Withdrawal Phase Of Colonoscopy Research Articles

Evaluation of the Effectiveness of Patient’s Position Change during the Withdrawal Phase of Colonoscopy from Left Lateral Decubitus to Supine Position on Increasing Adenoma Detection Rate: A Randomized Controlled Trial

Background: Improvement in adenoma detection rate (ADR) reduces colorectal cancer incidence by increasing the colonoscopy quality. Using dynamic patient position changes during the withdrawal phase has shown promise in increasing ADR. We conducted this study to assess the effectiveness of the supine position on the improvement of ADR to improve its feasibility and avoid frequent patient position changes, particularly in sedated patients. Methods: This was a randomized, single-blind, parallel-group, single-center study implemented in the Mehregan private in Babol. Inclusion criteria were 40 to 85 years old, 4 L application of polyethylene glycol from the day before the procedure, no history of inflammatory bowel disease, bowel surgery, musculoskeletal problems, and negative familial history of colorectal cancer. Patients were allocated in a 1:1 ratio to the supine or left lateral positions during the withdrawal phase. All colonoscopies were performed by a single physician using a Fujifilm colonoscope. A P-value of <0.005 was considered statistically significant. Results: A total of 880 patients were assessed for eligibility, of which 472 patients were included in the final analysis; 53.4% were female, the mean age of participants was 55.86±10.30 years old, 95.1% of patients had adequate bowel preparation, and adenomatous polyps were the most common histopathologic type (63.7%). Despite the intervention group’s higher rate of ADR and PDR (19.5% vs. 17.7% for ADR and 27.2% vs. 26.5% for PDR), no statistically significant difference in ADR or PDR was detected (P=0.613 and 0.866, respectively). Conclusion: No statistical significance was observed despite the increase in ADR when the supine position was used exclusively during the withdrawal phase. As a result, we recommend that the dynamic position change method be used if a position change is required. Nonetheless, additional research is required to determine a more effective alternative to dynamic position change in obese or heavily sedated patients.

Effect of dynamic position changes on adenoma detection rate during colonoscope withdrawal: systematic review and meta-analysis.

Background and study aims The adenoma detection rate (ADR) is an important quality metric of colonoscopy. Higher ADR correlates with lower incidence of interval colorectal cancer. ADR is variable between endoscopists and depends upon the withdrawal technique amongst other factors. Dynamic position change (lateral rotation of patients with a view to keep the portion of the colon being inspected at a higher level) helps with luminal distension during the withdrawal phase. However, impact of this on ADR is not known in a pooled sample. We performed a systematic review and meta-analysis to study the impact of dynamic position changes during withdrawal phase of colonoscopy on ADR Methods A comprehensive search of MEDLINE, EMBASE, Google Scholar, and the Cochrane Database was conducted from each database’s inception to search for studies comparing dynamic position changes during colonoscope withdrawal with static left lateral position (control). The primary outcome of interest was ADR. Other studied outcomes were polyp detection rate (PDR) and withdrawal time. Outcomes were reported as pooled odds ratio (OR) with 95 % confidence intervals (CI) with statistical significance ( P < 0.05). RevMan 5.3 software was used for statistical analysis. Results Six studies were included in our analysis with 2860 patients. Of these, dynamic position change was implemented in 1177 patients while 1183 patients served as the controls. ADR was significantly higher in the dynamic position change group with pooled OR 1.36 (95 % CI, 1.15–1.61; P < 0.01). There was low heterogeneity in inclusion studies (I 2 = 0 %). PDR was numerically higher in position change group (53.4 % vs 49.6 %) but not statistically significant ( P = 0.16). Mean withdrawal time did not significantly change with dynamic position change (12.43 min vs 11.46 min, P = 0.27). Conclusion Position change during the withdrawal phase of colonoscopy can increase the ADR compared to static left lateral position. This is an easy and practical technique that can be implemented to improve ADR.

Clinical significance of colorectal polyp detection on colonoscopy insertion.

Colorectal lesions are generally evaluated during the withdrawal phase of colonoscopy. Minimising the risk of missed lesions is crucial to determine an appropriate future surveillance colonoscopy interval. This study aimed to evaluate the clinical significance of detecting sigmoid colon lesions during the insertion phase. This retrospective study included 172 consecutive patients undergoing colonoscopy between October 2017 and April 2018. The total number of detected polyps, mean polyps per procedure, mean polyps per positive procedure, and histological and clinical characteristics of detected lesions were recorded. The primary endpoint was the difference in sigmoid colon polyp detection rates during insertion and withdrawal. A total of 172 colonoscopies were performed for each patient and 322 lesions were detected. Sixty-two (19%) polyps were detected during insertion, 312 (97%) during withdrawal, and 52 (16%) during both insertion and withdrawal. Although all polyps except for those in the sigmoid colon could be detected during withdrawal, 10 of 87 (11%) polyps in the sigmoid colon could only be detected during insertion. In this study, attempts to detect polyps, even in the insertion phase, showed the clinical significance to decrease the risk of missed adenomatous polyps in the sigmoid colon.

Gaze patterns hold key to unlocking successful search strategies and increasing polyp detection rate in colonoscopy.

The adenoma detection rate (ADR) is an important quality indicator in colonoscopy. The aim of this study was to evaluate the changes in visual gaze patterns (VGPs) with increasing polyp detection rate (PDR), a surrogate marker of ADR. 18 endoscopists participated in the study. VGPs were measured using eye-tracking technology during the withdrawal phase of colonoscopy. VGPs were characterized using two analyses - screen and anatomy. Eye-tracking parameters were used to characterize performance, which was further substantiated using hidden Markov model (HMM) analysis. Subjects with higher PDRs spent more time viewing the outer ring of the 3 × 3 grid for both analyses (screen-based: r = 0.56, P = 0.02; anatomy: r = 0.62, P < 0.01). Fixation distribution to the "bottom U" of the screen in screen-based analysis was positively correlated with PDR (r = 0.62, P = 0.01). HMM demarcated the VGPs into three PDR groups. This study defined distinct VGPs that are associated with expert behavior. These data may allow introduction of visual gaze training within structured training programs, and have implications for adoption in higher-level assessment.

Not All Visual Data Acquired During Withdrawal Phase (WP) of Colonoscopy Is Interpretable. Introducing the Concept of “Effective” WP Time: 2016 ACG Presidential Poster Award

Introduction: A high quality colonoscopy improves adenoma detection rate (ADR) and low ADR is linked to development of interval colon cancer. Both patient and endoscopist-related factors are associated with ADR. A Longer withdrawal phase (WP) time is associated with higher ADR. Six minutes or longer WP time has been recommended. We wanted to investigate how much of WP time is actually spent on inspection of the mucosa as opposed to uninterpretable visual data. We wanted to test a novel image-based approach in assessing meaningful adequate information acquired during WP. We call this adequate visual data as the “effective” WP time. Aim1) Characterize each representative image from withdrawal phase of colonoscopy videos as adequate or inadequate. 2) Calculate proportion of visual data acquired during WP that is effective. Methods: Ten randomly selected WP from screening colonoscopy videos that had adequate cleansing preparation score were selected. Every 200th image was selected to represent the entire visual data acquired during WP. Each image was classified as 1) Adequate(Figure 1): >75% of image was interpretable 2) Inadequate(Figure 2): < 50% interpretable 3) Ambiguous: >50% but < 75%. 2 readers in a blinded manner analyzed each image independently and each ambiguous image was analyzed twice. Both readers had >10 year experience and ADR>40%. Kappa statistics were used for agreement scores.Figure 1Figure 2Results: 1005 individual images from WP of 10 colonoscopies was analyzed. On average for each WP, 32% of acquired visual data was inadequate, 57% adequate and 11% ambiguous for reader one. For the second reader, 27% was inadequate, 61% adequate 12% ambiguous (Table 1). Inter-observer agreement scores between two readers for inadequate images was good (Kappa Score 0.64, p< 0.001). Intra-observer agreement score was excellent (Kappa 0.8 and 0.81) for each reader (p < 0.001).Table 1: Percentage of individual images for each WP video, that had inadequate visual data, for interpretation of mucosa.Conclusion: Not all visual data acquired during WP of colonoscopy is adequate for visual interpretation of mucosa. In our study, up to 32% of the WP images were inadequate, introducing the concept of “effective” withdrawal time. This can be a potential target for improvement for endoscopist with low ADRs. Several approaches, including training programs for better hand-eye coordination can be employed to reduce the inadequate data acquired during WP and maximize the effective time during the WP. Our study generates feasibility of an image analyzing software that can be employed to track this particular indicator.

Adenoma detection at colonoscopy by polypectomy in withdrawal only versus both insertion and withdrawal: a randomized controlled trial.

Colonic configuration during insertion phase (IP) and withdrawal phase (WP) is different and some polyps seen during IP are difficult to find during WP and vice versa. To determine if polypectomy performed during both IP and WP of colonoscopy (study arm) increases adenoma detection rate (ADR) compared to WP only (control arm). In this prospective randomized controlled trial, adults undergoing out-patient colonoscopy were enrolled. The primary outcome was mean number of adenomas detected per patient. Secondary outcomes were ADR, defined as the proportion of colonoscopies with at least one adenoma, polyp detection rates (PDR), number of patients classified as high-risk group (presence of ≥3 adenomas of any size, any adenoma ≥1 cm in size, or adenoma with villous component, or high grade dysplasia), procedural times, patients discomfort, and ease of procedure. Among 772 patients enrolled, 610 were included (329 in study arm and 281 in control arm). In both arms, mean number of adenomas detected per patient were similar, 0.78 ± 1.4 vs. 0.74 ± 1.5, P = 0.75. Also, ADR (39.2 vs. 38.1 %, P = 0.77) and PDR (57.1 and 54.1 %, P = 0.45) were similar. Mean insertion time was significantly higher in study arm (10.2 ± 5.8 vs. 9.3 ± 5.6 min, p = 0.046). Proportion of patients identified as high-risk group were significantly higher in study arm (18.8 vs. 11.7 %, P = 0.016). Polypectomy performed during both IP and WP compared to the WP only, did not improve ADR or mean number of adenomas detected per patient. Clinicaltrials.gov, #NCT01025960.

Mo1564 Water-Exchange During Insertion Significantly Reduces the Number of Distractions From Quality Inspection in the Proximal Colon During the Withdrawal Phase of Colonoscopy - an Effect With Potential Impact on Increasing the Adenoma Detection Rate (ADR)

Mo1564 Water-Exchange During Insertion Significantly Reduces the Number of Distractions From Quality Inspection in the Proximal Colon During the Withdrawal Phase of Colonoscopy - an Effect With Potential Impact on Increasing the Adenoma Detection Rate (ADR)

797 Comparison of Adenoma Detection by Inspection During Both Insertion and Withdrawal Phases Versus Only Withdrawal Phase of Colonoscopy: A Randomized Controlled Trial

Standard method of colonoscopy is to insert the colonoscope rapidly to reach the cecum, with careful inspection and polyp removal during the withdrawal phase (WP). However, some polyps seen during insertion phase (IP) are difficult to find during withdrawal phase. Also, colon is in different conformation during insertion and withdrawal phases. Hence we hypothesized that careful inspection and removal of polyps during insertion also may improve adenoma detection rate (ADR).

Comparison of Polyp Detection Rates During Colonoscopy by Attending Staff Alone Versus Trainee Plus Attending Staff: Are Two People Better Than One?

Background: Effectiveness of colon cancer screening and prevention depends on effective detection of polyps and their removal. Traditionally, polyps are detected during withdrawal phase of colonoscopy by careful and thorough visualization. There are reports of detecting missed polyps in tandem colonoscopies performed by two different individuals. Hence, we hypothesize that there is higher likelihood of detecting polyps by two people in colonoscopies performed by trainee plus attending staff compared to colonoscopies by attending staff alone. Aims: To determine and compare the polyp detection rates between attending staff alone (group 1) versus trainee plus attending staff (group 2) performed colonoscopies. Methods: Retrospective chart review of all colonoscopies from November 2003 to October 2004 in the Division of Gastroenterology at Metro Health Medical Center. Ten trainees under attending supervision or eight attending staff themselves performed the colonoscopies. Patient demographics, indications for colonoscopy and colonoscopic findings including presence or absence of polyps, number of polyps, size, location and histology were compared between the two groups. Patients with inadequate bowel preparation, incomplete procedures and partial colectomy were excluded from analysis. Results: A total of 575 and 1358 colonoscopies were included in analysis from group 1 and group 2 respectively. Patient demographics and indications for colonoscopy were similar in the two groups. Polyp detection rate in group 1 was 38.8% versus 37.8% in group 2 (p > 0.05). Polyp characteristics were also similar between the two groups. Conclusions: There is no difference in overall polyp detection rates in the colonoscopies when performed by the trainee plus attending or the attending alone. Two people visualizing colonic mucosa during withdrawal phase of colonoscopy might not improve overall polyp detection rates. Background: Effectiveness of colon cancer screening and prevention depends on effective detection of polyps and their removal. Traditionally, polyps are detected during withdrawal phase of colonoscopy by careful and thorough visualization. There are reports of detecting missed polyps in tandem colonoscopies performed by two different individuals. Hence, we hypothesize that there is higher likelihood of detecting polyps by two people in colonoscopies performed by trainee plus attending staff compared to colonoscopies by attending staff alone. Aims: To determine and compare the polyp detection rates between attending staff alone (group 1) versus trainee plus attending staff (group 2) performed colonoscopies. Methods: Retrospective chart review of all colonoscopies from November 2003 to October 2004 in the Division of Gastroenterology at Metro Health Medical Center. Ten trainees under attending supervision or eight attending staff themselves performed the colonoscopies. Patient demographics, indications for colonoscopy and colonoscopic findings including presence or absence of polyps, number of polyps, size, location and histology were compared between the two groups. Patients with inadequate bowel preparation, incomplete procedures and partial colectomy were excluded from analysis. Results: A total of 575 and 1358 colonoscopies were included in analysis from group 1 and group 2 respectively. Patient demographics and indications for colonoscopy were similar in the two groups. Polyp detection rate in group 1 was 38.8% versus 37.8% in group 2 (p > 0.05). Polyp characteristics were also similar between the two groups. Conclusions: There is no difference in overall polyp detection rates in the colonoscopies when performed by the trainee plus attending or the attending alone. Two people visualizing colonic mucosa during withdrawal phase of colonoscopy might not improve overall polyp detection rates.

Selective sedation for colonoscopy

A study of selective sedation for colonoscopy was conducted in two parts. All procedures were performed by one experienced colonoscopist. In the first phase, 41 patients received intravenous sedation before colonoscopy and were then prospectively randomized to either a “not-reversed” group, which did not receive flumazenil before withdrawal of the colonoscope, or to a “reversed” group, which received flumazenil before colonoscope withdrawal. None of the 20 patients reversed and 1 of the 21 patients not reversed experienced pain during the withdrawal phase of colonoscopy. Sixty percent of patients in the reversed group and 10% in the not-reversed group remembered the colonoscopic findings being explained during the procedure. Ninety percent and 81% of patients in the reversed and not-reversed groups, respectively, expressed a preference to be awake to watch the withdrawal of the colonoscope. In the second phase of this study, 40 patients underwent colonoscopy without prior intravenous sedation. Sedation was given only if pain was experienced during the procedure. Thirty percent had no pain at all, 55% minimal pain, 8% moderate pain, and 3% severe pain. Twenty-three percent required intravenous sedation, whereas 78% did not receive any sedation. Ninety-three percent were willing to undergo another colonoscopy without prior sedation. Only 8% preferred prior intravenous sedation before any future colonoscopy. (Gastrointest Endosc 1994;40:661-4.)