Early transfusion of factor VIII/von Willebrand factor concentrates seems to be effective in the treatment of gastrointestinal bleeding in patients with von Willebrand type III disease

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

BACKGROUND

Qualitative or quantitative defects of von Willebrand factor (VWF) such as in von Willebrand disease (VWD) are associated with vascular abnormalities, especially in the gastrointestinal (GI) tract. However, the locations, extent, and natural history of vascular abnormalities in patients with VWD is not well understood. To summarize the existing literature on the topic, we conducted a scoping review of vascular abnormalities in patients with VWD.

METHODS

We searched MEDLINE and EMBASE from inception to September 1, 2020, for studies clinically describing vascular abnormalities in VWD patients. Screening and data extraction was completed independently and in duplicate and each abnormality was documented individually.

RESULTS

After screening, 54 studies that reported patient level data comprising 146 patients were included. Type 2A (39%) and type 3 (14.4%) were the most common VWD subtypes. The most common site of vascular malformation was the GI tract, occurring in 124 patients (84.9%), whereas 18 (12.3%) had non-GI vascular abnormalities and 4 (2.7%) had both GI and non-GI vascular abnormalities. With respect to outcomes, the clinical course was not specified in the majority (55.5%) of patients. Survey and population level data were reported in nine studies, demonstrating vascular abnormalities occurred at higher rates in VWD and that VWD patients are overrepresented among those with those abnormalities.

CONCLUSION

Vascular malformations in patients with VWD occur primarily in the gastrointestinal tract. Type 2A and type 3 VWD are the most common subtypes affected. The clinical treatment and natural history of these abnormalities remains understudied and further research is needed.

Abnormal angiogenesis in blood outgrowth endothelial cells derived from von Willebrand disease patients

: Bleeding associated with angiodysplasia is a common, often intractable complication in patients with von Willebrand disease (VWD). von Willebrand factor (VWF), the protein deficient or defective in VWD, is a negative regulator of angiogenesis, which may explain the pathologic blood vessel growth in VWD. This study explores the normal range of angiogenesis in blood outgrowth endothelial cells (BOECs) derived from healthy donors and compares this to angiogenesis in BOECs from VWD patients of all types and subtypes. BOECs were assessed for VWF and angiopoietin-2 (Ang-2) gene expression, secretion, and storage. To explore angiogenic potential, we characterized cellular proliferation, matrix protein adhesion, migration, and tubule formation. We found great angiogenic variability in VWD BOECs with respect to each of the angiogenesis parameters. However, type 1 and 3 VWD BOECs had higher Ang-2 secretion associated with impaired endothelial cell migration velocity and enhanced directionality. Type 2A and 2B BOECs were the most proliferative and multiple VWD BOECs had impaired tubule formation in Matrigel. This study highlights the angiogenic variability in BOECs derived from VWD patients. Abnormal cell proliferation, migration, and increased Ang-2 secretion are common features of VWD BOECs. Despite the many abnormalities of VWD BOECs, significant heterogeneity among individual VWD phenotypes precludes a simple description of relationship between VWD type and in vitro surrogates for angiodysplasia.

Gastrointestinal angiodysplasia and bleeding in von Willebrand disease

Von Willebrand disease (VWD), the most common genetic bleeding disorder, is characterised by a quantitative or qualitative defect of von Willebrand factor (VWF). Patients with VWD suffer from mucocutaneous bleeding, of severity usually proportional to the degree of VWF defect. In particular, gastrointestinal bleeding associated with angiodysplasia is often a severe symptom of difficult management. This review focuses on the pathophysiology, diagnosis and treatment of VWD-associated gastrointestinal angiodysplasia and related bleeding.

Angiodysplasia in von Willebrand Disease: Understanding the Clinical and Basic Science

Severe and intractable gastrointestinal bleeding caused by angiodysplasia is a debilitating problem for up to 20% of patients with von Willebrand disease (VWD). Currently, the lack of an optimal treatment for this recurrent problem presents an ongoing challenge for many physicians in their management of affected patients. Over the past few years, studies have pointed to a regulatory role for the hemostatic protein, von Willebrand factor (VWF), in angiogenesis, providing a novel target for the modulation of vessel development. This article will review the clinical implications and molecular pathology of angiodysplasia in VWD.

High variation in treatment strategies for gastrointestinal angiodysplasias

OBJECTIVE

Angiodysplasias (ADs) are the second leading cause of gastrointestinal bleeding in the elderly. The impact extends from no symptoms to chronic anaemia. Treatment guidelines are lacking. The aim of this study was to assess the current practice of gastrointestinal ADs and explore possible new research areas. On the basis of existing evidence, we would like to propose a treatment algorithm.

METHODS

We administered a 19-item web-based survey to gastroenterologists in the Netherlands between February and April of 2015.

RESULTS

A total of 111 (response rate 28%) gastroenterologists completed the survey (mean age=47 years; 24% women). The respondents identified Von Willebrand disease (17%), chronic kidney disease (21%) and aortic stenosis (77%) as risk factors for the development of ADs. Colonoscopy (54%) and esophagogastroduodenoscopy (43%) were the preferred first tools to screen for ADs. The favoured (77%) first treatment option is endoscopic argon plasma coagulation, whereas 20% start iron supplementation or blood transfusions. Treatment strategy is mostly (65%) based on the location of the ADs. Small bowel ADs are considered the most difficult to treat, because of the need for balloon enteroscopy. Of the gastroenterologists, 13% would treat ADs as a coincident finding during endoscopy. Medical therapy is mostly started in refractory ADs, and thalidomide (40%) is preferred over octreotide (19%). Thalidomide is more preferred by gastroenterologists working in a teaching hospital.

CONCLUSION

Identification of risk factors and treatment of ADs vary widely between gastroenterologists in the Netherlands. Further research is needed to create an evidence-based guideline and thereby optimize the management of symptomatic ADs.

Treatment of gastrointestinal angiodysplasia and unmet needs

BACKGROUND

Gastrointestinal angiodysplasia (GIAD) may either be asymptomatic or induce overt or obscure bleeding with a high risk of recurrence. Numerous therapeutic options are available but evidence bases are lacking.

AIM

We conducted a comprehensive review of pharmacological and endoscopic treatments for previous or active bleeding GIAD and established the unmet needs of the clinicians.

METHODS

Clinical trials, series, and reports, having been selected through PubMed inquiry, manual searching, and reference list reviewing, were classified by levels of evidence.

RESULTS

Controlled studies focusing on GIAD treatment, excluding other GI vascular malformations, are rare. Endoscopic destruction, preferably using non-contact endoscopic techniques, is most often proposed as a first-line treatment for GIAD (expert level). In addition, APC is preferred over Nd:Yag laser due to the lower risk of perforation (expert level). Pharmacological treatments for GIAD are considered either when endoscopy fails to access the AD or in order to prevent rebleeding for "chronic bleeding patients." Octreotide and oestroprogestative treatments are the best evaluated drugs; however, no appropriate comparison on cost-effectiveness and tolerance has been performed.

CONCLUSIONS

The most effective therapeutic strategy for bleeding GIAD is currently inconclusive, and new trials should be performed to address unmet needs.

Pharmacological therapy of vascular malformations of the gastrointestinal tract

Vascular malformation (AVM) in the gastrointestinal tract is an uncommon, but not rare, cause of bleeding and iron deficiency anemia, especially in an aging population. While endoscopic coagulative therapy is the method of choice for controlling bleeding, a substantial number of cases require additional therapy. Adjunctive or even primary phamacotherapy may be indicated in recurrent bleeding. However, there is little evidence-based proof of efficacy for any agent. The bulk of support is derived from anecdotal reports or case series. The present review compares the outcome of AVM after no intervention, coagulative therapy or focus on pharmacological agents. Most of the literature encompasses two common AVMs, angiodysplasia and hereditary hemorrhagic telangiectasia. Similarly, the bulk of information evaluates two therapies, hormones (estrogen and progesterone) and the somatostatin analogue octreotide. Of these, the former is the only therapy evaluated in randomized trials, and the results are conflicting without clear guidelines. The latter therapy has been reported only as case reports and case series without prospective trials. In addition, other anecdotally used medications are discussed.

Small Bowel Angiodysplasia Associated with von Willebrand's Disease: Report of a Case

The association between angiodysplasia (AD) and von Willebrand's disease (vWD) was first described by Quick in 1967. The clinical course of patients with vWD and AD is characterized by multiple admissions to hospital for gastrointestinal bleeding, necessitating transfusions of packed red cells, factor VIII, and von Willebrand factor concentrates. The therapeutic management of these patients is difficult. Both medical and endoscopic techniques have been tried, but no treatment modality has been completely successful. We describe the clinical course of a patient affected by vWD, who suffered repeated massive gastrointestinal bleeding caused by small bowel AD. Intestinal resection was the only effective treatment, resulting in complete remission of the gastrointestinal bleeding.

Advances in the therapy of von Willebrand disease

von Willebrand disease (vWD) is a very common autosomal inherited bleeding disorder, caused by a quantitative deficiency or a qualitative structural defect of von Willebrand factor (vWF). Two main therapeutic options are available for the treatment of spontaneous bleeding episodes and for prevention of bleeding: desmopressin (DDAVP) and replacement therapy with plasma products. DDAVP is the treatment of choice for most patients with type 1 vWD. In patients with the type 3 disease and in most subjects with type 2 disease, DDAVP alone is ineffective or contraindicated, and it is usually necessary to switch to plasma concentrates containing both factor VIII (FVIII) and vWF. Concentrates subjected to virucidal treatment (e.g. solvent/detergent treatment) during manufacture should always be used in preference to cryoprecipitate. A recombinant vWF concentrate is now undergoing preclinical development and preliminary data suggest it possesses good haemostatic function and may correct the bleeding in vWD after its administration in several animal models. Although treatment of vWD is relatively simple (assuming access to even basic laboratory facilities), actual diagnosis is often far from straightforward, and the patients should be well characterized phenotypically to tailor the treatment to the different types and subtypes of the disease. It is probably wise to refer samples for the characterization to expert laboratories.