Risk factors for inadequate bowel preparation in colonoscopy: a comprehensive systematic review and meta-analysis.

INTRODUCTION: Inadequate bowel preparation (IBP) prior to colonoscopy remains a common problem. This meta-analysis aimed to assess the risk factors associated with IBP. METHODS: We searched multiple databases for studies that assessed risk factors for IBP after adjustment and reported the data as adjusted odds ratios (OR) with 95% confidence intervals. Meta-analyses were conducted using a random-effects model, and pooled adjusted ORs for risk factors reported in ≥3 studies were constructed. RESULTS: 154 studies with 258,257 participants were included. We analyzed 48 unique risk factors. Sociodemographic predictors of IBP were Medicaid insurance, obesity, current tobacco use, age≥65, Black race, low education level, male gender, and unmarried status. Comorbidity-related predictors of IBP were any psychiatric disease, cirrhosis, ASA class≥3, poor functional status, constipation, diabetes, prior abdominopelvic surgery, and hematochezia. Medication-related predictors of IBP were tricyclic antidepressants (TCA), antidepressants, opioid, non-TCA antidepressants, and calcium channel blockers. Preparation/procedure-related predictors of IBP were brown liquid rectal effluent, any incomplete bowel preparation (BP) intake, lack of split-dose BP, increased BP-to-defecation interval, any non-adherence to dietary instructions, increased BP-to-colonoscopy interval, any BP intolerance, prior IBP, and inpatient status. While afternoon colonoscopy was a predictor of IBP, subgroup analysis of prospective studies revealed no significant association. CONCLUSIONS: Our meta-analysis focused on adjusted risk factors to provide precise estimates of the most important risk factors for IBP. Our findings could help develop a validated prediction model to identify high-risk patients for IBP, improve colonoscopy outcomes, reduce the need for repeat colonoscopies, and reduce associated healthcare costs.

Performance of bowel preparation quality scales in patients with Crohn's disease.

BACKGROUND: The performance of bowel preparation (BP) in patients with Crohn's disease (CD) is unknown. AIMS: To evaluate the operating properties of instruments used to assess BP quality in patients with CD. METHODS: We used the Boston Bowel Preparation Scale, modified Boston Bowel Preparation Scale, Harefield Cleansing Scale, Food and Drug Administration Bowel Cleansing Assessment Scale (BCAS), and a 100-mm visual analogue scale of bowel cleanliness to assess BP quality in 50 videos from 40 patients with CD. We assessed endoscopic activity with the Simple Endoscopic Score for CD (SES-CD). Assessments were on endoscope insertion and withdrawal. Reliability was quantified using the intraclass correlation coefficient (ICC). We assessed validity by within-patient correlation between instruments and the visual analogue scale using mixed-effect models. The correlation between BP quality and SES-SD scores was assessed using Spearman's rho. RESULTS: Inter- and intra-rater reliability for all BP quality instruments was substantial (ICC ≥0.61) except for the Food and Drug Administration BCAS on insertion (inter-rater reliability ICC ≥0.41). The visual analogue scale had substantial inter- and almost perfect (ICC ≥0.81) intra-rater reliability. Correlation coefficients for the validity of the instruments exceeded 0.58. BP quality and endoscopic disease activity scores in the colon were negatively correlated. CONCLUSION: Most existing instruments reliably assess BP quality in patients with CD. These results support the use of these instruments in clinical practice, provide a framework for scoring BP quality in CD clinical trials, and support evaluation of novel BP agents in patients with CD.

Accuracy of Computer-aided Diagnosis in Colonoscopy Varies according to Polyp Location. A Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Computer-Aided Diagnosis (CADx) assists endoscopists in differentiating between neoplastic and non-neoplastic polyps during colonoscopy. This study aimed to evaluate the impact of polyp location (proximal vs. distal colon) on the diagnostic performance of CADx for ≤5mm polyps. METHODS: We searched for studies evaluating the performance of real-time CADx alone (i.e., independently of endoscopist judgement) for predicting the histology of colorectal polyps ≤5mm. The primary endpoints were CADx sensitivity and specificity in the proximal and distal colon. Secondary outcomes were the negative predictive value (NPV), positive predictive value (PPV), and the accuracy of the CADx alone. Distal colon was limited to the rectum and sigmoid. RESULTS: We included 11 studies for analysis with a total of 7,782 <5mm polyps. CADx specificity was significantly lower in the proximal colon compared to the distal colon (62% versus 85%; Risk ratio (RR): 0.74 [95% CI: 0.72-0.84]). Conversely, sensitivity was similar (89% vs 87% (EC-1); RR: 1.00 [95% CI: 0.97-1.03]. The NPV (64% versus 93%; RR: 0.71 [95% CI: 0.64-0.79]) and accuracy (81% vs 86%; RR: 0.95 [95% CI: 0.91-0.99]) were significantly lower in the proximal than distal colon, while PPV was higher in the proximal colon (87% vs 76%; RR: 1.11 [95% CI: 1.06-1.17]). CONCLUSION: The diagnostic performance of CADx for polyps in the proximal colon is inadequate, exhibiting significantly lower specificity compared to its performance for distal polyps. While current CADx systems are suitable for use in the distal colon, they should not be employed for proximal polyps until more performant systems are developed specifically for these lesions.

Distal Cap-assisted Endoscopic Mucosal Resection allows the safe and effective resection of adherent, dysplastic lesions in the setting of inflammatory bowel disease: a multicenter, retrospective study with video.

BACKGROUND AND AIMS: Endoscopic mucosal resection (EMR) is established as the primary approach for large/complex dysplastic lesions. However, submucosal fibrosis caused by previous attempts at removal, biopsy, inflammation, or tattoo can cause a benign "negative lift sign" and create difficulty for EMR. Here, we present the use of distal-cap assisted EMR (EMR-DC) specifically for the use of resecting dysplastic colon lesions when submucosal fibrosis is present in IBD patients. METHODS: 16 IBD patients were retrospectively evaluated from two high volume centers. The patient demographics, lesion pathology and classification, outcomes including time and success of resection, SAEs within 30 days of the procedure, and efficacy were measured. RESULTS: 75% of patients treated with EMR-DC achieved complete resection with 0 serious adverse events within 30 days of the procedure. CONCLUSION: EMR-DC represents an attractive option for the resection of adherent dysplastic lesions in chronic IBD which is effective, safe, and inexpensive.

International consensus on the management of large (≥20 mm) colorectal laterally spreading tumors: World Endoscopy Organization Delphi study.

OBJECTIVES: There have been significant advances in the management of large (≥20 mm) laterally spreading tumors (LSTs) or nonpedunculated colorectal polyps; however, there is a lack of clear consensus on the management of these lesions with significant geographic variability especially between Eastern and Western paradigms. We aimed to provide an international consensus to better guide management and attempt to homogenize practices. METHODS: Two experts in interventional endoscopy spearheaded an evidence-based Delphi study on behalf of the World Endoscopy Organization Colorectal Cancer Screening Committee. A steering committee comprising six members devised 51 statements, and 43 experts from 18 countries on six continents participated in a three-round voting process. The Grading of Recommendations, Assessment, Development and Evaluations tool was used to assess evidence quality and recommendation strength. Consensus was defined as ≥80% agreement (strongly agree or agree) on a 5-point Likert scale. RESULTS: Forty-two statements reached consensus after three rounds of voting. Recommendations included: three statements on training and competency; 10 statements on preresection evaluation, including optical diagnosis, classification, and staging of LSTs; 14 statements on endoscopic resection indications and technique, including statements on en bloc and piecemeal resection decision-making; seven statements on postresection evaluation; and eight statements on postresection care. CONCLUSIONS: An international expert consensus based on the current available evidence has been developed to guide the evaluation, resection, and follow-up of LSTs. This may provide guiding principles for the global management of these lesions and standardize current practices.

A new through-the-scope clip with anchor prongs is safe and successful for a variety of endoscopic uses.

Background and study aims Endoscopic through-the-scope clips (TTSC) are used for hemostasis and closure. We documented the performance of a new TTSC with anchor prongs. Patients and methods We conducted a prospective case series of the new TTSC in 50 patients with an indication for endoscopic clipping at three hospitals in the United States and Canada. Patients were followed for 30 days after the index procedure. Outcomes included defect closure and rate of serious adverse events (SAEs) related to the device or procedure. Results Fifty patients had 56 clipping procedures. Thirty-four procedures were clipping after endoscopic mucosal resection (EMR) in the colon (33) or stomach (1), 16 after polypectomy, two for hemostasis of active bleeding, and one each for fistula closure, per-oral endoscopic myotomy mucosal closure, or anchoring a feeding tube. Complete defect closure was achieved in 32 of 33 colon EMR defects and 21 of 22 other defects. All clips were placed per labeled directions for use. In 41 patients (82.0%), prophylaxis of delayed bleeding was reported as an indication for endoscopic clipping. There were three instances of delayed bleeding. There were no device-related SAEs. The only technical difficulty was one instance of premature clip deployment. Conclusions A novel TTSC with anchor prongs showed success in a range of defect closures, an acceptable safety profile, and low incidence of technical difficulties.

Safety of first surveillance colonoscopy at 12 months after piecemeal EMR of large nonpedunculated colorectal lesions.

BACKGROUND AND AIMS: After piecemeal EMR (pEMR) of nonpedunculated colorectal lesions ≥20 mm, guidelines recommend first endoscopic surveillance at 6 months. However, initial surveillance at 12 months may be adequate for selected low-risk lesions and could save the cost, risk, and inconvenience of 1 surveillance examination. METHODS: This study retrospectively examined a prospectively collected database of all colorectal lesions referred to our center for endoscopic resection between August 2019 and April 2023. We report recurrence rates of patients with colorectal lesions ≥20 mm removed by pEMR who were assigned to 6-month first surveillance or to 12-month first surveillance (or assigned to a 6-month surveillance visit but did not return until after 10 months). RESULTS: There were 561 nonpedunculated lesions ≥20 mm that underwent first follow-up, including 490 lesions in 443 patients assigned to 6-month surveillance and 71 lesions in 65 patients assigned to 12-month surveillance. Lesions assigned to 12-month surveillance were smaller (mean size, 25.9 ± 6.1 mm vs 37.0 ± 17.4 mm), more likely serrated (63.4% vs 9.6%), and more often removed by cold pEMR (74.6% vs 20.4%). Twenty-nine lesions in 24 patients assigned to 6-month surveillance presented after 10 months, and their recurrence data were included in the group assigned to 12-month surveillance. Overall recurrence rates at 6 months and 12 months were 10.0% (46 of 461) and 10.0% (10 of 100), respectively. Mean recurrence sizes at 6 and 12 months were 10.9 ± 6.2 mm and 5.0 ± 3.1 mm, respectively. One patient in the 6-month surveillance group had cancer at the pEMR site, but no other recurrences at 6 or 12 months had either cancer or high-grade dysplasia. CONCLUSIONS: Twelve-month surveillance seems acceptable for selected colorectal lesions ≥20 mm removed by pEMR. A randomized trial comparing initial 6-month versus 12-month surveillance is warranted for selected lesions.

Using Computer-aided Optical Diagnosis and Expert Review to Evaluate Colorectal Polyps Diagnosed as Normal Mucosa in Pathology.

Pathological assessment of colorectal polyps is considered the current reference standard for histologic diagnosis. About 10% of polyps sent to the pathology lab are returned with the diagnosis of mucosal folds, mucosal prolapse, or normal mucosa.1,2 Two recent publications have indicated that disagreements between endoscopic optical diagnosis and the subsequent pathological diagnoses might be due to misdiagnosis in pathology.3,4 We were therefore interested in re-evaluating pathology-based diagnosis of "mucosal polyps" using expert endoscopists and computer-assisted diagnosis (CADx) evaluation.

Computer-Aided Diagnosis for Leaving Colorectal Polyps In Situ : A Systematic Review and Meta-analysis.

BACKGROUND: Computer-aided diagnosis (CADx) allows prediction of polyp histology during colonoscopy, which may reduce unnecessary removal of nonneoplastic polyps. However, the potential benefits and harms of CADx are still unclear. PURPOSE: To quantify the benefit and harm of using CADx in colonoscopy for the optical diagnosis of small (≤5-mm) rectosigmoid polyps. DATA SOURCES: Medline, Embase, and Scopus were searched for articles published before 22 December 2023. STUDY SELECTION: Histologically verified diagnostic accuracy studies that evaluated the real-time performance of physicians in predicting neoplastic change of small rectosigmoid polyps without or with CADx assistance during colonoscopy. DATA EXTRACTION: The clinical benefit and harm were estimated on the basis of accuracy values of the endoscopist before and after CADx assistance. The certainty of evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) framework. The outcome measure for benefit was the proportion of polyps predicted to be nonneoplastic that would avoid removal with the use of CADx. The outcome measure for harm was the proportion of neoplastic polyps that would be not resected and left in situ due to an incorrect diagnosis with the use of CADx. Histology served as the reference standard for both outcomes. DATA SYNTHESIS: Ten studies, including 3620 patients with 4103 small rectosigmoid polyps, were analyzed. The studies that assessed the performance of CADx alone (9 studies; 3237 polyps) showed a sensitivity of 87.3% (95% CI, 79.2% to 92.5%) and specificity of 88.9% (CI, 81.7% to 93.5%) in predicting neoplastic change. In the studies that compared histology prediction performance before versus after CADx assistance (4 studies; 2503 polyps), there was no difference in the proportion of polyps predicted to be nonneoplastic that would avoid removal (55.4% vs. 58.4%; risk ratio [RR], 1.06 [CI, 0.96 to 1.17]; moderate-certainty evidence) or in the proportion of neoplastic polyps that would be erroneously left in situ (8.2% vs. 7.5%; RR, 0.95 [CI, 0.69 to 1.33]; moderate-certainty evidence). LIMITATION: The application of optical diagnosis was only simulated, potentially altering the decision-making process of the operator. CONCLUSION: Computer-aided diagnosis provided no incremental benefit or harm in the management of small rectosigmoid polyps during colonoscopy. PRIMARY FUNDING SOURCE: European Commission. (PROSPERO: CRD42023402197).

Artificial Intelligence for Real-Time Prediction of the Histology of Colorectal Polyps by General Endoscopists.

BACKGROUND: Real-time prediction of histologic features of small colorectal polyps may prevent resection and/or pathologic evaluation and therefore decrease colonoscopy costs. Previous studies showed that computer-aided diagnosis (CADx) was highly accurate, though it did not outperform expert endoscopists. OBJECTIVE: To assess the diagnostic performance of histologic predictions by general endoscopists before and after assistance from CADx in a real-life setting. DESIGN: Prospective, multicenter, single-group study. (ClinicalTrials.gov: NCT04437615). SETTING: 6 centers across the United States. PARTICIPANTS: 1252 consecutive patients undergoing colonoscopy and 49 general endoscopists with variable experience in real-time prediction of polyp histologic features. INTERVENTION: Real-time use of CADx during routine colonoscopy. MEASUREMENTS: The primary end points were the sensitivity and specificity of CADx-unassisted and CADx-assisted histologic predictions for adenomas measuring 5 mm or less. For clinical purposes, additional estimates according to location and confidence level were provided. RESULTS: The CADx device made a diagnosis for 2695 polyps measuring 5 mm or less (96%) in 1252 patients. There was no difference in sensitivity between the unassisted and assisted groups (90.7% vs. 90.8%; P = 0.52). Specificity was higher in the CADx-assisted group (59.5% vs. 64.7%; P < 0.001). Among all 2695 polyps measuring 5 mm or less, 88.2% and 86.1% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be resected and discarded without pathologic evaluation. Among 743 rectosigmoid polyps measuring 5 mm or less, 49.5% and 47.9% (P < 0.001) in the CADx-assisted and unassisted groups, respectively, could be left in situ without resection. LIMITATION: Decision making based on CADx might differ outside a clinical trial. CONCLUSION: CADx assistance did not result in increased sensitivity of optical diagnosis. Despite a slight increase, the specificity of CADx-assisted diagnosis remained suboptimal. PRIMARY FUNDING SOURCE: Olympus America Corporation served as the clinical study sponsor.

Audit of hemostatic clip use after colorectal polyp resection in an academic endoscopy unit.

Background and study aims Prophylactic closure of endoscopic resection defects reduces delayed hemorrhage after resection of non-pedunculated colorectal lesions ≥ 20 mm that are located proximal to the splenic flexure and removed by electrocautery. The risk of delayed hemorrhage after cold (without electrocautery) resection is much lower, and prophylactic clip closure after cold resection is generally unnecessary. The aim of this study was to audit clip use after colorectal polyp resection in routine outpatient colonoscopies at two outpatient centers within an academic medical center. Patients referred for resection of known lesions were excluded. Patients and methods Retrospective chart analysis was performed as part of a quality review of physician adherence to screening and post-polypectomy surveillance intervals. Results Among 3784 total lesions resected cold by 29 physicians, clips were placed after cold resection on 41.7% of 12 lesions ≥ 20 mm, 19.3% of 207 lesions 10 to 19 mm in size, and 2.8% of 3565 lesions 1 to 9 mm in size. Three physicians placed clips after cold resection of lesions 1 to 9 mm in 18.8%, 25.5%, and 45.0% of cases. These physicians accounted for 8.1% of 1- to 9-mm resections, but 69.7% of clips placed in this size range. Electrocautery was used for 3.1% of all resections. Clip placement overall after cold resection (3.9%) was much lower than after resection with electrocautery (71.1%), but 62.4% of all clips placed were after cold resection. Conclusions Audits of clip use in an endoscopy practice can reveal surprising findings, including high and variable rates of unnecessary use after cold resection. Audit can potentially reduce unnecessary costs, carbon emissions, and plastic waste.

Expert endoscopist assessment of colorectal polyp size using virtual scale endoscopy, visual or snare-based estimation: a prospective video-based study.

BACKGROUND AND AIMS: Accurate polyp size estimation during colonoscopy has an impact on clinical decision-making. A laser-based virtual scale endoscope (VSE) is available to allow measuring polyp size using a virtual adaptive scale. This study evaluates video-based polyp size measurement accuracy among expert endoscopists using either VSE or visual assessment (VA) with either snare as reference size or without any reference size information. METHODS: A prospective, video-based study was conducted with 10 expert endoscopists. Video sequences from 90 polyps with known reference size (fresh specimen measured using calipers) were distributed on three different slide sets so that each slide set showed the same polyp only once with either VSE, VA or snare-based information. A slide set was randomly assigned to each endoscopist. Endoscopists were asked to provide size estimation based on video review. RESULTS: Relative accuracies for VSE, VA, and snare-based estimation were 75.1% (95% CI [71.6-78.5]), 65.0% (95% CI [59.5-70.4]) and 62.0% (95% CI [54.8-69.0]), respectively. VSE yielded significantly higher relative accuracy compared to VA (p = 0.002) and to snare (p = 0.001). A significantly lower percentage of polyps 1-5 mm were misclassified as >5 mm using VSE versus VA and snare (6.52% vs. 19.6% and 17.5%, p = 0.004) and a significantly lower percentage of polyps >5 mm were misclassified as 1-5 mm using VSE versus VA and snare (11.4% vs. 31.9% and 14.9%, p = 0.038). CONCLUSIONS: Endoscopists estimate polyp size with the highest accuracy when virtual adaptive scale information is displayed. Using a snare to assist sizing did not improve measurement accuracy compared to displaying visual information alone.