Paul Shao, MD, MS1, Aileen Bui, MD1, Hui Jia, MD2, Felix Leung, MD, FACG3
1David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; 2VA Greater Los Angeles Healthcare System, North Hills, CA; 3Sepulveda Ambulatory Care Center, VAGLAHS, David Geffen School of Medicine at UCLA, North Hills, CA
Introduction: Advanced adenomas, defined as adenomas ≥10mm, significant villous features ( >25%), or high-grade dysplasia, are important targets for colorectal cancer screening. They represent the subpopulation of adenomas that are most likely to progress into carcinoma and are associated with increased risk for future CRC incidence. Advanced adenoma detection rate (AADR) is therefore an important measure in assessing new screening methods. Water exchange (WE) colonoscopy has been shown to improve AADR consistently while modern accessories, such as cap and endocuff, have variable impacts on AADR. We assessed the impact on AADR between WE, cap and Endocuff by indirect comparison with standard air insufflation (AI) as the common comparator.
Methods: A literature search was done to identify all relevant RCTs comparing WE, Cap and Endocuff with AI colonoscopy published since 2000 as full text in English and included AADR among the outcomes. EMBASE, Medline, SCOPUS, and Cochrane Library were searched systematically using the following terms in their titles, abstracts, or keyword lists: colonoscopy, and water exchange, cap, or Endocuff. Two investigators screened the articles manually and separately. The results were compared, and a discussion was held with a third investigator to resolve any discrepancies.
Results: 1,453 articles resulted from keywords search and were manually screened. 14 RCTs met criteria and were included in the analysis. A total of 12,085 subjects underwent AI, WE, cap (CC) or Endocuff-assisted (EC) colonoscopy. AADR of WE, CC, and EC were compared against AI. Table 1 shows that WE significantly increases AADR compared to AI (8.1% vs 6.0%, p=0.0001, Fisher exact test). CC does not significantly change AADR compared to AI (8.7% vs 8.2%, p=0.585). No significant difference in AADR exists between EC and AI (16.6% vs 17.0%, p=0.815). AADR in WE, CC, and EC as a percentage change of AI are 35.0%, 6.1% and -2.4%, respectively. While WE significantly increases AADR, CC and EC do not significantly impact AADR. Compared to CC and EC, WE has a higher percentage increase in AADR (vs the common comparator of AI). This may be related to the low AADR in the AI group in the WE trials.
Discussion: WE appears to significantly increase AADR, especially in patient cohort with lower AADR. Cap and Endocuff does not have significant impact on AADR.
Citation: Paul Shao, MD, MS; Aileen Bui, MD; Hui Jia, MD; Felix Leung, MD, FACG. P1278 - COMPARING ADVANCED ADENOMA DETECTION RATE OF WATER EXCHANGE, CAP, AND ENDOCUFF COLONOSCOPY: POOLED DATA OF RANDOMIZED CONTROLLED TRIALS WITH AIR INSUFFLATION AS THE COMMON COMPARATOR. Program No. P1278. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.