A comparison of 9-min colonoscopy withdrawal time and 6-min colonoscopy withdrawal time: A systematic review and meta-analysis.

INTRODUCTION: The optimal colonoscopy withdrawal time is still a controversial topic. While several studies demonstrate that longer withdrawal time improves adenoma detection rate, others have contradicted these findings. METHODS: Three independent reviewers performed a comprehensive review of all original articles published from inception to January 2021 and included studies reporting comparison of the two cohorts-(i) ≥ 6 but less than 9 min of colonoscopy withdrawal time (CWT) and (ii) ≥ 9 min of CWT. The outcome measures were the following: (i) adenoma detection rate (ADR), (ii) advanced ADR, and (iii) sessile serrated adenoma detection rate (SDR). The meta-analysis was performed, and the statistics were two-tailed. RESULTS: A total of seven studies met the inclusion criteria after a thorough search of the literature was completed. The analysis revealed that ≥ 9 min of CWT had significantly higher odds of adenoma detection as compared with 6-9 min of CWT (odds ratio [OR] 1.54, 95% confidence interval [CI] 1.30-1.82; I2  = 93.7). Additionally, a significantly higher odds of sessile serrated adenoma detection (OR 1.68, 95% CI 1.28-2.22; I2  = 0) and a trend towards higher odds of advanced adenoma detection (OR 1.38, 95% CI 0.98-1.95, I2  = 90) were seen with CWT of at least 9 min when compared with 6-9 min of CWT. CONCLUSION: This systematic review and meta-analysis analysis provides further evidence that at least 9 min of CWT cohort had significantly higher ADR and SDR as compared with the at least 6 min but less than 9 min of cohort.

Longer Withdrawal Time Is More Important than Excellent Bowel Preparation in Colonoscopy of Adequate Bowel Preparation.

BACKGROUND: Adequate bowel preparation is crucial for effective screening colonoscopy. However, it is unclear whether higher bowel preparation scores correspond to beneficial effects on the adenoma and polyp detection rate (ADR and PDR) in the adequate bowel preparation group. AIMS: This study aimed to evaluate the effects of bowel preparation, according to the Boston Bowel Preparation Scale (BBPS), and colonoscopy withdrawal time (CWT) on ADR and PDR in the adequate bowel preparation group. METHODS: Healthy examinees between 50 and 75 years old who underwent colonoscopy between September 2015 and August 2016 were included. BBPS scores, CWT, ADR, and PDR were reviewed retrospectively. Predictors of ADR and PDR were analyzed with a generalized linear mixed model. RESULTS: A total of 5073 cases with adequate bowel preparation (BBPS ≥ 6) were analyzed. Examinees with good (BBPS = 6, 7) and excellent (BBPS = 8, 9) bowel preparation were 1898 (37.4%) and 3175 (62.6%), respectively. Both ADR and PDR were higher in the good bowel preparation group than in the excellent bowel preparation group (ADR 47.3% vs. 45.0%, P = 0.035; PDR 73.7% vs. 69.5%, P = 0.004, respectively). In the multivariate analysis, CWT, rather than BBPS, was significantly associated with both ADR (OR 1.04; 95% CI 1.02-1.06; P < 0.001) and PDR (OR 1.05; 95% CI 1.02-1.07; P = 0.002). CONCLUSIONS: Both ADR and PDR were lower when bowel preparation was excellent rather than good. However, CWT, not BBPS, was significantly associated with ADR and PDR in the adequate bowel preparation group. Therefore, meticulous inspection is important for high-quality colonoscopy regardless of the BBPS score in examinees with adequate bowel preparation.

Improving trainee colonoscopy performance by investigating the withdrawal time from individual colonic segments: a single-center observational study.

BACKGROUND: The colonoscopy withdrawal time (WT) and adenoma detection rate (ADR) are widely used quality indicators for colonoscopy. However, no study has investigated the appropriate colonoscopy WTs of individual colonic segments that will allow trainees to achieve a higher ADR. Thus, we analyzed for the first time the relationship between colonoscopy WT and the ADR/polyp detection rate (PDR) in the proximal, left-sided and entire colon among trainees. METHODS: This retrospective study involved 611 consecutive patients who underwent colonoscopy from March 2018 to March 2019 performed by 6 trainees in the Endoscopy Center of Shanghai General Hospital. The WTs for the individual colonic segments and any significant findings of colonoscopies were retrospectively retrieved from the trainees' records and verified in the endoscopy center database. ADR/PDR was defined as the number of colonoscopies detecting at least 1 polyp/adenoma divided by the total number of colonoscopies. Comparisons of PDR and ADR between the 2 groups were conducted using chi-square test. Multilevel analysis was performed to consider individual differences among the 6 trainees. Multilevel binary logistic regression analysis was performed to analyze the factors that influenced the PDR, ADR and advanced adenoma detection rate (AADR) for the entire colon, and trainee status was included as a random effect. RESULTS: The mean WTs were 4.20±1.09, 4.27±1.12, and 8.48±1.87 minutes for the proximal, left-sided, and entire colon, respectively. A longer WT [odds ratio (OR) 1.499, 95% confidence interval (CI): 1.381-1.628, P<0.001; OR 1.409, 95% CI: 1.265-1.569, P<0.001, respectively] was significantly associated with a higher PDR and ADR. The PDR (P<0.001) and ADR (P<0.001) were significantly higher when the WT was >4 minutes than when the WT was ≤4 minutes in both the proximal and left-sided colon, while the PDR (P<0.001) and ADR (P<0.001) were significantly higher when the WT was >8 minutes in the entire colon. CONCLUSIONS: In order to improve trainee colonoscopy performance, trainees were recommended to have WTs of at least 4 minutes in the proximal colon, 4 minutes in the left-sided colon and 8 minutes in the entire colon during negative screening colonoscopies.

Technical interventions to increase adenoma detection rate in colonoscopy.

INTRODUCTION: Adenoma detection rate (ADR) is the most robust colonoscopy quality metric and clinical studies have adopted it as the ideal method to assess the impact of technical interventions. Areas covered: We reviewed papers focusing on the impact of colonoscopy technical issues on ADR, including withdrawal time and technique, second evaluation of the right colon, patient positional changes, gastrointestinal assistant participation during colonoscopy, water-aided technique, optimization of bowel preparation and antispasmodic administration. Expert commentary: Overall, technical interventions are inexpensive, available worldwide and easy to implement. Some of them, such as the adoption of split dose regimen and slow scope withdrawal to allow a careful inspection, have been demonstrated to significantly improve ADR. Emerging data support the use of water-exchange colonoscopy. According to published studies, other technical interventions seem to provide only marginal benefit to ADR. Unfortunately, the available evidence has methodological limitations, such as small sample sizes, the inclusion of expert endoscopists only and the evaluation of single technical interventions. Additionally, larger studies are needed to clarify whether these interventions might have a higher benefit on low adenoma detectors and whether the implementation of a bundle of them, instead of a single technical maneuver, might have a greater impact on ADR.