P1987 - Real Time Maximum Insertion Pain in Unsedated Colonoscopy - Water Exchange vs Water Exchange Plus Cap: A Multi-Site, Multi-Investigator Randomized Controlled Trial in Veterans

Felix W. Leung, MD, FACG¹, Ramsey Cheung, MD, PhD², Shai Friedland, MD³, Noam Jacob, MD⁴, Joseph Leung, MD, MACG⁵, Jennifer Pan, MD, MS², Susan Y. Quan, MD², James Sul, MD⁶, Andrew Yen, MD⁵, Nora Jamgotchian, MS¹, Yu Chen, MD⁷, Dixit Vivek, PhD¹, Aliya Sheikh, MS⁵, David Elashoff, PhD⁸, Angshuman Saha, MS⁸, Holly Wilhalme, MS^8
1Sepulveda ACC/VAGLAHS/UCLA, North Hills, CA; ²VA Palo Alto Health Care System/Stanford University, Palo Alto, CA; ³VA Palo Alto Health Care System/Standford University, Palo Alto, CA; ⁴VAGLAHS/UCLA, Los Angeles, CA; ⁵Sacramento VAMC, Veterans Affairs Northern California Healthcare System, Mather, CA; ⁶VAGLAHS, Los Angeles, CA; ⁷VA Palo Alto Health Care System, Palo Alto, CA; ⁸UCLA, Los Angeles, CA

Introduction: Water exchange (WE) and cap-assisted colonoscopy independently reduced insertion pain in unsedated colonoscopy. In pilot investigation, WE combined with cap (WECAC) lowered insertion pain. We hypothesize that real-time maximum insertion pain (RTMIP) is significantly lower in unsedated Veterans in a randomized controlled trial (RCT) of WECAC vs. WE.

Methods: Veterans across 3 sites presenting for unsedated colonoscopy were recruited, randomized and examined by 9 colonoscopists. Demographic and patient characteristics were recorded. Subjects were blinded to method. The highest segmental pain (0=no pain, 9=worst pain) during insertion yielded the RTMIP. RTMIP was analyzed with logistic regression using binarized (0 or 1) RTMIP score with a threshold of 0.5 (“no pain” vs. “some pain”) and 7.5 (“no or manageable pain” vs. “severe pain”) as the dependent variable. p < 0.05 was significant.

Results: Screening (84), surveillance (180) and FIT+ (13) cases were included. WE (135) and WECAC (142) were successful in 93% and 92%, respectively. Failure was due to poor preparation (9), stricture (1), technical difficulty (3) and other (2). Table 1A shows racial/ethnic distributions. The mean RTMIP was low in both groups and did not differ (Table 1B). Logistic regression revealed LA & SAC site (p=0.0058), high volume of water infused (p=0.0111) and suctioned (p=0.0241) were significantly associated with no pain. Low body mass index (p=0.0124), poor self-reported health (p=0.0165), and low weight (p=0.0176) were significantly associated with “severe pain”. Colonoscopy method was not significant for any RTMIP cutoff. Adenoma detection rates and adenomas per colonoscopy were satisfactorily high in both groups (Table 1B).

Discussion: In a single (patient) blinded multicenter RCT, WE and WECAC similarly yielded high success and low RTMIP in a racially diverse group of male and female Veterans. This study attests to both the feasibility of unsedated colonoscopy in those without escort and its utility in providing alternative option and access to Veterans who would otherwise have to forgo colonoscopy, including for urgent indications (e.g., FIT+). Intention-to-treat analysis showed high success rates and high adenoma detection rates ( >45%), consistent with quality examinations. Suction of all infused water during insertion (as original WE) is associated with pain reduction and addition of a cap does not further reduce it. Inadequate water exchange and patient specific factors contribute to high RTMIP.


Disclosures:


Felix W. Leung, MD, FACG¹, Ramsey Cheung, MD, PhD², Shai Friedland, MD³, Noam Jacob, MD⁴, Joseph Leung, MD, MACG⁵, Jennifer Pan, MD, MS², Susan Y. Quan, MD², James Sul, MD⁶, Andrew Yen, MD⁵, Nora Jamgotchian, MS¹, Yu Chen, MD⁷, Dixit Vivek, PhD¹, Aliya Sheikh, MS⁵, David Elashoff, PhD⁸, Angshuman Saha, MS⁸, Holly Wilhalme, MS⁸. P1987 - Real Time Maximum Insertion Pain in Unsedated Colonoscopy - Water Exchange vs Water Exchange Plus Cap: A Multi-Site, Multi-Investigator Randomized Controlled Trial in Veterans, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.