Ryan W. Stidham

Systematic review with network meta‐analysis: the efficacy of anti‐tumour necrosis factor‐alpha agents for the treatment of ulcerative colitis

Antibodies against tumour necrosis factor‐alpha (anti‐TNF) are effective therapies in the treatment of ulcerative colitis (UC), but their comparative efficacy is unknown.

Ultrasound Elasticity Imaging for Detecting Intestinal Fibrosis and Inflammation in Rats and Humans With Crohn's Disease

BACKGROUND Intestinal fibrosis causes many complications of Crohns disease (CD). Available biomarkers and imaging modalities lack sufficient accuracy to distinguish intestinal inflammation from fibrosis. Transcutaneous ultrasound elasticity imaging (UEI) is a promising, noninvasive approach for measuring tissue mechanical properties. We hypothesized that UEI could differentiate inflammatory from fibrotic bowel wall changes in both animal models of colitis and humans with CD. METHODS Female Lewis rats underwent weekly trinitrobenzene sulfonic acid enemas yielding models of acute inflammatory colitis (n = 5) and chronic intestinal fibrosis (n = 6). UEI scanning used a novel speckle-tracking algorithm to estimate tissue strain. Resected bowel segments were evaluated for evidence of inflammation and fibrosis. Seven consecutive patients with stenotic CD were studied with UEI and their resected stenotic and normal bowel segments were evaluated by ex vivo elastometry and histopathology. RESULTS Transcutaneous UEI normalized strain was able to differentiate acutely inflamed (-2.07) versus chronic fibrotic (-1.10) colon in rat models of inflammatory bowel disease (IBD; P = .037). Transcutaneous UEI normalized strain also differentiated stenotic (-0.87) versus adjacent normal small bowel (-1.99) in human CD (P = .0008), and this measurement also correlated well with ex vivo elastometry (r = -0.81). CONCLUSIONS UEI can differentiate inflammatory from fibrotic intestine in rat models of IBD and can differentiate between fibrotic and unaffected intestine in a pilot study in humans with CD. UEI represents a novel technology with potential to become a new objective measure of progression of intestinal fibrosis. Prospective clinical studies in CD are needed.

Systematic review with network meta-analysis: the efficacy of anti-TNF agents for the treatment of Crohn's disease

Anti‐tumour necrosis factor‐alpha agents (anti‐TNF) are effective therapies for the treatment of Crohns disease (CD), but their comparative efficacy is unknown.

US elastography-derived shear wave velocity helps distinguish acutely inflamed from fibrotic bowel in a Crohn disease animal model.

PURPOSE To determine if acoustic radiation force impulse elastography-derived bowel wall shear wave velocity (SWV) allows distinction of acutely inflamed from fibrotic intestine in a Crohn disease animal model. MATERIALS AND METHODS University Committee on the Use and Care of Animals approval was obtained. An acute inflammation Crohn disease model was produced by treating eight Lewis rats with a single administration of trinitrobenzenesulfonic acid (TNBS) enema, with imaging performed 2 days later in the surviving six rats. Colonic fibrosis in an additional eight Lewis rats was achieved by administering repeated TNBS enemas during 4 weeks, with imaging performed in the surviving seven rats 7 days later to allow acute inflammation resolution. Nine transcutaneous bowel wall SWV measurements were obtained from the colon in all rats without and with applied strain. Mean SWVs without and with applied strain were compared between animal cohorts by using the Student t test, and receiver operating characteristic (ROC) curves were created to assess diagnostic performance. RESULTS Mean bowel wall SWVs were significantly higher for fibrotic versus acute inflammation cohort of rats at 0% (3.4 ± 1.1 vs 2.3 ± 0.5 m/sec; P = .047) and 30% (6.3 ± 2.2 vs 3.6 ± 0.9 m/sec; P = .02) applied strain. Both acute inflammation and fibrotic cohort of rats demonstrated linear increases in mean SWV with increasing applied strain, with significantly different mean slopes (P = .02) and y-intercepts (P = .02). The area under the ROC curve of the SWV ratio (mean SWV/applied strain) for differentiating histopathologically confirmed fibrotic from inflamed bowel was 0.971. CONCLUSION Bowel wall SWV helps distinguish acutely inflamed from fibrotic intestine in a Crohn disease animal model.

Ultrasound Shear Wave Elastography Helps Discriminate Low-grade From High-grade Bowel Wall Fibrosis in Ex Vivo Human Intestinal Specimens

To determine whether bowel wall fibrosis can be detected in freshly resected human intestinal specimens based on ultrasound‐derived shear wave speed.

Comparison of noncontrast MRI magnetization transfer and T2 -Weighted signal intensity ratios for detection of bowel wall fibrosis in a Crohn's disease animal model.

To compare the abilities of magnetization transfer magnetic resonance imaging (MT‐MRI) and T2‐weighted signal intensity (T2WSI) ratios to detect intestinal fibrosis in a Crohns disease animal model.

Factors That Predict High Health Care Utilization and Costs for Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS A subset of patients with inflammatory bowel diseases (IBD) have continuously active inflammation, leading to a high number of complications and high direct health care costs (diagnostic tests, medications, and surgeries) and indirect costs (reduced employment and productivity and fewer opportunities for activities). Identifying these high‐risk patients and providing effective interventions could produce better outcomes and reduce costs. We used prior year data to create IBD risk models to predict IBD‐related hospitalizations, emergency department visits, and high treatment charges (>

A New Nonlinear Parameter in the Developed Strain-to-Applied Strain of the Soft Tissues and Its Application in Ultrasound Elasticity Imaging

30,000/year) in the subsequent year. METHODS We performed a retrospective study of medical records from all patients with IBD treated at the University of Michigan Hospital from fiscal years 2013–2015. We selected clinical variables from the prior year and tested their abilities to predict 3 adverse outcomes (IBD‐related hospitalizations, emergency department visits, and treatment charges >

Body fat composition assessment using analytic morphomics predicts infectious complications after bowel resection in Crohn's disease.

30,000/year) in the subsequent year. Individual patients were only included once in the data set. We created a multivariate model that was based on a 70% randomly selected cohort (1005 patients) and validated the model on the other 30% (425 patients). Logistic regression was used for bivariate and multivariate analyses. RESULTS Factors that predicted high‐cost outcomes included the presence of psychiatric illness, use of corticosteroids, use of narcotics, low levels of hemoglobin, and high numbers of IBD‐related hospitalizations. In the validation cohort, the model predicted IBD‐related hospitalizations, emergency department visits, and high charges in the following year with receiver operating characteristic curve values of 0.751, 0.738, and 0.744, respectively. CONCLUSIONS We identified 5 factors that can effectively identify patients with IBD at high risk for hospitalization, emergency department visits, and high treatment charges in the next year. These patients should be closely monitored and aggressively managed.

Cold snare piecemeal resection of colonic and duodenal polyps ≥1 cm

Strain developed under quasi-static deformation has been mostly used in ultrasound elasticity imaging (UEI) to determine the stiffness change of tissues. However, the strain measure in UEI is often less sensitive to a subtle change of stiffness. This is particularly true for Crohns disease where we have applied strain imaging to the differentiation of acutely inflamed bowel from chronically fibrotic bowel. In this study, a new nonlinear elastic parameter of the soft tissues is proposed to overcome this limit. The purpose of this study is to evaluate the newly proposed method and demonstrate its feasibility in the UEI. A nonlinear characteristic of soft tissues over a relatively large dynamic range of strain was investigated. A simplified tissue model based on a finite element (FE) analysis was integrated with a laboratory developed ultrasound radio-frequency (RF) signal synthesis program. Two-dimensional speckle tracking was applied to this model to simulate the nonlinear behavior of the strain developed in a target inclusion over the applied average strain to the surrounding tissues. A nonlinear empirical equation was formulated and optimized to best match the developed strain-to-applied strain relation obtained from the FE simulation. The proposed nonlinear equation was applied to in vivo measurements and nonlinear parameters were further empirically optimized. For an animal model, acute and chronic inflammatory bowel disease was induced in Lewis rats with trinitrobenzene sulfonic acid (TNBS)-ethanol treatments. After UEI, histopathology and direct mechanical measurements were performed on the excised tissues. The extracted nonlinear parameter from the developed strain-to-applied strain relation differentiated the three different tissue types with 1.96 ± 0.12 for normal, 1.50 ± 0.09 for the acutely inflamed and 1.03 ± 0.08 for the chronically fibrotic tissue. T-tests determined that the nonlinear parameters between normal, acutely inflamed and fibrotic tissue types were statistically significantly different (normal/ fibrotic [p = 0.0000185], normal/acutely inflamed [p = 0.0013] and fibrotic/acutely inflamed [p = 0.0029]). This technique may provide a sensitive and robust tool to assess subtle stiffness changes in tissues such as in acutely inflamed bowel wall.