The Role of Imaging for GI Bleeding: ACG and SAR Consensus Recommendations

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.

Polygenic risk score predicts risk of primary sclerosing cholangitis in inflammatory bowel disease

BACKGROUND

Forty distinct primary sclerosing cholangitis (PSC) genomic loci have been identified through multiancestry meta-analyses. The polygenic risk score (PRS) could serve as a promising tool to discover unique disease behaviour, like PSC, underlying inflammatory bowel disease (IBD).

AIM

To test whether PRS indicates PSC risk in patients with IBD.

MATERIALS AND METHODS

Mayo Clinic and Washington University at St Louis IBD cohorts were used to test our hypothesis. PRS was modelled through the published PSC loci and weighted with their corresponding effect size. Logistic regression was applied to predict the PSC risk.

RESULTS

In total, 63 (5.6%) among 1130 patients with IBD of European ancestry had PSC. Among 381 ulcerative colitis (UC), 12% had PSC; in contrast to 1.4% in 761 Crohn disease (CD). Compared with IBD alone, IBD-PSC had significantly higher PRS (PSC risk: 3.0% at the lowest PRS quartile vs 7.2% at the highest PRS quartile, Ptrend =.03). In IBD subphenotypes subgroup analysis, multivariate analysis shows that UC-PSC is associated with more extensive UC disease (OR, 5.60; p=0.002) and younger age at diagnosis (p=0.02). In CD, multivariate analysis suggests that CD-PSC is associated with colorectal cancer (OR, 50; p=0.005).

CONCLUSIONS

We found evidence that patients with IBD with PSC presented with a clinical course difference from that of patients with IBD alone. PRS can influence PSC risk in patients with IBD. Once validated in an independent cohort, this may help identify patients with the highest likelihood of developing PSC.

Novel Genetic Risk Variants and Clinical Predictors Associated With Primary Sclerosing Cholangitis in Patients With Ulcerative Colitis

INTRODUCTION

Patients with ulcerative colitis (UC) who are likely to have primary sclerosing cholangitis (PSC) should be identified because PSC can influence UC clinical behavior and outcomes.The aim of this study was to establish a model incorporating clinical and genetic risk predictors that identifies patients with UC at risk of developing PSC.

METHODS

We conducted a retrospective case-control study. Inflammatory bowel disease cohorts from multiple institutions were used as discovery and replicate datasets. Quality control criteria, including minor allele frequency, call rates, Hardy-Weinberg equilibrium, cryptic relatedness, and population stratification (through principal components), were used. Discriminative accuracy was evaluated with area under the receiver operating characteristic curve.

RESULTS

Fifty-seven of 581 patients (9.8%) with UC had PSC. Multivariate analysis showed that patients with UC-PSC had more extensive disease (odds ratio [OR], 5.42; P = 1.57E-04), younger diagnosis age (younger than 20 years; OR, 2.22; P = 0.02), and less smoking (OR, 0.42; P = 0.02) than those with UC. After linkage disequilibrium pruning and multivariate analyses, 3 SNPs (rs3131621 at 6p21.33; rs9275596 and rs11244 at 6p21.32) at the HLA region were found associated with a 2- to 3-fold increased risk of PSC. Our model demonstrated good discriminatory power (area under the receiver operating characteristic curve, 88%).

DISCUSSION

Three variants in HLA (6p21.3) region significantly distinguished patients with UC-PSC from patients with UC alone. Once further validated in an independent large cohort, our model could be used to identify patients with UC at risk of PSC, and it could also help guide disease management.

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.

Defining the Roles of Inflammatory Bowel Disease Clinical Pharmacists in the United States: A Systematic Review and National RAND/UCLA Consensus

BACKGROUND

Given the complexity of inflammatory bowel disease (IBD) care, utilization of multidisciplinary teams is recommended to optimize outcomes. There is a growing recognition that clinical pharmacists should be an integral part of this care model. We sought to define the roles of IBD clinical pharmacists in the United States.

METHODS

A national multidisciplinary expert panel of 12 gastroenterologists and clinical pharmacists practicing in IBD clinics was assembled. We used the RAND/University of California, Los Angeles appropriateness method, with a total of 281 statements generated based on a systematic literature review and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate in 2 rounds of voting.

RESULTS

The number of publications evaluating the clinical pharmacists' roles in IBD is limited, primarily focusing on thiopurine initiation and monitoring, medication adherence, and switching to biosimilars. Medication education; medication initiation and monitoring; therapeutic drug monitoring; biosimilar management; health maintenance review; and transitions of care were deemed by the panel to be appropriate roles for IBD clinical pharmacists. In considering real-world settings, IBD clinical pharmacists should practice clinically under a predefined scope and primarily focus on complex treatments (eg, immunomodulators, biologics, and small molecules). Clinical pharmacists should also be included in practice settings with IBD specialized physicians. Additionally, clinical pharmacists caring for patients with IBD should be residency trained and board certified.

CONCLUSIONS

This consensus defines IBD clinical pharmacists' roles and provides a framework for embedded clinical pharmacists in IBD care.

Interobserver agreement of the modified Paris classification and histology prediction of colorectal lesions in patients with inflammatory bowel disease

BACKGROUND AND AIMS

SCENIC (International Consensus Statement on Surveillance and Management of Dysplasia in IBD) guidelines recommend that visible dysplasia in patients with longstanding inflammatory bowel disease (IBD) should be endoscopically characterized using a modified Paris classification. This study aimed to determine the interobserver agreement (IOA) of the modified Paris classification and endoscopists' accuracy for pathology prediction of IBD visible lesions.

METHODS

One hundred deidentified endoscopic still images and 30 videos of IBD visible colorectal lesions were graded by 10 senior and 4 trainee endoscopists from 5 tertiary care centers. Endoscopists were asked to assign 4 classifications for each image: the standard Paris classification, modified Paris classification, pathology prediction, and lesion border. Agreement was measured using Light's kappa coefficient. Consensus of ratings was assessed according to strict majority.

RESULTS

The overall Light's kappa for all study endpoints was between .32 and .49. In a subgroup analysis between junior and senior endoscopists, Light's kappa continued to be less than .6 with a slightly higher agreement among juniors. Lesions with the lowest agreement and no consensus were mostly classified as Is, IIa, and mixed Paris classification and sessile and superficial elevated for modified Paris classification. Endoscopist accuracy for prediction of dysplastic, nondysplastic, and serrated pathology was 77%, 56%, and 30%, respectively. There was a strong association (P < .001) between the given morphology classification and the predicted pathology with Ip lesions carrying a much lower expectation of dysplasia than Is/IIc/III and mixed lesions. The agreement for border prediction was .5 for junior and .3 for senior endoscopists.

CONCLUSIONS

This study demonstrates very low IOA for Paris and modified Paris classifications and low accuracy and IOA for lesion histopathology prediction. Revisions of these classifications are required to create a clinically useful risk stratification tool and enable eventual application of augmented intelligence tools.

Serological profiling of Crohn’s disease and ulcerative colitis patients reveals anti-microbial antibody signatures

BACKGROUND

The healthcare burden of inflammatory bowel disease (IBD) is rising globally and there are limited non-invasive biomarkers for accurate and early diagnosis.

AIM

To understand the important role that intestinal microbiota play in IBD pathogenesis and identify anti-microbial antibody signatures that benefit clinical management of IBD patients.

METHODS

We performed serological profiling of 100 Crohn’s disease (CD) patients, 100 ulcerative colitis (UC) patients and 100 healthy controls against 1173 bacterial and 397 viral proteins from 50 bacteria and 33 viruses on protein microarrays. The study subjects were randomly divided into discovery (n = 150) and validation (n = 150) sets. Statistical analysis was performed using R packages.

RESULTS

Anti-bacterial antibody responses showed greater differential prevalence among the three subject groups than anti-viral antibody responses. We identified novel antibodies against the antigens of Bacteroidetes vulgatus (BVU_0562) and Streptococcus pneumoniae (SP_1992) showing higher prevalence in CD patients relative to healthy controls. We also identified antibodies against the antigen of Streptococcus pyogenes (SPy_2009) showing higher prevalence in healthy controls relative to UC patients. Using these novel antibodies, we built biomarker panels with area under the curve (AUC) of 0.81, 0.87, and 0.82 distinguishing CD vs control, UC vs control, and CD vs UC, respectively. Subgroup analysis revealed that penetrating CD behavior, colonic CD location, CD patients with a history of surgery, and extensive UC exhibited highest antibody prevalence among all patients. We demonstrated that autoantibodies and anti-microbial antibodies in CD patients had minimal correlation.

CONCLUSION

We have identified antibody signatures for CD and UC using a comprehensive analysis of anti-microbial antibody response in IBD. These antibodies and the source microorganisms of their target antigens improve our understanding of the role of specific microorganisms in IBD pathogenesis and, after future validation, should aid early and accurate diagnosis of IBD.

Prospective Cohort Study to Investigate the Safety of Preoperative Tumor Necrosis Factor Inhibitor Exposure in Patients With Inflammatory Bowel Disease Undergoing Intra-abdominal Surgery

BACKGROUND & AIMS

Whether preoperative treatment of inflammatory bowel disease (IBD) with tumor necrosis factor inhibitors (TNFis) increases the risk of postoperative infectious complications remains controversial. The primary aim of this study was to determine whether preoperative exposure to TNFis is an independent risk factor for postoperative infectious complications within 30 days of surgery.

METHODS

We conducted a multicenter prospective observational study of patients with IBD undergoing intra-abdominal surgery across 17 sites from the Crohn's & Colitis Foundation Clinical Research Alliance. Infectious complications were categorized as surgical site infections (SSIs) or non-SSIs. Current TNFi exposure was defined as use within 12 weeks of surgery, and serum was collected for drug-level analyses. Multivariable models for occurrence of the primary outcome, any infection, or SSI were adjusted by predefined covariates (age, sex, preoperative steroid use, and disease type), baseline variables significantly associated (P < .05) with any infection or SSI separately, and TNFi exposure status. Exploratory models used TNFi exposure based on serum drug concentration.

RESULTS

A total of 947 patients were enrolled from September 2014 through June 2017. Current TNFi exposure was reported by 382 patients. Any infection (18.1% vs 20.2%, P = .469) and SSI (12.0% vs 12.6%, P = .889) rates were similar in patients currently exposed to TNFis and those unexposed. In multivariable analysis, current TNFi exposure was not associated with any infection (odds ratio, 1.050; 95% confidence interval, 0.716-1.535) or SSI (odds ratio, 1.249; 95% confidence interval, 0.793-1.960). Detectable TNFi drug concentration was not associated with any infection or SSI.

CONCLUSIONS

Preoperative TNFi exposure was not associated with postoperative infectious complications in a large prospective multicenter cohort.

Utilizing Deep Learning to Analyze Whole Slide Images of Colonic Biopsies for Associations Between Eosinophil Density and Clinicopathologic Features in Active Ulcerative Colitis

BACKGROUND

Eosinophils have been implicated in the pathogenesis of ulcerative colitis and have been associated with disease course and therapeutic response. However, associations between eosinophil density, histologic activity, and clinical features have not been rigorously studied.

METHODS

A deep learning algorithm was trained to identify eosinophils in colonic biopsies and validated against pathologists' interpretations. The algorithm was applied to sigmoid colon biopsies from a cross-sectional cohort of 88 ulcerative colitis patients with histologically active disease as measured by the Geboes score and Robarts histopathology index (RHI). Associations between eosinophil density, histologic activity, and clinical features were determined.

RESULTS

The eosinophil deep learning algorithm demonstrated almost perfect agreement with manual eosinophil counts determined by 4 pathologists (interclass correlation coefficients: 0.805-0.917). Eosinophil density varied widely across patients (median 113.5 cells per mm2, interquartile range 108.9). There was no association between eosinophil density and RHI (P = 0.5). Significant differences in eosinophil density were seen between patients with Montreal E3 vs E2 disease (146.2 cells per mm2 vs 88.2 cells per mm2, P = 0.005). Patients on corticosteroids had significantly lower eosinophil density (62.9 cells per mm2 vs 124.1 cells per mm2, P = 0.006). No association between eosinophil density and biologic use was observed (P = 0.5).

CONCLUSIONS

We developed a deep learning algorithm to quantify eosinophils in colonic biopsies. Eosinophil density did not correlate with histologic activity but did correlate with disease extent and corticosteroid use. Future studies applying this algorithm in larger cohorts with longitudinal follow-up are needed to further elucidate the role of eosinophils in ulcerative colitis.

Germline Cancer Susceptibility Gene Testing in Unselected Patients With Colorectal Adenocarcinoma: A Multicenter Prospective Study

BACKGROUND & AIMS

Hereditary factors play a role in the development of colorectal cancer (CRC). Identification of germline predisposition can have implications on treatment and cancer prevention. This study aimed to determine the prevalence of pathogenic germline variants (PGVs) in CRC patients using a universal testing approach, association with clinical outcomes, and the uptake of family variant testing.

METHODS

We performed a prospective multisite study of germline sequencing using a more than 80-gene next-generation sequencing platform among CRC patients (not selected for age or family history) receiving care at Mayo Clinic Cancer Centers between April 1, 2018, and March 31, 2020.

RESULTS

Of 361 patients, the median age was 57 years (SD, 12.4 y), 43.5% were female, 82% were white, and 38.2% had stage IV disease. PGVs were found in 15.5% (n = 56) of patients, including 44 in moderate- and high-penetrance cancer susceptibility genes. Thirty-four (9.4%) patients had incremental clinically actionable findings that would not have been detected by practice guideline criteria or a CRC-specific gene panel. Only younger age at diagnosis was associated with the presence of PGVs (odds ratio, 1.99; 95% CI, 1.12-3.56). After a median follow-up period of 20.7 months, no differences in overall survival were seen between those with or without a PGV (P = .2). Eleven percent of patients had modifications in their treatment based on genetic findings. Family cascade testing was low (16%).

CONCLUSIONS

Universal multigene panel testing in CRC was associated with a modest, but significant, detection of heritable mutations over guideline-based testing. One in 10 patients had changes in their management based on test results. Uptake of cascade family testing was low, which is a concerning observation that warrants further study.

Novel Genetic Variant Predicts Surgical Recurrence Risk in Crohn's Disease Patients

BACKGROUND

We aimed to identify a model of clinical and genetic risk factors through hypothesis-free search across genome that can predict the surgical recurrence risk after the first abdominal surgery in CD patients.

MATERIALS AND METHODS

Two independent inflammatory bowel disease (IBD) cohort studies were used to derive and validate the genetic risk profile. The study subjects were genotyped using Illumina Immunochip custom genotyping array. Surgical recurrence was defined as having the second or more abdominal bowel resections after the first abdominal surgery at the time of study enrollment; nonsurgical recurrence was defined as having no further abdominal resection after the first abdominal surgery.

RESULTS

Among 372 CD patients who had at least 1 abdominal surgery at the study enrollment, 132 (35.5%) had subsequent surgical recurrence after their first abdominal surgery, and 240 (64.5%) required no subsequent abdominal surgery at the end of follow up. Among clinical factors, multivariable analysis showed that history of immunomodulatory use (odds ratio [OR], 3.96; P = 0.002) and early era of CD first surgery (OR, 1.12; P = 1.01E-04) remained significant. Genotypic association tests identified a genome-wide significant locus rs2060886 in TCF4 at chr18q21.2 associated with surgical recurrence risk (OR, dom, 4.10 [2.37-7.11]; P = 4.58E-08).

CONCLUSIONS

Novel genetic locus rs2060886 in TCF4 was associated with surgical recurrence risk at genome-wide significance level among CD patients after their first abdominal surgery. Early era of CD first intestinal surgery predicts higher surgical recurrence risk. These results suggest that genetic variants may help guide the CD management strategy in patients at the highest risk of repeated abdominal surgeries.

Validated Indices for Histopathologic Activity Predict Development of Colorectal Neoplasia in Ulcerative Colitis

BACKGROUND AND AIMS

To correlate histologic activity in surveillance colonoscopies with the development of colorectal neoplasia in ulcerative colitis [UC].

METHODS

Colorectal biopsies during surveillance [N = 764] from 52 UC patients with colorectal neoplasia were compared to 122 patients without neoplasia enrolled in a prospective natural history registry. All biopsies were scored using validated histologic scoring systems (Geboes score, Nancy histopathologic index [NHI], and Robarts histopathologic index [RHI]). Clinical, endoscopic, and histologic data were correlated with the development of colorectal neoplasia.

RESULTS

In multivariable analysis, mean RHI (hazard ratio [HR] 1.07 for each 1-unit increase in RHI, 95% confidence interval [CI] 1.03-1.12, p = 0.002) and mean NHI [HR 1.89 for each 1-unit increase in NHI, 95% CI 1.34-2.67, p = 0.002] for the entire surveillance period were significantly associated with colorectal neoplasia development. Shorter surveillance interval and increasing age were associated with increased risk of neoplasia development whereas mean Mayo endoscopic score was not significant. To generate a clinically useful measure of neoplasia risk, mean histologic activity in the preceding 5 years before the study endpoint was correlated with neoplasia development. In the preceding 5 years of surveillance, a mean RHI ≥ 8 had a 7.53-fold increased risk [95% CI 2.56-12.16, p < 0.001] and mean NHI ≥ 1.9 had a 5.89-fold increased risk [95% CI 2.18-15.92, p < 0.001] of developing colorectal neoplasia.

CONCLUSIONS

Persistent histologic activity during multiple surveillance episodes is an independent predictor of colorectal neoplasia. Mean RHI and mean NHI during a 5-year colonoscopic surveillance period can be used to assess risk for colorectal neoplasia and optimize UC surveillance.

Epidemiology and Clinical Outcomes of Patients With Inflammatory Bowel Disease Presenting With Acute Coronary Syndrome

BACKGROUND

Inflammatory bowel disease (IBD) is associated with an increased acute coronary syndrome (ACS) risk. Data are limited regarding the epidemiology and outcomes of ACS in patients with IBD.

METHODS

A retrospective cohort analysis of patients with IBD admitted for ACS in the U.S. Healthcare Cost and Utilization Project National Inpatient Sample for 2005 to 2015 was conducted. We analyzed trends in IBD-ACS admissions and mortality, differences in risk profiles, management strategies, and in-hospital mortality between IBD-ACS and non-IBD ACS and between ulcerative colitis (UC) and Crohn disease (CD).

RESULTS

We studied 6,872,415 non-IBD ACS and 24,220 IBD-ACS hospitalizations (53% with CD). During the study period, the number of hospitalizations for IBD-ACS increased, particularly those related to CD. Compared with non-IBD ACS, patients with IBD-ACS had a lower prevalence of cardiovascular risk factors and similar rates of coronary angiography and revascularization. The in-hospital mortality rate was lower with IBD-ACS (3.9%) compared with non-IBD ACS (5.3%; odds ratio, 0.81; 95% confidence interval, 0.69-0.96; P = 0.011) and was stable between 2005 and 2015. Risk factors, ACS management strategies, and mortality were similar between CD and UC. Coagulopathy, weight loss, and gastrointestinal bleeding were more frequent in IBD-ACS and were strong independent predictors of mortality.

CONCLUSIONS

Hospitalizations for ACS in patients with IBD increased in recent years but death rates were stable. The ACS-related risk profiles and mortality were modestly favorable with IBD-ACS than with non-IBD ACS and were similar between CD and UC. Complications more frequently associated with IBD were strongly associated with mortality. These findings indicate that aggressive management of IBD and ACS comorbidities is required to improve outcomes.

Role of Capsule Endoscopy in Inflammatory Bowel Disease

In Crohn disease (CD), the use of capsule endoscopy (CE) for suspected versus established disease is very different. Most patients with CD are diagnosed with ileocolonoscopy. In patients with a negative ileocolonoscopy, CE is the next best test in suspected CD. In patients with established CD, the potential benefits of CE are rating severity of disease, establishing extent and distribution, and following mucosal healing in a treat to target strategy. In those with proximal small bowel disease, CE can help in diagnosis and prognostication. In ulcerative colitis, CE has a limited role, but that may change with evolving technology.

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.

Unique Phenotypic Characteristics and Clinical Course in Patients With Ulcerative Colitis and Primary Sclerosing Cholangitis: A Multicenter US Experience

INTRODUCTION

Ulcerative colitis (UC) associated with primary sclerosing cholangitis (PSC) is a rare phenotype. We aimed to assess patients with UC-PSC or UC alone and describe differences in clinical and phenotypic characteristics, antitumor necrosis factor (TNF) therapy, and long-term clinical outcomes.

METHODS

This retrospective multicenter cohort study included patients who received a diagnosis of UC from 1962 through 2015. We evaluated clinical factors associated with UC-PSC vs UC alone and assessed associations by using multivariable logistic regression models.

RESULTS

Among 522 patients with UC, 56 (10.7%) had PSC. Compared with UC alone, patients with UC-PSC were younger (younger than 20 years) at diagnosis (odds ratios [OR], 2.35; adjusted P = 0.02) and had milder UC severity (adjusted P = 0.05), despite having pancolonic involvement (OR, 7.01; adjusted P < 0.001). In the biologics era (calendar year 2005 to 2015), patients with UC-PSC less commonly received anti-TNF therapy compared with patients with UC (OR, 0.38; adjusted P = 0.009), but their response rates were similar. Fewer patients with UC-PSC received corticosteroids (OR, 0.24; adjusted P = 0.005) or rectal 5-aminosalicyte acid (OR, 0.26; adjusted P < 0.001). Other differences were identified that were not statistically significant in a multivariable model: patients with UC-PSC more commonly were male, had lower rates of smoking, and had higher rates of colorectal cancer and colectomy.

DISCUSSION

This study identified a unique phenotype of UC with concurrent PSC, which had different clinical behavior compared with UC only. These phenotypic characteristics can help identify high-risk patients with UC before PSC is diagnosed and guide different management and monitoring strategies.

Development of Gut-Selective Pan-Janus Kinase Inhibitor TD-1473 for Ulcerative Colitis: A Translational Medicine Programme

BACKGROUND AND AIMS

Oral systemic pan-Janus kinase [JAK] inhibition is effective for ulcerative colitis [UC] but is limited by toxicities. We describe preclinical to clinical translation of TD-1473-an oral gut-selective pan-JAK inhibitor-from in vitro characterization through a Phase 1b study in patients with UC.

METHODS

TD-1473 JAK inhibition potency was evaluated in vitro; plasma pharmacokinetics, safety and efficacy were assessed in mice. In a first-time-in-human study, plasma pharmacokinetics and safety were assessed after single and multiple [14 days] ascending doses administered orally to healthy subjects. The Phase 1b study randomized patients with moderately to severely active UC to receive once-daily oral TD-1473 20, 80 or 270 mg, or placebo for 28 days. Plasma and colonic tissue concentrations were measured; safety was assessed; and efficacy was evaluated by UC clinical parameters, disease-surrogate biomarkers, endoscopy, histology and colonic tissue JAK signalling.

RESULTS

TD-1473 exhibited potent pan-JAK inhibitory activity in vitro. Oral TD-1473 administration to mice achieved high, biologically active colonic tissue concentrations with low plasma exposure and decreased oxazolone-induced colitis activity without reducing blood cell counts vs placebo. TD-1473 administration in healthy human subjects and patients with UC yielded low plasma exposure and was generally well tolerated; treatment in patients with UC resulted in biologically active colonic tissue concentrations and descriptive trends toward reduced clinical, endoscopic and histological disease activity vs placebo.

CONCLUSION

Gut-selective pan-JAK inhibition with TD-1473 administration resulted in high intestinal vs plasma drug exposure, local target engagement, and trends toward reduced UC disease activity. [Clinicaltrials.gov NCT02657122, NCT02818686].

Capsule Retention in Crohn's Disease: A Meta-analysis

BACKGROUND

The main factor that limits wider utilization of capsule endoscopy (CE) in Crohn's disease (CD) is the potential risk of retention. The aim of this systematic review was to evaluate capsule retention rates in adult and pediatric CD and determine if retention risk is reduced in established CD (ECD) with patency capsule (PC) or magnetic resonance/computed tomography (MR/CT) enterography.

METHODS

Studies of CD patients undergoing CE that reported retention were identified. Pooled estimates for retention rates and relative risk in ECD to suspected CD (SCD) were calculated. All hypothesis tests were 2-sided; statistical significance was set at a P value of <0.05.

RESULTS

In the overall CD cohort, retention rates were 3.32% (95% confidence interval [CI], 2.62%-4.2%): 4.63% (95% CI, 3.42%-6.25%) and 2.35% (95% CI, 1.31%-4.19%) in ECD and SCD, respectively. Retention rates were 3.49% (95% CI, 2.73%-4.46%) and 1.64% (95% CI, 0.68%-3.89%) in adult and pediatric CD, respectively. Retention risk in adult ECD was 3.4 times higher than SCD, but there was no difference in retention risk in pediatric ECD compared with SCD. Retention rates in ECD were decreased after patency capsule (2.88%; 95% CI, 1.74%-4.74%) and MR/CT enterography (2.32%; 95% CI, 0.87%-6.03%).

CONCLUSIONS

In comparison with older literature, this meta-analysis demonstrates lower CE retention rates in SCD and ECD. Retention rates in pediatric CD were lower than in adult CD. Retention rates in adult ECD were higher than SCD, but there were no differences between pediatric ECD and SCD. Retention rates in ECD were lower after negative PC or MR/CT enterography.

Novel Genetic Risk Variants Can Predict Anti-TNF Agent Response in Patients With Inflammatory Bowel Disease

BACKGROUND

It is important to identify patients with inflammatory bowel disease [IBD] refractory to anti-tumour necrosis factor [TNF] therapy, to avoid potential adverse effects and to adopt different treatment strategies. We aimed to identify and validate clinical and genetic factors to predict anti-TNF response in patients with IBD.

MATERIALS AND METHODS

Mayo Clinic and Washington University IBD genetic association study cohorts were used as discovery and replicate datasets, respectively. Clinical factors included sex, age at diagnosis, disease duration and phenotype, disease location, bowel resection, tobacco use, family history of IBD, extraintestinal manifestations, and response to anti-TNF therapy.

RESULTS

Of 474 patients with IBD treated with anti-TNF therapy, 41 [8.7%] were refractory to therapy and 433 [91.3%] had response. Multivariate analysis showed history of immunomodulator use (odds ratio 10.2, p = 8.73E-4) and bowel resection (odds ratio 3.24, p = 4.38E-4) were associated with refractory response to anti-TNF agents. Among genetic loci, two [rs116724455 in TNFSF4/18, rs2228416 in PLIN2] were successfully replicated and another four [rs762787, rs9572250, rs144256942, rs523781] with suggestive evidence were found. An exploratory risk model predictability [area under the curve] increased from 0.72 [clinical predictors] to 0.89 after adding genetic predictors. Through identified clinical and genetic predictors, we constructed a preliminary anti-TNF refractory score to differentiate anti-TNF non-responders (mean [standard deviation] score, 5.49 [0.99]) from responders (2.65 [0.39]; p = 4.33E-23).

CONCLUSIONS

Novel and validated genetic loci, including variants in TNFSF, were found associated with anti-TNF response in patients with IBD. Future validation of the exploratory risk model in a large prospective cohort is warranted.

Family History Associates With Increased Risk of Colorectal Cancer in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Individuals with inflammatory bowel diseases (IBDs) have an increased risk of developing colorectal cancer (CRC). Although family history of CRC is a well-established risk factor in healthy individuals, its role in patients with IBD is less clear. We aimed to estimate the risk of CRC in a cohort of patients with IBD from Utah and the significance of family history of CRC in a first-degree relative (FDR).

METHODS

We identified Utah residents with IBD, using the Intermountain Healthcare and University of Utah Health Sciences databases, from January 1, 1996, through December 31, 2011. CRCs were identified using the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. CRC incidence was compared with that of the state population by standardized incidence ratios (SIRs).

RESULTS

A cohort of 9505 individuals with IBD was identified and 101 developed CRC during the study period. The SIR for CRC in patients with Crohn's disease was 3.4 (95% CI, 2.3-4.4), and in patients with ulcerative colitis was 5.2 (95% CI, 3.9-6.6). Patients with IBD and a concurrent diagnosis of primary sclerosing cholangitis had the greatest risk of CRC (SIR, 14.8; 95% CI, 8.3-21.2). A history of CRC in a FDR was associated with a nearly 8-fold increase in risk of CRC in patients with IBD (SIR, 7.9; 95% CI, 1.6-14.3), compared with the state population.

CONCLUSIONS

Patients with IBD have a 3- to 5-fold increase in risk of CRC, and those with CRC in a FDR have an almost 8-fold increase in risk. Family history may act as a simple measure to identify individuals with IBD at highest risk for CRC and indicates the need for enhanced surveillance in this population.

Utility of video capsule endoscopy for longitudinal monitoring of Crohn's disease activity in the small bowel: a prospective study

BACKGROUND AND AIMS

This prospective, multicenter study evaluated small-bowel capsule endoscopy (CE) for the longitudinal assessment of mucosal inflammation in subjects with Crohn's disease (CD).

METHODS

Subjects with known CD underwent clinical evaluation with ileocolonoscopy and CE at baseline and 6-month follow-up. Small-bowel patency was confirmed before CE at both time points. The Simple Endoscopic Score for CD (SES-CD) was used for ileocolonoscopy, and the Lewis score and the CE CD Endoscopic Index of Severity (CECDEIS) were used for CE. Clinical scoring indices included the Physician Global Assessment (PGA), CD Activity Index (CDAI), and Harvey-Bradshaw Index (HBI). Laboratory markers including C-reactive protein, fecal calprotectin, and erythrocyte sedimentation rate were collected at baseline and follow-up. Correlation between endoscopic scores and clinical parameters were measured using Spearman tests.

RESULTS

A total of 74 subjects were enrolled, of whom 53 (72%) completed endoscopic procedures at baseline and 6-month follow-up. The SES-CD ileocolonoscopy score correlated with the Lewis score (P < .001, ρ = .59) and CECDEIS capsule score (P = .002, ρ = .48). None of the 3 endoscopic scores correlated with PGA, CDAI, HBI, C-reactive protein, erythrocyte sedimentation rate, or fecal calprotectin. Approximately 85% of subjects had proximal small-bowel inflammation identified on CE. There were no CE-related adverse events.

CONCLUSIONS

There was high correlation between CE and ileocolonoscopy scores for the assessment of mucosal disease activity over time; however, there were no correlations between endoscopic scores and clinical parameters. The use of serial CE for the assessment of small-bowel CD is feasible and valid. (Clinical trial registration number: NCT01942720.).

Impact of feedback on adenoma detection rates: Outcomes of quality improvement program

BACKGROUND AND AIM

Feedback has been shown to improve performance in colonoscopy including adenoma detection rate (ADR). The frequency at which feedback should be given is unknown. As part of a quality improvement program, we sought to measure the outcome of providing quarterly and monthly feedback on colonoscopy quality measures.

METHODS

All screening colonoscopies performed at endoscopy unit at Mayo Clinic Arizona by gastroenterologists between October 2010 and December 2012 were reviewed. Quality indicators, including ADR, were extracted for each individual endoscopist, and feedback was provided. The study period was divided into four distinct groups: pre-intervention that served as baseline, quarterly feedback, monthly feedback, and post-intervention. Based on ADR, endoscopists were grouped into "low detectors" (≤ 25%), "average detectors" (26-35%), and "high detectors" (> 35%).

RESULTS

A total of 3420 screening colonoscopies were performed during the study period (555 patients during pre-intervention, 1209 patients during quarterly feedback, 599 during monthly feedback, and 1057 during the post-intervention period) by 16 gastroenterologists. The overall ADR for the group improved from 30.5% to 37.7% (P = 0.003). Compared with the pre-interventional period, all quality indicators measured significantly improved during the monthly feedback and post-intervention periods but not in the quarterly feedback period.

CONCLUSIONS

In our quality improvement program, monthly feedback significantly improved colonoscopy quality measures, including ADR, while quarterly feedback did not. The impact of the intervention was most prominent in the "low detectors" group. Results were durable up to 6 months following the intervention.

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.

Approach to Incomplete Colonoscopy: New Techniques and Technologies

Colonoscopy is the most widely used screening modality for the detection and removal of colon polyps and for the prevention of colorectal cancer. To identify all colon lesions and reduce the risk of colorectal cancer, it is important to perform a complete colonoscopy. The success of screening colonoscopy depends upon several parameters, including bowel preparation and adenoma detection rate. Incomplete colonoscopy rates vary from 4% to 25% and are associated with higher rates of interval proximal colon cancer. This article reviews the potential causes of and preventive measures for incomplete colonoscopy, as well as techniques and technologies that may improve the rate of complete colonoscopy.

The receptor tyrosine kinase AXL promotes migration and invasion in colorectal cancer

The receptor tyrosine kinases (RTKs) TYRO3, AXL and MERTK (TAM) have well-described oncogenic functions in a number of cancers. Notwithstanding, TAM RTKs are also potent and indispensable inhibitors of inflammation. The combined deletion of Axl and Mertk in mice enhances chronic inflammation and autoimmunity, including increased inflammation in the gut and colitis-associated cancer. On the other hand, deletion of Tyro3 increases the risk of allergic responses. Therefore, the indiscriminate inhibition of these TAM RTKs could result in undesirable immunological diseases. Here we show that AXL, but not MERTK or TYRO3 expression is enhanced in late stage colorectal cancer (CRC) and AXL expression associates with a cell migration gene signature. Silencing AXL or the inhibition of AXL kinase activity significantly inhibits tumor cell migration and invasion. These results indicate that the selective inhibition of AXL alone might confer sufficient therapeutic benefit in CRC, while preserving at least some of the beneficial, anti-inflammatory effects of MERTK and TYRO3 RTKs.

Identification of Antibody Against SNRPB, Small Nuclear Ribonucleoprotein-Associated Proteins B and B', as an Autoantibody Marker in Crohn's Disease using an Immunoproteomics Approach

BACKGROUND

Current non-invasive biomarkers for Crohn's disease are limited in their utility. Progress in identifying individual autoantigens and autoantibodies in Crohn's disease has been challenging due to limitations of available immunoassays.

AIMS

Our aim was to identify autoantibodies associated with Crohn's disease that may be useful in diagnosis and management using an innovative protein array technology, namely nucleic acid programmable protein arrays [NAPPA].

METHODS

Serum samples of 96 patients with established Crohn's disease and 96 healthy controls were included and evenly split into discovery and validation sets randomly. Autoantibodies of both IgG and IgA classes were profiled against ~1900 human proteins in the discovery set on NAPPA. Autoantibodies discovered to be Crohn's disease-specific were further validated in the independent validation set by enzyme-linked immunosorbent assay.

RESULTS

Overall, reactivity of IgG autoantibodies was stronger than that of IgA autoantibodies; however, IgA autoantibodies showed greater differential reactivity between cases and controls. Four IgA autoantibodies against SNRPB, PRPH, PTTG1 and SNAI1 were newly identified with sensitivities above 15% at 95% specificity, among which anti-SNRPB-IgA had the highest sensitivity of 24.0%. Autoantibodies associated with specific disease subtypes were also found.

CONCLUSIONS

As one of the first studies to use immunoproteomics for the identification of autoantibodies in Crohn's disease, our results support the utility of NAPPA in implementing future expanded studies with better coverage of the human proteome and microbial proteomes relevant to Crohn's disease and identifying antibody markers that may have clinical impact in diagnosis and management.

Evidence-Based Guide on Capsule Endoscopy for Small Bowel Bleeding

Capsule endoscopy is the diagnostic test of choice for the evaluation of overt and occult small bowel bleeding. Its yield is higher in patients presenting with overt bleeding. The yield is also improved if the capsule is performed soon after the presentation of bleeding. Capsule endoscopy has a complementary role with cross-sectional imaging to triage patients for appropriate management, including deep enteroscopy, surgery, or, if negative, conservative management. Although capsule endoscopy is useful to detect vascular and inflammatory lesions, it appears to have a significant miss rate for solitary small bowel lesions, including tumors. The main adverse event is capsule retention in patients with underlying small bowel obstruction.

Inflammatory Disorders of the Small Bowel

The most common small bowel inflammatory disorders include Crohn disease, nonsteroidal antiinflammatory drug (NSAID) enteropathy, and celiac disease. Capsule endoscopy, computed tomography enterography, and magnetic resonance enterography have a complementary role in the diagnosis of Crohn disease and evaluation of patients with established Crohn disease. The higher risk of capsule retention with known Crohn disease and NSAID enteropathy can be minimized by cross-sectional imaging or the patency capsule. The main role of deep enteroscopy is tissue diagnosis, endoscopic management of small bowel lesions and strictures, and retrieval of retained capsules.

Comparing diagnostic yield of a novel pan-enteric video capsule endoscope with ileocolonoscopy in patients with active Crohn's disease: a feasibility study

BACKGROUND AND AIMS

Crohn's disease (CD) is typically diagnosed with ileocolonoscopy (IC); however, when inflammation is localized solely in the small bowel, visualization of the entire small-bowel mucosa can be challenging. The aim of this study was to compare the diagnostic yield of a pan-enteric video capsule endoscope (small-bowel colon [SBC] capsule) versus IC in patients with active CD.

METHODS

This was a prospective, multicenter study. Patients with known active CD and proven bowel luminal patency underwent a standardized colon cleansing protocol followed by ingestion of the capsule. After passage of the capsule, IC was performed and recorded. Lesions indicative of active CD were assessed.

RESULTS

One hundred fourteen subjects were screened; 66 subjects completed both endoscopic procedures. The per-subject diagnostic yield rate for active CD lesions was 83.3% for SBC and 69.7% for IC (yield difference, 13.6%; 95% confidence interval [CI], 2.6%-24.7%); 65% of subjects had active CD lesions identified by both modalities. Of the 12 subjects who were positive for active CD by SBC only, 5 subjects were found to have active CD lesions in the terminal ileum. Three subjects were positive for active CD by IC only. Three hundred fifty-five classifying bowel segments were analyzed; the per-segment diagnostic yield rate was 40.6% for SBC and 32.7% for IC (yield difference 7.9%; 95% CI, 3.3%-12.4%).

CONCLUSION

This preliminary study shows that the diagnostic yields for SBC might be higher than IC; however, the magnitude of difference between the two is difficult to estimate. Further study is needed to confirm these findings.

Detection of suspected small bowel bleeding: challenges and controversies

Detection of small bowel (SB) bleeding remains a challenge to gastroenterologists, with a dearth of standardized recommendations regarding evaluation and management. Areas covered: A recursive literature search was performed using PubMed, Cochrane and Medline databases for original and review articles on SB and obscure gastrointestinal bleeding (OGIB). Based upon the available literature, this review outlines the main challenges and controversies, and provides a practical and cost-effective approach towards SB bleeding. Expert commentary: SB bleeding is suspected in patients with persistent or recurrent bleeding after negative bidirectional endoscopy, and unexplained iron deficiency anemia. Selection of test(s) should be individualized based upon patient presentation and suspicion for type of underlying lesion. Endoscopic or radiologic evaluation and treatment is the mainstay in the majority of patients, while pharmacologic agents may have a role in patients with refractory bleeding, and those unable to undergo evaluation.

Accuracy of First- and Second-Generation Colon Capsules in Endoscopic Detection of Colorectal Polyps: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Colon capsule endoscopy (CCE) is a noninvasive technique used to explore the colon without sedation or air insufflation. A second-generation capsule was recently developed to improve accuracy of detection, and clinical use has expanded globally. We performed a systematic review and meta-analysis to assess the accuracy of CCE in detecting colorectal polyps.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and other databases from 1966 through 2015 for studies that compared accuracy of colonoscopy with histologic evaluation with CCE. The risk of bias within each study was ascertained according to Quality Assessment of Diagnostic Accuracy in Systematic Reviews recommendations. Per-patient accuracy values were calculated for polyps, overall and for first-generation (CCE-1) and second-generation (CCE-2) capsules. We analyzed data by using forest plots, the I² statistic to calculate heterogeneity, and meta-regression analyses.

RESULTS

Fourteen studies provided data from 2420 patients (1128 for CCE-1 and 1292 for CCE-2). CCE-2 and CCE-1 detected polyps >6 mm with 86% sensitivity (95% confidence interval [CI], 82%-89%) and 58% sensitivity (95% CI, 44%-70%), respectively, and 88.1% specificity (95% CI, 74.2%-95.0%) and 85.7% specificity (95% CI, 80.2%-90.0%), respectively. CCE-2 and CCE-1 detected polyps >10 mm with 87% sensitivity (95% CI, 81%-91%) and 54% sensitivity (95% CI, 29%-77%), respectively, and 95.3% specificity (95% CI, 91.5%-97.5%) and 97.4% specificity (95% CI, 96.0%-98.3%), respectively. CCE-2 identified all 11 invasive cancers detected by colonoscopy.

CONCLUSIONS

The sensitivity in detection of polyps >6 mm and >10 mm increased substantially between development of first-generation and second-generation colon capsules. High specificity values for detection of polyps by CCE-2 seem to be achievable with a 10-mm cutoff and in a screening setting.

Using Hybrid Change Strategies to Improve the Patient Experience in Outpatient Specialty Care

The emerging changes in healthcare impose significant burdens on integrated outpatient specialty services with respect to setting patient expectations, handling outside medical records; and coordinating specialty appointments scheduling. Moreover, because of the evolution of the electronic health record and its widespread use, it is critical that patient and physician interaction is maintained and clerical tasks are minimized. In the context of increased government regulation, declining reimbursement, and the rise of new payment models, outpatient practices need to be reimagined so that they are more efficient for the patient and the provider. The redesign of integrated outpatient specialty services can be accomplished only through teamwork, innovation, and efficient use of technology. To address these challenges, the Department of Medicine at Mayo Clinic in Scottsdale, Arizona, implemented an ideal practice design initiative that leveraged a hybrid set of change strategies. The change strategy, which was initiated after examination of current practices and design options, engaged key stakeholders and patients. A number of enablers and barriers to adoption were identified as a result of the implementation experience.

Nonneoplastic polypectomy during screening colonoscopy: the impact on polyp detection rate, adenoma detection rate, and overall cost

BACKGROUND

The frequency of nonneoplastic polypectomy (NNP) and its impact on the polyp detection rate (PDR) is unknown. The correlation between NNP and adenoma detection rate (ADR) and its impact on the cost of colonoscopy has not been investigated.

OBJECTIVE

To determine the rate of NNP in screening colonoscopy, the impact of NNP on the PDR, and the correlation of NNP with ADR. The increased cost of NNP during screening colonoscopy also was calculated.

DESIGN

We reviewed all screening colonoscopies. PDR and ADR were calculated. We then calculated a nonneoplastic polyp detection rate (patients with ≥1 nonneoplastic polyp).

SETTING

Tertiary-care referral center.

PATIENTS

Patients who underwent screening colonoscopies from 2010 to 2011.

INTERVENTIONS

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

ADR, PDR, NNP rate.

RESULTS

A total of 1797 colonoscopies were reviewed. Mean (±standard deviation) PDR was 47.7%±12.0%, and mean ADR was 27.3%±6.9%. The overall NNP rate was 10.4%±7.1%, with a range of 2.4% to 28.4%. Among all polypectomies (n=2061), 276 were for nonneoplastic polyps (13.4%). Endoscopists with a higher rate of nonneoplastic polyp detection were more likely to detect an adenoma (odds ratio 1.58; 95% confidence interval, 1.1-1.2). With one outlier excluded, there was a strong correlation between ADR and NNP (r=0.825; P<.001). The increased cost of removal of nonneoplastic polyps was $32,963.

LIMITATIONS

Retrospective study.

CONCLUSION

There is a strong correlation between adenoma detection and nonneoplastic polyp detection. The etiology is unclear, but nonneoplastic polyp detection rate may inflate the PDR for some endoscopists. NNP also adds an increased cost. Increasing the awareness of endoscopic appearances through advanced imaging techniques of normal versus neoplastic tissue may be an area to improve cost containment in screening colonoscopy.

Double-balloon enteroscopy in Crohn's disease: findings and impact on management in a multicenter retrospective study

BACKGROUND

Double-balloon enteroscopy (DBE) is effective in visualizing the small bowel to perform biopsy sampling and interventions. Few studies have evaluated the utility of DBE in patients with known or suspected Crohn's disease (CD).

OBJECTIVE

To evaluate the use of DBE in the diagnosis and impact on patient management in known and suspected CD and to compare capsule endoscopy (CE) with DBE findings.

DESIGN

Retrospective study from August 2004 to August 2009 of DBE procedures.

SETTING

Five academic, tertiary U.S. centers.

PATIENTS

Patients with known or suspected CD.

MAIN OUTCOME MEASURES

Diagnostic yield, impact on patient management, and comparison of DBE to CE findings in patients with known and suspected CD.

RESULTS

We analyzed 98 DBE procedures performed in 81 patients (38 with known CD and 43 with suspected CD). For patients with CD, common indications were abdominal pain and bleeding/anemia. The diagnostic yield was 87% (33/38 patients). The impact on subsequent management decisions was 82% (31/38). Common indications for DBE in patients with suspected CD were abnormal CE or other imaging. The diagnostic yield was 79% (34/43 patients). The impact on subsequent management decisions was 77% (33/43). In 17% of patients (14/81), DBE failed to reach the target lesion. There was 1 perforation, 3 strictures dilated, and 1 of 2 retained capsules recovered. When CE was followed by DBE, 46% of lesions were confirmed on DBE.

LIMITATIONS

Retrospective analysis, imperfect criterion standard.

CONCLUSIONS

DBE is an effective technique for assessment of the small bowel in known and suspected CD and affects management. Failure to reach target areas with DBE is not uncommon, and perforations can occur. There is poor correlation between CE and DBE.

Evaluation and management of small-bowel tumors in the era of deep enteroscopy

In summary, small-intestine tumors are a rare phenomenon, but they are being discovered more frequently with newer diagnostic techniques. Prior studies of the small bowel were limited, making the diagnosis difficult. With the advent of CE and deep enteroscopy, gastroenterologists are finding these tumors at an earlier stage, thereby offering better management options for these patients. Although the incidence of small-bowel tumors has increased, the survival rates have remained the same. This may be a lag-time bias but could be a future area of research in this emerging field.

Capsule endoscopy is superior to small-bowel follow-through and equivalent to ileocolonoscopy in suspected Crohn's disease

BACKGROUND & AIMS

Evaluation of the small intestine for inflammation has traditionally relied on small-bowel follow-through (SBFT), but multiple studies have demonstrated its low diagnostic accuracy. Capsule endoscopy (CE) transmits high-quality images of the small intestinal mucosa; it can be used to visualize the entire length of the small bowel and much of the mucosa. We compared the diagnostic yields of CE vs SBFT in a prospective study of patients with suspected small-bowel Crohn's disease.

METHODS

Eighty patients with signs and/or symptoms of small-bowel Crohn's disease (age, 10-65 years) underwent CE, followed by SBFT and ileocolonoscopy. Readers were blinded to other test results. The primary outcome was the diagnostic yield for inflammatory lesions found with CE before ileocolonoscopy compared with SBFT and ileocolonoscopy. A secondary outcome was the incremental diagnostic yield of CE compared with ileocolonoscopy and CE compared with SBFT.

RESULTS

The combination of CE and ileocolonoscopy detected 107 of 110 inflammatory lesions (97.3%), whereas the combination of SBFT and ileocolonoscopy detected only 63 lesions (57.3%) (P < .001). The diagnostic yield of CE compared with ileocolonoscopy was not different (P = .09). The diagnostic yield was higher for CE than for SBFT (P < .001). Of the 80 patients with suspected Crohn's disease, 25 (31.3%) had the diagnosis confirmed. Eleven were diagnosed by CE findings alone and 5 by ileocolonoscopy findings alone. In the remaining 9 patients, diagnostic findings were identified by at least 2 of the 3 modalities. No diagnoses were made on the basis of SBFT findings alone.

CONCLUSIONS

CE was better than SBFT and equivalent to ileocolonoscopy in detecting small-bowel inflammation. Although ileocolonoscopy remains the initial diagnostic test of choice, CE is safe and can establish the diagnosis of Crohn's disease in patients when ileocolonoscopy results are negative or the terminal ileum cannot be evaluated. ClinicalTrials.gov Number: NCT00487396.

A multicenter, prospective, randomized comparison of a novel signal transmission capsule endoscope to an existing capsule endoscope

BACKGROUND

MiroCam, a capsule endoscope, uses a novel transmission technology, electric-field propagation, which uses the human body as a conduction medium for data transmission.

OBJECTIVE

To compare the ability of the MiroCam (MC) and PillCam (PC) to identify sources of obscure GI bleeding (OGIB).

DESIGN

Prospective, multicenter, comparative study.

SETTING

Six academic hospitals.

PATIENTS

A total of 105 patients with OGIB.

INTERVENTION

Patients ingested both the MC and PC capsules sequentially in a randomized fashion.

MAIN OUTCOME MEASUREMENTS

Concordance of rates in identifying a source of OGIB, operational times, and rates of complete small-bowel examination.

RESULTS

Data analysis resulted in 43 (48%) "abnormal" cases identifying a source of OGIB by either capsule. Twenty-four cases (55.8%) were positive by both capsules. There was negative agreement in 46 of 58 cases (79.3%). The κ index was 0.547 (χ(2) = 1.32; P = .36). In 12 cases, MC positively identified a source that was not seen on PC, whereas in 7 cases, PC positively identified a source that was not seen on MC. MC had a 5.6% higher rate of detecting small-bowel lesions (P = .54). MC captured images at 3 frames per second for 11.1 hours, and PC captured images at 2 frames per second for 7.8 hours (P < .0001). Complete small-bowel examination was achieved in 93.3% for MC and 84.3% for PC (P = .10).

LIMITATIONS

Readers were not blinded to the particular capsule they were reading.

CONCLUSION

A positive diagnostic finding for OGIB was identified by either capsule in 48% of cases. The concordance rate between the 2 capsules was comparable to that of prior studies in identifying sources of small-bowel bleeding. The longer operational time of the MC may result in higher rates of complete small-bowel examination, which may, in turn, translate into a higher rate of detecting small-bowel lesions. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT00878982.).

Downregulation of hematopoietic MUC1 during experimental colitis increases tumor-promoting myeloid-derived suppressor cells

PURPOSE

MUC1 is a tumor-associated antigen that is aberrantly expressed in cancer and inflammatory bowel disease (IBD). Even though immune cells express low MUC1 levels, their modulations of MUC1 are important in tumor progression. Consistent with previous clinical data that show increased myeloid-derived suppressor cells (MDSCs) in IBD, we now show that downregulation of MUC1 on hematopoietic cells increases MDSCs in IBD, similar to our data in tumor-bearing mice. We hypothesize that MDSC expansion in IBD is critical for tumor progression.

EXPERIMENTAL DESIGN

To mechanistically confirm the linkage between Muc1 downregulation and MDSC expansion, we generated chimeric mice that did not express Muc1 in the hematopoietic compartment (KO→WT). These mice were used in two models of colitis and colitis-associated cancer (CAC) and their responses were compared with wild-type (WT) chimeras (WT→WT).

RESULTS

KO→WT mice show increased levels of MDSCs during colitis and increased protumorigenic signaling in the colon during CAC, resulting in larger colon tumors. RNA and protein analysis show increased upregulation of metalloproteinases, collagenases, defensins, complements, growth factors, cytokines, and chemokines in KO→WT mice as compared with WT→WT mice. Antibody-mediated depletion of MDSCs in mice during colitis reduced colon tumor formation during CAC.

CONCLUSION

Development of CAC is a serious complication of colitis and our data highlight MDSCs as a targetable link between inflammation and cancer. In addition, the lack of MUC1 expression on MDSCs can be a novel marker for MDSCs, given that MDSCs are still not well characterized in human cancers.

T cell-derived protein S engages TAM receptor signaling in dendritic cells to control the magnitude of the immune response

Dendritic cell (DC) activation is essential for the induction of immune defense against pathogens, yet needs to be tightly controlled to avoid chronic inflammation and exaggerated immune responses. Here, we identify a mechanism of immune homeostasis by which adaptive immunity, once triggered, tempers DC activation and prevents overreactive immune responses. T cells, once activated, produced Protein S (Pros1) that signaled through TAM receptor tyrosine kinases in DCs to limit the magnitude of DC activation. Genetic ablation of Pros1 in mouse T cells led to increased expression of costimulatory molecules and cytokines in DCs and enhanced immune responses to T cell-dependent antigens, as well as increased colitis. Additionally, PROS1 was expressed in activated human T cells, and its ability to regulate DC activation was conserved. Our results identify a heretofore unrecognized, homeostatic negative feedback mechanism at the interface of adaptive and innate immunity that maintains the physiological magnitude of the immune response.

Impact of fentanyl in lieu of meperidine on endoscopy unit efficiency: a prospective comparative study in patients undergoing EGD

BACKGROUND

Turnaround time is an important component of endoscopy unit efficiency. Any reduction in the total time from patient arrival in the endoscopy room to departure from the recovery area may translate into better endoscopy unit efficiency.

OBJECTIVE

To evaluate the effects on endoscopy unit efficiency of a change in narcotic choice for moderate sedation in patients undergoing EGD at an ambulatory surgery center.

DESIGN

Prospective, comparative, quality-improvement project.

SETTING

Endoscopy unit of a tertiary-care academic medical center.

PATIENTS

We enrolled consecutive patients (n = 1963) who underwent outpatient EGD by 1 of 5 endoscopists between November 2008 and November 2010.

INTERVENTION

Moderate sedation with midazolam plus fentanyl versus meperidine.

MAIN OUTCOME MEASUREMENTS

Sedation-dependent endoscopy unit efficiency and total procedure time (induction-to-intubation, intubation-to-extubation, and extubation-to-discharge).

RESULTS

Fentanyl was associated with reduced total procedure time by 10.1 minutes resulting from both shorter induction-to-intubation time and extubation-to-discharge time (P < .001). The mean (± SD) sedation-dependent endoscopy unit efficiency was 3.2 (± 1.9) procedures per hour for the meperidine group and 3.9 (± 2.7) procedures per hour for the fentanyl group (P = .012); this would translate into possibly increasing the endoscopy suite efficiency by 22%. Based on dosage equivalency conversion, equal doses of fentanyl and meperidine were used. No sedation-related complications or need for reversal agents were recorded.

LIMITATIONS

No randomization was performed.

CONCLUSION

Compared with meperidine, fentanyl in combination with midazolam was associated with significantly shorter total procedure time. By improving the turnaround time, sedation-dependent endoscopy unit efficiency may be improved by 22%.

Endoscopic techniques for small bowel imaging

Advances in small bowel enteroscopy have led to an increase in the endoscopic evaluation and management of small bowel disorders. The entire small bowel can now be visualized in a noninvasive manner by capsule endoscopy, while therapeutic management can be performed with deep enteroscopy techniques, including balloon-assisted and spiral enteroscopy. Each of these enteroscopy tools has its unique advantages and disadvantages, which need to be taken into consideration during selection of the appropriate tool. Capsule endoscopy and deep enteroscopy are often used as complementary tests in the evaluation of small bowel disorders.

Comparison of single- versus double-balloon assisted-colonoscopy for colon examination after previous incomplete standard colonoscopy

BACKGROUND

Colonoscopy fails to achieve cecal intubation in 5-10 % of cases. Many of these cases can be completed using balloon-assisted colonoscopy, either with the single-balloon colonoscopy (SBC) or the double-balloon colonoscopy (DBC) techniques.

AIM

To compare the completion rates of SBC and DBC in patients with previous incomplete conventional colonoscopy.

METHODS

Between August 2009 and July 2011 either SBC or DBC was performed in 53 patients in whom previous conventional colonoscopy did not achieve cecal intubation. The medical records of these 53 patients were reviewed retrospectively for details regarding (1) indication for the initial colonoscopy, (2) patient characteristics, (3) data from the initial colonoscopy, and (4) details on both SBC and DBC.

RESULTS

SBC was successful in intubating the cecum in 100 % (26/26) of patients and DBC was successful in 93 % (25/27) of patients. The median (range) time to reach the cecum was 17 (9-43) min in the SBC group and 20 (7-58) min in the DBC group (P = 0.37). The presence of polyps was an entirely new finding in 35 % (9/26) of patients in the SBC group and 30 % (8/27) of patients in DBC group. Therapeutics were performed in 73 % (19/26) of patients in SBC group and 67 % (18/27) of patients in DBC group.

CONCLUSION

For patients with incomplete conventional colonoscopy, SBC and DBC offer high cecal intubation rates as well as detection of additional polyps and therapeutic capability. Either SBC or DBC can be considered after incomplete conventional colonoscopy.

Increased adenoma detection rate with system-wide implementation of a split-dose preparation for colonoscopy

BACKGROUND

Recent studies using split-dose preparations (SDPs) suggest a significant improvement in the quality of preparation and patient compliance. However, the effects of SDP on other quality indicators of colonoscopy, such as cecal intubation and adenoma detection rates, have not been previously reported, to our knowledge.

OBJECTIVE

The primary objective of this study was to compare polyp detection rates (PDRs) and adenoma detection rates (ADRs) before and after the implementation of an SDP as the preferred bowel preparation. The secondary objectives were to compare the quality of the preparation and colonoscopy completion rates before and after implementation of the SDP.

DESIGN

Retrospective study.

SETTING

Tertiary care medical center.

PATIENTS

Patients undergoing colonoscopy for screening and surveillance of colon polyps and cancer.

INTERVENTIONS

System-wide implementation of SDP.

RESULTS

A total of 3560 patients in the pre-SDP group and 1615 patients in the post-SDP group were included in the study. SDP use increased significantly from 9% to 74% after implementation. In comparison with the pre-SDP group, both PDRs (44.1%-49.5%; P < .001) and ADRs (26.7%-31.8%; P < .001) significantly improved in the post-SDP group. The colonoscopy completion rate significantly increased from 93.6% to 95.5% in the post-SDP group (P = .008). Bowel preparation quality also improved significantly (P < .001) in the post-SDP group.

LIMITATIONS

Retrospective design; not all endoscopists were the same in both periods.

CONCLUSIONS

System-wide implementation of an SDP as the primary choice for colonoscopy significantly improved both PDRs and ADRs, overall quality of the preparation, and colonoscopy completion rates.