Air Insufflation Colonoscopy Research Articles

S180 Adenoma Detection Rate (ADR) and Mean Adenoma Per Patient (MAP) With the Perfectly Clean Colon: Water Exchange (WE) vs Air Insufflation (AI) Colonoscopy

S180 Adenoma Detection Rate (ADR) and Mean Adenoma Per Patient (MAP) With the Perfectly Clean Colon: Water Exchange (WE) vs Air Insufflation (AI) Colonoscopy

Clinical value of sigmoid colon water exchange colonoscopy: a prospective randomized clinical trial

This prospective randomized controlled trial investigated the clinical value of sigmoid colon water exchange (SWE) colonoscopy by comparing it with air insufflation (AI) colonoscopy in terms of the patient’s pain score, insertion time, and screening quality. Consecutive patients who underwent colonoscopy without sedation were randomized into an AI group (n = 267) or an SWE group (n = 255). Patient characteristics, history of abdominal or pelvic surgery, maximum pain score, insertion time, cecal intubation rate, polyp detection rate, and the need for maneuvers were recorded. There was no significant between-group difference in insertion time, cecal intubation rate, assisted maneuvers (abdominal pressure, changing patients’ position), or polyp detection rate (P > 0.05). The mean maximum pain score was significantly lower in the SWE group than in the AI group. (3.57 ± 2.01 vs. 4.69 ± 1.83, P < 0.001). For patients with a history of abdominal or pelvic surgery and those who were overweight (body mass index > 24), the maximum pain scores were lower in the SWE group than in the AI group (3.67 ± 1.95 vs. 4.88 ± 1.80, P < 0.001; 3.40 ± 1.96 vs. 4.79 ± 1.97, P < 0.001, respectively). SWE colonoscopy can significantly reduce abdominal pain with non-inferior screening quality and does not increase insertion time.Trial registration number: ChiCTR2200059057 (date April 23, 2022).

Effectiveness of Water-Assisted Colonoscopy without Sedation in Patients with Ulcerative Colitis

Background: Studies have found that water-assisted colonoscopy (WAC) including water immersion colonoscopy (WIC) and water exchange colonoscopy (WEC) is superior to air insufflation colonoscopy (AIC) in terms of the cecal intubation rate. However, the application of WAC in ulcerative colitis (UC) has rarely been reported. This study aimed to explore the effectiveness of WAC without sedation in patients with UC. Methods: One hundred and seventy-two UC patients were randomly divided into the AIC group (n = 56), WIC group (n = 58), and WEC group (n = 58). The cecal intubation rate, abdominal pain score, operator difficulty, bowel cleanliness, insertion, and total time were compared. Results: The cecal intubation rate was higher in the WIC (91.4% vs. 75.0%; mean difference = 16.4%; 95% CI: 3.0–29.8%) and WEC (93.1% vs. 75.0%; mean difference = 18.1%; 95% CI: 5.0–31.2%) compared to the AIC group, while there was no difference between the WIC and WEC groups. The abdominal pain score and operator difficulty were lower in the WIC and WEC groups than in the AIC group, while there was no difference between the WIC and WEC groups. The bowel cleanliness during withdrawal was higher in the WIC and WEC groups than in the AIC group, while the WEC was superior to WIC. Compared with the AIC and WIC groups, the insertion time and total time were longer in the WEC group, and there was no difference in the AIC group and WIC group. Conclusion: In comparison with AIC, WAC can increase the cecal intubation rate, reduce abdominal pain scores and improve bowel cleanliness in patients with UC.

Feasibility of salvage colonoscopy by water exchange for failed air-insufflated patients: a prospective, randomized, controlled trial

Background A complete colonoscopy is crucial for screening colorectal diseases and colorectal cancer. However, a failure rate of up to 43% still exists. Several studies have indicated that the water exchange method can enhance the cecal intubation rate while reducing discomfort of the patient. Water exchange colonoscopy (WEC) might be a salvage treatment for the patients who failed from air insufflation colonoscopy (AIC). We aimed to assess the feasibility of WEC as a salvage measure following the failure of conventional AIC Methods Patients willing to undergo unsedated colonoscopy at a tertiary-care referral center in China were randomly assigned 1:1 to WEC or AIC group for salvage after the initial AIC attempt failed. Patients were blinded to group assignment. The primary outcome was cecal intubation rate, the secondary outcomes included time to the cecum, maximum pain scores, and technical difficulty level. Results Recruited 104 patients were randomized to the WEC (n = 52) or AIC (n = 52) group. WEC significantly increased the cecal intubation rate (92.3% vs 73.1%; p = .02). The maximum pain scores and technical difficulty level in the WEC group were significantly lower than the AIC group during salvage procedure (p < .001). Conclusions This randomized, controlled trial confirms that the WEC significantly enhanced cecal intubation rate in difficult colonoscopy in unsedated patients after the failure of standard AIC. The increased cecal intubation rate, lower pain scores and technical difficulty level suggest WEC is a good alternative for incomplete unsedated colonoscopy. Clinical trial registration number: ChiCTR2100051483.

S175 Water Exchange Increased Advanced Adenoma Detection in the Ascending and Proximal Colon As Compared to Air Insufflation

Introduction: Randomized control trials (RCT) showed significant increase in adenoma detection rate (ADR) with water exchange (WE) compared with usual air or CO2 insufflation colonoscopy. Advanced adenoma detection rate (AADR) is a validated surrogate marker for colorectal cancer risk (GI Endosc Clin N Am 2002;12:1). There was limited data of the impact of WE on AADR, probably due to the small sample sizes of RCT. Pooled analysis of 6 published RCT suggested that WE significantly increased overall ADR and overall AADR of the entire colon (JCG 2020;54:212). The impact of WE on ADR and AADR in the ascending colon, where interval cancers tend to cluster (AJG 2014;109:1375), is unknown. We test the hypothesis that WE increased AADR by aggregating the data of 4 RCTs conducted by our group in Chiayi and Hualien, Taiwan. Methods: Data from 4 RCTs (NCT01894191, NCT02737514, NCT01535326, and NCT01699399) comparing WE and air insufflation were aggregated. The demographic characteristics, procedure related outcomes, ADR and AADR were tabulated. Results: Both the WE and air insufflation group included 503 patients. Table 1 shows that the demographic characteristics were similar between the two groups. WE had significantly shorter withdrawal time [mean (SD), 13.0 (6.8) vs 12.6 (8.5), P=0.017], and higher Boston Bowel Preparation Scale scores than the air insufflation group. The ratio of aspirate water volume to infused water volume at cecum (107%) indicated proper implementation of WE (Table 1). The WE group had significantly higher overall ADR (46.4% vs 54.9%, P=0.008), with the difference mainly occurring in the ascending colon (23.0% vs 30.9%, P=0.005) than the air insufflation group. The WE group had significantly higher AADR in the ascending (4.6% vs 7.8%, P=0.048) and proximal (6.4% vs 10.5%, P=0.023) colon. The overall AADR (16.3% vs 19.7%) was numerically higher in the WE group (P=0.189, possibly a type II error) (Table 1). Conclusion: Interval cancers tend to occur in the right and proximal colon. The beneficial effect for WE to increase right and proximal colon AADR (a validated surrogate marker for colorectal cancer risk) might hold the potential to reduce the occurrence of interval cancers. The aggregated data of 4 RCTs showed WE had significantly higher AADR in the right colon and proximal colon as compared to air insufflation. Future studies to evaluate the impact of WE on the occurrence of interval cancers are justified.Table 1.: †Chi-square test; ††Fisher’s exact test; *Mann-Whitney test; ADR, adenoma detection rate; AADR, advanced adenoma detection rate; BBPS, Boston Bowel Preparation Scale. Advanced adenoma was defined as an adenoma with a diameter of ≥ 10 mm, significant villous features (> 25%), or high-grade dysplasia. The ascending colon included the cecum, ascending colon and hepatic flexure. The proximal colon included the cecum, ascending and transverse colon.

Clinical effects of left-colon water exchange colonoscopy vs conventional air-insufflation colonoscopy

Clinical effects of left-colon water exchange colonoscopy vs conventional air-insufflation colonoscopy

Comparison of Water Immersion Versus Air Insufflation Colonoscopy Under Various Bowel Preparation Conditions.

To investigate the differences between water immersion (WI) and air insufflation (AI) for colonoscopy under various bowel preparation conditions. In this study, 526 outpatients were randomly assigned to two groups, namely a WI group (n = 263) and an AI group (n = 263). During the procedure, the quality of bowel preparation, abdominal pain score, cecal intubation rate (CIR), adenoma detection rate (ADR), the intubation times, and other indicators were recorded. After reaching the cecum, each group of patients was subdivided into one of four grades (excellent, good, fair, and poor) according to the quality of bowel preparation. Under various bowel preparation conditions, the pain scores of the AI group were higher than those of the WI group (P < .05), but there was no significant difference between the two groups in CIR (P > .05). For the WI group compared with the AI group, the cecal intubation time (CIT) was prolonged under good bowel preparation (P = .045) and fair bowel preparation (P < .001). No significant differences were observed between the two groups on ADR in all patients (P = .476). Compared with AI colonoscopy, WI colonoscopy can decrease colonoscopy-related pain in patients for unsedated colonoscopy under various bowel preparation conditions, but there is no significant difference in CIR. WI colonoscopy requires longer CIT in patients with good and fair bowel preparation conditions. WI colonoscopy does not significantly increase ADR.

A122 WATER EXCHANGE FACILITATES HIGH CECAL INTUBATION RATE FOLLOWING INCOMPLETE COLONOSCOPY

Abstract Background Incomplete colonoscopy is a complex problem that negatively affects the success of colon cancer screening programs. Failure to intubate the cecum is associated with a significant risk of missed colorectal cancer and increases costs through missed diagnoses and salvage investigations. Water exchange (WE) colonoscopy is associated with a high rate of patient comfort and cecal intubation (CI) and may be of value in preventing and following up on incomplete colonoscopy. Aims To estimate effectiveness of WE colonoscopy as initial salvage of incomplete colonoscopy. Methods All patients referred to the Kelowna Gastroenterology group for incomplete colonoscopy between Jan 2010 to Dec 2019 were included. Demographic, clinical, procedural, and pathological information were collected via retrospective chart review. Patients underwent WE colonoscopy by a single endoscopist. The outcomes evaluated were CI rate, sedation requirements, and adenoma detection. Results 116 patients met study criteria and underwent WE colonoscopy after a previously failed or incomplete colonoscopy for technical reasons. The mean age was 66 years (range 21–89). 83 (72%) patients were female. 53 (46%) patients had previous abdominal surgery, and 42 (36%) had previous pelvic surgery. 65 (56%) patients had previous bowel disease. 81 (70%) patients had previously incomplete conventional air insufflation (AI) colonoscopy, 9 (8%) patients had previously incomplete WE colonoscopy, and 5 (4%) patients underwent unsuccessful combination of WE and AI colonoscopy. 17 (15%) patients had previously incomplete flexible sigmoidoscopy, and 4 (3%) patients had previously incomplete water immersion colonoscopy. The most common cause of unsuccessful CI was redundant colon (n=39, 34%) followed by strictures/angulations (n=16, 14%). 105 (91%) patients underwent repeat WE colonoscopy only, while 7 (6%) patients had combination WE and AI colonoscopy and 4 (3%) patients had concurrent gastroscopy. CI was successful in 114 (98%) patients and unsuccessful in 2 (2%) patients. 87 (75%) study patients received conscious sedation, 16 (14%) opted for no sedation, and 7 (6%) attempted no sedation then switched to conscious sedation. 5 patients (4%) required general anesthesia. CI was achieved in all 16 unsedated patients. 236 polyps were identified in 79 (68%) patients, 2 (1%) of which were malignant. Conclusions There is no standardized approach to incomplete colonoscopy. In this cohort of patients with previous failed attempt at colonoscopy, WE as a primary technique was associated with a high success rate with minimal need for general anesthesia and a high rate of polyp detection. A significant rate of colon cancer was identified, similar to that seen in general screening populations. Funding Agencies None

Underwater Colonoscopy Training for Surgery Residents More Effective Than Air-Insufflation Colonoscopy Training

Underwater Colonoscopy Training for Surgery Residents More Effective Than Air-Insufflation Colonoscopy Training

284 Factors That Underpin the Increase in Right Colon Adenoma Detection Rate: A Pooled Analysis of Three Reports Comparing Water Exchange, Water Immersion, and Air Insufflation Colonoscopy

INTRODUCTION: Interval cancers due to missed adenomas tend to cluster in the right colon. Both water immersion (WI) and water exchange (WE) use water infusion to aid insertion. WI, which is easy to adopt at the discretion of the colonoscopist, removes water mainly during withdrawal. WE, which has evolved from WI, removes water mainly during insertion using new skills. WE, but not WI, provides insertion cleansing and improves bowel cleanliness. Reduced cleaning-related multi-tasking distractions from search for polyps, but not improved bowel cleanliness per se, is linked significantly to the improved adenoma detection rate (ADR) with WE (UEGJ Dec 5, 2018). In a pooled data analysis of three reports, WE significantly increased right colon adenoma detection rate (rADR) compared with WI and air insufflation (AI) (DDW 2019). However, the significant and independent factors that account for the increased rADR have not been described. We aim to assess the factors associated with an increase in rADR by multiple logistic regression analysis of the pooled individual patient data in the three aforementioned reports. METHODS: Three reports with data on rADR comparing WE with WI and AI were identified. The demographic and procedural data were extracted, pooled to optimize sample size and analyzed. Multiple logistic regression analysis was conducted using backward likelihood ratio selection procedure. RESULTS: Table 1 shows comparable pooled demographic data. Table 2 shows volume infused and suctioned confirm use of WE, WI and AI. WE has highest cleanliness scores, least use of adjunct maneuvers, and highest willingness to repeat. rADR of WE (22.4%) is significantly higher than those of WI (17.4%) (P = 0.009) and AI (15.7%) (P &lt; 0.001); but WI and AI are similar (reported 2019 DDW). Table 3 shows multiple logistic regression analysis (unreported): older age, shorter insertion time, longer withdrawal time, and WE; but not WI (when compared with AI), are significant and independent factors associated with a higher rADR. CONCLUSION: WE, compared with AI, was significantly associated with a higher rADR, adjusting for other confounding factors. The improved quality adds value to WE colonoscopy, and justifies the call to incorporate WE into colorectal cancer prevention programs. Since WE = WI + suction of water during insertion, the higher rADR of WE provides incentive for transitioning from WI to WE. The impact of WE on right colon interval cancers warrants further assessment.

551 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

INTRODUCTION: Advanced adenomas, defined as adenomas ≥10mm, significant villous features (&gt;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. CONCLUSION: WE appears to significantly increase AADR, especially in patient cohort with lower AADR. Cap and Endocuff does not have significant impact on AADR.

525 Impact of Water Exchange, Cap and Endocuff on Adenoma Detection Rate: An Indirect Comparison With Air Insufflation as the Common Comparator

INTRODUCTION: Adenoma detection rate (ADR) is an important quality indicator for colonoscopy. Interval cancer (IC) is associated with low ADR. Every 1% increase in ADR is associated with a 3% and 5% reduction of the risk of IC and fatal IC, respectively. Water exchange (WE) colonoscopy is considered the best insertion method for improving ADR when compared with water immersion and air insufflation (AI). Attachment devices such as cap and Endocuff also improve ADR. We assessed the effectiveness of improving ADR between WE, cap and Endocuff colonoscopy by indirect comparison with 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 including ADR among the outcomes. EMBASE, Medline, SCOPUS, and Cochrane Library were searched systematically for all RCTs that included 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: A total of 1,453 articles resulted from initial keywords search. 37 articles were identified based on titles and abstracts alone. After thorough review of full texts, and discussion between the investigators, 21 RCTs were included in the analysis. A total of 16,572 subjects underwent AI, WE, cap (CC) or Endocuff (EC) colonoscopy. ADR of WE, CC, and EC were compared to AI. Table 1 shows that there is a significant difference in ADR between AI and WE (24.2%, 30.8%, P = 0.0001). ADR in AI and EC were significantly different (41.7%, 48.0%, P = 0.0001). No significant difference in ADR exists between AI and CC, (36.8%, 36.6%, P = 0.92). ADR as a percentage change of AI in WE, EC and CC were 27.4%, 15.1% and -0.42%, respectively. We found that WE and EC significantly improved ADR while CC does not significantly change ADR. Compared to EC and CC, WE has a higher percentage increase in ADR. This greater increase in ADR by WE may be related to the low ADR in the AI group. CONCLUSION: The impact of the study method in enhancing overall ADR is more prominent with the WE method, especially in patient cohort with lower ADR.

174 The Effectiveness of Right vs. Left-lateral Starting Position in Unsedated Colonoscopy With Modified-Water Immersion Method Colonoscopy

INTRODUCTION: Water immersion (WI) which emphasizes removal of infused water during withdrawal significantly reduced pain and increased willingness to repeat unsedated colonoscopy compared with air insufflation (JIG 2013;3:12). One study in sedated patients with air insufflation colonoscopy method showed that right-lateral (RLP) vs. left-lateral (LLP) starting position improved abdominal discomfort and reduced cecal intubation time (AJG 2015;110:1576). We aim to determine if RLP may reduce the pain score and improve other parameters comparing with LLP in unsedated patients examined with a modified water immersion (m-WI) method which involved episodic water infusion and suction to facilitate insertion. METHODS: Consecutive symptomatic patients meeting the inclusion criteria were consented, enrolled and randomized. Both patients and colonoscopists were unblinded. Patients underwent unsedated colonoscopy with m-WI method with room temperature water. The suction procedure during insertion in this study was not only for fecal debris evacuation but also used as a method to facilitate passage through difficult colonic flexures. We infused the water as needed. The air pump was turned off during insertion. The examinations were performed by PB. The primary outcome of insertion pain was recorded by a visual analogue scale (VAS). We proposed bowel visualization scale (BVS) as shown in Figure 1 to evaluate the interference of fecal debris with cecal intubation rate and time (NCT03489824). RESULTS: Interim analysis was conducted for 105 recruited patients (54 in RLP and 51 in LLP) (74% of sample size). The procedural parameters are shown in Table 1. Changed patient position during colonoscopy showed that fixed position (RLP or LLP) was found in 8 RLP patients and 2 LLP patients; changed only into supine position: 36 patients in RLP and 30 patients in LLP; 3 RLP patients changed into supine then left lateral decubitus and 12 LLP patients changed into supine then right lateral decubitus. Table 1 shows that there was no significant difference between pain score of RLP and LLP. LLP showed faster cecal intubation time in general, in constipation sub group, and also in scale 2 of BVS as shown in Table 2. CONCLUSION: This study support that LLP may a better choice than RLP in performing m-WI colonoscopy examination in unsedated patients. Limitation: The endoscopist (PB) did not have RLP colonoscopy experience before the study was started.

Feasibility of sedation on demand in Taiwan using water exchange and air insufflation: A randomized controlled trial.

Completion of colonoscopy without sedation eliminates sedation cost and complications. Reported in the United States and Europe, on-demand sedation is not routine practice in Taiwan. Water exchange (WE), characterized by infusion and nearly complete removal of infused water during insertion, reduces insertion pain compared to air insufflation (AI) during colonoscopy. We evaluated the feasibility of on-demand sedation in Taiwan. In a randomized controlled trial of WE vs AI colonoscopy, we also aimed to determine if WE augmented the implementation by reducing insertion pain and decreasing sedation requirement. This prospective patient-blinded study randomized patients to AI or WE (75 patients/group) to aid insertion. The primary outcome was the proportion of patients completing without sedation. In the AI and WE groups, 76.0% and 93.3% (P=0.006) completed without need for sedation, respectively. The WE group had lower insertion pain score (mean [SD]) (4.0 [2.9] vs 2.1 [2.6], P<0.001), lower doses of propofol (25.7 [52.7] mg vs 9.1 [35.6] mg, P=0.012), and less time in the recovery room (3.4 [7.4] vs 1.5 [5.5], P=0.027) than the AI group. Patient satisfaction scores and willingness to repeat if needed in the future were similar. On-demand sedation was feasible in Taiwan. The completion rate without sedation was high in patients (76.0% with standard AI) open to the option (no prior intent to receive the standard of full or minimal sedation). WE augmented the implementation by reducing insertion pain and decreasing sedation requirement without adversely affecting patient satisfaction or willingness to repeat.

Factors Associated With Adenoma Detection in Propofol-sedated Patients.

To assess the factors associated with adenoma detection in propofol-sedated patients. Low adenoma detection rate (ADR) are linked to increased risk of interval cancer and related deaths. Compared with air insufflation (AI) colonoscopy, the method of water exchange (WE) significantly decreased insertion pain and increased ADR in unsedated patients. Deep sedation with propofol has been increasingly used in colonoscopy. One report suggested that WE significantly increased ADR in propofol-sedated patients, but the factors associated with adenoma detection were not analyzed. Post hoc multiple logistic regression analyses were performed based on pooled data from 2 randomized controlled trials to assess the factors associated with adenoma detection in propofol-sedated patients. Propofol-sedated patients (n=510) were randomized to AI and WE. The baseline characteristics were comparable. Multiple logistic regression analyses show that age, withdrawal time, indications (screening vs. diagnostic), and WE were significantly and independently associated with higher ADR. WE had fewer patients with inadequate Boston Bowel Preparation Scale score of <6. Despite a significantly shorter inspection time, WE had significantly higher overall ADR than AI, especially in those with adequate Boston Bowel Preparation Scale of ≥6. Right colon ADR (17.5% vs. 10.5%), flat ADR (32.3% vs. 19.4%), combined advanced and sessile serrated ADR (13.1% vs. 7.4%) of WE were significantly higher than those of AI. WE enhanced quality of colonoscopy in propofol-sedated patients by significantly improving colon cleanliness and overall ADR. Colonoscopists with patients under propofol sedation might consider evaluating WE method for performance improvement.

The advantages of water immersion colonoscopy in ambulatory service

The purpose of this prospective study was to compare patients' discomfort during water immersion (WI) colonoscopy without sedation or available on request, with that of patients during air insufflation (AI) colonoscopy with sedation, in the ambulatory setting. A prospective observational study was conducted in 100 patients who performed a colonoscopy between August 2015 and February 2016 in an Ambulatory Gastroenterology Center in Cluj-Napoca, Romania. They were divided into two branches A and B. Patients in Group A underwent a classic colonoscopy with AI and standard sedation (2 mg of midazolam and 50 mg of tramadol), while patients in Group B underwent an unsedated or on demand sedation colonoscopy with WI technique. The patients in group A presented a higher discomfort (statistically significant) compared to those in group B, and had also the median total discomfort score higher than those in group B. The patients in group A had also a higher discomfort score after examination. The total time of examination was the same in the two groups, but in group B the progression to cecum time was 3 minutes lower than for those in group A. A greater discomfort of the patient was correlated with the longer time required to reach the cecum. In conclusion, WI colonoscopy is superior to AI technique in reducing insertion pain, progression-to-cecum time, minimizing sedation requirements and also in the willingness to repeat the technique.

Mo1622 – Which Combo Works Best? a Comparison of Endocuff and Amplifeye in Underwater and Air-Insufflation Colonoscopy

Mo1622 – Which Combo Works Best? a Comparison of Endocuff and Amplifeye in Underwater and Air-Insufflation Colonoscopy

Tu1043 – Gastroenterology Fellows Have Similar Polyp, Adenoma and Sessile Serrated Adenoma Detection Rates with Underwater Colonoscopy Vs Air-Insufflation Colonoscopy Each Quarter of Fellowship

Tu1043 – Gastroenterology Fellows Have Similar Polyp, Adenoma and Sessile Serrated Adenoma Detection Rates with Underwater Colonoscopy Vs Air-Insufflation Colonoscopy Each Quarter of Fellowship

Clean and Clear Colonoscopy: Underwater Insertion Techniques Associated With Higher Rates of Adequate Bowel Prep

Introduction: Bowel preparation is a key determinant of colonoscopy quality, particularly when performed for colorectal cancer screening. Underwater colonoscopy (UW), performed using water exchange or water immersion techniques, has been suggested to improve bowel prep scores compared to air insufflation colonoscopy (AI). Objective: Determine if UW, compared to AI, are associated with higher rates of adequate bowel prep scores Methods: Colonoscopy quality data was collected prospectively at our single tertiary referral center beginning in June 2012. For this study, the dataset included all colonoscopies performed for screening or surveillance indications for which UW and AI were recorded (September 2014 to May 2017). 5037 colonoscopies, including 2841 underwater (UW) and 2196 air insufflation colonoscopies (AI), were included. These two groups were compared with respect to mean Boston Bowel Prep Scores (BBPS) overall and by location within colon, as well for number of procedures with “adequate” bowel prep, defined as an average BBPS score ≥8.0. Subgroup analysis was conducted on basis of gender, race and BMI. Statistical analysis was performed using unpaired T-test and Fischer's exact test. Results: Compared to AI, UW was associated with higher BBPS overall (7.8 vs. 8.0, p = 0.007), as well as in the transverse (2.6 vs. 2.7, p = 0.003), and left colon (2.6 vs. 2.7, p = 0.002). UW was also associated with significantly higher percentage of procedures with adequate bowel prep (73.2% vs. 76.5%, p = 0.009). On subgroup analysis, UW was associated with higher rates of adequate bowel preparation in women (75.2% vs 78.6%, p = 0.03), normal BMI individuals (73.1% vs. 78.3%, p = 0.006), and Caucasians (71.7% vs. 75.2%, p = 0.02). Liters of bowel preparation utilized was similar between the two groups (3.46L vs. 3.53L, p = 0.22). Conclusion: Adequate bowel preparation is necessary to allow for thorough inspection of the colon during screening and surveillance colonoscopy. Inadequate prep may obscure smaller or more subtle lesions, such as sessile adenomas, allowing them to progress towards malignancy. UW technique has many benefits, including improved patient tolerance, lower sedation requirements and higher adenoma detection rates. Our results indicate that UW is also associated with improved bowel preparation, providing further support for use of UW.Table: Table. Mean Boston Bowel Prep Scores (BBPS) in AI vs. UWTable: Table. Comparison of Rates of Adequate Bowel Prep in AI vs. UW

Comparison of Adenoma Detection Rate Between Water Exchange Colonoscopy and Air Insufflation Colonoscopy: A Meta-Analysis

Introduction: Colonoscopy is the preferred procedure for prevention of colorectal cancer by detecting its precursor lesion, adenomas. However, several studies have reported an adenoma miss rate of 10-25% despite technical improvements in endoscopic techniques. Adenoma detection rate(ADR) is an important quality indicator for colonoscopies. Water exchange(WE)technique has been shown to reduce postprocedural discomfort and also helpful in difficult colonoscopy. However its impact on ADR when compared to air insufflation(AI) has yield mixed results. We aimed to do a meta-analysis to answer this question Methods: Comprehensive literature search was performed in EMBASE, Scopus, Pubmed, Cochrane databases from 1946 to May 31, 2017 to identify potential articles. MeSH headings included in the search included adenoma detection rate, colonoscopy, water exchange, air insufflation. All references from the identified articles were further searched to find more articles. Studies were included if they reported ADR on cohorts of patients undergoing colonoscopy with WE and AI techniques. Odds ratio of ADR and cecal intubation time were compared between WE and AI. Statistical analysis were done using Revman version 5.3. Results: A total of 156 articles were identified from the search strategy and from articles identified through references and abstracts. A total of 11 studies met the inclusion criteria. Total number of patients included in the analysis was 6976(3483 in WE group, 3493 in AI group). WE technique improved ADR when compared to AI technique and the results were statistically significant(1.41; 95% CI 1.26-1.58) (image 1). There was no heterogeneity between the studies (I2=0%). Six studies reported cecal intubation time and the use of WE increased the cecal intubation time by an average of 3.42 minutes (95% CI 1.63-5.21) or 3 minutes 25 seconds.(image 2). Conclusion: WE technique is superior to AI technique with respect to adenoma detection rate during colonoscopy. However the disadvantage of WE in terms of longer cecal intubation time should be taken into account in interpretation of these results. WE also improves patient experience by reducing postprocedural abdominal discomfort and should be considered at least in patients with difficult colonoscopies.Figure: Adenoma detection rate.Figure: Mean difference of cecal intubation time.