Comparing adenoma and polyp miss rates for total underwater colonoscopy versus standard CO(2): a randomized controlled trial using a tandem colonoscopy approach

Most large colorectal polyps missed by gastroenterology fellows at colonoscopy are sessile serrated lesions

Background and study aims  Data on adenoma and sessile serrated lesion (SSL) miss rates for gastroenterology fellows during colonoscopy are limited. We aimed to describe the miss rate of fellows based on a second examination by a colonoscopist with a high rate of detection. Patients and methods  Second- and third-year gastroenterology fellows at a single, tertiary center performed initial examinations. A single experienced attending doctor then performed a complete examination of the colon. We recorded the size and pathology of all lesions found at both examinations and calculated the adenoma and SSL miss rates for fellows. Results  Ten trainees performed 100 examinations. Miss rates for conventional adenomas and SSLs were 30.5 % and 85.7 %, respectively. Among pre-cancerous polyps ≥ 10 mm, 10 of 14 lesions missed were SSLs. Conclusions  While conventional adenoma detection skills of gastroenterology fellows are acceptable, SSL detection is poor.

Comparison of Right Colon Adenoma Miss Rates Between Water Exchange and Carbon Dioxide Insufflation: A Prospective Randomized Controlled Trial

GOALS

To test the hypothesis that water exchange (WE), when compared with carbon dioxide (CO2) insufflation, significantly reduces the right colon adenoma miss rate (rAMR) in a blinded randomized controlled trial with cap-assisted colonoscopy.

BACKGROUND

The unblinded consecutive group observational data showed that WE significantly decreased rAMR. The unblinded data are limited by potential bias.

STUDY

Consecutive patients aged 45 years or more were randomized to undergo insertion with WE or CO2. Withdrawal and polypectomy were performed with CO2 in both groups to the hepatic flexure. The colonoscope was reinserted to the cecum. A second colonoscopist re-examined the right colon. The second colonoscopist was unaware, but made a guess, of the initial insertion method. The number of additional adenomas divided by the total number detected in both examinations equaled rAMR.

RESULTS

Among 262 patients (131/group), demographic variables were similar. The body mass index was significantly higher in the WE group. Compared with CO2, WE significantly decreased rAMR [18.0% (33/183) vs. 34.6% (62/179), P=0.0025] and right colon serrated polyp miss rate [17.4% (27/155) vs. 39.3% (33/84), P=0.002]. Multivariate logistic regression analysis showed that WE was an independent predictor of rAMR (odds ratio, 0.42; 95% confidence interval, 0.21-0.86), and so was ≥2 adenomas in the right colon (odds ratio, 2.35; 95% confidence interval, 1.17-4.76). Whether the second colonoscopist guessed the insertion method correctly or not, and demographic and procedure variables were not associated with rAMR.

CONCLUSIONS

The randomized controlled trial validated unblinded observational data showing that WE significantly decreased rAMR and right colon serrated polyp miss rate (clinical trial registration number: NCT03845933).

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations

BACKGROUND AND AIMS

Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR.

METHODS

Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements.

RESULTS

In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11).

CONCLUSIONS

The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Predictive factors for adenoma detection rates: a video study of endoscopist practices

Background and study aims  In 2015, the American Society for Gastrointestinal Endoscopy (ASGE) and American College of Gastroenterology (ACG) Task Force on Quality in Endoscopy deemed adenoma detection rate (ADR) the most important quality measure for colonoscopy. There has been much interest in factors that can increase ADR. To date, however, few studies have looked at what intra-procedural endoscopist practices are associated with improving ADR. We conducted a retrospective review of colonoscopy videos to evaluate intra-procedural practices that could be associated with ADR. Methods  Videos were recorded of colonoscopies performed between September and December 2017 at the Palo Alto Veterans Affairs Health Care System. Colonoscopies for screening and surveillance were included for video review. Factors assessed included withdrawal time, intra-procedural cleaning, inspection technique, and other variables (colon distention, removal of equivocal/hyperplastic polyps). A series of multiple regression analyses was conducted on variables of interest before running a final model of significant predictors. Results  A total of 130 videos were reviewed from nine endoscopists whose ADRs ranged between 37.5 % and 73.7 %. The final regression model was significant (F = 15.35, df = 2, P  = 0.0044), R ²  = 0.8365) with close inspection of behind folds and quality of cecal inspection being the factors highly correlated with predicting ADR. Withdrawal and inspection times, colonic wall distention, removal of equivocal/hyperplastic polyps, quality of rectal inspection, suctioning, and washing were factors moderately correlated with predicting ADR. Conclusions  We found that behind-fold inspection and a meticulous cecal inspection technique were predictive of a high ADR.

Room temperature water infusion during colonoscopy insertion induces rectosigmoid colon mucus production

BACKGROUND

Water filling during colonoscopy improves several colonoscopy outcomes. We evaluated an anecdotal observation that room temperature water filling during colonoscope insertion results in mucus production in the left colon, which may impair mucosal visualization during withdrawal.

METHODS

We performed 55 colonoscopies with either water or saline filling during insertion, and video recorded the examinations. Three blinded observers scored the amount of mucus visible on the video recordings.

RESULTS

29 patients had water filling and 26 patients had saline filling during insertion. Demographic features, procedure indications, volume of infused fluid, and insertion time to the cecum were similar in the two groups. All three blinded observers rated the mucus as greater after water filling than after saline (median 3 out of 5 vs. 1 out of 5; P < 0.001), with a kappa value for interobserver agreement of 0.364 (P < 0.001).

CONCLUSION

Room temperature water filling is associated with mucus production by the rectosigmoid colon, requiring additional cleansing during withdrawal.

GIE Editorial Board top 10 topics: advances in GI endoscopy in 2019

The American Society for Gastrointestinal Endoscopy's GIE Editorial Board reviewed original endoscopy-related articles published during 2019 in Gastrointestinal Endoscopy and 10 other leading medical and gastroenterology journals. Votes from each individual member were tallied to identify a consensus list of 10 topic areas of major advances in GI endoscopy. Individual board members summarized important findings published in these 10 areas of disinfection, artificial intelligence, bariatric endoscopy, adenoma detection, polypectomy, novel imaging, Barrett's esophagus, third space endoscopy, interventional EUS, and training. This document summarizes these "top 10" endoscopic advances of 2019.

Colorectal Cancer Screening for the Serrated Pathway

Serrated polyps are classified into hyperplastic polyps, sessile serrated adenomas/polyps, and traditional serrated adenomas. Although all serrated polyps share characteristic colonic crypts serrations, distinguishing hyperplastic polyps from sessile serrated adenomas/polyps is challenging. Traditional serrated adenomas are cytologically dysplastic lesions; sessile serrated adenomas/polyps develop cytologic dysplasia as they progress to colorectal cancer. A flat and pale appearance of serrated polyps may make detection difficult. Endoscopic mucosal resection has higher rates of complete resection. Close surveillance is recommended for sessile serrated adenomas/polyps, sessile serrated adenomas/polyp with dysplasia, hyperplastic polyps ≥10 mm, and traditional serrated adenomas.

Efficacy and safety of water-exchange enteroscopy compared to carbon dioxide insufflation during enteroscopy

INTRODUCTION

carbon dioxide (CO2) insufflation during enteroscopy reduces procedure time and subsequent symptoms and increases the insertion depth compared with room air. In colonoscopy, the water-exchange (WE) technique is associated with less pain compared with CO2 insufflation. The WE technique is not well studied in enteroscopy. The aim of this study was to compare the efficacy and safety of enteroscopy with WE and CO2.

METHODS

a prospective, comparative and observational study was performed of double balloon enteroscopies (DBE) that were randomized in two groups. The first group used WE while the second group used CO2 insufflation. The data collected was evaluated via univariate analysis and multiple logistic regression (variables with p ≤ 0.10 according to the univariate analysis).

RESULTS

forty-six DBE were included; 23 in each arm. The median age of cases was 63.5 years and 37% were female. There were no statistical differences between the groups with regard to the access route, findings, therapy and complications. Four patients (20%) in the CO2 group had adverse events (abdominal distension and pain) and one in the WE group (nausea), which was not statistically significant. The median insertion depth was greater in the CO2 group; 260 cm vs 160 cm (p = 0.048). Multiple logistic regression showed a statistically significant difference in the insertion depth using CO2 insufflation (OR 1.009, 1.001-1.017; p = 0.034).

CONCLUSIONS

DBE with a CO2 insufflation technique and WE are safe with a greater insertion depth with CO2.

Underwater endoscopic mucosal resection without submucosal injection (UEMR) for large colorectal polyps: A community-based series

BACKGROUND

Underwater endoscopic mucosal resection without submucosal injection (UEMR) is an appealing therapy for large colorectal polyps. However, this technique is not practiced widely and there are limited data evaluating UEMR in community settings.

METHODS

The study comprised patients undergoing UEMR of large (≥20 mm) sessile colorectal lesions at a community-based center. Residual neoplasia was assessed via follow-up colonoscopy.

RESULTS

Among 264 lesions (diameter 38 ± 18 mm; range 20-110 mm) 99% were successfully resected with UEMR. Two lesions involving the cecum/IC valve required multiple sessions. There were no cases of perforation or post-polypectomy syndrome. Delayed bleeding occurred in 1.6%, all managed conservatively. Residual neoplasia was present in 5.7% and was amenable to UEMR.

CONCLUSION

This large community-based series demonstrated high efficacy and safety of UEMR for large sessile colorectal lesions. The results support UEMR as first-line therapy for these lesions.

SUMMARY

Underwater endoscopic mucosal resection without submucosal injection (UEMR) is a recently developed method that has advantages over conventional EMR for treatment of large colorectal lesions. However, UEMR is not practiced widely and there are limited data evaluating this technique in everyday practice. This large community-based series demonstrated high efficacy and safety of UEMR for large sessile colorectal lesions.

Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

BACKGROUND & AIMS

Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors.

METHODS

We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness.

RESULTS

Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75-1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6-9 mm was 0.62 (95% CI, 0.44-0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33-0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16-2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49-4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34-1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47-1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21-1.33) than women (0.86; 95% CI, 0.80-0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57-0.94).

CONCLUSIONS

In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men.

Water exchange colonoscopy decreased adenoma miss rates compared with literature data and local data with CO2 insufflation: an observational study

Background

Reports showed adenoma miss rates (AMRs) of 22.5–27% in the right colon and 23.4–33.3% in the proximal colon. Missed lesions could contribute to postcolonoscopy cancers. Water exchange (WE) with near-complete removal of infused water during insertion increased adenoma detection rate but the impact on AMR had not been reported. We hypothesized that WE could reduce AMRs. Study 1 compared the AMRs of WE with literature data. Study 2 developed local AMR data with CO₂ insufflation.

Methods

The lead author attended a research seminar in 2017 on WE colonoscopy. For performance improvement, study 1 was undertaken. When data in study 1 confirmed WE produced a considerably lower AMRs in the right and proximal colon, study 2 with CO₂ insufflation was performed.

Results

Eighty-six patients completed each study. In study 1, WE removed 89% of infused water upon arrival to the cecum. The AMRs of right colon (17.5%) and proximal colon (15.5%) were considerably lower than those in the literature. Upon completion of study 2, compared with local data of CO₂ insufflation, WE showed a significantly lower AMR in the right (17.5% vs. 33.8%, P = 0.034) and proximal (15.5% vs. 30.4%, P = 0.018) colon, respectively. The major limitation was that the investigation consisted of two consecutive observational studies, not a randomized controlled trial (RCT).

Conclusions

WE with near-complete (89%) removal of infused water during insertion significantly decreased AMRs in the right and proximal colon compared with literature data and those of CO₂ insufflation in our hands. The provocative data warrant confirmation in a RCT.

Trial registration

NCT03832322 (Retrospectively registered on February 2, 2019).