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

Optimized computer-assisted technique for increasing adenoma detection during colonoscopy: a randomized controlled trial

BACKGROUND

Efforts to improve colonoscopy have recently focused on improving adenoma detection through individual interventions. We evaluated an optimized computer-assisted technique (CADopt) versus standard colonoscopy.

METHODS

A prospective randomized controlled trial was conducted enrolling adults (45-80 years) undergoing elective colonoscopy. Participants were randomized (1:1) to the intervention group (CADopt), and control group. In the CADopt group, endoscopists used a computer-aided polyp detection combined with linked color imaging, water exchange colonoscopy, and cecal retroflexion. In the control group, standard colonoscopy was performed. Primary outcome was Adenoma Detection Rate (ADR) in the intervention and control groups. Secondary outcomes included polyp detection rate (PDR), advanced ADR (AADR), sessile-serrated lesion detection rates (SDR), and Adenoma per colonoscopy (APC).

RESULTS

A total of 467 patients were recruited and randomized (CADopt group 229 patients, 50.2% female vs 238 patients, 48.3% female in the control group). ADR was 49.3% (95% CI 42.7-56.0) for the CADopt group vs 38.2% (95% CI 32.0-44.7) for the control group (p = 0.016). PDR, AADR, SDR, and APC were 78.2% (95% CI 72.2-83.3), 13.1% (95% CI 9.0-18.2), 6.6% (95% CI 3.7-10.6), and 0.86 (95% CI 0.70-1.02) for the CADopt group versus 59.2% (95% CI 52.7-65.5), 8.0% (95% CI 4.9-12.2), 7.1% (95% CI 4.2-11.1), and 0.75 (95% CI 0.58-0.92) for the control group, respectively.

CONCLUSION

Using an optimized computer-assisted technique led to significant improvements in ADR, PDR, and a trend towards AADR improvements.

Minimal water exchange by the air-water valve versus left colon water exchange in unsedated colonoscopy: a randomized controlled trial

BACKGROUND

Water exchange colonoscopy is the least painful method for unsedated colonoscopies. Simplified left colon water exchange (LWE) reduces the cecal intubation time but it is difficult to avoid the use of an additional pump. Minimal water exchange (MWE) is an improved novel method that eliminates the need for pumps, but it is not clear whether MWE has the same efficiency as LWE.

METHODS

This was a prospective, randomized, controlled, noninferiority trial conducted in a tertiary hospital. Enrolled patients were randomized 1:1 to the LWE group or MWE group. The primary outcome was recalled insertion pain measured by a 4-point verbal rating scale. Secondary outcomes included adenoma detection rate (ADR), cecal intubation time, volume of water used, and patient willingness to repeat unsedated colonoscopy.

RESULTS

226 patients were included (LWE n = 113, MWE n = 113). The MWE method showed noninferior moderate/severe pain rates compared with the LWE method (10.6 % vs. 9.7 %), with a difference of 0.9 percentage points (99 % confidence interval [CI] -9.5 to 11.3; threshold, 15 %). ADR, cecal intubation time, and willingness to repeat unsedated colonoscopy were not significantly different between the two groups, but the mean volume of water used was significantly less with MWE than with LWE (163.7 mL vs. 407.2 mL; 99 %CI -298.28 to -188.69).

CONCLUSION

Compared with LWE, MWE demonstrated a noninferior outcome for insertion pain, and comparable cecal intubation time and ADR, but reduced the volume of water used and eliminated the need for a water pump.

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).

Effect of water exchange method on adenoma miss rate of patients undergoing selective polypectomy: A randomized controlled trial

BACKGROUND

Adenomas may be missed in up to 40% of screening colonoscopies. Although the water exchange (WE) method can improve ADR, as shown in several RCTs, it remains uncertain whether it can increase the detection of missing adenomas compared with standard air-insufflated (AI) colonoscopy.

METHODS

Patients aged 18-80 years who underwent selective polypectomy were randomly allocated to the WE or AI group. The primary endpoint was the adenoma miss rate (AMR), defined as the number of patients with one or more additional adenomas during the polypectomy procedure divided by the total number of patients in each group.

RESULTS

A total of 450 patients were enrolled, with 225 in each group. The overall AMRs were 45.8% (103/225) in the WE group and 35.6% (80/225) in the AI group (p = 0.035). More patients in the WE group had at least one missed adenoma in the proximal colon (38.2% vs 24.4%, p = 0.002). The adenoma-level miss rate was also higher in the WE group than in the AI group (35.1% vs 29.0%, p = 0.036). Subgroup analysis showed that patients in the WE group had more missed adenomas located in the proximal colon or with flat shapes.

CONCLUSIONS

This study confirmed that substantial adenomas were missed in patients undergoing selective polypectomy. The WE method significantly improved the detection of missed adenomas, especially those located in the proximal colon or with flat shapes. (ClnicalTrials.gov number: NCT02880748).

A review of water exchange and artificial intelligence in improving adenoma detection

Water exchange (WE) and artificial intelligence (AI) have made critical advances during the past decade. WE significantly increases adenoma detection and AI holds the potential to help endoscopists detect more polyps and adenomas. We performed an electronic literature search on PubMed using the following keywords: water-assisted and water exchange colonoscopy, adenoma and polyp detection, artificial intelligence, deep learning, neural networks, and computer-aided colonoscopy. We reviewed relevant articles published in English from 2010 to May 2020. Additional articles were searched manually from the reference lists of the publications reviewed. We discussed recent advances in both WE and AI, including their advantages and limitations. AI may mitigate operator-dependent factors that limit the potential of WE. By increasing bowel cleanliness and improving visualization, WE may provide the platform to optimize the performance of AI for colonoscopies. The strengths of WE and AI may complement each other in spite of their weaknesses to maximize adenoma detection.

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.