Multicenter Retrospective Study From 5 Hemostasis Treatment Centers in Western France: Severe Hemorrhagic Treated Occurrences' Patterns and Global Substitutive COagulation Factors THerapy in the Inherited Von WILLebrand Disease

von Willebrand Disease (vWD) represents the most common autosomal inherited bleeding disorders with a prevalence up to 1%; nevertheless the clinical relevant patients represent only 0.01% of the population.

vWD is caused by a deficiency and/or abnormality of von Willebrand factor (VWF), inhibiting a satisfactory hemostasis. vWD is usually classified into three main types according to quantitative (Types 1 and 3) or qualitative (Types 2A, 2B, 2M, 2N) deficiencies. Type 3 patients have the highest bleeding risk, type 2 patients are intermediate and type 1 patients have the lowest bleeding risk. Beyond the typology, VWF levels, and therefore the hemorrhagic exposition, are also notably influenced by physiological (age, exercise, pregnancy, gene mutations) or pathological (inflammation and cancer) variables. Furthermore, blood group plays a major role in plasma VWF levels; in fact they are 25%-35% lower in type-0 individuals than in non-0. As a result, the clinical and biological identification of vWD can be extremely challenging and may lead to a delay in the diagnosis.

In vWD, the clinical manifestations are essentially mucosal bleeding symptoms. Epistaxis, menorrhagia, easy bruising, gingival bleeding are flagrant manifestations of the disease and, despite the mostly small somatic impact in the majority of patients; they may significantly affect the quality of life. Nevertheless, severe affected patients may face upper consequences: gastrointestinal (GI) bleeding may be particularly frequent and difficult to manage, and they are as well at high risk to develop major and life-threatening bleeds after surgical procedures, even after minor ones such as tooth extraction.

To guarantee the best medical care management, VWD patients are followed in specialized rare disease centers, both for the ambulatory follow-up and the hospitalizations & outpatient aftercare. These hospital structures are the only ones authorized to prescribe and dispense in- & outpatients' substitutive treatments.

Indeed, the optimal effective treatment of the disorder is the replacement of VWF by using VWF concentrate obtained by fractionation of human plasma; in emergency, recombinant or plasma-derived factor VIII (FVIII) can be added to the VWF. In case of history of inhibitors, high dose of FVIII or by-passing agents can also be used. The current treatment for vWD involves intravenous injections of VWF that are either given on demand in response to a bleeding event or as a prophylactic therapy that is administered 2 to 4 times a week. Numerous studies have shown the efficacy of prophylactic therapy in severe patients, but the investigators lack data about surgery procedures and perioperative management. Moreover, regardless of the small amounts of patients, those treatments remain quite costly and may represent an economic burden for the Assurance Health System.