The role of von Willebrand factor in gastrointestinal angiodysplasia and obscure gi bleeding: a narrative review.

چکیده اصلی

OBJECTIVE: Gastrointestinal bleeding (GIB) is a major cause of morbidity in von Willebrand disease (vWD), most commonly resulting from angiodysplasia. Current obscure gastrointestinal bleeding (OGIB) algorithms are primarily anatomy-based and often overlook underlying hemostatic disorders, delaying diagnosis and promoting recurrent bleeding. This review summarizes current evidence on the molecular basis, diagnosis, and management of vWD-associated GIB and proposes a mechanism-oriented diagnostic framework. METHODS: A comprehensive narrative review of experimental, translational, and clinical studies was conducted, focusing on inherited vWD, acquired von Willebrand syndrome (AvWS), gastrointestinal angiodysplasia, endothelial biology, and diagnostic and therapeutic strategies. RESULTS: Deficiency or dysfunction of high-molecular-weight von Willebrand factor (vWF) multimers promotes angiodysplasia by disrupting Weibel-Palade body homeostasis, enhancing Ang-2/Tie2 and VEGF signaling, impairing integrin αvβ3 function, and fostering pro-inflammatory endothelial activation. Genetic and epigenetic modifiers, including FLI1, STXBP5, ABO blood group, and miR-24, further influence vascular susceptibility. Based on these mechanisms, we propose a four-stage diagnostic framework integrating bleeding assessment, platelet function screening, and targeted vWF testing with conventional endoscopic evaluation to facilitate earlier recognition of vWD/AvWS in patients with recurrent or obscure GIB. This strategy supports mechanism-based treatment combining hemostatic replacement therapies with selected anti-angiogenic approaches. CONCLUSION: vWD-associated GIB should be regarded as a systemic vascular-hemostatic disorder rather than an isolated structural gastrointestinal disease. Integrating hemostatic evaluation into OGIB pathways may improve diagnostic accuracy, reduce unnecessary procedures, and enable personalized management of patients with recurrent bleeding.

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