Water exchange colonoscopy improves adenoma detection, patient comfort

WASHINGTON — The water exchange method of colonoscopy was superior to both the water immersion and air or carbon dioxide insufflation techniques and supported patient comfort, according to research presented at Digestive Disease Week.

Perspective from Carol Burke, MD

Ashutosh Gupta, MD, of Texas Tech University, and colleagues performed a systematic review and meta-analysis to compare the efficacy of the three methods based on adenoma detection rate (ADR), as well as reduction in maximum pain score during insertion.

“Lately, there has been a lot of interest in optimizing the technique of the colonoscopy to obtain better results,” Gupta wrote in an email to Healio Gastroenterology and Liver Disease. “Water exchange [WE], water immersion [WI] and air or carbon dioxide insufflation [AI] are established but variably accepted techniques of colonoscopy.”

Gupta and colleagues included 30 randomized controlled trials totaling 9,077 patients in their meta-analysis. In addition to ADR and pain scores, they included cecal intubation rate, total time for colonoscopy, cecal intubation time, position changes, willingness to repeat colonoscopy and the quality of the bowel preparation as secondary outcomes for the study.

The data showed that WE helped increase ADR compared with both AI (OR = 1.45; 95% CI, 1.3–1.62) and WI (OR = 1.36; 95% CI, 1.1–1.67). Further, WE was associated with lower maximum pain score compared with AI (mean difference [MD] = –1.73; 95% CI, –2.23 to –1.24) and with WI (MD = –0.94; 95% CI, –1.21 to –0.66).

Gupta said that the WE technique receives criticism because of the added time it takes to complete. However, researchers found that the mean increase in time was just 1.45 minutes, which Gupta said was justified by the increase in ADR.

Investigators also found that there was less need for abdominal compression with the WE methods, as well as an increased willingness from patients to undergo repeat colonoscopies.

Gupta said that the WE technique is preferable to WI and AI for both screening and surveillance colonoscopy.

“Using water exchange method will thus help in decreasing interval cancer,” he said. “Procedures can be performed with less pain to the patients undergoing the procedure with conscious or no sedation and will lead to an increased willingness to repeat the procedure. – by Alex Young

Reference:

Gupta A, et al. Poster Mo1687. Presented at: Digestive Disease Week; June 2-5, 2018; Washington, D.C.

Disclosures: Gupta reports no relevant financial disclosures. Please see the DDW faculty disclosure index for a list of all other authors’ relevant financial disclosures.

Perspective

Carol Burke, MD

The technical performance of colonoscopy has come a long way in the last 40 years. The strong inverse correlation between adenoma detection rate (ADR) and the incidence and mortality of interval colorectal cancer is irrefutable. While national quality statements recommend the average risk screening ADR be 30% or greater in men and 20% or greater in women, respectively, the highest protection against CRC is afforded to patients undergoing procedures by physicians with the highest ADRs. The meta-analysis of numerous contemporary colonoscopy studies by Gupta, et al. highlights the benefit of water exchange (WE) colonoscopy over air insufflation (AI) or water immersion (WI) on ADR with only a 1.5-minute increase in procedure time. However, what I believe is most striking about the studies evaluated in the meta-analysis is the ADR. In the comparison of the 11 WE vs. AI studies, every WE study but one had an ADR of 34% or greater (range 18%-67%) and only two studies in the AI arm had an ADR less than 20% (range 14%-58%). I believe these high ADRs reflect the pervasive understanding by endoscopists of the importance of quality colonoscopy. I believe that WE should be a technique learned by all colonoscopists and to include in our armentarium to enhance the efficacy of colonoscopy. We await studies which demonstrate the impact of WE on interval CRC compared to AI or WI.

Carol Burke, MD

Department of Gastroenterology and Hepatology

Cleveland Clinic

Disclosures: Burke reports financial ties to Cancer Prevention Pharmaceuticals, Ferring Pharmaceuticals, Sucampo and Aries Pharmaceuticals.