Sedated Colonoscopy may not be Beneficial for Polyp/Adenoma Detection.

BACKGROUND: Sedated colonoscopy has been increasingly selected. However, the effect of sedated colonoscopy on polyp/adenoma detection rate (PDR/ADR) remains controversial among studies. METHODS: In this retrospective study, the medical records of 11 504 consecutive patients who underwent colonoscopy at our department from July 1, 2021 to December 31, 2022 were collected. Patients were divided into sedated and unsedated groups according to the use of intravenous sedation during colonoscopy. Overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR were calculated. By adjusting for age, gender, body mass index, inpatient, screening/surveillance, cecal intubation time, colonoscopy withdrawal time ≥6 min, and an endoscopist's experience ≥5 years, multivariate logistic regression analyses were performed to evaluate the association of sedated colonoscopy with overall PDR/ADR, right-side, transverse, and left-side colon PDR/ADR, and single and multiple PDR/ADR, where the absence of PDR/ADR was used as reference. Odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated. RESULTS: Overall, 2275 patients were included, of whom 293 and 1982 underwent sedated and unsedated colonoscopy, respectively. Multivariate logistic regression analyses showed that sedated colonoscopy was independently associated with lower overall PDR/ADR (OR = 0.640, 95% CI = 0.460-0.889, P = 0.008), right-side colon PDR/ADR (OR = 0.591, 95% CI = 0.417-0.837, P = 0.003), single PDR/ADR (OR = 0.659, 95% CI = 0.436-0.996, P = 0.048), and multiple PDR/ADR (OR = 0.586, 95% CI = 0.402-0.855, P = 0.005), but not transverse or left-side colon PDR/ADR. CONCLUSION: Sedated colonoscopy may not be beneficial in terms of overall PDR/ADR, right-side colon PDR/ADR, and number of polyps/adenomas. Thus, it should be selectively recommended. Additionally, it should be necessary to explore how to improve the quality of sedated colonoscopy.

Epidemiology of overall and early-onset serrated polyps versus conventional adenomas in a colonoscopy screening cohort.

Serrated polyps (SPs) are precursors to one-third of colorectal cancers (CRCs), with histological subtypes: hyperplastic polyps (HPs), sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). The incidence of early-onset CRC before the age of 50 is increasing, with limited understanding of SPs in younger cohorts. Using a large colonoscopy-based cohort, we characterized epidemiologic profiles of SP subtypes, compared to conventional adenomas, with secondary analysis on early-onset polyps. Ninety-four thousand four hundred and twenty-seven patients underwent screening colonoscopies between 2010 and 2018. Demographic, endoscopic and histopathologic characteristics of each polyp subtype were described. High-risk polyps included SSLs ≥10 mm/with dysplasia and conventional adenomas ≥10 mm/with tubulovillous/villous histology/high-grade dysplasia. We examined polyp prevalence with age and compared early- (age < 50) and late-onset polyps (age ≥ 50). Eighteen thousand one hundred and twenty-five patients had SPs (4357 SSLs, 15 415 HPs, 120 TSAs) and 26 699 had conventional adenomas. High-risk SSLs were enriched in the ascending colon (44.1% vs 2.6-35.8% for other locations; P < .003). Early- and late-onset SPs had similar subsite distribution. Early-onset conventional adenomas were more enriched in the distal colon/rectum (51.8% vs 43.4%, P < .001). Multiple conventional adenomas were more represented in late-onset groups (40.8% vs 33.8%, P < .001), with no difference in SSLs. The prevalence of conventional adenomas/high-risk conventional adenomas increased continuously with age, whereas the prevalence of SSLs/high-risk SSLs was stable from age 40 years onwards. A higher proportion of women were diagnosed with early-onset than late-onset SSLs (62.9% vs 57.6%, P = .03). Conventional adenomas, SSLs, early- and late-onset polyps have distinct epidemiology. The findings have implications for improved colonoscopy screening and surveillance and understanding the etiologic heterogeneity of CRC.

Colonoscopy performance monitoring: do we need to adjust for case mix?

INTRODUCTION: Overall caecum intubation rate(oCIR) and overall polyp detection rate(oPDR) have been proposed as performance indicators, but varying complexity in case mix among endoscopists may potentially affect validity. The study aims to explore the effect of adjusting for case mix on individual endoscopist performance by calculating case mix-adjusted performance estimates (cmCIR and cmPDR) and comparing them to overall performance estimates (oCIR and oPDR). The study also provides an R program for case mix analysis. METHODS: Logistic regression associated endoscopist, colonoscopy indication, patient age and patient gender with the binary outcomes of cecum intubation and polyp detection. Case mix-adjusted performance indicators were calculated for each endoscopist based on logistic regression and bootstraps. Endoscopists were ranked from best to worst by overall and case mix-adjusted performance estimates, and differences were evaluated using percentage points(pp) and rank changes. RESULTS: The dataset consisted of 7376 colonoscopies performed by 47 endoscopists. The maximum rank change for an endoscopist comparing oCIR and cmCIR was eight positions, interquartile range (IQR 1-3). The maximum change in CIR was 1.95 percentage point (pp) (IQR 0.27-0.86). The maximum rank change in the oPDR versus cmPDR analysis was 17 positions (IQR 1.5-8.5). The maximum change in PDR was 11.21 pp (IQR 2.05-6.70). Three endoscopists improved their performance from significantly inferior to within the 95% confidence interval (CI) range of performance targets using case mix-adjusted estimates. CONCLUSIONS: The majority of endoscopists were unaffected by adjustment for case mix, but a few unfortunate endoscopists had an unfavourable case mix that could invite incorrect suspicion of inferior performance.

Polyps are detected more often in early colonoscopies.

OBJECTIVE: To examine the time variation in polyp detection for colonoscopies performed in a tertiary hospital and to explore independent factors that predict polyp detection rate (PDR). METHODS: Data on all patients who underwent colonoscopy for the diagnostic purpose at our endoscopy center in Zhongnan Hospital of Wuhan University from January 2021 to December 2021 were reviewed. The start time of included colonoscopies for eligible patients was recorded. PDR and polyps detected per colonoscopy (PPC) were calculated. The endoscopists' schedules were classified into full-day and half-day shifts according to their participation in the morning and afternoon colonoscopies. RESULTS: Data on a total of 12116 colonoscopies were analyzed, with a PDR of 38.03% for all the patients and 46.38% for patients ≥50 years. PDR and PPC significantly decreased as the day progressed (both p < .001). For patients ≥50 years, PDR declined below 40% at 13:00-13:59 and 16:00-16:59. The PDR in the morning was higher than that in the afternoon for both half-day (p = .019) and full-day procedures (p < .001). In multivariate analysis, start time, patient gender, age, conscious sedation, and bowel preparation quality significantly predicted PDR (p < .001). CONCLUSIONS: The polyp detection declined as the day progressed. A continuous work schedule resulted in a subpar PDR. Colonoscopies performed in the morning had a higher PDR than that in the afternoon. Patient gender, age, conscious sedation, and bowel preparation quality were identified as the independent predictors of PDR.

Effect of computer-aided colonoscopy on adenoma miss rates and polyp detection: A systematic review and meta-analysis.

BACKGROUND AND AIM: Multiple computer-aided techniques utilizing artificial intelligence (AI) have been created to improve the detection of polyps during colonoscopy and thereby reduce the incidence of colorectal cancer. While adenoma detection rates (ADR) and polyp detection rates (PDR) are important colonoscopy quality indicators, adenoma miss rates (AMR) may better quantify missed lesions, which can ultimately lead to interval colorectal cancer. The purpose of this systematic review and meta-analysis was to determine the efficacy of computer-aided colonoscopy (CAC) with respect to AMR, ADR, and PDR in randomized controlled trials. METHODS: A comprehensive, systematic literature search was performed across multiple databases in September of 2022 to identify randomized, controlled trials that compared CAC with traditional colonoscopy. Primary outcomes were AMR, ADR, and PDR. RESULTS: Fourteen studies totaling 10 928 patients were included in the final analysis. There was a 65% reduction in the adenoma miss rate with CAC (OR, 0.35; 95% CI, 0.25-0.49, P < 0.001, I2  = 50%). There was a 78% reduction in the sessile serrated lesion miss rate with CAC (OR, 0.22; 95% CI, 0.08-0.65, P < 0.01, I2  = 0%). There was a 52% increase in ADR in the CAC group compared with the control group (OR, 1.52; 95% CI, 1.39-1.67, P = 0.04, I2  = 47%). There was 93% increase in the number of adenomas > 10 mm detected per colonoscopy with CAC (OR 1.93; 95% CI, 1.18-3.16, P < 0.01, I2  = 0%). CONCLUSIONS: The results of the present study demonstrate the promise of CAC in improving AMR, ADR, PDR across a spectrum of size and morphological lesion characteristics.

Retroflexed view for reexamination of the right colon after forward view examination: Systematic review and meta-analysis.

BACKGROUND: The effect of retroflexed view (RV) for the reexamination of the right colon after forward view (FV) examination has not been fully understood. METHODS: We searched multiple databases including PubMed, Embase, and the Cochrane Library for prospective studies exploring the role of RV for reexamination of the right colon. A meta-analysis was performed on outcomes including lesion detection rates, lesion miss rates, and withdrawal time. RESULTS: Four randomized controlled trials aimed to compare the impact of the second withdrawal from the right colon in RV vs. FV following a standard colonoscopy. Both the additional adenoma detection rate (AADR) and additional polyp detection rate (APDR) of the right colon were lower in the RV group compared with the FV group (risk ratio [RR] 0.73 for AADR; RR 0.76 for APDR); similar results were noted in comparisons of the adenoma miss rate and polyp miss rate. Six prospective cohort studies aimed to describe the effect of the RV examination of the right colon after one or two rounds of FV examination. Both the adenoma detection rate (ADR) and polyp detection rate (PDR) of the right colon were slightly higher in combined examinations with RV examination than single FV examination (RR 1.11 for ADR; RR 1.16 for PDR) or two FV examinations (RR 1.21 for ADR; RR 1.22 for PDR). CONCLUSIONS: FV may detect more adenomas and polyps than RV during the second withdrawal from the right colon. RV may detect additional adenomas and polyps in the right colon after two FV examinations.

Impact of second forward-view examination on adenoma detection rate during unsedated colonoscopy: a randomized controlled trial.

OBJECTIVES: Colorectal cancer on the right side of the colon has been suggested to be harder to detect by colonoscopy. The aim of this study was to evaluate whether a second forward-view examination of the right side of the colon could increase the adenoma detection rate (ADR) and/or polyp detection rate (PDR). METHODS: This was a single-centre randomized controlled trial. Patients undergoing colonoscopy were recruited and randomly assigned to the second forward-view examination (SFE) group, in which the right side of the colon was examined twice or the traditional colonoscopy (TC) group in which the colonoscopy was performed in a standard manner. The primary outcome was the ADR of right colon. The overall PDR and ADR, PDR of the right colon, per-adenoma miss rate of the right colon, and advanced lesion detection rate were also recorded and compared. RESULTS: A total of 392 patients were included in the study (SFE group 197 vs. TC group 195). The ADR and PDR of the right colon in the SFE group were significantly higher than those in the TC group (ADR 10.7% vs. 5.1%; P = 0.042); PDR 17.8% vs. 9.7%, P = 0.021). No significant difference was found in overall PDR/ADR, or advanced lesion detection rate between the two groups. CONCLUSIONS: This prospective controlled study revealed that a second forward-view examination could modestly increase the ADR and PDR of the right colon during unsedated colonoscopies. This simple, safe and time-effective technique might be recommended for routine unsedated colonoscopy. TRIAL REGISTRATION: Clinical Trials.gov, NCT03619122. Registered on 7/8/2018.

AmplifEYE assisted colonoscopy versus standard colonoscopy: A randomized controlled study.

BACKGROUND AND AIM: AmplifEYE is a mucosal exposure device mounted to the tip of colonoscope to improve polyp or adenoma detection. We aim to compare the adenoma detection rates (ADR) of AmplifEYE-assisted colonoscopy (AC) with standard colonoscopy (SC). METHODS: We performed a randomized controlled trial involving patients aged 50 to 79 who underwent AC or SC in two centers. Procedures were performed by five experienced colonoscopists. RESULTS: Three hundred fifty-five patients were recruited, with 334 patients (170 AC and 164 SC) included into analysis. The ADR was numerically higher in AC (47.1%) versus SC (40.9%), P = 0.253. The polyp detection rate (PDR) in AC was 68.2% versus 54.3% in SC, P = 0.009, and serrated polyp detection rate (SDR) in AC was 37.6% versus 20.1% in SC, P < 0.001, both statistically significant higher in the study group. The mean cecal intubation time was shorter with AmplifEYE (8.0 min in AC vs 8.9 min in SC, P = 0.030), and there was no difference in pain score (3 in AC vs 4 in SC, P = 0.121). CONCLUSIONS: AmplifEYE-assisted colonoscopy significantly improved the PDR and SDR, while the ADR was numerically higher in AC that did not reach statistical significance. Using the device resulted in shorter cecal intubation time and did not cause more pain.

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

BACKGROUND AND AIM: Sessile serrated adenoma/polyp (SSA/P) may contribute to interval cancer. In a recent meta-analysis, water exchange (WE) was shown to be superior to Endocuff and cap colonoscopy at adenoma and advanced adenoma detection. The strong positive correlation between adenoma detection rate (ADR), advanced adenoma detection rate (AADR), and sessile serrated adenoma/polyp detection rate (SSA/PDR) prompted us to hypothesize that WE could significantly improve SSA/PDR compared with Endocuff and cap colonoscopy. METHODS: The literature was searched for all randomized controlled trials (RCTs) that reported SSA/PDR as an outcome and included the keywords colonoscopy, and water exchange, Endocuff, or cap. We performed traditional network meta-analyses with random effect models comparing SSA/PDR of each method using air insufflation as the control and reported the odds ratios (ORs) with 95% confidence interval (CI). Performances were ranked based on P-score. RESULTS: A total of 531 articles resulted from initial keywords search. Eleven RCTs were included in the analysis. A total of 7856 patients underwent air insufflation, WE, Endocuff, or cap colonoscopy. WE significantly increased SSA/PDR (OR 2.04; 95% CI 1.33-3.13). Endocuff (OR 1.15; 95% CI 0.94-1.41) and cap (OR 1.08; 95% CI 0.42-2.74) did not significantly impact SSA/P detection. P-scores for WE (0.96), Endocuff (0.49), cap (0.37), and air insufflation (0.17) suggested that WE had the highest SSA/PDR. The results did not change after adjusting for mean withdrawal time and indication for colonoscopy. CONCLUSION: Water exchange significantly increases SSA/PDR and is superior to Endocuff and cap colonoscopy at detecting SSA/P.

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

BACKGROUND: Colonoscopies are considered to be the primary screening test and gold standard test for colorectal cancer. Position changes during colonoscope withdrawal are believed to be associated with an increased adenoma detection rate (ADR) and polyp detection rate (PDR). However, previous results conflicted, and this study aimed to elucidate the effectiveness of dynamic position changes during colonoscope withdrawal. METHODS: The relevant publications were identified by searching the medical databases. The primary outcomes were the ADR and PDR, which were pooled and analyzed. The secondary outcome was the withdrawal time. The studies that supplied the ADR and PDR for different segments of the colon were separated into subgroup analyses. RESULTS: Five randomized controlled trials were eligible for analysis. The total ADR was higher with dynamic position changes than with a static position (odds ratio, [OR] 1.34; 95% confidence interval [CI] 1.13-1.59; p < 0.001), with low evidence of between-study heterogeneity (I2 = 0%). Although the total PDR was slightly higher with dynamic position changes than with a static position (OR 1.23; 95% CI 0.88-1.73), there difference was not statistically significant (p = 0.22). The withdrawal time was only increased by 0.47 min (95% CI - 0.11 to 1.06) with dynamic position changes, without statistical significance (p = 0.11). The subgroup analysis showed that the ADR and PDR for the transverse colon were higher with dynamic position changes, with pooled estimates of ADR (OR 1.72; 95% CI 1.02-2.88; p = 0.04) and PDR (OR 1.79; 95% CI 1.08-2.96; p = 0.02). CONCLUSION: Dynamic position changes during colonoscope withdrawal increased the total ADR; however, no obvious increase was found in the total PDR. The withdrawal time was not significantly prolonged with dynamic position changes. Subgroup analysis showed that the ADR and PDR in the transverse colon were obviously improved with dynamic position changes.

Longer Withdrawal Time Is More Important than Excellent Bowel Preparation in Colonoscopy of Adequate Bowel Preparation.

BACKGROUND: Adequate bowel preparation is crucial for effective screening colonoscopy. However, it is unclear whether higher bowel preparation scores correspond to beneficial effects on the adenoma and polyp detection rate (ADR and PDR) in the adequate bowel preparation group. AIMS: This study aimed to evaluate the effects of bowel preparation, according to the Boston Bowel Preparation Scale (BBPS), and colonoscopy withdrawal time (CWT) on ADR and PDR in the adequate bowel preparation group. METHODS: Healthy examinees between 50 and 75 years old who underwent colonoscopy between September 2015 and August 2016 were included. BBPS scores, CWT, ADR, and PDR were reviewed retrospectively. Predictors of ADR and PDR were analyzed with a generalized linear mixed model. RESULTS: A total of 5073 cases with adequate bowel preparation (BBPS ≥ 6) were analyzed. Examinees with good (BBPS = 6, 7) and excellent (BBPS = 8, 9) bowel preparation were 1898 (37.4%) and 3175 (62.6%), respectively. Both ADR and PDR were higher in the good bowel preparation group than in the excellent bowel preparation group (ADR 47.3% vs. 45.0%, P = 0.035; PDR 73.7% vs. 69.5%, P = 0.004, respectively). In the multivariate analysis, CWT, rather than BBPS, was significantly associated with both ADR (OR 1.04; 95% CI 1.02-1.06; P < 0.001) and PDR (OR 1.05; 95% CI 1.02-1.07; P = 0.002). CONCLUSIONS: Both ADR and PDR were lower when bowel preparation was excellent rather than good. However, CWT, not BBPS, was significantly associated with ADR and PDR in the adequate bowel preparation group. Therefore, meticulous inspection is important for high-quality colonoscopy regardless of the BBPS score in examinees with adequate bowel preparation.

Data quality and colonoscopy performance indicators in the prevalent round of a FIT-based colorectal cancer screening program.

Objective: From the prevalent round of the Danish FIT-based colorectal cancer (CRC) screening program, we aimed (i) to evaluate the quality of recorded data and (ii) to characterize the colonoscopies by measuring variation in performance indicators between colonoscopists and assessing the ratio between adenoma detection rate (ADR) and polyp detection rate (PDR). Materials and methods: This study included screening colonoscopies performed in Central Denmark Region within 60 days of a positive FIT-result from 1 July 2015 through 30 June 2017. The participants were the colonoscopists, performing these procedures. The quality indicators cecal intubation rate (CIR), PDR, polyp retrieval rate (PRR), ADR and withdrawal time (WT) were evaluated. ADR/PDR ratios were calculated. Results: The concordance between the recorded data and the colonoscopy reports showed Kappa values in the range of 0.47-0.97. The overall CIR was 90.6% (range 73.7%-100%), PDR: 51.9% (range 18.4%-70.2%), PRR: 94.6% (range 69.6%-100%), ADR (conventional adenomas): 50.6% (range 18.4%-70.2%), ADRx (conventional adenomas, traditional serrated adenomas and sessile serrated lesions with dysplasia): 50.9% (range 18.4%-70.2%) and the mean WT was 11.3 min (range 4.5-24.9 min). The ADR/PDR ratio was 92.8% (95% CI: 92.0%-93.6%) and the ADRx/PDR ratio was 93.2% (95% CI: 92.4%-93.9%). Conclusion: Data quality was generally high. We found considerable variation in performance indicators between colonoscopists reflecting the potential for improvement. Further, our findings revealed that the PDR might be a good proxy for ADR in the context of the prevalent round of FIT-based CRC screening programs.

The performance indicator of colonic intubation (PICI) in a FIT-based colorectal cancer screening program.

Objective: Cecal intubation rate (CIR) is known to be inversely associated with interval colorectal cancer (CRC) risk. Cecal intubation may be achieved by the use of force and sedation jeopardizing patient safety. The Performance Indicator of Colonic Intubation (PICI) is defined as the proportion of colonoscopies achieving cecal intubation with use of ≤2 mg midazolam and no-mild patient-experienced discomfort. We aimed (i) to measure the variation of PICI between colonoscopists and colonoscopy units; (ii) to assess the correlation between the individual components of PICI; and (iii) to evaluate the association between PICI and commonly used performance indicators. Materials and methods: For the period 1 July 2015 through 30 June 2017 of the prevalent round of the Danish FIT-based CRC screening program, we included colonoscopies performed at four units in the Central Denmark Region within 60 days after a positive FIT-test. The PICI variation was evaluated using rates and ranges. Correlations between individual PICI components were assessed using Pearson correlation coefficients. Polyp detection rate (PDR), Adenoma detection rate (ADR), Polyp retrieval rate (PRR) and Withdrawal time (WT) were assessed within PICI quartiles. Results: The overall PICI was 78.7% with substantial variation between colonoscopists (40.0-91.9%) and units (72.6-82.0%). CIR was significantly correlated with patient-experienced comfort (r = 0.49, n = 73, p < .0001) and we observed that colonoscopists with a PICI between 79.9% and 84.3%) had the highest ADR. Conclusion: We found a substantial variation in PICI between colonoscopists and between colonoscopy units, which may reflect potential for quality improvements.

Impact of differences in adenoma and proximal serrated polyp detection rate on the long-term effectiveness of FIT-based colorectal cancer screening.

BACKGROUND: Both the adenoma detection rate (ADR) and proximal serrated polyp detection rate (PSPDR) vary among endoscopists. It is unclear how these variations influence colorectal cancer (CRC) screening effectiveness. We evaluated the effect of variation in these detection rates on the long-term impact of fecal immunochemical test (FIT) based screening. METHODS: The Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model was set up to simulate the Dutch national biennial FIT-based CRC screening program between 2014 and 2044. Adherence to FIT and colonoscopy was 73 and 92%. Besides a 'no screening scenario', several screening scenarios varying in ADR and PSPDR were evaluated. Using the available literature on colonoscopy miss rates led to a base-case ADR of 59% and PSPDR of 11%, which were varied with intervals of 3 and 2%. RESULTS: Compared to no screening, FIT-screening in the base-case scenario reduced long-term mortality with 51.8%. At a fixed PSPDR of 11%, an increase in ADR from 44 to 62% would result in a 10.7% difference in mortality reduction. Using a fixed ADR of 59%, changing the PSPDR from 3 to 15% did not substantially influence long-term mortality (51.0 to 52.3%). CONCLUSIONS: An increase in ADR gradually reduces CRC burden in a FIT-based screening program, whereas an increase in PSPDR only minimally influences long-term outcomes at a population-level. The limited effect of the PSPDR can be explained by the limited sensitivity of FIT for serrated polyps (SPs). Other triage modalities aiming to detect relevant SPs should be explored.

Diagnostic yield is not influenced by the timing of screening endoscopy: morning versus afternoon.

BACKGROUND: Previous studies have shown the colonoscopy quality affected by the endoscopist's fatigue. This study was aimed to evaluate this potential factor in a colorectal cancer-screening cohort of Chinese patients. METHODS: The attendances at department of gastroenterology for colorectal cancer screening between 2013 and 2015 were retrospectively analyzed. The procedure time-of-day and hours elapse were recorded. The primary outcome was defined as adenoma detection rate (ADR). RESULTS: A total of 1342 screening colonoscopies were performed by 19 gastroenterologists in the study. Detection rates were 7.7% for all polyps and 20.0% for adenomas. Time-of-day was not significantly associated with ADR. With time elapsing, the first climax for ADR was presented at 09:00-10:00, and persistently rose again after the lunch break. Significant inclined trend in ADR was noted for each hour blocks of a full day (p = .0021). CONCLUSIONS: The procedure time-of-day, morning versus afternoon, did not affect the diagnostic efficacy of screening endoscopy in Chinese patients.

Influence of Simethicone Added to the Rinse Water during Colonoscopies on Polyp Detection Rates: Results of an Unintended Cohort Study.

BACKGROUND AND AIMS: Simethicone is a common antifoaming agent that is added to endoscopic rinse solutions, but data regarding its effect on polyp detection rates is lacking. In this study, we report the effect of discontinuation of this practice on polyp detection rates. METHODS: Procedure data of 4,254 consecutive colonoscopies were used. Patients underwent standard bowel preparation with polyethyleneglycol (Glycoprep®). Colonoscopies were performed utilising Olympus EVIS EXERA III, CV-190 equipment, while quality data (withdraw times, polyp detection rates, quality of bowel preparation) was assessed utilising an endoscopy reporting system (Provation®). Following an educational event that highlighted that simethicone may form deposits in the channels of endoscopes, the practice to add simethicone (InfacolR, Nice Pak) to the auxiliary channel water pump was abandoned, but endoscopists were not notified about this change. After 5 days and performing 75 colonoscopies, the change of practice was identified and addition of simethicone recommenced. RESULTS: The discontinuation of simethicone use reduced the polyp detection rate from 55% (95% CI 53-56) to 45% (95% CI 34-56, 1-sided, p = 0.028); the polyp detection rate returned to the pre-intervention levels of 55% (95% CI 52-58) upon resumption of normal practice. CONCLUSION: The addition of simethicone to the auxiliary water pump during colonoscopy results in a 10% increase in polyp detection rates.

The use of high definition colonoscopy versus standard definition: does it affect polyp detection rate?

BACKGROUND: Polyp detection rate (PDR) during lower gastrointestinal endoscopy (LGIE) is of clinical importance. Detecting adenomatous polyps early in the adenoma-carcinoma sequence can halt disease progression, enabling treatment at a favourable stage. High definition colonoscopy (HDC) has been used in our hospital alongside standard definition equipment since 2011. We aim to determine what affect the use of HDC has on PDR. METHODS: Post-hoc analysis of a prospectively maintained database on all patients undergoing LGIE was performed (01/01/2012-31/12/2015), n = 15,448. Analysis tested the primary outcome of HD's effect on PDR across LGIE and secondary outcome stratified this by endoscopist group (Physician (PE), Surgeon (SE) and Nurse Endoscopist (NE)). RESULTS: Of 15,448 patients, 1353 underwent HDC. Unmatched analysis showed PDR increased by 5.3% in this group (p < 0.001). Matched analysis considered 2288 patients from the total cohort (1144 HDC) and showed an increase of 1% in PDR with HDC (p = 0.578). Further unmatched analysis stratified by endoscopist groups showed a PDR increase of 1.8% (p = 0.375), 5.4% (p = 0.008) and 4.6% (p = 0.021) by PE, SE and NE respectively. Matched analysis demonstrated an increase of 1% (p = 0.734) and 1.5% (p = 0.701) amongst PE and NE, with a decrease of 0.6% (p = 0.883) by SE. CONCLUSION: The introduction of HDC increased PDR across all LGIE in our hospital, though this was not clinically significant. This marginal benefit was present across all endoscopist groups with no group benefiting over another in matched analysis.

Can polyp detection rate be used prospectively as a marker of adenoma detection rate?

BACKGROUND: Adenoma detection rate (ADR) is a quality indicator for screening colonoscopy, but its calculation is time-consuming. Polyp detection rate (PDR) has been found to correlate with ADR; however, its use as a quality indicator has been criticized out of concern for endoscopists artificially inflating the PDR. We aim to evaluate whether active monitoring affects PDR. METHODS: In March 2015, 14 endoscopists were made aware that their personal PDRs would be tracked monthly as a quality improvement project. Endoscopists received a report of their individual monthly and cumulative PDR, departmental averages, and a benchmark PDR. Following the intervention, data were collected for consecutive patients undergoing average risk screening colonoscopy for six months. PDR, ADR, and adenoma to polyp detection ratio quotient (APDRQ) were compared to a six-month pre-intervention period. RESULTS: 2203 patients were included in the study. There was no statistically significant difference in PDR when comparing pre- and post-intervention (44 vs. 45%, OR 1.04; 95% CI 0.77-1.36). No statistically significant difference in ADR was observed when comparing pre- and post-intervention (29 vs. 30%, OR 1.03; 95% CI 0.64-1.52). There was no statistically significant difference in APDRQ when comparing pre- and post-intervention (0.67 vs. 0.66, OR 0.99; 95% CI 0.69-1.33). CONCLUSIONS: Monthly report cards did not result in a change in PDR or APDRQ. In some environments, PDR can be used as a surrogate marker of ADR, despite endoscopist awareness that PDR is being measured.

Bayesian network meta-analysis: Efficacy of air insufflation, CO2 insufflation, water exchange, and water immersion in colonoscopy.

BACKGROUND AND AIM: Colonoscopy is an excellent screening tool for colorectal cancer. There are four colonoscopy techniques: air insufflation, CO2 insufflation, water exchange, and water immersion. Some studies reported that the latter three methods are better than the criterion standard (air insufflation), whereas some studies did not. In order to evaluate the efficacy of the four colonoscopy techniques, a network meta-analysis was carried out. METHODS: We searched randomized controlled trials (RCT) published up to September 2017 from PubMed, Embase, Cochrane library, and Web of Science. Studies referencing the comparison between at least two of air insufflation, CO2 insufflation, water exchange, and water immersion were selected. Primary outcomes included pain score during insertion, polyp detection rate, and adenoma detection rate, and secondary outcomes included cecal intubation time and cecal intubation rate. Mean differences or odds ratios and their corresponding 95% credible intervals were pooled with Bayesian modeling. RESULTS: Forty RCT with 13 734 patients were included in this network meta-analysis. Our analysis showed that air insufflation had the highest pain score (surface under the cumulative ranking curve [SUCRA]: 98.8%) and the lowest detection rate of adenoma (SUCRA: 21.3%) and polyp (SUCRA: 16.8%). Water exchange had the lowest pain score (SUCRA: 1.1%) and highest detection rate of adenoma (SUCRA: 96.0%) and polyp (SUCRA: 98.9%), although it led to the longest cecal intubation time (SUCRA: 86.9%). CONCLUSIONS: Air insufflation might be the most unsatisfactory colonoscopy. Meanwhile, water exchange might be the most efficient colonoscopy.

High-definition colonoscopy increases adenoma detection rate.

BACKGROUND: The adenoma detection rate (ADR) is a quality indicator for colonoscopy. High-definition (HD) imaging has been reported to increase polyp detection rates. OBJECTIVE: The primary objective of this study was to compare polyp detection rate (PDR) and adenoma detection rate (ADR) before and after the implementation of HD colonoscopy. METHODS: A retrospective chart review was performed on patients aged 48-55 years old, who underwent first-time screening colonoscopy. The first group underwent standard-definition (SD) colonoscopy in the first 6 months of 2011. The second group underwent screening with HD colonoscopy during the first 6 months of 2012. We compared age, gender, PDR, ADR, and average sizes of adenomatous polyps between gastroenterologist and colorectal surgeon and among physicians themselves. Statistical analysis was performed with Fischer's exact test and Pearson Chi-square. RESULTS: A total of 1268 patients were involved in the study (634 in each group). PDR (35.6 vs. 48.2 %, p < 0.001) and ADR (22.2 vs. 30.4 %, p = 0.02) were higher in the HD group. The average size of an adenomatous polyp was the same in the two groups (0.58 vs. 0.57, p = 0.69). However, this difference was not seen among colorectal surgeons PDR (35.7 vs. 37 %, p = 0.789), ADR (22.9 vs. 24.5 % p = 0.513), but clearly seen among gastroenterologist, PDR (35.6 vs. 53.1 % p < 0.001) and ADR (21.9 vs. 32.9 % p < 0.001). When polyps were categorized into size groups, there was no difference in ADR between the two timeframes (<5 mm in size (41.5 vs. 35.4 %), 5-10 mm (49.3 vs. 60.1 %) and >10 mm (9.2 vs. 4.5 %), p = 0.07). Polyps were most commonly seen in the sigmoid colon (26.1 vs. 24.7 %). There was no difference in the rate of synchronous polyp detection between modalities (25.6 vs. 29 %, p = 0.51). Withdrawal time was the same in both procedure (9.2 vs. 8.5 min, p = 0.10). CONCLUSION: Screening colonoscopy with high-definition technology significantly improved both PDR and ADR. In addition, high-definition colonoscopy may be particularly useful and advantageous among less experienced endoscopists in various community settings. However, there needs to be application to specific patient populations in future studies to assess for any statistical differences between standard- and high-definition modalities to determine clinical utility.