Gastrointestinal bleeding in von Willebrand patients: special diagnostic and management considerations.

INTRODUCTION: Severe and recurrent gastrointestinal (GI) bleeding caused by angiodysplasia is a significant problem in patients with von Willebrand disease (VWD) and in those with acquired von Willebrand syndrome (AVWS). At present, angiodysplasia-related GI bleeding is often refractory to standard treatment including replacement therapy with von Willebrand factor (VWF) concentrates and continues to remain a major challenge and cause of significant morbidity in patients despite advances in diagnostics and therapeutics. AREAS COVERED: This paper reviews the available literature on GI bleeding in VWD patients, examines the molecular mechanisms implicated in angiodysplasia-related GI bleeding, and summarizes existing strategies in the management of bleeding GI angiodysplasia in patients with VWF abnormalities. Suggestions are made for further research directions. EXPERT OPINION: Bleeding from angiodysplasia poses a significant challenge for individuals with abnormal VWF. Diagnosis remains a challenge and may require multiple radiologic and endoscopic investigations. Additionally, there is a need for enhanced understanding at a molecular level to identify effective therapies. Future studies of VWF replacement therapies using newer formulations as well as other adjunctive treatments to prevent and treat bleeding will hopefully improve care.

Von Willebrand disease (VWD) is the most common inherited bleeding disorder. It is caused by problems with von Willebrand factor (VWF), a protein in blood that helps stop bleeding. People with VWD either have low levels of VWF or VWF that does not work properly. The disease causes bleeding symptoms in 1 in 1000 individuals. Three main types of VWD exist. Depending on the type, people can have minimal symptoms or serious bleeding that needs hospital care.Patients with severe VWD may often experience repeated bleeding from the gastrointestinal tract. This is usually due to the formation of abnormal fragile vessels (malformations) called angiodysplasia, which have been linked to the absence or abnormal function of VWF. These fragile vessels are very difficult to find and diagnose. At present, available treatments for angiodysplasia, including long-term VWF replacement therapy, are not very effective. As a result, VWD patients with angiodysplasia have a poor quality of life.More research is needed to better evaluate current treatments and explore the contribution of abnormal VWF in the development of angiogenesis and angiodysplasia in VWD which may reveal new targets for treatment.

Lessons Learned from POCUS Instruction in Undergraduate Medicine During the COVID-19 Pandemic.

Point of care Ultrasound (POCUS) has been adopted into clinical practice across many fields of medicine. Undergraduate medical education programs have recognized the need to incorporate POCUS training into their curricula, traditionally done in small groups with in-person sessions. This method is resource intensive and requires sufficient equipment and expertise. These requirements are often cited as barriers for implementation. During the Coronavirus Disease 2019 (COVID-19) pandemic, POCUS education was required to adapt to physical distancing regulations, giving rise to novel teaching methods for POCUS. This article outlines the implementation of a POCUS teaching session before and during the pandemic. It describes how these innovations can scale POCUS teaching and overcome barriers moving forward. A flipped classroom model was implemented for all learners. Learners were given an introductory POCUS module before the scheduled in-person or virtual teaching session. Sixty-nine learners participated in conventional in-person teaching, while twenty-two learners participated in virtual teaching following the pandemic-related restrictions. Learners completed a written test before and following the teaching. In-person learners were assessed using an objective structured assessment of ultrasound skills (OSAUS) pre- and post-learning sessions. A follow-up survey was conducted three years after the teaching sessions were completed. Both in-person and virtual groups demonstrated statistically significant improvement in knowledge scores (p <0.0001). Both groups had similar post-test learning scores (74.2 ± 13.6% vs. 71.8 ± 14.5 %, respectively). On follow-up questionnaires, respondents indicate that they found our online and in-person modes of teaching helpful during their residency. POCUS education continues to face a variety of barriers, including limitations in infrastructure and expertise. This study describes an adapted POCUS teaching model that is scalable, uses minimal infrastructure and retains the interactivity of conventional small-group POCUS teaching. This program can serve as a blueprint for other institutions offering POCUS teaching, especially when conventional teaching methods are limited.

Special considerations in GI bleeding in VWD patients.

Gastrointestinal (GI) bleeding is an important cause of morbidity and mortality in von Willebrand disease (VWD). It has been noted that GI bleeding caused by angiodysplasia is overrepresented in VWD patients compared to other causes. The bleeding from angiodysplasia is notoriously difficult to treat; recurrences and rebleeds are common. A growing body of basic science evidence demonstrates that von Willebrand factor negatively regulates angiogenesis through multiple pathways. VWD is clinically highly associated with angiodysplasia. The predisposition to angiodysplasia likely accounts for many of the clinical difficulties related to managing GI bleeding in VWD patients. Diagnosis and treatment are challenging with the current tools available, and much further research is needed to further optimize care for these patients with regard to acute treatment, prophylaxis, and adjunctive therapies. In this review we provide an overview of the available literature on GI bleeding in VWD and explore the molecular underpinnings of angiodysplasia-related GI bleeding. Considerations for diagnostic effectiveness are discussed, as well as the natural history and recurrence of these lesions and which therapeutic options are available for acute and prophylactic management.