Increased Adenoma Detection Rate Research Articles

Use of 2 Observers Increases Adenoma Detection Rate During Colonoscopy: Systematic Review and Meta-analysis

Current efforts are directed toward improving quality metrics such as adenoma/polyp detection rates during colonoscopy to decrease the incidence of colorectal cancer.1 Previous studies have reported variable detection rates for adenomas/polyps during colonoscopy for active participation/observation by nurses, trainees, and/or technician (dual observer [DO] group) with an endoscopist.2,3 We performed a systematic review and meta-analysis to evaluate the detection rate of adenomas/polyps during colonoscopy via DO versus single observers (ie, endoscopist alone).

3052 Colonic Polyp Found on Capsule Endoscopy After a Normal Colonoscopy: A Case Report and Literature Review

INTRODUCTION: Video capsule endoscopy (VCE) is a vital diagnostic tool in detecting occult gastrointestinal bleeding but has limited use in detecting colonic polyps due to low sensitivity and specificity. We present a case of a missed colonic polyp by colonoscopy that was detected with capsule endoscopy. CASE DESCRIPTION/METHODS: A 50-year-old man with an extensive cardiac history on systemic anticoagulation presented with symptomatic anemia, intermittent melena, and labs consistent with blood loss anemia. He underwent an endoscopy and colonoscopy in July 2018 and a push enteroscopy in February 2019 due to persistent symptoms, which were all normal and did not identify the etiology of obscure GI blood loss. Given the unresolved symptomatic anemia, the patient underwent VCE that did not identify any etiologies of small bowel bleeding, however, it did show a medium to large sized sessile polyp in the colon that not appreciated on colonoscopy eight months earlier. DISCUSSION: A head to head comparison of colonoscopy and VCE has shown that VCE's sensitivity and specificity for detecting adenomas 6 mm or larger are 64% and 84%, respectively. In fair or poorly prepped colons, VCE sensitivity and specificity for detecting adenomas 6 mm or larger dropped to 44% and 81%, making VCE an inferior choice for colon polyp detection. While colonoscopy remains the gold standard for colorectal cancer surveillance, the potential for missed polyps exists. In a recent tandem study with same-day consecutive colonoscopies, the adenoma miss rate was 24.1%. However, advanced adenomas and carcinoma miss rate was lower and significantly dropped to 1.2% and 0%, respectively. Right-sided, sessile, small adenomas were more likely to be missed than left-sided, pedunculated, large adenomas. Additionally, findings greater than two polyps were also associated with an increased missed rate. Current proposed methods for increasing adenoma detection rate include increased withdrawal time, multiple observers, and enhanced imaging modalities such as narrow band imaging. In this case, VCE identified a polyp not seen on colonoscopy from eight months prior. Although VCE currently does not meet the standards of a colorectal cancer screening, VCE's minimally invasive nature, lack of sedation and patient preference warrants continued work to define its role in the cancer-screening algorithm.

272 Artificial Intelligence Based Computer Aided Detection System Reliably Detects Polyps Earlier Than Physicians During Colonoscopy

INTRODUCTION: Artificial intelligence (AI) is increasingly being used as an aid to physicians in multiple areas of medicine. Computer aided detection (CAD) has the potential to assist endoscopists in detection of colon polyps and flat lesions during colonoscopy. Real-time detection of polyps can potentially increase adenoma detection rates and decrease adenoma miss rates, as computerized algorithms are able to analyze the entire field of view more rapidly than humanly possible and do not suffer from fatigue or distraction. METHODS: We designed a deep learning based CAD system that is able to process 30 endoscopy video frames per second in real time and highlight one or more polyps that are detected anywhere in the field of view. Our deep learning algorithm was trained on 26000 images extracted from hundreds of procedure recordings. The detection performance of the CAD system was measured on 100 colonoscopies. To compare how early the CAD system detects relative to endoscopists, 25 different colonoscopy video clips of varying length (30–180 sec) that included a single polyp were reviewed by 5 experienced endoscopists. The endoscopist pressed a button on the computer keyboard as soon as the polyp was visualized, and the time was recorded. This was compared to the time at which the CAD system detected the polyp. RESULTS: In the 100 clinical colonoscopy cases, a total of 250 polyps were found and removed in 86 patients (14 patients had no polyps detected). There were 171 tubular adenomas, 54 hyperplastic polyps/mucosal excrescences, 11 inflammatory polyps, 6 villous adenomas, 6 sessile serrated polyps and 2 traditional serrated adenomas. The CAD system detected 247/250 polyps (98.8%). The 3 polyps that were not detected were: one 6 mm serrated polyp, one 4 mm tubular adenoma and one 3 mm tubular adenoma. Separately, as shown in Figure 1, the early detection experimental analysis revealed that more than 49% of the polyps were detected earlier by the CAD system by 2 seconds or more. CAD system typically detected much earlier when physicians initially missed brief transient visibility (<500 ms) of the polyps. CONCLUSION: Our deep learning based CAD system is capable of detecting 99% of polyps that are found during routine colonoscopy. The system detects polyps significantly faster than physicians. Future studies will address whether this translates into higher adenoma detection rates or reduced miss rates in clinical practice.

A prospective randomized study of colonoscopy using blue laser imaging and white light imaging in detection and differentiation of colonic polyps.

Background and study aims Published data on blue laser imaging (BLI) for detection and differentiation of colonic polyps are limited compared to narrow band imaging (NBI). This study investigated whether BLI can increase the detection rate of colonic polyps and adenomas when compared to white light imaging (WLI), and examined use of NICE (NBI International Colorectal Endoscopic) and JNET (Japan NBI Expert Team) classifications with BLI. Patients and methods Patients aged 50 years and above referred for colonoscopy were randomized to BLI or WLI on withdrawal. Detected polyps were characterized using NICE and JNET classifications under BLI mode and correlated with histology. Primary outcome was adenoma detection rate. Secondary outcomes were utility of NICE and JNET classifications to predict histology using BLI. Results A total of 182 patients were randomized to BLI (92) or WLI (90). Comparing BLI with WLI, the polyp detection rate was 59.8 % vs 40.0 %, P = 0.008, and the adenoma detection rate was 46.2 % vs 27.8 %, P = 0.010. NICE 1 and JNET 1 diagnosed hyperplastic polyps with sensitivity of 87.18 % and specificity of 84.35 %. NICE 2 diagnosed low- (LGD) or high-grade dysplasia (HGD) with sensitivity of 92.31 % and specificity of 77.45 %. JNET 2A diagnosed LGD with sensitivity of 91.95 %, and specificity of 74.53 %. Four cases of focal HGD all had JNET 2A morphology. Conclusion BLI increased adenoma detection rate compared to WLI. NICE and JNET classifications can be applied when using BLI for endoscopic diagnosis of HP and LGD but histological confirmation remains crucial.

Efficacy of withdrawal time monitoring in adenoma detection with or without the aid of a full-spectrum scope.

Background and study aims Withdrawal time (WT) monitoring and full-spectrum endoscopy (FUSE) have been suggested to increase adenoma detection rate (ADR) due to more accurate evaluation of the hidden areas of the colon. We aimed to evaluate the efficacy of WT monitoring and FUSE on ADR. Patients and methods This was a prospective observational study involving consecutive outpatients, aged 18 to 85 years, undergoing colonoscopy with unselected indications. In phase 1, endoscopists performed 660 colonoscopies either with standard forward-viewing endoscope (SFVE) (n = 330) or with FUSE (n = 330). In this phase, WTs were measured without endoscopist awareness of being monitored. In phase 2, endoscopists were informed of being monitored and performed additional 660 colonoscopies either with SFVE (n = 330) or with FUSE (n = 330). Results WT was lower in phase 1 compared to phase 2 (SFVE: 269 ± 83 vs. 386 ± 60 sec, P < 0.001; FUSE: 289 ± 97 vs. 403 ± 65 sec, P < 0.001). Use of FUSE increased ADR both in phase 1 (33.0 % vs. 27.3 %, P = 0.127) and in phase 2 (41.8 % vs. 33.6 %, P = 0.037). When endoscopists were aware of being monitored, ADR was higher in SFVE (33.6 % vs. 27.3 %; P = 0.090) and FUSE arms (41.8 % vs. 33.0 %; P = 0.024). Improvement in detection of proximal adenomas was associated with WT monitoring [OR 1.577 (95 % C. I. 1.158 – 2.148); P = 0.004], whereas detection of distal adenomas was associated with use of FUSE [OR 1.320 (95 % C. I. 1.022 – 1.705); P = 0.037]. Conclusions Unmonitored endoscopists have suboptimal WT, which increases when they are monitored. WT monitoring and use of FUSE are two reliable and alternative strategies to increase ADR.

Water exchange colonoscopy decreased adenoma miss rates compared with literature data and local data with CO2 insufflation: an observational study

BackgroundReports showed adenoma miss rates (AMRs) of 22.5–27% in the right colon and 23.4–33.3% in the proximal colon. Missed lesions could contribute to postcolonoscopy cancers. Water exchange (WE) with near-complete removal of infused water during insertion increased adenoma detection rate but the impact on AMR had not been reported. We hypothesized that WE could reduce AMRs. Study 1 compared the AMRs of WE with literature data. Study 2 developed local AMR data with CO2 insufflation.MethodsThe lead author attended a research seminar in 2017 on WE colonoscopy. For performance improvement, study 1 was undertaken. When data in study 1 confirmed WE produced a considerably lower AMRs in the right and proximal colon, study 2 with CO2 insufflation was performed.ResultsEighty-six patients completed each study. In study 1, WE removed 89% of infused water upon arrival to the cecum. The AMRs of right colon (17.5%) and proximal colon (15.5%) were considerably lower than those in the literature. Upon completion of study 2, compared with local data of CO2 insufflation, WE showed a significantly lower AMR in the right (17.5% vs. 33.8%, P = 0.034) and proximal (15.5% vs. 30.4%, P = 0.018) colon, respectively. The major limitation was that the investigation consisted of two consecutive observational studies, not a randomized controlled trial (RCT).ConclusionsWE with near-complete (89%) removal of infused water during insertion significantly decreased AMRs in the right and proximal colon compared with literature data and those of CO2 insufflation in our hands. The provocative data warrant confirmation in a RCT.Trial registrationNCT03832322 (Retrospectively registered on February 2, 2019).

P-027 - Multidirectional colonoscopy quality improvement increases adenoma detection rate: results of the Seoul national university hospital healthcare system Gangnam center colonoscopy quality upgrade project (Gangnam-CUP)

P-027 - Multidirectional colonoscopy quality improvement increases adenoma detection rate: results of the Seoul national university hospital healthcare system Gangnam center colonoscopy quality upgrade project (Gangnam-CUP)

1023 ADENOMA DETECTION DURING BOTH THE INSERTION AND WITHDRAWAL VERSUS ONLY WITHDRAWAL OF COLONOSCOPY: A PROSPECTIVE RANDOMIZED CONTROLLED TRIAL

Polyps seen and not removed during colonoscope insertion are sometimes unable to be found during withdrawal. We aimed to evaluate whether additional inspection and polypectomy during insertion increases adenoma detection rate (ADR) compared with inspection and polypectomy at withdrawal only.

Risk of colon adenoma in patients with breast cancer.

1541 Background: In our clinical practice at a tertiary cancer center, we have observed increased adenoma detection rate (ADR) in patients with breast cancer. Here, we describe ADR in patients with breast cancer to define the appropriate timing to initiate colonoscopy screening in these patients. Methods: We conducted a retrospective study of patients with breast cancer who underwent a colonoscopy after their diagnosis of breast cancer between 2000 and 2017. A control group ( n = 3295) comprised patients without any type of cancer who underwent their first screening colonoscopy between 2008 and 2017 was used in the logistic regression. Results: Of the 62,820 patients who had a diagnosis of breast cancer, 3304 were included. The mean age was 59 years. Regarding ADR, 1803 patients (55%) had adenomas. High-grade dysplasia was evident in 28% of polyps and invasive adenocarcinoma in 172 (5%). The median time from breast cancer diagnosis to adenoma detection was 3 years (IQR 1-6). The ADR was 21% in patients younger than 40 years ( n=63), 39% in patients between 40 and 50 years ( n=314), 54% in patients between 50 and 60 years ( n=1420), and 60% in patients older than 60 years ( n=1507). ADR in patients younger than 50 years of age who do not have a family history of colorectal cancer or a body mass index (BMI) higher than 30 kg/m2 was 26%. A subsequent colonoscopy was performed in 831 patients who had colonic adenoma in the initial colonoscopy. The ADR was 40% in patients who had a repeat colonoscopy within 3 years, 50% within 3-5 years, and 53% &gt; 5 years. Multivariate logistic regression analyses revealed an increased risk of colon adenoma with older age, male sex, higher BMI, and personal history of breast cancer ( P&lt;0.05). Conclusions: In patients with breast cancer, ADR was higher than that of patients without history of cancer. Notably, breast cancer was an independent risk factor for colon adenoma. In patients who are younger than 40 years of age, screening colonoscopy should be considered within five years of breast cancer diagnosis. Multivariate logistic regression: risk factors of adenoma. [Table: see text]

Reduction of multitasking distractions underlies the higher adenoma detection rate of water exchange compared to air insufflation - blinded analysis of withdrawal phase videos.

Experts have hypothesized that a reduction of multitasking distractions and improved bowel cleanliness can explain why insertion water exchange enhances adenoma detection rate. The purpose of this study was to test the role of both distractions during withdrawal and bowel cleanliness in enhancing adenoma detection rate using coded video records of colonoscopy. The withdrawal phase of videos of 299 consecutive colonoscopies from two randomized controlled trials comparing water exchange versus air insufflation at a regional hospital in Taiwan were coded. The primary outcome was distractions; activities that preclude full attention being paid to inspection of the mucosa for polyps. A single blinded reviewer collected the data. There were significant agreements in inter-rater reliability indexes. Compared to air insufflation, water exchange had significantly fewer distractions; higher diagnostic yield (intervention time and number), adenoma detection rate, and Boston Bowel Preparation Scale score. Water exchange had a higher withdrawal technique score (predominantly adequacy of cleaning). The association between increased adenoma detection rate and water exchange was mediated by the number of distractions and withdrawal time, but not the Boston Bowel Preparation Scale score. The speculation by experts that a reduction of multitasking distractions underlies the significantly higher adenoma detection rate of water exchange is supported by the current study. Increased bowel cleanliness did not contribute to the increased adenoma detection rate by use of water exchange.

Water Exchange Produces Significantly Higher Adenoma Detection Rate Than Water Immersion: Pooled Data From 2 Multisite Randomized Controlled Trials.

To test the hypothesis that water exchange (WE) significantly increases adenoma detection rates (ADR) compared with water immersion (WI). Low ADR was linked to increased risk for interval colorectal cancers and related deaths. Two recent randomized controlled trials of head-to-head comparison of WE, WI, and traditional air insufflation (AI) each showed that WE achieved significantly higher ADR than AI, but not WI. The data were pooled from these 2 studies to test the above hypothesis. Two trials (5 sites, 14 colonoscopists) that randomized 1875 patients 1:1:1 to AI, WI, or WE were pooled and analyzed with ADR as the primary outcome. The ADR of AI (39.5%) and WI (42.4%) were comparable, significantly lower than that of WE (49.6%) (vs. AI P=0.001; vs. WI P=0.033). WE insertion time was 3 minutes longer than that of AI (P<0.001). WE showed significantly higher detection rate (vs. AI) of the >10 mm advanced adenomas. Right colon combined advanced and sessile serrated ADR of AI (3.4%) and WI (5%) were comparable and were significantly lower than that of WE (8.5%) (vs. AI P<0.001; vs. WI P=0.039). Compared with AI and WI, the superior ADR of WE offsets the drawback of a significantly longer insertion time. For quality improvement focused on increasing adenoma detection, WE is preferred over WI. The hypothesis that WE could lower the risk of interval colorectal cancers and related deaths should be tested.

Prevalence and Predictors of Adenomas in the 40-49 Year Old Patients Undergoing Colonoscopy

Background: Recently the American Cancer Society made a qualified recommendation to start screening for colorectal cancer (CRC) at 45 years of age in all average risk individuals. In this study, our primary aim is to calculate the prevalence and also evaluate the predictors of increased prevalence of detected adenomas in the 40 to 49-year-old individuals undergoing colonoscopy. Methods: A retrospective cross sectional study was performed using our electronic endoscopy database. Study subjects included all 40 to 49-year-old patients undergoing their first colonoscopy at our institution from January 1, 2010 to September 30, 2017. Exclusion criteria included patients who underwent colonoscopy for overt gastrointestinal bleeding, inflammatory bowel disease, a history of familial adenomatous polyposis, hereditary non polyposis CRC. Univariate analysis and multivariate analysis was performed to identify factors associated with increased adenoma detection rate (ADR). Findings: A total of 2059 patients were included in the study and 317 of these patients had family history (FH) of CRC. Patients with FH of CRC had significantly higher ADR (27.8% versus 19.7%, p=0.001) as compared to those without family history of CRC. There was no significant difference in ADR in patients between 40-44-years versus 45-49-years of age (17.7% vs 21.4%, p=0.058). On a multivariate analysis while adjusting for multiple patient and procedural variables; FH of CRC, male gender, BMI > 30 kg/m2, chronic kidney disease, and age were associated with high ADR. Interpretation: Our study shows that in addition to FH of CRC, age, male gender, BMI, and CKD are independent predictors of increased ADR in patients between 40 to 49 years of age. Funding Statement: The authors state: No funding sources to be declared. Declaration of Interests: The authors report no conflicts of interest. Ethics Approval Statement: The study protocol was approved by the institutional review board (IRB) at the University of Texas Medical Branch, Galveston, TX.

G-EYE colonoscopy is superior to standard colonoscopy for increasing adenoma detection rate: an international randomized controlled trial (with videos)

Colorectal cancer (CRC) is largely preventable with routine screening and surveillance colonoscopy; however, interval cancers arising from precancerous lesions missed by standard colonoscopy still occur. An increased adenoma detection rate (ADR) has been found to be inversely associated with interval cancers. The G-EYE device includes a reusable balloon integrated at the distal tip of a standard colonoscope, which flattens haustral folds, centralizes the colonoscope's optics, and reduces bowel slippage. The insufflated balloon also aims to enhance visualization of the colon during withdrawal, thereby increasing the ADR. In this randomized, controlled, international, multicenter study (11 centers), patients (aged≥50 years) referred to colonoscopy for screening, surveillance, or changes in bowel habits were randomized to undergo either balloon-assisted colonoscopy by using an insufflated balloon during withdrawal or standard high-definition colonoscopy. The primary endpoint was the ADR. One thousand patients were enrolled between May 2014 and September 2016 to undergo colonoscopy by experienced endoscopists; 803 were finally analyzed (standard colonoscopy n= 396; balloon-assisted colonoscopy n= 407). Baseline parameters were similar in both groups. Balloon-assisted colonoscopy provided a 48.0% ADR compared with 37.5% in the standard colonoscopy group (28% increase; P= .0027). Additionally, balloon-assisted colonoscopy provided for a significant increase in detection of advanced (P= .0033) flat adenomas (P<.0001) and sessile serrated adenomas/polyps (P= .0026). Balloon-assisted colonoscopy yielded a higher ADR and increased the detection of advanced, flat, and sessile serrated adenomas/polyps when compared with standard colonoscopy. Improved detection by the G-EYE device could impact the quality of CRC screening by reducing miss rates and consequently reducing interval cancer incidence. (Clinical trial registration number: NCT01917513.).

The B-ADENOMA Study: Bowelscope - Accuracy of Detection using Endocuff Optimisation of Mucosal Abnormalities: Study Protocol for randomised controlled trial.

Background and study aims UK Bowel Cancer Screening flexible sigmoidoscopy (BowelScope) currently offers patients aged 55 a one-off flexible sigmoidoscopy for adenoma clearance to decrease colorectal cancer incidence by interrupting the adenoma-carcinoma sequence. Recent evidence has shown maximum benefit in increasing adenoma detection rate (ADR) using the Endocuff Vision device in the left side of the colon and in screening patients. Currently, ADR is low and shows unacceptable variation in BowelScope. ADR is a quality indicator in screening sigmoidoscopy and higher rates have been shown to reduce colorectal cancer incidence. Patients and methods This will be a prospective, multicenter, UK-based randomized controlled trial (RCT) comparing ADR in Endocuff-assisted versus standard bowel cancer screening flexible sigmoidoscopy (BowelScope). All patients aged 55 to 61 years invited to BowelScope screening and able to give informed consent will be eligible for recruitment. Exclusion criteria include absolute contraindications to flexible sigmoidoscopy, known or suspected large bowel obstruction or pseudo-obstruction, colonic strictures or polyposis syndromes, known severe diverticular segment, active colitis, inability to give informed consent, anticoagulation precluding polypectomy and pregnancy. Patients will be randomized on the day of procedure to Endocuff-assisted flexible sigmoidoscopy or standard flexible sigmoidoscopy, stratified by age group and sex. Baseline, endoscopy and polyp data were collected as well as nurse and patient assessment of comfort. Polyp histology was collected when available. Patients will be asked to return a comfort questionnaire the following day and were followed up for 14 days for complications. Results The ADENOMA trial will be designed to demonstrate a significant improvement in ADR with maximal effect in the left colon and in fecal occult blood test-positive screening patients. This trial will be the first RCT to look at Endocuff Vision in bowel cancer screening flexible sigmoidoscopy. We will aim to establish whether Endocuff vision improves ADR in this population.

Tu1076 A NEW STANDARD: AN OPEN-LABEL TRIAL EXAMINING THE EFFECTIVENESS OF INDIVIDUALIZED WEB BASED COLONOSCOPY PREPARATION INSTRUCTION

Non-pharmalogical factors such as patient education have been shown to significantly improve bowel preparation quality for colonoscopy. For the endoscopist, optimal bowel cleaning increases cecal intubation rates, increases adenoma detection rates, and minimizes necessity for repeat procedures. Following a randomized study demonstrating that the web based patient education tool was superior to traditional paper instructions, this study aims to implement the program at a larger scale; a real life scenario. To determine the effectiveness of web-based pre-colonoscopy instructions for patients, as measured by the percentage of patients achieving an excellent level of colon cleanliness, equivalent to Boston Bowel Preparation Score (BBPS) ≥ 8. Secondary goals were to assess the patient satisfaction and practicality of this means of education being used by the entire GI clinic for all outpatient colonoscopies. Prospective, single center, open label study. Adult outpatients scheduled for non-urgent colonoscopy, aged 19 or greater with English proficiency or an available family member/friend who can translate the instructions for them who have a functioning email account were recruited for this study. Patient demographics, cancellations, and quality of bowel preparation (assessed using Boston and Ottawa Bowel preparation scales) were collected. Patient satisfaction surveys were completed the day of their colonoscopy before their procedure to assess clarity and usefulness of the standardized online instructions. Results: Finalized data analysis (n = 900) shows that 84.5% of patients have achieved a score demonstrating adequacy on the BBPS (mean 7.0; adequate score considered ≥ 6 and 90.1% have scored adequately on the OBPS (mean 3.4; adequate considered ≤ 7). 94.2% of patients scored the web education tool as “Very Helpful” (8 or higher out of 10 on our usefulness scale), and 92.1% scored as “Very Clear” (8 or higher in terms of the clarity of information presented to them). Our analysis suggests that the online instruction pathway is a sufficient alternative to paper instruction, and can be effectively utilized as a standard of care in a real life scenario. Although we did not attain the excellent score (BBPS) ≥ 8, the majority of our preparations were adequately prepared. Our instruction methodology also presents advantages compared to paper because it is uniquely modified for each patient and limits the instruction required by an assistant. Patient satisfaction scales have demonstrated an overwhelming majority of patients who are very satisfied with the clarity and helpfulness of the program.

Mo1654 - Increasing Adenoma Detection Rate (ADR) in the Right Colon - Which Technique is Better: Retro-Flexion or a Second Forward Look: A Systematic Review of the Published Literature

Mo1654 - Increasing Adenoma Detection Rate (ADR) in the Right Colon - Which Technique is Better: Retro-Flexion or a Second Forward Look: A Systematic Review of the Published Literature

Melanosis Coli: A Helpful Contrast Effect or a Harmful Pigmentation?

Background:Melanosis coli, a brown discoloration of colonic mucosa, is considered as a benign condition mainly observed in patients under chronic anthranoid laxatives. Recent data link this condition with an increased adenoma detection rate. Moreover, its tumorigenic potential and possible association with the development of colorectal cancer remains uncertain. We conducted this study to compare the polyp detection rate and colorectal cancer diagnosis in patients with melanosis against matched control group without melanosis.Patients and methods:A retrospective single-center study. Patients diagnosed with melanosis coli on colonoscopy over a 15-year period were included. Each melanosis coli patient was matched with three controls by age, gender, setting (inpatient/outpatient), and procedure’s indication. Polyp detection rate and diagnosis of colorectal cancer were recorded and compared between the groups before and after adjustment for bowel preparation.Results:A cohort of 718 patients with melanosis and 2154 controls were included. The polyp detection rates were 33.4% and 21.8% of melanosis and control groups, respectively (P < .001). Melanosis coli, however, was associated with less diagnosis of colorectal cancer than controls (0.3% vs 3.9%; P < .001). In multivariate analysis, melanosis diagnosis on endoscopy was significantly associated with higher polyp detection rate (odds ratio [OR] = 1.986, 95% confidence interval [CI]: 1.626-2.425; P value < .01).Conclusions:Melanosis coli is not associated with increased diagnosis of colorectal cancer. It is associated, however, with enhanced polyp detection likely due to chromo-endoscopy-like effect.

Can technology increase adenoma detection rate?

Colorectal cancer is the third most common cancer worldwide and the second most common cause of cancer-related death in Europe and North America. Colonoscopy is the gold standard investigation for the colon but is not perfect, and small or flat adenomas can be missed which increases the risk of patients subsequently developing colorectal cancer. Adenoma detection rate is the most widely used marker of quality, and low rates are associated with increased rates of post-colonoscopy colorectal cancer. Standards of colonoscopy and adenoma detection vary widely between different endoscopists. Interventions to improve adenoma detection rate are therefore required. Many devices have been purported to increase adenoma detection rate. This review looks at current available evidence for device technology to improve adenoma detection rate during colonoscopy.

Longer observation time increases adenoma detection in the proximal colon - a prospective study.

Background and study aims Longer observation times are associated with increased adenoma detection rates (ADR) in the entire colon. However, adenomas in the proximal colon are at risk of being missed during colonoscopy. The aim of this study was to investigate the impact of observation time on detection of adenomatous polyps in the proximal colon. Patients and methods This was a prospective study at a university hospital in Germany. Colonoscopies were conducted using magnetic endoscope imaging (MEI) in order to determine the exact position of the scope. Exact observation times spent for the detection of polyps in the proximal and distal colon segments were assessed. The primary outcome was adenoma detection in the proximal colon. ROC curves were generated in order to test the correlation between observation time and adenoma detection. Logistic regression analysis was used to check for interfering factors. Results A total 480 procedures with 538 polyps were available for analysis. The overall adenoma detection rate was 38.5 %. ADR in the proximal colon was 28.0 %. There was a significant association between observation time in the proximal colon and the detection of proximal adenomas ( P < 0.001). The impact of the time factor on ADR was stronger in the proximal compared to the distal colon ( P = 0.030). A net period of 4 min 7 sec was found to be the minimum time span for sufficient adenoma detection in the proximal colon. Conclusion Observation time is significant in terms of adenoma detection in the proximal colon. The impact of observation time on ADR is stronger in the proximal compared to the distal colon. In the proximal colon a minimum time span of 4 minutes should be spent in order to ensure adequate adenoma detection.

Water Exchange versus Air Insufflation for Colonoscopy: A Systematic Review and Meta-Analysis

Introduction: Colonoscopy is a widely used modality for screening and diagnostic purposes and is the most important tool in the prevention and early detection of colorectal cancer. In settings where un-sedated colonoscopy is offered, minimal pain and discomfort are desired by the patients. Prominent efforts have been made in the last few years to improve the quality of the procedure and minimize patient discomfort, costs and side effects related to the procedure. The water exchange (WE) method that involves infusion and withdrawal of water during the insertion phase of colonoscopy has been shown to be superior to the more conventional air insufflation (AI) method in several aspects including reduction in pain scores, increased adenoma detection rate and improved quality of bowel preparation. We performed a systematic review and meta-analysis to compare the efficacy of WE method with the conventional AI method.Figure: Maximum Pain score during colonoscopy.Methods: We searched key bibliographic databases using keywords and MeSH terms related to ‘water exchange', ‘colonoscopy' and ‘air insuffl ation'. We included only randomized controlled trials (RCTs) that compared the WE method with the AI method. Our primary analysis included maximum pain score during insertion, adenoma detection rate and cecal intubation rate. Secondary outcomes included total time for colonoscopy, cecal intubation time, position changes, willingness to repeat colonoscopy and the quality of the bowel preparation. Relevant data were extracted and meta-analyses were performed using RevMan. Results: Thirteen RCTs with a total of 7543 participants were included in the meta-analysis after full text review that matched the inclusion and exclusion criteria. There was a significant reduction in maximum pain score with the WE method compared to the AI method (mean difference: -1.44; 95% CI: -1.85 to -1.03). There was an overall increase in the adenoma detection rate (odds ratio [OR]: 1.72; 95% CI: 1.35-2.20) and an increase in adenoma detection in the proximal colon (OR: 1.60; 95% CI: 1.35-1.90). There was no difference in cecal intubation rate between the WE and the AI methods. Although the time to reach cecum was increased with the WE method, there was no difference in the total time to complete colonoscopy. More people who underwent WE method were willing to repeat the colonoscopy and had better bowel preparation. These results are displayed in Table 1. Conclusion:: WE method appears to be a promising addition to colorectal cancer screening given the reduction in pain scores, increased adenoma detection rate and the willingness of the patients to repeat un-sedated colonoscopy. Further, there appears to be no difference in the time to perform colonoscopy which has been perceived to be a barrier to this method.Table: Table. Primary and Secondary Outcomes