Faculty Bibliography

Gastrointestinal (GI) bleeding is the most common GI diagnosis leading to hospitalization within the United States. Prompt diagnosis and treatment of GI bleeding is critical to improving patient outcomes and reducing high health care utilization and costs. Radiologic techniques including CT angiography, catheter angiography, CT enterography, MR enterography, nuclear medicine red blood cell scan, and technetium-99m pertechnetate scintigraphy (Meckel scan) are frequently used to evaluate patients with GI bleeding and are complementary to GI endoscopy. However, multiple management guidelines exist, which differ in the recommended utilization of these radiologic examinations. This variability can lead to confusion as to how these tests should be used in the evaluation of GI bleeding. In this document, a panel of experts from the American College of Gastroenterology and Society of Abdominal Radiology provide a review of the radiologic examinations used to evaluate for GI bleeding including nomenclature, technique, performance, advantages, and limitations. A comparison of advantages and limitations relative to endoscopic examinations is also included. Finally, consensus statements and recommendations on technical parameters and utilization of radiologic techniques for GI bleeding are provided. © Radiological Society of North America and the American College of Gastroenterology, 2024. Supplemental material is available for this article. This article is being published concurrently in American Journal of Gastroenterology and Radiology. The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Citations from either journal can be used when citing this article. See also the editorial by Lockhart in this issue.

INTRODUCTION/BACKGROUND:Risk factors for gastric cancer in the United States are not well understood, especially in populations with a low proportion of immigrants. We conducted a matched case-control study in a Veteran Affairs Medical Center to identify risk factors for gastric cancer. MATERIALS AND METHODS/METHODS:Gastric cancer patients and age- and sex-matched controls were identified in a 1:4 ratio from January 1, 1997 to October 31, 2018. Demographic, medical, endoscopic, and histologic data were extracted. We performed conditional logistic regression to estimate odds ratios and 95% CIs for associations between potential risk factors and gastric cancer. RESULTS:Most gastric cancer cases were diagnosed on initial endoscopy (71.4%). Of these, the most common presenting stage was stage IV (40.8%). Risk factors for gastric cancer included Black and Asian race and never or current (compared to former) drinkers, although Helicobacter pylori eradication and pernicious anemia were associated with decreased risk. CONCLUSIONS:The high proportion of late-stage gastric cancer diagnoses highlights the need for improved risk stratification as well as screening and surveillance protocols in the U.S. population. Racial disparities among veterans in an equal-access system necessitate further investigation into the etiology of these disparities.

BACKGROUND:There is a paucity of data on the real-world effectiveness of therapies in patients with Crohn's Disease of the Pouch (CDP). METHODS:This was a prospective, multicenter study evaluating the primary outcome of remission at 12 months of therapy for CDP. RESULTS:134 patients were enrolled. Among the 77 patients with symptoms at baseline, 35 (46.7%) achieved remission at 12-months. Of these, 12 (34.3%) changed therapy. There was no significant association between therapy patterns and remission status. CONCLUSION/CONCLUSIONS:Approximately 50% with symptoms at enrollment achieved clinical remission at 12 months, the majority of whom did so without a change in therapy.

BACKGROUND AND AIMS/UNASSIGNED: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/UNASSIGNED: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/UNASSIGNED: = 0.038). CONCLUSIONS/UNASSIGNED: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.

BACKGROUND & AIMS/OBJECTIVE:Inflammatory bowel disease (IBD) is linked to reduced female fertility, but it is unclear how fertility rates vary by histological disease activity. METHODS:Nationwide IBD cohort of Swedish women aged 15-44 years. We examined fertility rates during periods with vs. without histological inflammation (n=21,046; follow-up: 1990-2016) and during periods with vs. without clinical activity (IBD-related hospitalization, surgery, or treatment escalation) (n=24,995; follow-up: 2006-2020). Accounting for socio-demographics and comorbidities, we used Poisson regression to estimate adjusted fertility rate ratios (aFRRs) for live-births conceived during 12-month-periods of histological inflammation (vs. histological remission) and 3-month-periods of clinically active IBD (vs. quiescent IBD). RESULTS:During periods with vs. without histological inflammation, there were 6.35 (95%CI=5.98-6.73) and 7.09 (95%CI=6.48-7.70) live-births conceived per 100 person-years of follow-up, respectively, or one fewer child per fourteen women with 10 years of histological inflammation (aFRR=0.90; 95%CI=0.81-1.00). In women with histological inflammation fertility was similarly reduced in ulcerative colitis (UC, aFRR=0.89 [95%CI=0.78-1.02]) and Crohn's disease (CD, aFRR=0.86 [95%CI=0.72-1.04]). Clinical IBD activity was associated with an aFRR of 0.76 (95%CI=0.72-0.79) or one fewer child per six women with 10 years of clinical activity. Fertility was reduced in clinically active UC (aFRR=0.75 [95%CI=0.70-0.81]) and CD (aFRR=0.76 [95%CI=0.70-0.82]). Finally, also among women with clinically quiescent IBD, histological inflammation (vs. histological remission) was associated with reduced fertility (aFRR=0.85 [95%CI=0.73-0.98]). CONCLUSIONS:An association between histological and clinical activity and reduced female fertility in CD and UC was found. Notably, histological inflammation was linked to reduced fertility also in women with clinically quiescent IBD.

BACKGROUND AND AIMS/OBJECTIVE:Resection of colorectal polyps has been shown to decrease the incidence and mortality of colorectal cancer. Large non-pedunculated colorectal polyps are often referred to expert centres for endoscopic resection, which requires relevant information to be conveyed to the therapeutic endoscopist to allow for triage and planning of resection technique. The primary objective of our study was to establish minimum expected standards for the referral of LNPCP for potential ER. METHODS:A Delphi methodology was employed to establish consensus on minimum expected standards for the referral of large colorectal polyps among a panel of international endoscopy experts. The expert panel was recruited through purposive sampling, and three rounds of surveys were conducted to achieve consensus, with quantitative and qualitative data analysed for each round. RESULTS:A total of 24 international experts from diverse continents participated in the Delphi study, resulting in consensus on 19 statements related to the referral of large colorectal polyps. The identified factors, including patient demographics, relevant medications, lesion factors, photodocumentation and the presence of a tattoo, were deemed important for conveying the necessary information to therapeutic endoscopists. The mean scores for the statements ranged from 7.04 to 9.29 out of 10, with high percentages of experts considering most statements as a very high priority. Subgroup analysis by continent revealed some variations in consensus rates among experts from different regions. CONCLUSION/CONCLUSIONS:The identified consensus statements can aid in improving the triage and planning of resection techniques for large colorectal polyps, ultimately contributing to the reduction of colorectal cancer incidence and mortality.

Ginger has been associated with a decreased incidence of colorectal cancer (CRC) through reduction in inflammatory pathways and inhibition of tumor growth. Recent pre-clinical models have implicated changes in the gut microbiome as a possible mediator of the ginger effect on CRC. We hypothesized that, in adults previously diagnosed with a colorectal adenoma, ginger supplementation would alter the fecal microbiome in the direction consistent with its CRC-inhibitory effect. Sixty-eight adults were randomized to take either ginger or placebo daily for 6 weeks, with a 6-week washout and longitudinal stool collection throughout. We performed 16S rRNA sequencing and evaluated changes in overall microbial diversity and the relative abundances of pre-specified CRC-associated taxa using mixed-effects logistic regression. Ginger supplementation showed no significant effect on microbial community structure through alpha or beta diversity. Of 10 pre-specified CRC-associated taxa, there were significant decreases in the relative abundances of the genera Akkermansia (p < 0.001), Bacteroides (p = 0.018), and Ruminococcus (p = 0.013) after 6-week treatment with ginger compared to placebo. Ginger supplementation led to decreased abundances of Akkermansia and Bacteroides, which suggests that ginger may have an inhibitory effect on CRC-associated taxa. Overall, ginger supplementation appears to have a limited effect on gut microbiome in patients with colorectal adenomas.

INTRODUCTION/BACKGROUND:Data suggest atherosclerotic-related inflammation may play a role in the pathogenesis of inflammatory bowel disease (IBD), but large-scale studies are missing. METHODS:In this nationwide case-control study, we used the Swedish Patient Register and the Epidemiology Strengthened by histoPathology Reports in Sweden cohort to identify adult cases of incident IBD between 2002 and 2021, with each case matched to up to 10 general population controls. We used conditional logistic regression to calculate odds ratios (OR) for exposure to an atherosclerotic-related condition (myocardial infarction, thromboembolic stroke, or atherosclerosis itself) before being diagnosed with IBD. RESULTS:There were a total of 56,212 individuals with IBD and 531,014 controls. Of them, 2,334 (4.2%) cases and 18,222 (3.4%) controls had a prior diagnosis of an atherosclerotic-related condition, corresponding to an OR of 1.30 (95% confidence interval [CI] 1.24-1.37). Results were statistically significant for both Crohn's disease (OR 1.37, 95% CI 1.26-1.48) and ulcerative colitis (OR 1.27, 95% CI 1.20-1.35) and for individuals who developed IBD at 40-59 years of age and 60 years or older. In addition, associations persisted when adjusting for underlying comorbidities, including the presence of immune-mediated diseases and prior aspirin and/or statin use. The highest odds of an atherosclerotic-related condition were seen in the 6-12 months before IBD diagnosis, though odds were increased even ≥5 years before. A higher magnitude of odds was also observed when having 2 or more atherosclerotic-related conditions when compared with having only 1 condition. DISCUSSION/CONCLUSIONS:A history of an atherosclerotic-related condition is associated with increased odds of developing IBD, particularly among older adults. Future studies should investigate whether drugs targeting atherosclerotic-related inflammation may prevent IBD in higher-risk individuals.

INTRODUCTION/BACKGROUND:Recent randomized controlled trials (RCTs) and meta-analysis have demonstrated improved adenoma detection rate (ADR) for colonoscopy with artificial intelligence (AI) compared with high-definition (HD) colonoscopy without AI. We aimed to perform a systematic review and network meta-analysis of all RCTs to assess the impact of AI compared with other endoscopic interventions aimed at increasing ADR such as distal attachment devices, dye-based/virtual chromoendoscopy, water-based techniques, and balloon-assisted devices. METHODS:A comprehensive literature search of PubMed/Medline, Embase, and Cochrane was performed through May 6, 2022, to include RCTs comparing ADR for any endoscopic intervention mentioned above. Network meta-analysis was conducted using a frequentist approach and random effects model. Relative risk (RR) and 95% CI were calculated for proportional outcome. RESULTS:A total of 94 RCTs with 61,172 patients (mean age 59.1±5.2 y, females 45.8%) and 20 discrete study interventions were included. Network meta-analysis demonstrated significantly improved ADR for AI compared with autofluorescence imaging (RR: 1.33, CI: 1.06 to 1.66), dye-based chromoendoscopy (RR: 1.22, CI: 1.06 to 1.40), endocap (RR: 1.32, CI: 1.17 to 1.50), endocuff (RR: 1.19, CI: 1.04 to 1.35), endocuff vision (RR: 1.26, CI: 1.13 to 1.41), endoring (RR: 1.30, CI: 1.10 to 1.52), flexible spectral imaging color enhancement (RR: 1.26, CI: 1.09 to 1.46), full-spectrum endoscopy (RR: 1.40, CI: 1.19 to 1.65), HD (RR: 1.41, CI: 1.28 to 1.54), linked color imaging (RR: 1.21, CI: 1.08 to 1.36), narrow band imaging (RR: 1.33, CI: 1.18 to 1.48), water exchange (RR: 1.22, CI: 1.06 to 1.42), and water immersion (RR: 1.47, CI: 1.19 to 1.82). CONCLUSIONS:AI demonstrated significantly improved ADR when compared with most endoscopic interventions. Future RCTs directly assessing these associations are encouraged.