Neoplasia Diagnosis After Multi-target Stool DNA Is Enhanced Among Lowest Baseline Detectors.

BACKGROUND AND AIMS: Variation in colorectal neoplasia detection limits the effectiveness of screening colonoscopy. By evaluating neoplasia detection rates of individual colonoscopists, we aimed to quantify the effects of pre-procedural knowledge of a positive (+) multi-target stool DNA (mt-sDNA) on colonoscopy quality metrics. METHODS: We retrospectively identified physicians who performed a high volume of + mt-sDNA colonoscopies; colorectal neoplasia at post-mt-sDNA colonoscopy was recorded. These colonoscopists were stratified into quartiles based on baseline adenoma detection rates. Baseline colonoscopy adenoma detection rates and sessile serrated lesion detection rates were compared to post-mt-sDNA colonoscopy neoplasia diagnosis rates among each quartile. Withdrawal times were measured from negative exams. RESULTS: During the study period (2014-17) the highest quartile of physicians by volume of post-mt-sDNA colonoscopies were evaluated. Among thirty-five gastroenterologists, their median screening colonoscopy adenoma detection rate was 32% (IQR, 28-39%) and serrated lesion detection rate was 13% (8-15%). After + mt-sDNA, adenoma diagnosis increased to 47% (36-56%) and serrated lesion diagnosis increased to 31% (17-42%) (both p < 0.0001). Median withdrawal time increased from 10 (7-13) to 12 (10-17) minutes (p < 0.0001) and was proportionate across quartiles. After + mt-sDNA, lower baseline detectors had disproportionately higher rates of adenoma diagnosis in female versus male patients (p = 0.048) and higher serrated neoplasia diagnosis rates among all patients (p = 0.0092). CONCLUSIONS: Knowledge of + mt-sDNA enriches neoplasia diagnosis compared to average risk screening exams. Adenomatous and serrated lesion diagnosis was magnified among those with lower adenoma detection rates. Awareness of the mt-sDNA result may increase physician attention during colonoscopy. Pre-procedure knowledge of a positive mt-sDNA test improves neoplasia diagnosis rates among colonoscopists with lower baseline adenoma detection rates, independent of withdrawal time.

The Role of Clips in Preventing Delayed Bleeding After Colorectal Polyp Resection: An Individual Patient Data Meta-Analysis.

BACKGROUND & AIMS: Nonpedunculated colorectal polyps are normally endoscopically removed to prevent neoplastic progression. Delayed bleeding is the most common major adverse event. Clipping the resection defect has been suggested to reduce delayed bleedings. Our aim was to determine if prophylactic clipping reduces delayed bleedings and to analyze the contribution of polyp characteristics, extent of defect closure, and antithrombotic use. METHODS: An individual patient data meta-analysis was performed. Studies on prophylactic clipping in nonpedunculated colorectal polyps were selected from PubMed, Embase, Web of Science, and Cochrane database (last selection, April 2020). Authors were invited to share original study data. The primary outcome was delayed bleeding ≤30 days. Multivariable mixed models were used to determine the efficacy of prophylactic clipping in various subgroups adjusted for confounders. RESULTS: Data of 5380 patients with 8948 resected polyps were included from 3 randomized controlled trials, 2 prospective, and 8 retrospective studies. Prophylactic clipping reduced delayed bleeding in proximal polyps ≥20 mm (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.44-0.88; number needed to treat = 32), especially with antithrombotics (OR, 0.59; 95% CI, 0.35-0.99; number needed to treat = 23; subgroup of anticoagulants/double platelet inhibitors: n = 226; OR, 0.40; 95% CI, 0.16-1.01; number needed to treat = 12). Prophylactic clipping did not benefit distal polyps ≥20 mm with antithrombotics (OR, 1.41; 95% CI, 0.79-2.52). CONCLUSIONS: Prophylactic clipping reduces delayed bleeding after resection of nonpedunculated, proximal colorectal polyps ≥20 mm, especially in patients using antithrombotics. No benefit was found for distal polyps. Based on this study, patients can be identified who may benefit from prophylactic clipping. (PROSPERO registration number CRD42020104317.).

Detection of Postcolonoscopy Colorectal Neoplasia by Multi-target Stool DNA.

INTRODUCTION: Significant variability between colonoscopy operators contributes to postcolonoscopy colorectal cancers (CRCs). We aimed to estimate postcolonoscopy colorectal neoplasia (CRN) detection by multi-target stool DNA (mt-sDNA), which has not previously been studied for this purpose. METHODS: In a retrospective cohort of patients with +mt-sDNA and completed follow-up colonoscopy, positive predictive value (PPV) for endpoints of any CRN, advanced adenoma, right-sided neoplasia, sessile serrated polyps (SSP), and CRC were stratified by the time since previous colonoscopy (0-9, 10, and ≥11 years). mt-sDNA PPV at ≤9 years from previous average-risk screening colonoscopy was used to estimate CRN missed at previous screening colonoscopy. RESULTS: Among the 850 studied patients with +mt-sDNA after a previous negative screening colonoscopy, any CRN was found in 535 (PPV 63%). Among 107 average-risk patients having +mt-sDNA ≤9 years after last negative colonoscopy, any CRN was found in 67 (PPV 63%), advanced neoplasia in 16 (PPV 15%), right-sided CRN in 48 (PPV 46%), and SSP in 20 (PPV 19%). These rates were similar to those in 47 additional average risk persons with previous incomplete colonoscopy and in an additional 68 persons at increased CRC risk. One CRC (stage I) was found in an average risk patient who was mt-sDNA positive 6 years after negative screening colonoscopy. DISCUSSION: The high PPV of mt-sDNA 0-9 years after a negative screening colonoscopy suggests that lesions were likely missed on previous examination or may have arisen de novo. mt-sDNA as an interval test after negative screening colonoscopy warrants further study.

Active, continual fine tuning of convolutional neural networks for reducing annotation efforts.

The splendid success of convolutional neural networks (CNNs) in computer vision is largely attributable to the availability of massive annotated datasets, such as ImageNet and Places. However, in medical imaging, it is challenging to create such large annotated datasets, as annotating medical images is not only tedious, laborious, and time consuming, but it also demands costly, specialty-oriented skills, which are not easily accessible. To dramatically reduce annotation cost, this paper presents a novel method to naturally integrate active learning and transfer learning (fine-tuning) into a single framework, which starts directly with a pre-trained CNN to seek "worthy" samples for annotation and gradually enhances the (fine-tuned) CNN via continual fine-tuning. We have evaluated our method using three distinct medical imaging applications, demonstrating that it can reduce annotation efforts by at least half compared with random selection.

Establishing key research questions for the implementation of artificial intelligence in colonoscopy: a modified Delphi method.

BACKGROUND : Artificial intelligence (AI) research in colonoscopy is progressing rapidly but widespread clinical implementation is not yet a reality. We aimed to identify the top implementation research priorities. METHODS : An established modified Delphi approach for research priority setting was used. Fifteen international experts, including endoscopists and translational computer scientists/engineers, from nine countries participated in an online survey over 9 months. Questions related to AI implementation in colonoscopy were generated as a long-list in the first round, and then scored in two subsequent rounds to identify the top 10 research questions. RESULTS : The top 10 ranked questions were categorized into five themes. Theme 1: clinical trial design/end points (4 questions), related to optimum trial designs for polyp detection and characterization, determining the optimal end points for evaluation of AI, and demonstrating impact on interval cancer rates. Theme 2: technological developments (3 questions), including improving detection of more challenging and advanced lesions, reduction of false-positive rates, and minimizing latency. Theme 3: clinical adoption/integration (1 question), concerning the effective combination of detection and characterization into one workflow. Theme 4: data access/annotation (1 question), concerning more efficient or automated data annotation methods to reduce the burden on human experts. Theme 5: regulatory approval (1 question), related to making regulatory approval processes more efficient. CONCLUSIONS : This is the first reported international research priority setting exercise for AI in colonoscopy. The study findings should be used as a framework to guide future research with key stakeholders to accelerate the clinical implementation of AI in endoscopy.

ASGE guideline on the role of endoscopy in the management of benign and malignant gastroduodenal obstruction.

This American Society for Gastrointestinal Endoscopy guideline provides evidence-based recommendations for the endoscopic management of gastric outlet obstruction (GOO). We applied the Grading of Recommendations, Assessment, Development and Evaluation methodology to address key clinical questions. These include the comparison of (1) surgical gastrojejunostomy to the placement of self-expandable metallic stents (SEMS) for malignant GOO, (2) covered versus uncovered SEMS for malignant GOO, and (3) endoscopic and surgical interventions for the management of benign GOO. Recommendations provided in this document were founded on the certainty of the evidence, balance of benefits and harms, considerations of patient and caregiver preferences, resource utilization, and cost-effectiveness.

Breast Cancer Metastasis Presenting as Colonic Polyps.

Breast cancer is the most common malignancy among women and is the second leading cause of cancer-related death among women in the United States. Rarely, breast cancer can metastasize to the gastrointestinal tract. We present a case of metastatic breast cancer diagnosed after finding metastatic lesions appearing as polyps during a colonoscopy.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in familial adenomatous polyposis syndromes.

Familial adenomatous polyposis (FAP) syndrome is a complex entity, which includes FAP, attenuated FAP, and MUTYH-associated polyposis. These patients are at significant risk for colorectal cancer and carry additional risks for extracolonic malignancies. In this guideline, we reviewed the most recent literature to formulate recommendations on the role of endoscopy in this patient population. Relevant clinical questions were how to identify high-risk individuals warranting genetic testing, when to start screening examinations, what are appropriate surveillance intervals, how to identify endoscopically high-risk features, and what is the role of chemoprevention. A systematic literature search from 2005 to 2018 was performed, in addition to the inclusion of seminal historical studies. Most studies were from worldwide registries, which have compiled years of data regarding the natural history and cancer risks in this cohort. Given that most studies were retrospective, recommendations were based on epidemiologic data and expert opinion. Management of colorectal polyps in FAP has not changed much in recent years, as colectomy in FAP is the standard of care. What is new, however, is the developing body of literature on the role of endoscopy in managing upper GI and small-bowel polyposis, as patients are living longer and improved endoscopic technologies have emerged.

ASGE guideline on minimum staffing requirements for the performance of GI endoscopy.

Efforts to increase patient safety and satisfaction, a critical concern for health providers, require periodic evaluation of all factors involved in the provision of GI endoscopy services. We aimed to develop guidelines on minimum staffing requirements and scope of practice of available staff for the safe and efficient performance of GI endoscopy. The recommendations in this guideline were based on a systematic review of published literature, results from a nationwide survey of endoscopy directors, along with the expert guidance of the American Society for Gastrointestinal Endoscopy (ASGE) Standards of Practice Committee members, ASGE Practice Operation Committee members, and the ASGE Governing Board.

Multitarget Stool DNA Screening in Clinical Practice: High Positive Predictive Value for Colorectal Neoplasia Regardless of Exposure to Previous Colonoscopy.

OBJECTIVES: Multitarget stool DNA (MT-sDNA) testing has grown as a noninvasive screening modality for colorectal cancer (CRC), but real-world clinical data are limited in the post-FDA approval setting. The effect of previous colonoscopy on MT-sDNA performance is not known. We aimed to evaluate findings of colorectal neoplasia (CRN) at diagnostic colonoscopy in patients with positive MT-sDNA testing, stratified by patient exposure to previous colonoscopy. METHODS: We identified consecutive patients completing MT-sDNA testing over a 39-month period and reviewed the records of those with positive tests for neoplastic findings at diagnostic colonoscopy. MT-sDNA test positivity rate, adherence to diagnostic colonoscopy, and the positive predictive value (PPV) of MT-sDNA for any CRN and neoplastic subtypes were calculated. RESULTS: Of 16,469 MT-sDNA tests completed, testing returned positive in 2,326 (14.1%) patients. After exclusion of patients at increased risk for CRC, 1,801 patients remained, 1,558 (87%) of whom underwent diagnostic colonoscopy; 918 of 1,558 (59%) of these patients had undergone previous colonoscopy, whereas 640 (41%) had not. Any CRN was found in 1,046 of 1,558 patients (PPV = 67%). More neoplastic lesions were found in patients without previous colonoscopy (73%); however, the rates remained high among those who had undergone previous colonoscopy (63%, P < 0.0001). The large majority (79%) of patients had right-sided neoplasia. DISCUSSION: MT-sDNA has a high PPV for any CRN regardless of exposure to previous colonoscopy. Right-sided CRN was found at colonoscopy in most patients with positive MT-sDNA testing, representing a potential advantage over other currently available screening modalities for CRC.

Proposal of high-risk adenoma detection rate as an impactful, complementary quality indicator of colonoscopy.

BACKGROUND AND AIMS: Adenoma detection rate (ADR), a validated quality indicator (QI) of colonoscopy, does not take into account risk stratification of adenomas. Low-risk adenomas are not associated with a significantly increased risk of future colorectal cancer (CRC). On the other hand, high-risk adenomas (HRA) are associated with up to six fold higher risk of future CRC. Therefore, HRA detection rate (HR-ADR) as a QI in addition to ADR may further enhance the efficacy of screening colonoscopy. Our aim was to calculate ADR and HR-ADR in a large cohort of average risk screening colonoscopy patients and propose HR-ADR which correlates with current threshold ADR. METHODS: This is a retrospective chart review of all colonoscopies performed in patients aged ≥ 50 years at our institution between 2012 and 2014. Average risk patients who had complete colonoscopy with good, excellent and adequate bowel preparation were included. Overall and gender-specific ADR and HR-ADR were calculated. HR-ADR was defined as proportion of colonoscopies with HRA. RESULTS: Among 4158 colonoscopies included, ADR was 26.4 ± 10.9% overall, 32.7 ± 14.5% in men, and 22.1 ± 12.6% in women. HR-ADR was 8.0 ± 5.7% overall, 10.2 ± 8.6% in men, and 6.1 ± 6% in women. There was only moderate correlation between ADR and HR-ADR [r = 0.57 (0.40-0.70)]. HR-ADR corresponding with minimum threshold ADR of 30% in men and 20% in women were calculated to be 7% in men and 4% in women. CONCLUSIONS: HR-ADR correlates only moderately with ADR. Based on the current threshold ADRs, we propose a benchmark HR-ADR of 7% in men and 4% in women as complementary QI to ADR.

Prospective multicenter study to evaluate capsule endoscopy competency using a validated assessment tool.

BACKGROUND AND AIMS: Capsule endoscopy (CE) is an established, noninvasive modality for examining the small bowel. Minimum training requirements are based primarily on guidelines and expert opinion. A validated tool to assess the competence of CE is lacking. In this prospective, multicenter study, we determined the minimum number of CE procedures required to achieve competence during gastroenterology fellowship; validated a capsule competency test (CapCT); and evaluated any correlation between CE competence and endoscopy experience. METHODS: We included second- and third-year gastroenterology fellows from 3 institutions between 2013 and 2018 in a structured CE training program with supervised CE interpretation. Fellows completed the CapCT with a maximal score of 100. For comparison, expert faculty completed the same CapCT. Trainee competence was defined as a score ≥90% compared with the mean expert score. Fellows were tested after 15, 25, and 35 supervised CE interpretations. CapCT was validated using expert consensus and item analysis. Data were collected on the number of previous endoscopies. RESULTS: A total of 68 trainees completed 102 CapCTs. Fourteen CE experts completed the CapCT with a mean score of 94. Mean scores for fellows after 15, 25, and 35 cases were 83, 86, and 87, respectively. Fellows with at least 25 interpretations achieved a mean score ≥84 in all 3 institutions. CapCT item analysis showed high interobserver agreement among expert faculty (k = 0.85). There was no correlation between the scores and the number of endoscopies performed. CONCLUSION: After a structured CE training program, gastroenterology fellows should complete a minimum of 25 supervised CE interpretations before assessing competence using the validated CapCT, regardless of endoscopy experience.

ASGE guideline on the management of achalasia.

Achalasia is a primary esophageal motor disorder of unknown etiology characterized by degeneration of the myenteric plexus, which results in impaired relaxation of the esophagogastric junction (EGJ), along with the loss of organized peristalsis in the esophageal body. The criterion standard for diagnosing achalasia is high-resolution esophageal manometry showing incomplete relaxation of the EGJ coupled with the absence of organized peristalsis. Three achalasia subtypes have been defined based on high-resolution manometry findings in the esophageal body. Treatment of patients with achalasia has evolved in recent years with the introduction of peroral endoscopic myotomy. Other treatment options include botulinum toxin injection, pneumatic dilation, and Heller myotomy. This American Society for Gastrointestinal Endoscopy Standards of Practice Guideline provides evidence-based recommendations for the treatment of achalasia, based on an updated assessment of the individual and comparative effectiveness, adverse effects, and cost of the 4 aforementioned achalasia therapies.

ASGE review of adverse events in colonoscopy.

Colonoscopy is the most commonly performed endoscopic procedure and overall is considered a low-risk procedure. However, adverse events (AEs) related to this routinely performed procedure for screening, diagnostic, or therapeutic purposes are an important clinical consideration. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on estimates of AEs related to colonoscopy in an evidence-based fashion. A systematic review and meta-analysis of population-based studies was conducted for the 3 most common and important serious AEs (bleeding, perforation, and mortality). In addition, this document includes an updated systematic review and meta-analysis of serious AEs (bleeding and perforation) related to EMR and endoscopic submucosal dissection for large colon polyps. Finally, a narrative review of other colonoscopy-related serious AEs and those related to specific colonic interventions is included.

ASGE guideline on the role of endoscopy in the evaluation and management of choledocholithiasis

Each year choledocholithiasis results in biliary obstruction, cholangitis, and pancreatitis in a significant number of patients. The primary treatment, ERCP, is minimally invasive but associated with adverse events in 6% to 15%. This American Society for Gastrointestinal Endoscopy (ASGE) Standard of Practice (SOP) Guideline provides evidence-based recommendations for the endoscopic evaluation and treatment of choledocholithiasis. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the contemporary literature regarding the following topics: EUS versus MRCP for diagnosis, the role of early ERCP in gallstone pancreatitis, endoscopic papillary dilation after sphincterotomy versus sphincterotomy alone for large bile duct stones, and impact of ERCP-guided intraductal therapy for large and difficult choledocholithiasis. Comprehensive systematic reviews were also performed to assess the following: same-admission cholecystectomy for gallstone pancreatitis, clinical predictors of choledocholithiasis, optimal timing of ERCP vis-à-vis cholecystectomy, management of Mirizzi syndrome and hepatolithiasis, and biliary stent therapy for choledocholithiasis. Core clinical questions were derived using an iterative process by the ASGE SOP Committee. This body developed all recommendations founded on the certainty of the evidence, balance of risks and harms, consideration of stakeholder preferences, resource utilization, and cost-effectiveness.

ASGE guideline on the role of endoscopy in the evaluation and management of choledocholithiasis.

Each year choledocholithiasis results in biliary obstruction, cholangitis, and pancreatitis in a significant number of patients. The primary treatment, ERCP, is minimally invasive but associated with adverse events in 6% to 15%. This American Society for Gastrointestinal Endoscopy (ASGE) Standard of Practice (SOP) Guideline provides evidence-based recommendations for the endoscopic evaluation and treatment of choledocholithiasis. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the contemporary literature regarding the following topics: EUS versus MRCP for diagnosis, the role of early ERCP in gallstone pancreatitis, endoscopic papillary dilation after sphincterotomy versus sphincterotomy alone for large bile duct stones, and impact of ERCP-guided intraductal therapy for large and difficult choledocholithiasis. Comprehensive systematic reviews were also performed to assess the following: same-admission cholecystectomy for gallstone pancreatitis, clinical predictors of choledocholithiasis, optimal timing of ERCP vis-à-vis cholecystectomy, management of Mirizzi syndrome and hepatolithiasis, and biliary stent therapy for choledocholithiasis. Core clinical questions were derived using an iterative process by the ASGE SOP Committee. This body developed all recommendations founded on the certainty of the evidence, balance of risks and harms, consideration of stakeholder preferences, resource utilization, and cost-effectiveness.

Comparison of Small Versus Large Volume Split Dose Preparation for Colonoscopy: A Study of Colonoscopy Outcomes.

BACKGROUND: Split dose bowel preparations (SDP) have superior outcomes for colonoscopy as compared to evening before regimens. However, the association of the actual volume of the SDP to colonoscopy outcome measures has not been well studied. AIMS: Compare adenoma detection rate (ADR), sessile serrated polyp detection rate (SDR), mean bowel cleanse score, and predictors of inadequate exams between small volume SDP and large volume SDP. METHODS: We have conducted a retrospective study in patients undergoing colonoscopy with small volume SDP versus large volume SDP between July 2014 and December 2014. Basic demographics (age, gender and BMI) along with clinical co-morbidities were recorded. Quality of the bowel preparation, ADR and SDR was compared between these groups. Univariate and multivariable logistic regressions were used to assess the determinants of inadequate exams in each group. RESULTS: 1573 patients with split dose preparation were included in this retrospective study. 58.4% (920/1573) patients took small volume SDP. There was no difference in ADR (37.9 vs. 38.8%, p = 0.2); however, SDR was higher for small volume SDP compared to large volume SDP (11.9 vs. 7.9% p = 0.005). There was no difference in the rate of inadequate exams between the two groups (p = 0.7). A history of diabetes and constipation was associated with inadequate exams only in the small volume SDP. CONCLUSIONS: SDR was higher in small volume SDP. There was no difference in rate of inadequate exams between the two groups. A history of diabetes and constipation was associated with inadequate exams only in patients with the small volume SDP.

Is the level of cleanliness using segmental Boston bowel preparation scale associated with a higher adenoma detection rate?

BACKGROUND: The impact of Boston bowel preparation scale (BBPS) scores on the adenoma detection rate (ADR) in each segment has not been adequately addressed. The aim of this study was to determine the association between segmental or overall ADR and serrated polyp detection rate (SDR) with segmental and total BBPS scores. METHODS: All outpatient screening colonoscopies with documented BBPS scores were retrospectively reviewed at a tertiary institution from January to December 2013. Chi-square tests and logistic regression were used to analyze the detection rates of adenomas and serrated polyps with bowel prep scores. Odds ratios were calculated using logistic regression that controlled for withdrawal time, age, body mass index, diabetes status and sex. RESULTS: We analyzed 1991 colonoscopies. The overall ADR was 37.5% (95% confidence interval [CI], 35.3-39.6). There was a significant difference in the overall ADR, and in SDR across all bowel category groups, with total BBPS scores of 8 and 9 having lower detection rates than scores of 5, 6 and 7. As the quality of bowel preparation increased, there was a statistical decrease in the ADR (odds ratio [OR] 0.79 [CI 0.66-0.94], P=0.04) of the right colon, while in the left colon, there was a statistical decrease in SDR (OR 0.78, [CI 0.65-0.92] P=0.019). CONCLUSION: Segmental ADR and SDR both decreased as prep scores increased, decreasing notably in patients with excellent prep scores of 8 and 9. A possible explanation for this unexpected discrepancy may be related to longer and better visualization of the mucosa when cleansing and suctioning is necessary.

Severe Diarrhea in the Setting of Immune Checkpoint Inhibitors.

Immune checkpoint inhibitors (ICPIs) are novel therapeutic agents targeting a variety of cancers by enhanced T cell activation. Immune-related adverse events (irAEs) commonly occur with ICPI use and can affect multiple organ systems including the gastrointestinal tract. Due to irAEs, the use of ICPIs is limited in autoimmune diseases. We present a case of microscopic colitis diagnosed after the initiation of nivolumab and a case of ipilimumab colitis and Clostridium difficile in the setting of Crohn's colitis.