No abstract

reported in 85%-100% of cases 7,10 and fibrostenotic stricture is the most common indication for surgery in CD. 3,9 Surgical resection is related with major morbidity, higher costs, higher risk of unemployment, and poorer quality of life. 3,11,12 Although the introduction of biologics including anti-TNF, anti-integrin, and anti-interleukin (IL) has modified the disease course of CD in the short term, the long-term outcome of those drugs on the development of fibrostenosis and the need for surgery remains to be elucidated. 5 Fibrostenotic strictures were previously considered an inevitable and irreversible consequence of long-term inflammation in CD patients whose conditions are unresponsive to anti-inflammatory therapies. This paradigm has been changing rapidly due to recent advances in our understanding regarding the process of intestinal fibrosis and the introduction of promising candidates for targeted anti-fibrotic therapy. 1 This review aimed to provide a comprehensive overview of fibrostenotic strictures in CD, including mechanisms and factors that predict its progression, as well as diagnosis and treatment strategies. It also introduces promising anti-fibrotic agents for intestinal fibrosis and discuss the obstacles to be overcome in developing clinically available anti-fibrotic agents for CD stricture.

The introduction of biologics such as anti-tumor necrosis factor (TNF) monoclonal antibodies followed by anti-integrins has dramatically changed the therapeutic paradigm of inflammatory bowel diseases (IBD). Furthermore, a newly developed anti-p40 subunit of interleukin (IL)-12 and IL-23 (ustekinumab) has been recently approved in the United States for patients with moderate to severe Crohn’s disease who have failed treatment with anti-TNFs. However, these immunosuppressive therapeutics which focus on anti-inflammatory mechanisms or immune cells still fail to achieve long-term remission in a significant percentage of patients. This strongly underlines the need to identify novel treatment targets beyond immune suppression to treat IBD. Recent studies have revealed the critical role of intestinal epithelial cells (IECs) in the pathogenesis of IBD. Physical, biochemical and immunologic driven barrier dysfunctions of epithelial cells contribute to the development of IBD. In addition, the recent establishment of adult stem cell-derived intestinal enteroid/organoid culture technology has allowed an exciting opportunity to study human IECs comprising all normal epithelial cells. This long-term epithelial culture model can be generated from endoscopic biopsies or surgical resections and recapitulates the tissue of origin, representing a promising platform for novel drug discovery in IBD. This review describes the advantages of intestinal enteroids/organoids as a research tool for intestinal diseases, introduces studies with these models in IBD, and gives a description of the current status of therapeutic approaches in IBD. Finally, we provide an overview of the current endeavors to identify a novel drug target for IBD therapy based on studies with human enteroids/organoids and describe the challenges in using enteroids/organoids as an IBD model.

For the palliation of malignant distal biliary obstruction, endoscopic placement of partially covered SEMSs with anti-migration designs and identical mesh structures to uncovered SEMSs failed to prolong cumulative stent patency or reduce stent migration.