Congenital and acquired disorders of primary hemostasis

Abstract

Hemostasis depends on a large number of interdependent processes to prevent spontaneous bleeding and to stop hemorrhage when vascular injury occurs. Although it is commonly divided into primary and secondary for the purpose of simplification and patient evaluation, both processes occur almost simultaneously in vivo. Primary hemostasis describes the interaction of blood vessels with platelets, including the central role of von Willebrand factor (VWF). In this review, we describe the most common congenital abnormalities of primary hemostasis except for those that relate to blood vessels or are manifested purely with thrombocytopenia: von Willebrand disease (VWD), defects of platelet receptors, and storage pool deficiencies. While congenital abnormalities of primary hemostasis are not rare, bleeding due to acquired defects in platelet function are a lot more prevalent. Conditions discussed in this review include drug-induced, liver and renal disease, malignancy and mechanical intravascular devices. Combined, the latter affect a large percentage of hospitalized patients, whose effective evaluation and management depend on proper utilization of laboratory testing (when available) and current treatment options. In every section, we briefly include background, pathophysiology, diagnosis, and treatment with relevant references to give the reader the opportunity to seek more details in the literature. We have also created tables to aid in the presentation of the information, and a figure prepared specifically for this publication highlighting the various steps of the platelet plug formation.