may result in a practice change to implement WAS in screening and non-screening endoscopic practice directly impacting on 256,000 people a year who will undergo BSSP FSIG by 2020. Trial funding came from National Institute for Health Research (NIHR) Research for Patient Benefit (RfPB) supported by the NIHR Clinical Research Network. The trial is actively recruiting. ID: 35866 ISRCTN: 81466870.

Recent advances in colonoscopy

Colonoscopy continues to evolve as equipment and techniques improve. Traditionally, colonoscopy has focused on adenoma detection, characterisation and resection as the primary aims, and there has certainly been considerable activity over the last few years in terms of addressing these important issues. This review article not only will discuss progress made in these areas but also will focus on when to colonoscope in terms of introduction of faecal immunochemical testing, how to insert with the advent of water-assisted insertion, and how to withdraw using a bundle of evidence-based techniques to improve adenoma detection. In addition, the ramifications of failing to discover polyps and of post-colonoscopy colorectal cancer are highlighted.

My approach to water-assisted colonoscopy

The goal of diagnostic colonoscopy is to achieve procedural completion while maximising effectiveness, patient acceptance and safety. In recent years, international interest in water-assisted colonoscopy (WAC) has been steadily gathering pace. A plethora of high-quality randomised controlled trials and meta-analyses now offer incontrovertible evidence into the benefits of WAC, both for the endoscopist and the patient. Despite this, uptake of WAC within the UK has been limited, with the lack of educational resources representing a significant barrier. This practical step-by-step guide is aimed at both existing practitioners and trainees, with a view to promoting familiarity with WAC and potentially for incorporation into daily practice which may ultimately have a positive effect on quality of colonoscopy and patient experience.

Does Increased Adenoma Detection Reduce the Risk of Colorectal Cancer, and How Good Do We Need to Be?

PURPOSE OF REVIEW

Colorectal cancer (CRC) is largely preventable with colonoscopy and other screening modalities. However, the effectiveness of screening and surveillance depends on the quality of the colonoscopy exam. Adenoma detection rate (ADR) is the best-validated metric by which we measure individual physicians' performance.

RECENT FINDINGS

Recent evidence suggests that ADR benchmarks may be inappropriately low. There is proof that improving ADR leads to significant reductions in post-colonoscopy CRC (PCCRC). Two studies have demonstrated that when a colonoscopy is performed by physicians with higher ADRs, patients are less likely to have advanced adenomas on surveillance and less likely to develop or die from PCCRC. Finally, there is at least some evidence that higher ADRs do not lead to more cumulative surveillance exams. The ADR is a useful outcome measure that can provide individual endoscopists and their patients with information about the likelihood of developing PCCRC. To achieve the lowest possible PCCRC rate, we should be striving for higher ADRs. While strategies and innovations may help a bit in improving ADRs, our efforts should focus on ensuring a complete mucosal exam for each patient. Behavioral psychology theories may provide useful frameworks for studying motivating factors that drive a careful exam.

Is water exchange superior to water immersion in detecting adenomas during colonoscopies? Results from a Bayesian network meta-analysis

AIM

Water-assisted colonoscopy (water exchange [WE] and water immersion [WI]) has been shown to improve the adenoma detection rate. However, few studies have compared these two methods head-to-head. Thus, we conducted a network meta-analysis to integrate both direct and indirect evidence comparing the effectiveness of these two procedures.

METHOD

We searched PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for original papers and abstracts published up to March 2018. Randomized controlled trials (RCTs) reporting data in accordance with the eligibility criteria were included in this study. We performed a Bayesian random effects network meta-analysis with mixed comparisons.

RESULTS

Twenty-nine studies (n = 11464 patients) including 6 direct and 23 indirect comparisons were included in this network meta-analysis. There was a statistically significant difference in the efficacy of adenoma detection when WE was compared with WI (risk ratio [RR]: 1.2, 95% credible interval [CrI]: 1.1-1.3), air insufflation (AI; RR: 1.3, 95% CrI: 1.1-1.4), and carbon dioxide (CO2) insufflation (RR: 1.2, 95% CrI: 1.1-1.5). The different methods were ranked in order from the most to least effective in adenoma detection as follows: WE, WI, AI, and CO2. Moreover, although there were no significant differences in pain scores, willingness to repeat, caecal intubation rate, or total procedure time between WI and WE colonoscopy, WE required a longer caecal intubation time than WI.

CONCLUSION

This network meta-analysis supposes that WE may be superior to WI in detecting adenomas during colonoscopies without affecting other technical features or patient acceptance.

Management of Serrated Polyps of the Colon

PURPOSE OF REVIEW

The purpose of this review is to summarize the management of serrated colorectal polyps (SPs), with a particular focus on the most common premalignant SP, sessile serrated adenoma or polyp (SSA/P). These lesions present a challenge for endoscopists with respect to detection and resection, and are also susceptible to pathologic misdiagnosis.

RECENT FINDINGS

Patients with SSA/Ps are at an increased risk of future colorectal neoplasia, including advanced polyps and cancer. Reasonable benchmarks for SP detection rates are 5-7% for SSA/Ps and 10-12% for proximal SPs. Certain endoscopic techniques such as chromoendoscopy, narrow band imaging, water immersion, and wide-angle viewing may improve SSA/P detection. Emerging endoscopic techniques such as underwater polypectomy, suction pseudopolyp technique, and piecemeal cold snare polypectomy are helpful tools for the endoscopist's armamentarium for removing SSA/Ps. Proper orientation of SSA/P specimens can improve the accuracy of pathology readings. Patients with confirmed SSA/Ps and proximal HPs should undergo surveillance at intervals similar to what is recommended for patients with conventional adenomas. Patients with SSA/Ps may also be able to lower their risk of future polyps by targeting modifiable risk factors including tobacco and alcohol use and high-fat diets. NSAIDs and aspirin appear to be protective agents. SPs and SSA/Ps in particular are important colorectal cancer precursors that merit special attention to ensure adequate detection, resection, and surveillance.

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.

Feasibility and outcomes of underwater endoscopic mucosal resection for ≥ 10 mm colorectal polyps

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) is an emerging strategy for the management of colorectal polyps. We aimed to evaluate the efficacy and safety of UEMR for clinically significant (≥ 10 mm) colorectal polyps.

METHODS

We performed a prospective dual-centre study of polyps ≥ 10 mm undergoing UEMR between June 2014 and March 2017. Outcomes measured comprised: (1) completeness of resection at index UEMR, (2) intraprocedural and 30-day complications, (3) rates and predictors of submucosal lift, en bloc resection, polyp/adenoma recurrence and (4) pain score. Endoscopy records were correlated with histology.

RESULTS

85 patients underwent UEMR of 97 polyps. Resection was endoscopically complete at index UEMR in 97.9%. The median pain score was 0 (no pain). Submucosal lift was required in 29.9% and correlated with polyp size ≥ 30 mm (p = 0.03) and clip placement (p = 0.004). En bloc resection was achieved in 45.4%, and inversely correlated with polyp size ≥ 20 mm (p < 0.001). 30-day complications (4.1%) were minor and consisted of intraprocedural bleeding (n = 2) and delayed bleeding (n = 2). 60.8% attended endoscopy post-UEMR after a median interval of 6 months, with 20.3% polyp and 13.6% adenoma recurrence. Polyp recurrence was associated with piecemeal resection (p = 0.04), recurrent polyp (p = 0.02), female sex (p = 0.01) and poor access (p = 0.005). Predictors for adenoma recurrence included female gender (p = 0.01) and difficult access (p < 0.001). Recurrence rates did not differ with polyp size, site, morphology, dysplasia status, submucosal injection, patient age, or study centre.

CONCLUSIONS

UEMR is an effective, safe and well tolerated option for significant colorectal polyps. Piecemeal resection, recurrent polyp, female gender, and difficult access are predictors of post-UEMR polyp recurrence.

Training in Endoscopy: Colonoscopy

Colonoscopy is effective in reducing the morbidity and mortality associated with colorectal cancer (CRC). Interval cancers or post-colonoscopy CRCs, are cancers detected within the surveillance interval, or between 6–36 months after a clearing colonoscopy. The incidence of interval cancers is 3.4%–9.2% of all detected CRCs, as reported in population-based studies. Colonoscopy is a technically difficult procedure that is challenging to learn, and needs time and effort to gain competency. Therefore, trainee competence is a critical component of CRC screening and surveillance. Herein, we review the colonoscopy training methods and quality assessment metrics for colonoscopy competency.

Quality Indicators in Colonoscopy

OPINION STATEMENT

Colonoscopy is one of the most commonly performed endoscopic procedures. It is the gold standard examination for work-up of colonic symptoms, for follow-up of positive colorectal cancer screening tests and for detection and removal of neoplastic polyps. Colonoscopy is a complex and invasive procedure with a potential not only for colorectal cancer prevention, but also for serious complications. Numerous factors may affect the balance of benefit versus harm of colonoscopy, including the performance of the endoscopist. These factors are commonly called quality indicators. As an increasing number of countries are recommending the general population to undergo colorectal cancer screening, the quality of colonoscopy should be considered a public health concern. Key quality indicators have been identified, and several professional organizations have issued recommendation statements to promote high-quality colonoscopy. To achieve high quality, these key quality indicators must be monitored, results must be analysed, and measures must be undertaken to correct substandard performance. High-quality training in colonoscopy and polypectomy should be a quality assurance priority.

Endoscopic Improvement of the Adenoma Detection Rate during Colonoscopy - Where Do We Stand in 2015?

BACKGROUND

The presence of colorectal adenomas is considered a major risk factor for colorectal cancer development. The implementation of screening colonoscopy programs in the Western world has led to a substantial reduction of colorectal cancer death. Many efforts have been made to reduce the adenoma miss rates by the application of new endoscopic devices and techniques for better adenoma visualization.

SUMMARY

This special review gives the readership an overview of current endoscopic innovations that can aid in the increase of the adenoma detection rate (ADR) during colonoscopy. These innovations include the use of devices like EndoCuff® and EndoRings® as well as new technical equipment like third-eye endoscope® and full-spectrum endoscopy (FUSE®).

KEY MESSAGE

Technical improvements and newly developed accessories are able to improve the ADR. However, additional costs and a willingness to invest into potentially expensive equipment might be necessary. Investigator-dependent skills remain the backbone in the ADR detection.

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.

Does carbon dioxide insufflation impact adenoma detection rate? A single-center retrospective analysis

Background and study aims: Carbon dioxide (CO₂) has been associated with reduced post-procedural pain and improved patient satisfaction when compared to air insufflation (AI). The effect of CO₂ insufflation (CO₂I) on the adenoma detection rate (ADR) remains unclear. The aims of this study are to compare ADR in patients undergoing screening colonoscopy with AI vs. CO₂I and identify predictors of ADR. Patients and methods: Single-center retrospective cohort study of 2,107 patients undergoing screening colonoscopy at the University of Florida Hospital between November 2011 and June 2015. Patient demographics, procedural parameters, and histology results were retrospectively obtained from a prospectively maintained colonoscopy database. Univariate and multivariate analysis were performed to identify predictors of ADR. Results: A total of 2107 colonoscopies (644 with AI and 1463 with CO₂I) were analyzed. Overall ADR was 27.8 %. There was no significant difference in ADR between AI (27.6 %) vs. CO₂I (27.8 %) (P = 0.93). Method of insufflation (AI vs. CO₂I) was not significantly associated with ADR (OR 0.9; 95 % CI:0.7 - 1.2). Older age (OR: 1.02; 95 % CI: 1.001 - 1.03 per year increase), male gender (OR 1.48; 95 % CI: 1.17 - 1.87), and longer scope withdraw time (OR 1.13; 95 % CI: 1.1 - 1.16 per minute) were associated with a higher ADR. Fellow involvement was negatively associated with ADR (OR 0.60; 95 % CI: 0.47 - 0.77). Conclusion: ADR was similar between patients who underwent screening colonoscopy with AI vs. CO₂I. While CO₂I has been associated with improved patient comfort and post-procedural recovery time, there is no definitive evidence to suggest that this method of luminal distention enhances ADR.

Chromoscopy versus conventional endoscopy for the detection of polyps in the colon and rectum

BACKGROUND

Although conventional colonoscopy is the most accurate test available for the investigation of the colorectum for polyps, data exist that raise concerns about its sensitivity. Chromoscopy (spraying dye onto the surface of the colon to make polyps more visible) may be one way of enhancing the ability of colonoscopy to detect polyps, particularly diminutive flat lesions, which otherwise may be difficult to detect.

OBJECTIVES

To determine whether the use of chromoscopy enhances the detection of polyps and neoplasia during endoscopic examination of the colon and rectum.

SEARCH METHODS

We searched the following databases: Cochrane Colorectal Cancer Group Specialised Register (October 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library; Issue 10, 2015), MEDLINE (January 1950 to October 2015), EMBASE (January 1974 to October 2015), and ClinicalTrials.gov and World Health Organization International Clinical Trials Registry Platform (both November 2015). We also handsearched abstracts from relevant meetings from 1980 to 2015. Search terms included 'randomised trials' containing combinations of the following: 'chromoscopy' 'colonoscopy' 'dye-spray' 'chromo-endoscopy' 'indigo-carmine' 'magnifying endoscopy'.

SELECTION CRITERIA

We included all prospective randomised trials comparing chromoscopic with conventional endoscopic examination of the whole of the colon and rectum. We excluded studies of people with inflammatory bowel disease or polyposis syndromes and any studies that combined chromoscopy with additional interventions (cap assistance, water-perfused, etc.).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the methodological quality of potentially eligible trials, and two review authors independently extracted data from the included trials. Outcome measures included the detection of polyps (neoplastic and non-neoplastic), the detection of diminutive lesions, the number of participants with multiple neoplastic lesions, and the extubation time.

MAIN RESULTS

We included seven trials (2727 participants) in this update. Five trials were of sufficiently similar design to allow for pooled results. Two trials differed substantially in design and were included in a subgroup analysis. All the trials had some methodological drawbacks. However, combining the results showed a significant difference in favour of chromoscopy for all detection outcomes. In particular, chromoscopy was likely to yield significantly more people with at least one neoplastic lesion (odds ratio (OR) 1.53, 95% confidence interval (CI) 1.31 to 1.79; 7 trials; 2727 participants), and at least one diminutive neoplastic lesion (OR 1.51, 95% CI 1.19 to 1.92; 4 trials; 1757 participants). Significantly more people with three or more neoplastic lesions were also detected, but only when studies that used high-definition colonoscopy in the control group were excluded (OR 4.63, 95% CI 1.99 to 10.80; 2 trials; 519 participants). None of the included studies reported any adverse events related to the use of the contrast dye.

AUTHORS' CONCLUSIONS

There is strong evidence that chromoscopy enhances the detection of neoplasia in the colon and rectum. People with neoplastic polyps, particularly those with multiple polyps, are at increased risk of developing colorectal cancer. Such lesions, which presumably would be missed with conventional colonoscopy, could contribute to the interval cancer numbers on any surveillance programme.

Achieving competence in colonoscopy: Milestones and the need for a new endoscopic curriculum in gastroenterology training

Colonoscopy is considered to be the most effective tool for reducing colorectal cancer (CRC) morbidity and mortality. As a result, certifying trainee competence in the performance of colonoscopy is critical to maximizing CRC screening and prevention efforts. Guidelines on training and accreditation around the world have been revised to emphasize the attainment of milestones in the technical and cognitive skills necessary to perform the procedure. To meet this challenge, new evaluation systems have been developed to measure trainee competence through all aspects of colonoscopy training. These changes stem from increased recognition that procedural numbers alone do not necessarily guarantee trainees’ proficiency in the performance of colonoscopy. Variability in endoscopic practice and in CRC screening outcomes also point to deficiencies in the current approach towards colonoscopy instruction. However, technological innovations hold great promise in training endoscopists to perform high quality colonoscopy. Furthermore, potential advances in the use of feedback as a training tool provide new avenues for research. This review summarizes the latest evidence on the effort to define, evaluate and promote the achievement of competence in colonoscopy among trainees.