Gordon, I

Abstract Background Colonic strictures in Crohn’s disease (CD) present a complex and relatively underexplored clinical issue. Imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), and intestinal ultrasound (IUS), have established criteria for evaluating small bowel CD strictures. However, radiologic definitions of benign colonic strictures and their diagnostic accuracy are not well-developed. Endoscopic definitions of colonic strictures are the most well-described. We conducted a systematic review to summarize definitions, diagnosis, and identification of inflammation and fibrosis of colonic strictures on endoscopy, CT, MR, and IUS. Methods A systematic review following PRISMA guidelines, from inception to October 6, 2024, was conducted using MEDLINE, Scopus, CINAHL, and CENTRAL databases to identify literature on diagnostic imaging of patients with colonic CD strictures. Only studies with comparison to endoscopy or imaging to a full-thickness histologic gold standard to differentiate fibrosis from inflammation were included. Two stage screening was completed in duplicate, and risk of bias was assessed using QUADAS-2. Results 46 studies were eligible for inclusion of 4623 abstracts screened. Definitions of colonic strictures on CT, MR, and IUS were highly variable with combinations of bowel wall thickness, luminal narrowing, and pre-stenotic dilation. Endoscopic definitions of colonic strictures were the most consistently reported as lack of passage of a colonoscope through a narrowed lumen. Diagnostic imaging definitions used various combinations of increased bowel wall thickness, luminal narrowing, and pre-stenotic dilation with no clear cutoffs. Few studies directly compared imaging features with histologic or endoscopic gold standards, limiting evaluation of diagnostic accuracy. Meta-analyses were not conducted due to methodological heterogeneity of grading fibrosis across studies. In addition, statistical heterogeneity of sensitivity, specificity, and accuracy of colonic stricture diagnoses was limited by pooling with small bowel strictures in the studies. Conclusion This systematic review highlighted the absence of standardized definitions for diagnosing colonic Crohn’s disease strictures, particularly on diagnostic imaging, and the limited data distinguishing inflammatory from fibrotic components. Bowel wall thickening, luminal narrowing, and pre-stenotic dilation are key features of small bowel strictures, but their relevance to the colon requires further assessment. Establishing standardized definitions for colonic strictures that incorporate both endoscopic and imaging modalities is essential to advancing the field. Conflict of interest: Dr. Lu, Cathy: Advisory board - Abbvie, Johnson and Johnson, Takeda, Ferring, Merck, Celltrion, Lilly, Pfizer, Pendopharm, Agomab. Research Funding - Abbvie, Helmsley Charitable Trust, Alberta Innovates Dhaliwal, Ravdip: No conflict of interest Kellar, Amelia: No conflict of interest Rowan, Catherine: No conflict of interest St-Pierre, Joelle: Consultant for Pfizer, Abbvie, Eli Lilly and Pendopharm, and speaker for Takeda. Ernest-Suárez, Kenneth: Consulting/Advisory Board fees: Abbvie, AstraZeneca, Johnson & Johnson, Pfizer, Ferring, Sandoz, SatisfAI, Takeda O’Brien, Maureen: No conflict of interest Rosentreter, Ryan: No conflict of interest Gulhati, Vishrut: No conflict of interest Baker, Mark: No conflict of interest Bettenworth, Dominik: DB is on the advisory board or consultant for AbbVie, Amgen, Arena, Atheneum, BNG Service GmbH, Bristol Myers Squibb, CED-Service GmbH, Celltrion, Doctorflix, DGVS, Diaplan, Else Kröner-Fresenius Foundation, Falk Foundation, Galapagos, Guidepoint, Impulze, Ferring, Janssen Cilag, Lilly, Medical Tribune, MedTriX, MSD, Mylan, Onkowissen, Pharmacosmos, Pfizer, Roche, Sandoz, Takeda, Tetrameros, Thieme, Tillotts Pharma, UCB Biopiharma, Viatris and Vifor Pharma. Bruining, David: Advisory board fees from Janssen Bari, Dane: Grant from Helmsley Charitable Trust speaker honorarium from Siemens Healthineers support for attending meetings or travel from Siemens Healthineers member of the Olympus advisory board co-chair Society of Abdominal Radiology (SAR) Inflammatory Bowel Disease Disease Focused Panel (IBD DFP) and SAR Photon-Counting Detector CT Emerging Technology Commission and chair of the Society for Advanced Body Imaging Scientific Committee. Dillman, Jonathan: Grants from Philips Healthcare, GE HealthCare, Motilent, Perspectum, Guerbet, and Bracco. El Ouali, Sara: Speaker and/or consulting fees from Takeda, Eli Lilly, Janssen, Abbvie. Fletcher, John: Grant supports from Siemens Healthineers Gordon, Ilyssa: Grants to institution from Morphic Therapeutics, Alimentiv, Pliant Therapeutics, and UCB patent pending with Case Western Reserve University on radiomics signatures Jairath, Vipul: Consulting Fees: Abbvie, Alimentiv, Amgen, Anaptys Bio, Asahi Kasei, Asieris, Astra Zeneca, Attovia, Blackbird Labs, BMS, Boehringer Ingleheim, Biomebank, Caldera, Calluna, Catalytic Health, Celltrion, Ensho, Enthera, Exeliome Biosciences, Ferring, Fresenius Kabi, Gilead, Granite Bio, GSK, Janssen, Lilly, Merck, Mountainfield, MRM Health, Nxera, Organon, OSE Immunotherapeutics, Pendopharm, Pioneering Medicine, Pfizer, Prometheus, Roche/Genentech, Sanofi, SCOPE, Shattuck Labs, Sorriso, Spyre, Synedgen, Takeda, Teva, Tillotts, Union Therapeutics, Ventus, Ventyx, Vividion, Xencor, Zealand Pharma. Feagan, Brian Gordon: Consulting Fees: AbbVie, Abivax, Adaxion, Adiso, AgomAB Therapeutics, Akros, Alira Health, Ally Bridge Group, Apini Therapeutics, Argenx, Attovia Tx, Avoro Capital Advisors, Belmore Law, Biora Therapeutics, Blackbird Laboratories, Boehringer-Ingelheim, BMS, Boxer Capital, Celgene/BMS, Clarivate, Connect Biopharm, EcoR1, Eli Lilly, Ensho Therapeutics, Equillium, Evida, Enveda, Evommune Inc. Faes Farma, First Wave, Forbion, Galapagos, Genentech/Roche, General Atlantic, Genesis Therapeutics, Gerson Lehrman Group, Gilead, Guidepoint, Imhotex, ImiDomics, Immunic Therapeutics, Janssen, Japan Tobacco Inc., LifeMine Therapeutics, Mage Biologics, Merck, Mirador Therapeutics, Mobius Care, Monte Rosa Tx, Morphic Therapeutics, Nimbus Therapeutics, Novartis, Nxera, OncoC3, Palisade Bio, Pendopharm, Pfizer,Q32 Bio, REDX, Roche, Sanofi, Sobi, Sorriso, Spyre Therapeutics, Sun Pharma, Surrozen Inc., Synedgen, Takeda, Tegus Inc., Teva, Tillotts, Trex Bio, TR1X Inc. TVM Lifesciences, Ventyx Biosciences, Versant Ventures, Vida Ventures, Ysios Capital, Zagbio Stock Shareholder: Connect Biopharm, EnGene, Evida, SRT, Imidomics, Enveda Rieder, Florian: Personal Fees: Adiso, Adnovate, Agomab, Allergan, AbbVie, Arena, Astra Zeneca, Boehringer-Ingelheim, Celgene/BMS, Celltrion, CDISC, Celsius, Cowen, Ferring, Galapagos, Galmed, Genentech, Gilead, Gossamer, Granite, Guidepoint, Helmsley, Horizon Therapeutics, Image Analysis Limited, Index Pharma, Landos, Jannsen, Koutif, Mestag, Metacrine, Mopac, Morphic, Organovo, Origo, Palisade, Pfizer, Pliant, Prometheus Biosciences, Receptos, RedX, Roche, Samsung, Sanofi, Surmodics, Surrozen, Takeda, Techlab, Teva, Theravance, Thetis, UCB, Ysios, 89Bio

Abstract Background Small bowel fibrostenotic strictures are common in patients with Crohn’s disease (CD). No global consensus recommendations on definitions, diagnosis and clinical management are available. Methods Several systematic reviews followed by a RAND/University of California Los Angeles appropriateness study on the definitions, diagnosis and clinical management of fibrostenosing CD in clinical practice were performed. A panel of 28 global experts and a patient representative were convened. They assessed a total of 152 candidate items. The items were subsequently evaluated for appropriateness. Results No accurate predictive biomarkers are available for naïve or anastomotic fibrostenosing strictures. Accurate diagnosis of fibrostenosing CD requires cross-sectional imaging which should evaluate bowel wall thickness, luminal narrowing and prestenotic dilatation. A potential inflammatory component should be assessed. Abdominal cross-sectional imaging was considered necessary prior to any treatment decision. The panel proposed an approach to medical, endoscopic, and surgical therapies (Figure 1 and Table 1). Technical characteristics for endoscopic balloon dilation and follow up strategies after successful dilation therapy were identified. Appropriateness, types and performance of different surgical approaches in various settings were evaluated. Conclusion This global consensus provides clinical guidance for the diagnostic and therapeutic management of patients with fibrostenotic CD.