Microvascular thrombosis: a serious and deadly pathologic process in multiple diseases

Much of our understanding of the pathogenesis of thrombosis has long been based on observations made on large blood vessels. Nevertheless, there has been a recent shift in our attention to the microvasculature and to how microcirculatory occlusion affects function of various organs in diseases. This article provides an overview of microthrombosis in small blood vessels, with discussion of the progressive stages of its development. The initial event is triggered by a variety of diseases, followed by a second phase when multiple contributory factors amplify the process with the final phase of microvascular occlusion and microvascular thrombosis. The outcome is either recovery or injury to the affected organ. If the process is generalized, it is often associated with catastrophic or fatal outcomes. Our current knowledge of the major role of contributory factors leads to a new paradigm. A therapeutic approach limited to a single target of the underlying pathogenic factor, such as the use of anticoagulants, is insufficient and too often unsuccessful. Simultaneous management of all the contributory factors should therefore be considered.