Vascular abnormalities in patients with von Willebrand disease: A scoping review

Retrospective chart review of GI bleeding in people with von Willebrand disease

INTRODUCTION

Gastrointestinal (GI) bleeding events (BEs) in von Willebrand disease (VWD) are difficult to diagnose and often recurrent. Limited data from clinical trials has led to lack of consensus on treatment options.

AIM

Describe current treatments and outcomes for GI BEs in people with VWD.

METHODS

This retrospective, observational, multicentre chart review study was conducted from January 2018 through December 2019 and included patients with inherited VWD with ≥1 GI BE in the preceding 5 years. Baseline characteristics, number and aetiology of BEs, associated GI-specific morbidities/lesions, treatment and outcomes were analysed descriptively.

RESULTS

Sixty bleeds were reported in 20 patients with type 1 (20%), type 2 (50%) and type 3 (30%) VWD. During the 5-year study period, 31 (52%) BEs had one identified or suspected cause; multiple causes were reported in 11 (18%). Most GI BEs (72%) were treated with a combination of von Willebrand factor (VWF), antifibrinolytics and/or other haemostatic or non-haemostatic treatments. Time to resolution did not differ by VWF treatment use; however, BEs treated with non-VWF treatments tended to resolve later. In patients with GI-specific morbidities/lesions, 84% resolved with first-line treatment; time to resolution tended to be longer than in patients without such morbidities/lesions. Thirteen BEs occurred in patients receiving prophylaxis and 47 in patients receiving on-demand treatment; 18 BEs resulted in a switch to prophylaxis after bleed resolution.

CONCLUSIONS

This study confirms the unmet need for the management of recurrent GI BEs in people with VWD and the need for prospective data, especially on prophylaxis.

What can historical literature on von Willebrand disease teach us?

Dr Erik von Willebrand first described a family with bleeding symptoms in a Finnish publication in 1926. A closer look at this landmark publication sheds light on some pathophysiological aspects of von Willebrand disease that may be applicable even in the current era. We attempt to relay in this article how the teachings from this original description may provide a benchmark for further research in this condition.

Colon cancer surgery in von Willebrand disease type 3 setting triggering vascular abnormalities on bowel anastomosis

Background

von Willebrand disease (VWD) is associated with vascular malformations in the gastrointestinal tract. This complication, more frequent in VWD types 2A and 3, may be due to abnormal angiogenesis, but the precise mechanism is still unclear. Angiogenesis and inflammation are closely linked and can potentiate each other.

Key Clinical Question

Can colon inflammation in the setting of cancer surgery potentiate angiogenesis in the VWD setting?

Clinical Approach

A woman with VWD type 3 underwent partial colectomy twice for an adenocarcinoma. After managing the first surgery with a plasma-derived von Willebrand factor (VWF) concentrate (Wilfactin; LFB), refractory gastrointestinal bleeding occurred from neovessels on bowel anastomosis. After a multidisciplinary discussion, a second surgery was undertaken with a recombinant VWF concentrate (Veyvondi; Takeda Pharmaceuticals). Pathologic neovessels were again observed on the new anastomosis.

Conclusion

Colectomy was complicated twice by pathologic neovessels on bowel anastomosis in 2 distinct procedures managed either with plasma-derived VWF or with recombinant VWF.

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.

Anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia: A scoping review

INTRODUCTION

Data describing safety and tolerability of anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia (HHT), the second-most-common inherited bleeding disorder, is limited.

METHODS

We performed a scoping review, searching MEDLINE and EMBASE from inception to March 2023 for eligible studies reporting detailed clinical data describing antithrombotic use in HHT. Data extracted included study design, patient population, and characteristics and outcomes of antithrombotic therapy.

RESULTS

Of 625 unique manuscripts identified through database search, 77 were included: 64 case reports/case series describing 65 patients and 13 cohort studies. Data were extracted on a total of 466 patients with HHT, covering 587 episodes of antithrombotic therapy. The most common reasons for antithrombotic therapy were venous thromboembolism (VTE) (44.6 %), atrial arrhythmias (17.8 %) and stroke (10.5 %). anticoagulation was used in in 356 episodes (61.9 %), antiplatelet therapy in 140 episodes (24.3 %), and both together in 50 episodes (8.7 %). Complications of therapy included worsened HHT-associated bleeding (primarily epistaxis and gastrointestinal bleeding) in 198 antithrombotic treatment episodes (38.9 %) and premature antithrombotic therapy discontinuation in 142 episodes (28.9 %). Bleeding-directed therapy (local ablative therapy and systemic therapies) were employed to address worsening bleeding in 14.6 % of episodes. No specific complications of therapy were reported in 322 total antithrombotic events (58.4 %). Rates of bleeding (8.3 % to 80 %), therapy discontinuation (14.3 % to 57.1 %), and other complications ranged considerably from study to study.

CONCLUSION

Current publications vary widely on the outcomes and tolerability of antithrombotics in HHT, but confirm the clinical challenge of adequate antithrombotic therapy in this population. More formal studies are needed to better guide optimal antithrombotic use in HHT.

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.

The Vascular Endothelium and Coagulation: Homeostasis, Disease, and Treatment, with a Focus on the Von Willebrand Factor and Factors VIII and V

The vascular endothelium has several important functions, including hemostasis. The homeostasis of hemostasis is based on a fine balance between procoagulant and anticoagulant proteins and between fibrinolytic and antifibrinolytic ones. Coagulopathies are characterized by a mutation-induced alteration of the function of certain coagulation factors or by a disturbed balance between the mechanisms responsible for regulating coagulation. Homeostatic therapies consist in replacement and nonreplacement treatments or in the administration of antifibrinolytic agents. Rebalancing products reestablish hemostasis by inhibiting natural anticoagulant pathways. These agents include monoclonal antibodies, such as concizumab and marstacimab, which target the tissue factor pathway inhibitor; interfering RNA therapies, such as fitusiran, which targets antithrombin III; and protease inhibitors, such as serpinPC, which targets active protein C. In cases of thrombophilia (deficiency of protein C, protein S, or factor V Leiden), treatment may consist in direct oral anticoagulants, replacement therapy (plasma or recombinant ADAMTS13) in cases of a congenital deficiency of ADAMTS13, or immunomodulators (prednisone) if the thrombophilia is autoimmune. Monoclonal-antibody-based anti-vWF immunotherapy (caplacizumab) is used in the context of severe thrombophilia, regardless of the cause of the disorder. In cases of disseminated intravascular coagulation, the treatment of choice consists in administration of antifibrinolytics, all-trans-retinoic acid, and recombinant soluble human thrombomodulin.

Prophylactic management of patients with von Willebrand disease

Von Willebrand disease, the most common inherited bleeding disorder that affects both males and females, is due to quantitative or qualitative defects of the multimeric glycoprotein von Willebrand factor, which cause mucous membrane bleeding but also soft tissue bleeding owing to the secondary deficiency of factor VIII. The aim of treatment is to correct this dual defect of hemostasis. In addition to the episodic management of bleeding episodes, therapy includes their short- or long-term prevention. Short-term prophylaxis is mainly warranted in order to provide effective hemostatic coverage to patients undergoing surgery or invasive procedures and to affected women at the time of delivery or during menstruations associated with excessive bleeding. The aim of long-term prophylaxis is to prevent bleeding in particular categories of patients at increased risk of frequent and spontaneous bleeding in the joints, nose, and gastrointestinal tract.