Thrombosis & Embolism Flashcards
Define thrombosis
Formation of a solid mass of blood within the circulatory system
Why does a thrombosis occur?
Abnormal vessel wall = atheroma, direct injury, inflam.
Abnormal blood flow = stagnation, turbulence.
Abnormal blood components = smokers, post-partum, post-op.
How does the appearance of an arterial vs venous thrombus vary?
A = pale, granular, lines of Zahn, lower cell content.
V = soft, gelatinous, deep red, higher cell content.
What is Virchow’s triad?
three broad categories of factors that are thought to contribute to thrombosis =
Hypercoagulability,
Hemodynamic changes (stasis, turbulence),
Endothelial injury/dysfunction
Explain thrombosis resolution
Complete dissolution of thrombus, fibrinolytic system active, blood flow re-established
Explain thrombosis propagation
progressive spread of thrombosis
Explain thrombosis organisation
repair, ingrowth of fibroblasts and capillaries, but lumen remains obstructed
Explain thrombosis recanalization
through organisation 1 or more channels are formed = blood flow re-established but usually incompletely
Outline how a thrombosis can turn into an embolism
part of the thrombus breaks off, travels bloodstream, lodges at distant site
What are the arterial effects of a thrombosis vs the venous effects?
A = ischemia, infarction, depends of site and collateral circulation.
V = congestion, oedema, ischemia, infarction
Define embolism
Blockage of blood vessel by solid, liquid or gas at a site distant from its origin
What do nearly all thrombo-emboli present as?
From systemic veins pass to lungs = pulmonary emboli
Other than pulmonary where can thrombo-emboli come from?
From heart, pass via aorta to renal, mesenteric, other arteries.
From atheromatous carotid artery to the brain.
From atheromatous abdominal aorta to arteries of legs
Outline the predisposing factors to DVT
Immobility, post-op, preg/post-partum, oral contraceptives, severe burns, cardiac failure, disseminated cancer
How is a DVT treated?
IV heparin, oral warfarin
