S4743 Refractory Gastrointestinal Bleeding Secondary to Angiodysplasia in the Setting of Acquired Von Willebrand Syndrome

Introduction: Bleeding from arteriovenous malformations (AVMs) in the small intestine accounts for approximately 5%–10% of all gastrointestinal bleeding cases. When bleeding is recurrent, severe, and refractory to standard endoscopic or interventional treatments, an underlying hematologic disorder should be considered. Acquired von Willebrand syndrome (aVWS) is a rare bleeding disorder linked to lymphoproliferative, autoimmune, and cardiovascular disease. Despite its clinical importance, particularly in treatment-resistant gastrointestinal bleeding associated with angiodysplasia, aVWS is frequently underdiagnosed due to its subtle symptoms and overlap with more common causes of anemia and bleeding. Here, we present a case of recurrent gastrointestinal bleeding from angiodysplasia, ultimately attributed to aVWS. Case Description/Methods: A 68-year-old man with a longstanding history of iron deficiency anemia and recurrent melena presented with severe acute-on-chronic anemia. Over the course of 4 years, extensive GI evaluations, including endoscopies, capsule endoscopy, and computed tomography angiography, failed to identify active bleeding. Despite iron therapy and transfusions, symptoms persisted. Repeat capsule endoscopy revealed both bleeding and non-bleeding AVMs in the jejunum. These lesions were treated endoscopically with argon plasma coagulation (APC) and mechanical clipping. Post-procedure, however, the patient had multiple readmissions for ongoing blood loss anemia. Given the recurrence despite treatment, a hematologic cause was suspected. Coagulation studies confirmed aVWS. Treatment with desmopressin (DDAVP) led to symptom improvement and stabilized hemoglobin levels. Discussion: This case highlights the link between refractory GI bleeding from angiodysplasia and acquired bleeding disorders like aVWS. Endoscopic therapy such as APC is the first-line treatment for accessible lesions, with mechanical hemostasis for refractory cases. Continued bleeding despite these measures should prompt investigation for coagulopathies. aVWS involves qualitative or quantitative defects in von Willebrand factor, causing mucocutaneous and GI bleeding. In this patient, a poor response to endoscopic therapy raised suspicion for aVWS, which was confirmed and explained the bleeding severity. Desmopressin, which promotes the release of von Willebrand factor and factor VIII, improved bleeding. Early recognition and management of aVWS can decrease morbidity and transfusion needs, so clinicians should suspect it in refractory GI bleeding cases.