Air Insufflation Colonoscopy Research Articles

Turning the Tides of Training: Underwater Colonoscopy Is Associated With Higher Polyp, Adenoma and Sessile Serrated Adenoma Detection Rates Among Gastroenterology Fellows

Introduction: Underwater colonoscopy has been associated with increased patient tolerance and decreased need for sedation compared to traditional air-insufflation colonoscopy. The effect of underwater colonoscopy on polyp detection has not been as thoroughly assessed, especially among those in gastroenterology fellowship. Our objective was to determine if GI fellows performing underwater colonoscopies have higher detection rates of polyps, adenoma and sessile serrated adenomas compared to fellows performing air-insufflation colonoscopies.Figure: Percent Improvement in Detection Rates with Underwater vs. Air-Insufflation Colonoscopy.Table: Table. Baseline CharacteristicsTable: Table. Average Polyp Detection Rates in Underwater vs. Air-Insufflated ColonoscopyMethods: Colonoscopy quality data was collected prospectively at our single tertiary referral center from June 2012 to May 2017 using Qualoscopy (Docbot, Inc.). 29 GI fellows performed 2270 colonoscopies (1237 underwater (UW) and 1033 air-insufflation (AI)). UW and AI cases were compared for detection rates of polyps (PDR), adenomas (ADR), and sessile serrated adenoma (SSADR), as well as procedure times and cecal intubation rates. Subgroup analysis included polyp location. Significance was determined by a two-tailed Fischer's exact test and T-test. Results: UW compared to AI was associated with a higher PDR (77.0% vs. 69.3%, P=0.0001), ADR (53.1% vs. 48.2%, P=0.02) and SSDAR (15.6% vs. 10.2%, P=0.0001) among fellow-performed colonoscopies. Significant differences were retained in the left colon for ADR (29.2% vs. 23.6%, P=0.003) and SSADR (7.10% vs. 3.20%, P=0.0001). In the right colon, significant differences were retained for PDR (60.9% vs. 50.5%, P=0.0001) and SSADR (13.0% vs. 9.60%, P=0.01). Insertion time (14.1 vs. 13.9min, P=0.96), withdrawal time (24.5 vs. 21.9min, P=0.29), total time (38.6 vs. 35.8min, P=0.46) and cecal intubation rates (98.9% vs. 98.8%, P=0.44) were similar within UW and AI colonoscopy, respectively. Conclusion: GI fellow-performed UW colonoscopy compared to air-insufflation colonoscopy is associated with higher PDR, ADR and SSDAR. This data supports future prospective randomized studies to verify improved polyp detection with underwater colonoscopy and suggest that underwater techniques should be included in the training curriculum of GI fellows to further improve colonoscopy quality and reduce interval colorectal cancers.

Perfect Boston Bowel Preparation Score and Adenoma Detection Rate: Air Insufflation versus Water Exchange Colonoscopy

Perfect Boston Bowel Preparation Score and Adenoma Detection Rate: Air Insufflation versus Water Exchange Colonoscopy

Carbon dioxide insufflation during colonoscopy in inflammatory bowel disease patients: a double-blind, randomized, single-center trial.

Bowel distension by insufflated air causes abdominal discomfort after colonoscopy. Carbon dioxide (CO2) instead of air insufflation during colonoscopy can reduce postprocedural discomfort in diagnostic and screening cases. Discomfort after colonoscopy and CO2 insufflation have never been studied in inflammatory bowel disease (IBD) patients, characterized by younger age, structural changes of the colon, and need for repeated and frequently uncomfortable colonoscopies. Our trial was designed to evaluate postprocedural discomfort associated with CO2 compared with air insufflation in unsedated or minimally sedated patients with known IBD. In a double-blind, randomized, single-center study, 64 patients were randomized to either CO2 insufflation (CO2) or air insufflation colonoscopy (Air). Abdominal pain, bloating, and flatulence scores during 24 h after colonoscopy were recorded using a continuous scale of 0-10 (0=none, 10=maximum discomfort). The primary endpoint used for power calculation was bloating score at 1 h after colonoscopy. Pain, bloating, and flatulence scores at end, 1, and 3 h after colonoscopy were significantly lower in CO2 than in Air arm (P<0.001). Scores at 6, 12, and 24 h were comparable. Procedural parameters such as cecal and terminal ileum intubation rate, intubation and total time, pain during insertion, need for repositioning, and abdominal compression were not different between arms. No complications were recorded in the study. Compared with air, CO2 insufflation significantly reduces abdominal pain, bloating, and flatulence scores during at least 3 h after colonoscopy in IBD patients, achieving comparable intraprocedural outcomes.

Carbon dioxide insufflation or warm-water infusion for unsedated colonoscopy: A randomized controlled trial in patients with chronic constipation in China.

Aims:The effect of carbon dioxide (CO2) insufflation and warm-water infusion during colonoscopy on patients with chronic constipation remains unknown. We evaluated CO2 insufflation and warm-water irrigation versus air insufflation in unsedated patients with chronic constipation in China.Patients and Methods:This randomized, single–center, controlled trial enrolled 287 consecutive patients, from January 2014 to January 2015, who underwent colonoscopy for chronic constipation. Patients were randomized to CO2 insufflation, warm-water irrigation and air insufflation colonoscopy insertion phase groups. Pain scores were assessed by the visual analog scale (VAS). The primary outcome was real-time maximum insertion pain, recorded by an unblinded nurse assistant. At discharge, the recalled maximum insertion pain was recorded. Meanwhile, patients were requested to select the VAS at 0, 10, 30, and 60 min after the procedure. In addition, cecal intubation and withdrawal time, total procedure time, and adjunct measures were recorded.Results:A total of 287 patients were randomized. The correlation between real-time and recalled maximum insertion pain ((Pearson coefficient r = 0.929; P < 0.0001) confirmed internal validation of the primary outcome. The mean real-time maximum pain scores during insertion 2.9 ± 2.1 for CO2, 2.7 ± 1.9 for water achieved a significantly lower pain score compared with air (5.7 ± 2.5) group (air vs CO2 P < 0.001; air vs water P < 0.001). However, no significant pain score differences were found between the patients in the CO2 and water groups (CO2 vs water, P = 0.0535). P values in painless colonoscopy and only discomfort colonoscopy (pain 1–2) were, respectively, 6 (6.4%) and 8 (8.5%) for air; 17 (17.7%) and 29 (30.2%) for CO2; 16 (16.5%) and 31 (31.9%) for water. At 0, 10, 30, and 60 min postprocedure, pain scores showed in the CO2 and water groups had significantly reduced than in air group. Insertion time was significantly different between air (10.6 ± 2.5) and CO2 (7.2 ± 1.4) (air vs CO2 P < 0.001), air and water (6.9 ± 1.3) (air vs water P < 0.001). However, CO2 and was not significantly different in cecum-intubated time (CO2 vs water, P = 0.404). CO2 and water group in extubation time were significantly different, respectively, CO2 (7.9 ± 1.1) and water (8.0 ± 1.1) (CO2 vs water, P = 0.707). CO2 or water group required less implementation of adjunct measures and more willingness to repeat the procedure.Conclusions:Compared with air, the CO2 or water-aided method reduced real-time maximum pain and cecum-intubated time for chronic constipated patients in unsedated colonoscopy. The CO2 insufflation or warm-water irrigation may be a simple and inexpensive way to reduce discomfort in unsedated patients with constipation. This study demonstrated an advantage of using CO2 insufflation and warm-water irrigation during colonoscopy in unsedated constipated patients in China.

A randomized controlled study of water exchange colonoscopy and air insufflation colonoscopy

Objective To investigate the clinical application prospect of water exchange colonoscopy. Methods A total of 300 outpatients who underwent unsedated colonoscopy were randomized to the WEC group(n=150)or the AIC group(n=150). The maximum pain score, insertion time, the cecal intubation rate and the polyp detection rate were reported by an assistant during the insertion phase and at the end of colonoscopy. Results The maximum abdominal pain scores were 1.77±1.29 in the WEC group and 2.84±1.55 in the AIC group with significant difference(P=0.000). The intubation time of WEC was longer than that of AIC(11.91±3.58 VS 8.03±3.19, P=0.000)with no significant difference. There was no significant difference in the cecal access rate between the two groups(97.3% VS 94.0%, P=0.157). The polyp detection of WEC was higher than that of AIC(16.7% VS 10.0%, P=0.089). In the post abdominal operation subject of colonoscopy procedure, WEC had higher rate of cecal intubation than AIC, the maximum abdominal pain score were 2.25±1.63 in the WEC group, lower than 3.48±1.45 in the AIC group. Conclusion Water exchange colonoscopy can alleviate patients' abdominal pain symptoms, but with longer insertion time. There are no significant difference in the cecal access rate and the polyp detection rate between two groups. For difficult colonoscopy, water exchange colonoscopy is helpful to increase the rate of cecal intubation. Key words: Colonoscopy; Polyp detection rate; Water exchange colonoscopy; Air immersion colonoscopy

Randomized-Controlled Trial Comparing Adenoma Detection Rate Using Water Exchange Versus Air Insufflation Colonoscopy in a U.S. Community-Based Setting

Introduction: Efforts are underway to improve adenoma detection rate during screening colonoscopies, especially in the right colon. Water exchange colonoscopy has demonstrated promising results, purportedly by better cleansing of the colon, and has also resulted in less patient discomfort. Majority of these studies were conducted in a predominantly male and Caucasian VA population. We report the first community-based RCT in the USA that includes female and minority populations, comparing water exchange with air insufflation method in assessing adenoma detection rate. Methods: A prospective sample of 178 patients above 50 years of age presenting for screening and surveillance colonoscopies at a community-based endoscopy center, with no personal or family history of colon cancer, familial polyposis syndromes, inflammatory bowel disease, or prior history of colonic surgery, who consented for the study were blinded and randomized to either water exchange (n=88) or air insufflation colonoscopy (n=88). Four endoscopists participated in the trial. All patients received adequate sedation prior to scope insertion, followed by sequential doses as needed. All patient received a split bowel prep. Prep quality was assessed by the Boston Bowel Prep Score. Post-procedure pain and recovery time were assessed by a nurse blinded to the colonoscopy technique. All colon polyps were assessed by expert GI pathologists. Sessile serrated lesions were reported when found. Advanced adenomas were defined as villous or tubulovillous in histology, or size > 1 cm. Adenomas found proximal to splenic flexure were reported as proximal adenomas. Results: Of 178 patients, 3 were excluded from final analysis, 1 in the air group diagnosed with FAP, and 2 in the water group requiring switch to pediatric colonoscopes due to tortuous sigmoids. There were no statistically significant differences between the 2 groups in terms of sex, race (Caucasian, Black, Hispanic, Asian), age, BMI, alcohol and tobacco use, bowel prep quality, sedation requirement, abdominal pressure application, patient position change, endoscope stiffner use, or scope length at cecum. The cecum was intubated in all patients. Conclusion: Water exchange colonoscopy is a viable technique in a busy community-based endoscopy center. It demonstrated a trend towards higher polyp, adenoma, sessile serrated lesion and advanced adenoma detections. It resulted in significantly lower post procedure pain and recovery time, without significantly increasing procedure time.Table 1: Baseline patient characteristicsTable 2: Polyp detection rates, procedure and recovery times, and post procedure pain

Water infusion versus air insufflation for colonoscopy.

Colonoscopy is a widely used diagnostic and therapeutic modality. A large proportion of the population is likely to undergo colonoscopy for diagnosis and treatment of colorectal diseases, or when participating in colorectal cancer screening programs. To reduce pain, water infusion instead of traditional air insufflation during the insertion phase of the colonoscopy has been proposed, thereby improving patients' acceptance of the procedure. Moreover, the water infusion method may improve early detection of precancerous neoplasms. To compare water infusion techniques with standard air insufflation, specifically evaluating technical quality and screening efficacy, as well as patients' acceptance of the water infusion procedure. We searched the Cochrane Colorectal Cancer Group Specialized Register (February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 1), Ovid MEDLINE (1950 to February 2014), Ovid EMBASE (1974 to February 2014), and ClinicalTrials.gov (1999 to February 2014) for eligible randomised controlled trials. We included randomised controlled trials comparing water infusion (water exchange or water immersion methods) against standard air insufflation during the insertion phase of the colonoscopy. Two review authors independently assessed the studies for inclusion and extracted data from eligible studies. We performed analysis using Review Manager software (RevMan 5). We included 16 randomised controlled trials consisting of 2933 colonoscopies. Primary outcome measures were cecal intubation rate and adenoma detection; secondary outcomes were time needed to reach the cecum, pain experienced by participants during the procedure, completion of cecal intubation without sedation/analgesia, and adverse events. Completeness of colonoscopy, that is cecal intubation rate, was similar between water infusion and standard air insufflation (risk ratio 1.00, 95% confidence interval (CI) 0.97 to 1.03, P = 0.93). Adenoma detection rate, that is number of participants with at least one detected adenoma, was slightly improved with water infusion (risk ratio 1.16, 95% CI 1.04 to 1.30, P = 0.007). Assuming the fraction of patients undergoing screening colonoscopy who had one or more adenomas detected was 20 per 100 with standard colonoscopy, the use of water colonoscopy may increase the fraction to 23 per 100 individuals. From our findings, it is possible that up to 68,000 more of the 1.7 million outpatient screening colonoscopies performed annually in the United States, could detect adenomas if water infusion colonoscopy was used. In addition, with water infusion participants experienced significantly less pain (mean difference in pain score on a 0 to 10 scale: -1.57, 95% CI -2.00 to -1.14, P < 0.00001) and a significantly lower proportion of participants requested on-demand sedation or analgesia, or both (risk ratio 1.20, 95% CI 1.14 to 1.27, P < 0.00001). Qualitative analysis suggests that water infusion colonoscopy was not associated with a markedly increased rate of adverse events compared with the standard procedure. Completeness of colonoscopy, that is cecal intubation rate, was not improved by water infusion compared with standard air insufflation colonoscopy. However, adenoma detection, assessed with two different measures (that is adenoma detection rate and number of detected adenomas per procedure), was slightly augmented by the water infusion colonoscopy. Improved adenoma detection might be due to the cleansing effects of water infusions on the mucosa. Detection of premalignant lesions during standard colonoscopy is suboptimal, and so improvements in adenoma detection by water infusion colonoscopy, although small, may help to reduce the risk of interval colorectal carcinoma. The most obvious benefit of water infusion colonoscopy was reduction of procedure-related abdominal pain, which may enhance the acceptance of screening/surveillance colonoscopy.

Sa1430 Outcomes of the Water Exchange Technique During Screening Colonoscopy At an Academic Medical Center

Prior studies of water-assisted colonoscopy, mostly in men, have demonstrated less insertion pain, better tolerance of minimal sedation, and a reduced need for pain medication compared with standard air insufflation (AI) colonoscopy. Effects on adenoma detection rates (ADRs) have been mixed. Aims: To evaluate and compare the effect of Water Exchange (WE) colonoscopy on procedure -and patient-related outcomes with conventional air insufflation (AI) colonoscopy in a cohort of men and women undergoing screening colonoscopy at an academic medical center.

Su1654 Water-Aided Colonoscopy in Inflammatory Bowel Disease Patients - a Randomized, Single-Center Trial

Compared to air insufflation, water-aided insertion reduces patients' discomfort and need for sedation during the diagnostic and screening colonoscopies. Water-aided colonoscopy has never been studied in inflammatory bowel disease patients, characterized by younger age, structural changes of the colon and need for repeated and often difficult colonoscopies. Our trial was designed to evaluate discomfort associated with water-aided colonoscopy compared to air insufflation colonoscopy in unsedated patients with known inflammatory bowel disease.

Left-colon water exchange preserves the benefits of whole colon water exchange at reduced cecal intubation time conferring significant advantage in diagnostic colonoscopy — a prospective, randomized controlled trial

Objectives: Whole-colon water exchange (WWE) reduces insertion pain, increases cecal intubation success and adenoma detection rate, but requires longer insertion time, compared to air insufflation (AI) colonoscopy. We hypothesized that water exchange limited to the left colon (LWE) can speed up insertion with equivalent results. Methods: This prospective, randomized controlled study (NCT01735266) allocated patients (18–80 years) to WWE, LWE or AI group (1:1:1). The primary outcome was cecal intubation time. Results: Three hundred subjects were randomized to the WWE (n = 100), LWE (n = 100) or AI group (n = 100). Ninety-four to ninety-five per cent of patients underwent diagnostic colonoscopy. Baseline characteristics were balanced. The median insertion time was shorter in LWE group (4.8 min (95%CI: 3.2–6.2)) than those in WWE (7.5 min (95%CI: 6.0–10.3)) and AI (6.4 min (95%CI: 4.2–9.8)) (both p < 0.001) groups. The cecal intubation rates in unsedated patients of the two water exchange methods (WWE 99%, LWE 99%) were significantly higher than that (89.8%) in AI group (p = 0.01). The final success rates were comparable among the three groups after sedation was given. Maximum pain scores and number of patients needing abdominal compression between WWE and LWE groups were comparable, both lower than those in AI group (p < 0.05). No significant difference was observed regarding PDR, although the PDR in right colon tended to be higher in WWE group. Conclusion: By preserving the benefits of WWE and reducing insertion time, LWE is appropriate for diagnostic colonoscopy, especially in settings with tight scheduling of patients. The higher PDR in the right colon in WWE group deserves to be further investigated.

A two-center randomized controlled trial of water-aided colonoscopy versus air insufflation colonoscopy

Water-aided colonoscopy includes water immersion and water exchange. Several small single-center studies have suggested that the use of water rather than air insufflation during colonoscopy reduces pain on insertion. The aim of this study was to investigate whether water-aided colonoscopy is less painful than air insufflation in a large cohort of patients. This was a two-center, randomized controlled trial. Consecutive patients who agreed to start colonoscopy without premedication were included. Sedation was administered on demand. Water-aided colonoscopy was performed using water immersion in the early phase of the study, and subsequently water exchange was used. The primary endpoint was cecal intubation with pain scores of ≤ 2 and sedation with no or ≤ 2 mg midazolam. Secondary outcomes were pain score at discharge, cecal intubation rate and time, and adenoma detection rate (ADR). A total of 672 patients were randomized to water exchange (n = 338) or air insufflation (n = 334). The primary endpoint was achieved in more patients in the water exchange group (83.8 % vs. 62 %; P < 0.0005). On-demand sedation was also required less (11.5 % vs. 26.0 %; P < 0.0005) and mean pain score was lower (1.3 vs. 2.3; P < 0.0005) in the water exchange group. The cecal intubation rates were comparable. Water exchange had a significantly higher overall ADR (25.8 % vs. 19.1 %; P = 0.041), proximal ADR (10.1 % vs. 4.8 %; P = 0.014), and proximal < 10 mm ADR (7.7 % vs. 3.9 %; P = 0.046); proximal ADR was also higher in screening-only patients in the water exchange group (18.9 % vs. 7.4 %; P = 0.015). No detailed analysis was possible for the air insufflation vs. water immersion comparison. The current results confirmed that water exchange minimized the requirement for sedation and increased the ADR.

Water Exchange (WE) Significantly Reduces the Need for Abdominal Compression during Colonoscopy: Prospective Comparison with Air Insufflation (AI) and Water Immersion (WI)

Background: Abdominal compression (Ac) to facilitate scope advancement may cause hand injury in endoscopy assistants. To minimize insertion discomfort, 85% vs. 57% required Ac when air insufflation (AI) and water exchange (We) were compared in unsedated colonoscopy. Aim: To compare the need for abdominal compression during colonoscopy using AI, We and water immersion (WI). We hypothesize that We significantly reduces need for Ac compared to AI and WI. Methods: A performance improvement project involved 8 endoscopists using AI (n=2), WI (n=3) and We (n=3) for sedated colonoscopy. (AI): conventional colonoscopy with air; (WI): water was infused to facilitate scope insertion and was removed mainly during scope withdrawal; (We): water was infused and removed predominantly on scope insertion, air button was off till cecum was reached and air was used on scope withdrawal. consecutive patients were scheduled with endoscopists and colonoscopy was performed with technique based on endoscopists’ preference. With insertion difficulty abdominal compression was applied by the assistant and/or patient was repositioned to facilitate scope advancement. Results: 259 patients were included, 6 were excluded due to poor bowel prep (n=2) and prior colonic resection (n=4). Abdominal compression and/or position change, and procedural outcomes were compared. There was a significant difference between We vs. WI and AI colonoscopy in need for abdominal compression but no significant difference between WI and AI. Conclusion: Water exchange colonoscopy required significantly less abdominal compression compared to WI or AI method and may potentially minimize risk of hand injury among endoscopy assistants.

Water infusion versus air insufflation for colonoscopy: a meta-analysis of randomized controlled trials

The aim of this meta-analysis was to determine whether water infusion colonoscopy (WIC) is a more effective diagnostic tool than standard air insufflation colonoscopy (AIC). All articles pertinent to a comparison of water-related methods and air insufflation to facilitate insertion of the colonoscope were retrieved from PubMed, Web of Science, Embase, and Cochrane databases. Pooling results were derived by using the Review Manager Software. Outcomes were assessed using the weighted mean difference (MD) with 95 % confidence intervals (CI) for continuous variables and the odds ratios (OR) with 95 % CI for dichotomous variables. Eighteen studies involving 2,797 patients were included. WIC was associated with a significantly higher cecal intubation rate than AIC (OR = 1.90; 95 % CI 1.21-2.99; p = 0.005). The intubation time was similar for the two types of colonoscopy, but in WIC there was a significantly lower visual analog scale score for abdominal pain than in AIC (MD = -1.30; 95 % CI -2.03 to -0.58; p < 0.001) without sacrificing the polyp detection rate (OR = 1.17; 95 % CI 0.78-1.77; p = 0.44). Statistically, the patient's willingness to repeat colonoscopy was significantly greater for WIC than for AIC (OR = 1.74; 95 % CI 1.14-2.67; p < 0.01). Furthermore, in the subgroup for trainees, the WIC group achieved a higher cecal intubation rate (OR = 1.83; 95 % CI 1.15-2.93; p = 0.01) and a shorter intubation time (MD = -1.72 min; 95 % CI -3.34 to -0.11; p = 0.04) than the AIC group. In contrast to AIC, WIC improved cecal intubation, alleviated abdominal pain, and increased patients' willingness to repeat the procedure.

Carbon Dioxide Insufflation or Warm-Water Infusion Versus Standard Air Insufflation for Unsedated Colonoscopy

The increasing demand for colonoscopy has renewed the interest for unsedated procedures. Alternative techniques, such as carbon dioxide insufflation and warm-water infusion, have been advocated to improve patient tolerance for colonoscopy in comparison with air insufflation. The aim of this study was to evaluate the benefits of carbon dioxide insufflation and warm-water irrigation over air insufflation in unsedated patients. This study was a randomized, controlled trial. This study was conducted at a nonacademic single center. Consecutive outpatients agreeing to start colonoscopy without premedication were included. Patients were assigned to either carbon dioxide insufflation, warm-water irrigation, or air insufflation colonoscopy insertion phase. Sedation/analgesia were administered on patient request if significant pain or discomfort occurred. The primary outcome measured was the percentage of patients requiring sedation/analgesia. Pain and tolerance scores were assessed at discharge by using a 100-mm visual analog scale. Three hundred forty-one subjects (115 in the carbon dioxide, 113 in the warm-water, and 113 in the air group) were enrolled. Intention-to-treat analysis showed that the proportion of patients requesting sedation/analgesia during colonoscopy was 15.5% in the carbon dioxide group, 13.2% in the warm-water group, and 25.6% in the air group (p = 0.04 carbon dioxide vs air; p = 0.03 warm water vs air). Median (interquartile range) scores for pain were 30 (10-50), 28 (15-50), and 46 (22-62) in the carbon dioxide, warm-water, and air groups (carbon dioxide vs air, p < 0.01; warm water vs air, p < 0.01); corresponding figures for tolerance were 20 (5-30), 19 (5-36), and 28 (10-50) (carbon dioxide vs air, p < 0.01; warm water vs air, p < 0.01). This investigation was limited because it was a single-center study and the endoscopists were not blinded to randomization. Carbon dioxide insufflation was associated with a decrease in the proportion of patients requesting on-demand sedation, improved patient tolerance, and decreased colonoscopy-related pain in comparison with air insufflation. The findings regarding warm-water irrigation confirmed the previously reported advantages, so that warm-water irrigation and carbon dioxide insufflation could represent competitive strategies for colonoscopy in unsedated patients.

Comparative effectiveness of water immersion and water exchange versus air insufflation for colonoscopy

Introduction: Water-aided colonoscopy can be categorized by the timing of removal of infused water, predominantly during withdrawal (water immersion) or during insertion (water exchange), respectively. Objective: To assess the impact of water immersion and water exchange on insertion pain and adenoma detection rate, when compared with air insufflation colonoscopy. Setting: published randomized controlled trial (RcT) that compared water immersion or water exchange with air insufflation. Patients: patients undergoing colonoscopy. Interventions: Medline, pubMed, Google searches (January 2008 to December 2011) to identify appropriate RcTs. Main Outcome Measurements: pain during insertion phase and adenoma detection rate. Method: Review Manager Software (Version 5.1, cochrane collaboration, UK). Results: pain scores of both water-aided methods are lower than that of the air insufflation method. Subgroup analysis shows that compared with air insufflation, the water exchange group had a greater mean reduction of maximum pain during insertion -2.73 (-3.29, -2.18) than the water immersion group -1.31 (-1.64, -0.97). There is no significant difference in overall adenoma detection rate between water-aided methods and air insufflation. Subgroup analysis shows that compared with air insufflation, the water exchange group had higher adenoma detection rate, OR 1.52, (95%cI: 1.08-2.14) than the water immersion group, OR 0.92, (95%cI: 0.70-1.21). Limitation: Unblinded colonoscopists exposed observations to uncertain bias. Conclusion: compared with air insufflation, the data presentation in a meta-analysis format show that both water immersion and water exchange significantly reduce insertion pain. Water exchange may be superior to water immersion in minimizing insertion pain and in increasing adenoma detection rate.

Experience with water-aided colonoscopy in a Canadian community population

Purpose: Water-aided colonoscopy, immersion (WI) or exchange (We), minimizes insertion pain and reduces sedation. We improves adenoma detection rates (ADR). In a performance improvement program, we assessed water-aided methods in a busy community GI practice in c anada. Methods: Over a 13 month period patients were offered water-aided colonoscopy with an option to complete the examination with on-demand sedation. WI was used in the first 1-2 months and replaced exclusively with W e thereafter. procedural outcomes were compared to a continuous retrospective cohort of standard sedated air insufflation (AI) colonoscopy. Results: 200 (106M/94F) water-aided colonoscopies were completed. cecal intubation without air insufflation was achieved in 93%. sedation was not required in 95% of patients accepting on-demand sedation. Average insertion time was 15 min with an average withdrawal time of 6 min. 145 (87M/58F) water-aided colonoscopies, completed for screening or surveillance were compared to a cohort of 145 (77M/68F) AI colonoscopies in the immediate prior period. The overall ADR of water-aided colonoscopy was 30% (43/145) with a proximal ADR of 21%. Using AI the overall ADR was 27.6% (40/145) with a proximal ADR of 14.5% (21/145). In males, the proximal colon ADR was 25% in water-aided colonoscopies and 14.3% using AI (p=0.0397). Conclusions: Water-aided colonoscopy is feasible in a busy community practice with respectable cecal intubation rates. A large percentage of patients consenting to on-demand sedation completed without sedation. ADR in male subjects is consistent with similar prior reports of a significantly higher ADR in the proximal colon using W e when compared to AI.

Cap‐assisted water immersion for minimal sedation colonoscopy: Prospective, randomized, single‐center trial

Water immersion insertion is able to reduce discomfort and need for sedation during colonoscopy. A cap attached to the colonoscope tip may improve insertion during air insufflation colonoscopy. According to several reports, both techniques alone may result in higher detection of neoplastic lesions. Our study was designed to evaluate the efficacy of cap-assisted water immersion compared to water immersion colonoscopy in minimally sedated patients. A total of 208 consecutive outpatients were randomized to either cap-assisted water immersion (Cap Water) or water immersion colonoscopy (Water). The primary endpoint was cecal intubation time. Cecal intubation time was 6.9 ± 2.9 min in Cap Water and 7.4 ± 4.2 min in the Water arm (P = 0.73). Success rate of minimal sedation colonoscopy was equal in both groups (92.9%, P = 1.00). From the endoscopist's point of view, there were non-significant trends towards lower discomfort (P = 0.06), less need for abdominal compression (P = 0.06) and lower difficulty score (P = 0.05) during Cap Water colonoscopy. Adenoma detection rate was similar in both arms (44% in Cap Water vs 45% in the Water group, P = 0.88). There were no complications recorded in the present study. In comparison with water immersion without cap, cap-assisted water immersion colonoscopy was not able to shorten the cecal intubation time. However, it has the possibility of reducing patient discomfort and difficulty of colonoscope insertion. Potential impact on improved detection of neoplastic lesions has to be evaluated by further studies.

Combined Water-Exchange and Cap-Assisted Colonoscopy—A Promising Method that Increases Lesion Detection in sSreening and Surveillance Colonoscopy

Purpose: Water immersion eases passage of the colonoscope through the sigmoid and decreases pain but is limited by poor visualization in patients with suboptimal bowel preparation (CGH 2011;9:1039). Water-exchange can provide salvage cleansing (Endoscopy 2011;43:816) and increase adenoma detection (JIG2011;1:121), but drawbacks include prolonged procedure time (GIE 2009;69:551), infusion of excessively large volumes (Gastroenterol Hepatol 2010;6:555), and anecdotally, mucosal trauma induced by suctioning. Cap-assisted colonoscopy (CAC) decreases cecal intubation time but is limited by impaired endoscopic views when residual feces lodges in the cap (AJG 2009;104:41) and difficult passage through segments of severe sigmoid diverticulosis (WJG 2010;16:3905). This study investigates the novel approach of combined water-exchange and cap-assisted colonoscopy (WCC) and its impact on detection of adenomas and proximal colon sessile serrated polyps (SSP). Methods: A single-center, single-colonoscopist, consecutive group observational study to compare WCC with conventional air insufflation colonoscopy was performed. Performance improvement data were collected prospectively from 100 consecutive patients undergoing outpatient colorectal cancer screening or polyp surveillance with WCC. Adenoma and SSP findings expressed as detection rates (DR) and per colonoscopy (PC) were compared to a control group of 101 consecutive patients examined with conventional air colonoscopy during the immediate prior period. Results: (Table) There were no significant differences in baseline patient characteristics or cecal intubation rates between groups. The polyp detection rate (PDR) (93.0% vs. 84.2%, p=0.07) and ADR (75.0% vs. 59.4%, p=0.02) were higher in the WCC group. Similarly, proximal colon ADR (61.0% vs. 47.5%, p=0.07) was higher for the WCC group. APC was significantly higher in the WCC group compared to historical controls (2.70 vs. 1.50, p=0.002). The proximal colon SSPDR (24.0% vs. 9.9%, p=0.009) and the mean number of proximal colon SSP per colonoscopy (0.38 vs. 0.12, p=0.004) were also significantly higher in the WCC group. There were no immediate procedural complications noted in either group.Table: [1958] Table. Baseline patient characteristics and comparison of polyp and adenoma detection between conventional air colonoscopy and combined water-exchange and cap-assisted colonoscopyConclusion: The observational data indicate APC and ADR are both sensitive indicators of quality colonoscopy. WCC shows promise as a novel technique that merges two simple methods to improve the performance of screening and surveillance colonoscopy. The data suggest larger, prospective studies are necessary to determine if there are differences between water-exchange combined with cap-assisted maneuvers and the individual components used alone in lesion detection in screening and surveillance colonoscopy.

A new method for screening and surveillance colonoscopy: Combined water-exchange and cap-assisted colonoscopy

Colonoscopy plays an important and central role in current colorectal cancer screening and prevention programs, but it is an imperfect tool. Adjunct techniques may help improve the performance of colonoscopy to increase the detection of polyps with neoplastic potential. This study investigates the novel approach of combined water-exchange and cap-assisted colonoscopy (WCC) and its impact on adenoma detection. A single-center single-colonoscopist consecutive group observational study to compare WCC with conventional air insufflation colonoscopy was performed. Data were collected from 50 consecutive patients undergoing outpatient colorectal cancer screening or polyp surveillance with WCC. Adenoma detection rates (ADR) and adenomas detected per colonoscopy (APC) were compared to a control group of 101 consecutive patients examined with conventional air colonoscopy during the immediate prior period. Cecal intubation was achieved in all patients. As an emerging and alternative quality metric for colonoscopy, APC was significantly higher in the WCC group (3.08 vs. 1.50, p=0.0021). The conventional quality metric, overall ADR, was higher in the WCC group compared to the air colonoscopy group (70.0% vs. 59.4%, p=0.22). This difference was not statistically significant, likely due to a type II error. The observational data suggest APC is a more sensitive indicator of quality colonoscopy than ADR. WCC shows promise as a novel technique that merges two simple adjunct methods to help improve the performance of colonoscopy. The data suggest larger, prospective studies are necessary to determine the true impact of water-exchange combined with cap-assisted maneuvers.

Tu1434 Water Infusion Versus Air Insufflation Colonoscopy in Unsedated Patients - Impact on Patient Discomfort

Tu1434 Water Infusion Versus Air Insufflation Colonoscopy in Unsedated Patients - Impact on Patient Discomfort