thrombi Flashcards
Morphology of Thrombi
1) arterial or cardiac at sites of
2) venous at sites of
1) Arterial or cardiac at sites of endothelial injury or turbulence
2) Venous at sites of stasis
Thrombi are focally attached to?
underyling vasculature
Thrombi propagate toward the heart in what direction?
1) arterial grow in a retrograde direction
2) venous grow in the direction of blood flow
what causes the risk of embolus formation?
The propagating portion of a thrombi is poorly attached to the underlying vasculature
Lines of Zahn
■ Concentric layers of platelets and fibrin alternating with RBCs.
■ Only noted in thrombi that form in flowing blood.
Mural thrombus occurs in the?
heart chamber or aortic lumen
Cardiac mural thrombus etiologies include?
abnormal cardiac contraction (MI, dilated cardiomyopathy) and endomyocardial injury (catheter trauma)
Aortic thrombi may result from ulcerated?
atherosclerotic plaques and aneurysms
Arterial thrombi are relatively rich in?
platelets
Arterial thrombi are often superimposed on?
ruptured atheroscelerotic plaques
Arterial thrombi may lead to?
cardiac or cerebral infarction
Venous thrombi may result in the formation of?
emboli
Venous thrombi often result from increased activation of?
coagulation factors
Venous thrombi mostly occur in?
veins of the lower extremities
what are the 4 steps to the cycle “fate” of thrombus?
1) propagation
2) Embolization
3) Dissolution
4) Organization and recanalization
define thrombus propagation
Enlargement by the addition of platelets and fibrin
define thrombus Embolization
Part or all is dislodged and transported to a distant site in the vasculature
define thrombus Dissolution
A new thrombus may be dissolved via fibrinolytic factors
define thrombus Organization and recanalization?
Older thrombi organized via the ingrowth of endothelial cells, smooth muscle cells, and fibroblasts. Later, formation of capillary channels within the thrombus. May incorporate into the wall of the remodeled vessel
what is often associated with varicose veins?
Superficial (saphenous veins) or
deep veins of the leg
**Rarely embolize, may be painful.
Superficial (saphenous veins) or Deep venous thromboses (DVTs) more at risk to embolism?
Deep venous thromboses (DVTs)
Deep venous thromboses (DVTs) occur in?
the larger leg veins at or above the knee. **Higher risk to embolize. May cause local pain and edema.
Lower Extremity DVTs are associated with?
stasis and hypercoagulable states
Lower Extremity DVTs predisposing factors
CHF, bed rest, immobilization, age
Lower Extremity DVTs do what with trauma, surgury and burns?
Immobilize, vascular injury, procoagulant release, increase hepatic synthesis of coagulation factors, decrease t-PA production
Pregnancy, tumor-associated procoagulant release is associated with what type of thrombi
Lower Extremity DVTs
