Colonoscopy Withdrawal Time Research Articles

Sa1414 Colonoscopic Withdrawal Time Is Below the Recommended 6 Minutes in Unobserved Endoscopists and Significantly Increases Under Monitoring

Sa1414 Colonoscopic Withdrawal Time Is Below the Recommended 6 Minutes in Unobserved Endoscopists and Significantly Increases Under Monitoring

296 Above and Beyond 6 Minutes: Withdrawal Technique Trumps Incremental Gains in Withdrawal Time in the Detection of Adenomatous Polyps During Colonoscopy

Colonoscopy Withdrawal Time (WTi) ≥ 6 minutes (min) is associated with higher Adenoma Detection Rate (ADR). However, studies that solely aim to improve WTi beyond 6 min have shown mixed results in enhancing adenoma detection. One hypothesis is that Withdrawal Technique (WTe) may be more important than additional gains in WTi in determining the yield for adenomas in colonoscopies that meet the 6 min threshold.

229 a Prospective, Randomized Trial of Adenoma Miss Rates At Colonoscopy Associated With 3-Minute vs. 6-Minute Withdrawal Time

Introduction: A minimum withdrawal time for screening colonoscopy of 6 minutes has been proposed, based on an observational study. The 6-minute withdrawal time remains controversial and has not been compared in a standardized fashion to alternate withdrawal times. Aim: To perform a prospective, randomized trial to compare adenoma miss rates (AMR) associated with withdrawal times of 6 minutes vs. 3 minutes. Methods: Consecutive patients undergoing colonoscopy at Stanford University and Palo Alto Veterans Administration Hospital were randomized to undergo either a 3-minute or 6-minute withdrawal (1st pass), followed immediately by a tandem 6-minute withdrawal (2nd pass). AMR was defined as the number of adenomas detected on the 2nd pass divided by total number of adenomas found. A chi-square statistic was used to directly compare AMR. A z-statistic was used to determine effect of polyp size/location on AMR. A mixed-effects logistic regression model was then created to compare AMR, controlling for endoscopist, size/location of adenoma, and patient. Finally, a Cochrane-Armitage test for trend was used to evaluate the trend of adenoma detection associated with increasing withdrawal time. Results: 200 subjects were enrolled (99 in the 3-minute group, 101 in the 6-minute group). Demographics and indications for colonoscopy were similar between the two groups (Table 1). AMR was significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group (48.5% vs 21.8%; p≤0.0001). Adenomas were significantly more likely to be missed in the 3-minute withdrawal group in all 3 locations of the colon (right, transverse and left colon). AMR was higher in the 3-minute withdrawal group among adenomas that were ≤5mm; there was no significant difference in AMR for adenomas that were 6-9mm or ≥10mm. After controlling for endoscopist, size/location of the polyp/adenoma, and the patient, AMR remained significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group (OR 2.92, 95% CI=1.54-5.55) (Table 1). Adenoma detection rate (ADR) was similar between both 3 and 6 minute withdrawal groups (38.4% vs 40.6%, p=0.75); however, this study was not powered to detect differences in ADR. There was a significant trend towards higher total number of adenomas detected as withdrawal time increased (52 at 3 minutes, 87 at 6 minutes, 101 at 9 minutes, and 111 at 12 minutes; p<0.001) (Figure 1). Conclusions: A 3-minute withdrawal time leads to an unacceptably high AMR. A 6minute withdrawal time is more appropriate for colorectal cancer screening. Location did not affect AMR; however, adenomas that were ≤5mm were more likely to be missed in the 3-minute withdrawal group. Further research into the optimal withdrawal time, including evaluation of withdrawal times longer than 6 minutes, is warranted.

A randomized controlled trial assessing the effect of prescribed patient position changes during colonoscope withdrawal on adenoma detection

High-quality colonoscope withdrawal technique is associated with a higher adenoma detection rate. Position change is routinely used in barium enema and CT colonography to facilitate adequate distension of the colon and promote movement of fluid from the segment of the colon being assessed. To determine whether prescribed position changes during colonoscope withdrawal affect the adenoma detection rate compared with the usual care per endoscopist. Prospective, randomized, controlled trial. Tertiary-care, university-affiliated hospital. Patients referred for outpatient colonoscopy between July 2011 and July 2012 were evaluated for eligibility. Inclusion criteria were outpatient status and age ≥40 years. Exclusion criteria were (1) complete colonoscopy within 1 year before the procedure, (2) inability to provide informed consent, (3) incomplete colonoscopy to the cecum, (4) previous bowel resection, (5) inflammatory bowel disease, (6) colonic polyposis syndrome, (7) inadequate bowel preparation, and (8) musculoskeletal disorder or other mobility issues limiting effective patient position changes during colonoscopy. Prescribed position changes during colonoscope withdrawal. Polyp detection rate (PDR) and adenoma detection rate (ADR). A total of 776 patients were enrolled, with 388 in the dynamic group. There was no difference in PDR (odds ratio [OR] 0.99; P = .93) or ADR (OR 1.17; P = .28). Colonoscope withdrawal time was longer in the dynamic group (median time 466.5 vs 422.5 seconds; P < .0001). Single-center study. Indication for procedure not controlled. Lack of standardized bowel preparation and blinding. Prescribed position changes during colonoscope withdrawal do not affect polyp/adenoma detection compared with the usual practice when the baseline ADR is above the recommended standard. ( NCT01395173.).

Difference in adenoma detection rates according to colonoscopic withdrawal times and the level of expertise.

Adequate screening colonoscopy in the general population decreases the mortality associated with colorectal cancer through detection and removal of adenomatous polyps. Prolonged colonoscopic withdrawal times (>6 min) are reportedly beneficial for adenoma detection rates (ADRs). However, the quality of the endoscopist compared with colonoscopic withdrawal times is not known. The aims of this study were to investigate the difference in ADRs between trainees and experienced examiners. A total of 967 consecutive patients who underwent screening colonoscopy in a single University hospital from June 2010 to November 2011 were enrolled in this prospective observational study. Colonoscopy was performed by four experienced staff and seven gastroenterology fellows. Seven gastroenterology fellows performed 633 colonoscopies and four experienced staff performed 334 colonoscopies. The overall detection rates of colorectal adenoma were 31.5% with ADRs of fellows and staff of 29.4% and 35.6%, respectively (p=0.047). Fellows also showed lower advanced ADRs (5.7% vs. 9.9%, p=0.016), and fellows had longer mean withdrawal times than staff (12.4±B1;4.9 min vs. 8.2±B1;4.1 min, p<0.001). Multivariate analysis showed significantly increased ADRs and advanced ADRs for staff compared with fellows (adjusted OR 2.41, 95% CI 1.70-3.43; adjusted OR 2.55, 95% CI 1.47-4.45, respectively). ADRs were significantly lower when colonoscopy was performed by trainees, although withdrawal times were longer than those of staff. Our results demonstrated that the quality of colonoscopy, as measured by ADRs, may be improved by experienced examiners.

Experience of Operator May Be More Crucial than Withdrawal Time of Colonoscopy for the Detection of Colonic Neoplasm

Experience of Operator May Be More Crucial than Withdrawal Time of Colonoscopy for the Detection of Colonic Neoplasm

Impact of a Natural Disaster on Gastroenterology Fellow Colonoscopy Performance

Purpose: Following the devastation of Hurricane Sandy, all three New York University (NYU) Hospital Centers (Manhattan Veterans Affairs Medical Center [VAMC], Bellevue Hospital Center and Langone Medical Center) were forced to temporarily shut down operations. During this time, all housestaff were systematically relocated to nearby hospitals in order to continue training. All Manhattan VAMC gastroenterology trainees were relocated to the Brooklyn VAMC. We compared the performance of gastroenterology trainees at their home site (Manhattan VAMC) prior to the disaster, with their performance after being transferred to the Brooklyn site after the disaster in order to assess the impact of a natural disaster and relocation on colonoscopy performance. The primary aim of our study was to examine the impact of relocation of gastroenterology trainees following the devastation caused by Hurricane Sandy on colonoscopy performance benchmarks. Methods: We studied 11 gastroenterology fellow trainees who performed a total of 202 colonoscopies prior to Hurricane Sandy and 175 colonoscopies after Hurricane Sandy, over a 5-month period. We analyzed differences in total colonoscopy procedure time, colonoscopy insertion time to cecum, colonoscopy withdrawal time, adenoma detection rate (ADR), cecal intubation rate, and the amount of sedation administered from pre-Hurricane Sandy and post-Hurricane Sandy procedures. Results: We compared the 202 colonoscopies performed by 11 gastroenterology fellows prior to Hurricane Sandy at the Manhattan VAMC with 175 colonoscopies performed by the same 11 gastroenterology fellows at the Brooklyn VAMC after the disaster. There were no differences in the sedation requirements for colonoscopies performed before or after the disaster. Still, the disaster seemed to have impacted colonoscopy performance as insertion time to cecum (15.48 min vs. 17.83 min; p=0.0089) and total procedure time (33.64 min vs. 36.24 min; p=0.0318) were significantly increased after the disaster, compared to before the disaster. Average withdrawal time (18.53 min vs. 18.63 min; p=0.5973) and ADR (38% vs. 37%; p=0.8308) were not impacted by displacement. Successful cecal intubation was achieved in 97% of the colonoscopies before relocation and in 94% of the colonoscopies after relocation (p=0.2078). Conclusion: In our study, the relocation of fellow trainees following Hurricane Sandy, a natural disaster which caused closure of the NYU Hospital Centers, was associated with longer insertion and total procedure times, but not cecal intubation rate or ADR. Whether performance was impacted by the stress of the disaster or unfamiliarity with working at an unfamiliar site will be explored.

Procedure Time and the Determination of Polypoid Abnormalities with Experience

Procedure length and agreement in detection of abnormalities may limit implementation of chromoendoscopy (CE) for dysplasia surveillance in ulcerative colitis (UC). We investigated these factors among endoscopists inexperienced in this technique. Six investigators performed surveillance colonoscopy with white light endoscopy (WLE) followed by CE on 75 patients with long-standing UC. Interobserver agreement for WLE and CE images of polyps and nonpolypoid mucosa was determined. Withdrawal times from the cecum were compared based on number of colonoscopies performed. Dysplasia detection rate with WLE was compared with CE. The analysis of 586 images (266 WLE and 320 CE) from 57 patients included images of 160 polyps (64 flat) with 29 dysplastic lesions. All investigators identified 10/11 WLE images of dysplasia and 4 identified all 18 CE dysplasia images, 1 missed 1 and 1 missed 3. Four dysplastic lesions were not identified by 1 or more investigators and all measured <5 mm. Interobserver agreement for lesions was high with kappa scores of 0.91 and 0.86 for WLE and CE, respectively. Among the 75 patients enrolled, dysplasia was found in 9.3% with WLE compared with 21.3% with WLE and CE (P = 0.007). Median colonoscopy withdrawal time improved from 31 minutes for endoscopists performing fewer than 5 procedures to 18 minutes for 5 to 14 and 19 minutes for more than 15 procedures. Indigo carmine CE for UC surveillance resulted in high rates of interobserver agreement for polyp detection, acceptable withdrawal times, and enhanced dysplasia detection. These results are encouraging for the implementation of CE programs for chronic UC.

Mo1559 Evaluating the Optimal Time for Colonoscopy Withdrawal: a Prospective Randomized Comparison of 3 Minute Versus 6 Minute Withdrawal

Mo1559 Evaluating the Optimal Time for Colonoscopy Withdrawal: a Prospective Randomized Comparison of 3 Minute Versus 6 Minute Withdrawal Sheila Kumar*, Rajan Kochar, Shai Friedland, Uri Ladabaum, Ann M. Chen, Subhas Banerjee Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, Palo Alto, CA Introduction: A minimum withdrawal time for screening colonoscopy of 6 minutes has been proposed, based on an observational study, and has become the de-facto standard of care. The 6-minute withdrawal time remains controversial and has not been compared in a standardized fashion to alternative withdrawal times. Aims: To perform a prospective randomized study to compare Polyp Miss Rates, Adenoma Miss Rates and Adenoma Detection Rates in patients undergoing colonoscopy with a 3-minute versus a 6-minute withdrawal time. Methods: Consecutive patients undergoing colonoscopy at Stanford University and the Palo Alto Veterans Administration Hospital were enrolled. Patients were prospectively randomized to undergo colonoscopy with either a 3-minute or 6minute withdrawal time during the 1st pass. A second pass was then performed with a 6-minute withdrawal in both groups to determine Polyp Miss Rates and Adenoma Miss Rates. The Adenoma Detection Rate (#colonoscopies where at least 1 adenoma was detected on the first pass/total #colonoscopies) was also determined for both groups. Results: 107 patients (73 men, 24 women) have been enrolled. 52 underwent 3-minute withdrawal and 55 underwent 6-minute withdrawal. Indications and baseline characteristics for both groups were similar (Table 1). The Polyp Miss Rate was significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group (57% vs. 26%, p 0.0012). The Adenoma Miss Rate was also significantly higher in the 3-minute withdrawal group compared to the 6-minute withdrawal group, (57% vs. 33%, p 0.013) (Table 2). The Adenoma Detection Rates were similar in both groups (31% vs. 24%, p NS). Conclusion: The Polyp Miss Rate and Adenoma Miss Rate were significantly higher in the 3-minute withdrawal group compared to the 6minute withdrawal group, suggesting that a 3-minute withdrawal may be inadequate and that a 6-minute withdrawal may be more appropriate for colorectal cancer screening. No significant difference was noted in the Adenoma Detection Rate between the two groups, which may be due to inadequate sample size.

Tu1329 Colonoscopy Withdrawal Time and Adenoma Detection Rate: Automation and Optimisation in a Tertiary Hospital in Singapore

Previous studies have attempted to define a minimal withdrawal time to attain an optimal adenoma detection rate during colonoscopies, with a suggested withdrawal time of 6 minutes. We aimed to determine the association between withdrawal time and adenoma detection rate at a tertiary hospital in Singapore.

In response to: Singh S, “Colonoscopy withdrawal time and adenoma detection rates for trainees”

In response to: Singh S, “Colonoscopy withdrawal time and adenoma detection rates for trainees”

Colonoscopy withdrawal time and adenoma detection rates for trainees

Calculations of withdrawal time (WT) should be based on colonoscopies where no intervention is performed. Inclusion of procedures with interventional maneuvers, such as polypectomy or biopsy, for estimation of WT can lead to measurement bias and affect the validity of the study.

Comparison of Pentax HiLine and Olympus Lucera systems at screening colonoscopy

To compare the performance characteristics of Pentax HiLine (PHL) (with i-scan) and Olympus Lucera (OL) systems in a screening population. Screening colonoscopies in asymptomatic guaiac faecal occult blood test-positive patients with PHL (n = 58) and OL (n = 425) colonoscopes were analysed. All procedures were performed by a single colonoscopist. PHL used white-light endoscopy (WLE) on scope insertion and contrast/surface enhancement (i-scan 1) on withdrawal, and OL utilised WLE both on insertion and withdrawal. Patient age, sex, instrument insertion and withdrawal times, nurse assessed patient comfort scores, midazolam and fentanyl doses, procedure completion and rates of lesion detection were recorded separately for each group. Comparisons between the groups were made using either Fisher's exact test (for dichotomous variables) or Mann-Whitney U test (for ordinal and continuous variables). Colonoscopy completion rates were similar in both groups: 413/425 (97.2%) for OL and 55/58 (94.9%) for PHL (P = 0.24). For complete colonoscopies, the two groups were well matched for age, sex, colonoscope insertion times (mean 11.1 min in OL vs 11.6 min in PHL, P = 0.93) and normal colonoscopy withdrawal times (mean 15.6 min in OL vs 14.7 min in PHL, P = 0.2). Patients in the PHL group experienced a small increase in discomfort (mean patient comfort scores were 0.49 in the OL and 0.95 in the PHL group, P < 0.0001). While Fentanyl doses required were similar between groups (mean 57.5 μg in OL vs 61.4 μg in PHL, P = 0.13), slightly more Midazolam was required in the PHL group (mean 2.1 mg in OL vs 2.4 mg in PHL, P = 0.035). There was no difference in polyp (58% in OL vs 67% in PHL) or adenoma (49% in OL vs 56% in PHL) detection rates between the groups. Neither the total number of polyps and adenomas, nor the characteristics of these (including size, location or presence of advanced features) were different between the two systems. This study suggests that there is no advantage of either colonoscope system in lesion detection.

Longer mean colonoscopy withdrawal time is associated with increased adenoma detection: evidence from the Bowel Cancer Screening Programme in England

Increasing colonoscopy withdrawal time (CWT) is thought to be associated with increasing adenoma detection rate (ADR). Current English guidelines recommend a minimum CWT of 6 minutes. It is known that in the Bowel Cancer Screening Programme (BCSP) in England there is wide variation in CWT. The aim of this observational study was to examine the relationship between CWT and ADR. The study examined data from 31 088 colonoscopies by 147 screening program colonoscopists. Colonoscopists were grouped in four levels of mean CWT ( < 7, 7 - 8.9, 9 - 10.9, and ≥ 11 minutes). Univariable and multivariable analysis (binary logistic and negative binomial regression) were used to explore the relationship between CWT, ADR, mean number of adenomas and number of right-sided and advanced adenomas. In colonoscopists with a mean CWT < 7 minutes, the mean ADR was 42.5 % compared with 47.1 % in the ≥ 11-minute group (P < 0.001). The mean number of adenomas detected per procedure increased from 0.77 to 0.94, respectively (P < 0.001). The increase in adenoma detection was mainly of subcentimeter or proximal adenomas; there was no increase in the detection of advanced adenomas. Regression models showed an increase in ADR from 43 % to 46.5 % for mean CWT times ranging from 6 to 10 minutes. This study demonstrates that longer mean withdrawal times are associated with increasing adenoma detection, mainly of small or right-sided adenomas. However, beyond 10 minutes the increase in ADR is minimal. Mean withdrawal times longer than 6 minutes are not associated with increased detection of advanced adenomas. Withdrawal time remains an important quality metric of colonoscopy.

Monitoring colonoscopy withdrawal times remains important

We read the recent paper on colonoscopy withdrawal time (CWT) with interest [1]. In the English Bowel Cancer Screening Programme, a diagnostic withdrawal time of at least 6 minutes remains a key quality metric for colonoscopic performance [2]. We feel that it is an important standard, as it helps to protect against the poor practice of rapid withdrawal without proper mucosal inspection. Although a slow withdrawal time is not the only aspect of a gold standard inspection technique, it remains one of its key principles.

Prevalence of Adenomas during Screening Colonoscopy Using a Comprehensive Colonoscopy Screening Protocol

Purpose: Background and Aim: The adenoma detection rate is an independent predictor of the risk of interval colorectal cancer after screening colonoscopy. A number of techniques have been shown to maximize adenoma detection. We incorporated a comprehensive colonoscopy screening protocol that includes: 1. Ensuring a clean quality of colon preparation; 2. Cecal intubation in over 95%; 3. Colonoscope withdrawal time > 6 min; 4. Colonoscopy Screening Techniques for better adenoma detection (a. Use of a cap fitted endoscope to examine behind the folds; b. Patient position change to optimize distention of the colon; c. Eyes trained to detect flat lesions after looking at several flat lesions' images & videos). We have reported the effect of combining all these various techniques to maximize adenoma detection rate in 100 consecutive average risk patients (pts) undergoing screening colonoscopy previously. We report the adenoma detection rate in larger pool of 535 consecutive patients undergoing their first screening colonoscopy from 2009-2011. Methods: Endoscopist: Screening colonoscopy was performed by a single operator. Patients (pts): 535 consecutive patients undergoing screening colonoscopy from 2009-2011 were included in the study. Average risk pts: 495. Increased risk pts (Family history of colorectal cancer or polyps <60 years): 40. We used the comprehensive colonoscopy screening protocol to maximize adenoma detection in all patients during screening. Colonoscopy Report: The data was recorded in a structured colonoscopy report with well-defined fields to capture all the data. Main Outcome Measurements: We analyzed the adenoma detection rates. Results: Mean age: 58.3 ± 7.7; Sex: Men: Women: 220:315; BMI: 27.4 ± 5.4. Caucasians: 395(73.8%).The adenoma detection rate in screening population: 64.9%. The advanced adenoma detection rate (>1 cm adenoma or villous histology of any size or high grade dysplasia):14%.The multiple adenoma (≥ 3 adenomas) detection rate: 17%. The combined adenoma or proximal hyperplastic polyp detection rate: 69.7%. The proximal hyperplastic polyp detection rate: 15.3%. The serrated adenoma detection rate: 15%. The proximal hyperplastic polyp or serrated adenoma detection rate: 26.7%. See Table 1.Table: [1974] Prevalence of adenomas in 535 consecutive patients undergoing screening colonoscopies using a comprehensive colonoscopy screening protocolConclusion: Routine use of techniques to maximize adenoma detection result in persistent increase in adenoma detection rates, several fold higher than the adenoma detection rate set by the U.S Multi-Society Task Force on Colorectal Cancer (25% in men & 15% in women).

PWE-213 Comparison of colonoscopy quality indicators between surgeons, physicians and nurse endoscopists in the NHS bowel cancer screening programme: analysis of the national database

IntroductionScreening colonoscopists in the NHS Bowel Cancer Screening Programme (BCSP) are predominantly surgeons, physicians or nurse endoscopists. There are a small number from other backgrounds such as general practice. All...

Su1288 High Synchronous Polyp Burden in Patients With ≥ 1 CM Colon Polyps

Colonoscopy screening techniques have evolved over the last decade. Techniques shown to maximize adenoma detection include: 1. Clean quality of colon preparation; 2. Cecal intubation; 3. Colonoscope withdrawal time > 6 min; 4. Colonoscopy Screening Techniques for better adenoma detection (a. Use of a cap fitted endoscope to examine behind the folds; b. Patient position change to optimize distention of the colon; c. Eyes trained to detect flat lesions after looking at several flat lesions' images & videos).

Mo1246 Colonoscopy Withdrawal Times and Adenoma Detection During Screening Colonoscopy

Mo1246 Colonoscopy Withdrawal Times and Adenoma Detection During Screening Colonoscopy

Trainees’ adenoma detection rate is higher if ≥10 minutes is spent on withdrawal during colonoscopy

It has been demonstrated that prolonged colonoscopic withdrawal times (WT; >6 min) are beneficial for the adenoma detection rate (ADR) for experienced endoscopists. There are little data, however, to guide the appropriate colonoscopic withdrawal times for trainees. The purpose of this study was to determine whether there is a relationship between WTs and ADR for first-year fellows training in colonoscopy. This is a prospective study of first-year gastroenterology fellows at a single academic teaching hospital who documented each colonoscopy with a self-report form over the course of an academic year (March 2010 to February 2011). The internal policy for the trainees was to have at least a 6-min withdrawal time for each colonoscopy. Four first-year fellows in gastroenterology at an academic medical center completed self-reports for 1,210 colonoscopies. Mean WT was 10.2 ± 3.4 min. The aggregate polyp detection rate was 33.2% and the aggregate ADR was 22.3%. For colonoscopies with WT < 10 min, ADR was 9.5%, and for colonoscopies with WT ≥ 10 min, ADR was 32.3% (p < 0.001). When the quality indicator of 25% goal ADR for males and 15% goal ADR for females is applied, this aggregate rate is achieved for both sexes for screening colonoscopies (n = 676) with WT ≥ 10 min. First-year trainees had a significantly higher ADR if their colonoscopic WT is ≥ 10 min.