Comprehensive review and update of stricturing Crohn's disease

Up to 50% of patients with Crohn's disease develop a stricture within 10 years of diagnosis. Crohn's strictures can compose of inflammation, fibrosis or smooth muscle expansion and usually a combination of these. There have been numerous new developments in imaging modalities in determining the composition of Crohn's strictures. Magnetic resonance imaging remains the best upfront imaging modality to characterize Crohn's strictures. Gastrointestinal ultrasound (GIUS) has an increasing role in clinical practice, particularly for monitoring stricture response as a treat-to-target tool. Novel imaging techniques to differentiate between fibrosis and inflammatory strictures have been developed including contrast-enhanced GIUS, strain or shear wave elastography with GIUS and multiple new magnetic resonance imaging (MRI) protocols, including diffusion weighted, delayed contrast enhancement and magnetization transfer MR protocols. However, these techniques require further validation and standardization. Regarding therapeutics, anti-tumor necrosis agents with a treat-to-target strategy have the highest quality evidence in treating strictures and can lead to stricture regression in some cases. Endoscopic balloon dilatation remains a mainstay in the treatment algorithm of treating predominantly fibrostenotic Crohn's strictures, particularly those which are symptomatic, < 5 cm in length and not causing prestenotic dilatation. Endoscopic balloon dilatation has greater effectiveness in anastomotic strictures. Surgery remains an important treatment option in Crohn's strictures, with segmental resection and stricturoplasty having their own advantages and disadvantages. Kono-S anastomosis may be superior to conventional anastomosis for endoscopic recurrence; however, further high-quality studies are required to confirm this. Using risk stratification models such as the BACARDI risk model is important to guide management decisions between a medical and surgical approach. Early post-operative medical prophylaxis with an advanced therapy is an important consideration to prevent disease recurrence. This review expands on the above topics, highlights research gaps and provides a suggested investigation and management pathway in stricturing Crohn's disease.