Thrombosis and Embolism

Question 1

Virchows triad

Answer 1

Change in flow - i.e. stasis post op, bed-ridden
Change in vessel - e.g. atheroma, aneurysms
change in constituency of blood - hypercoag. post injury/surgery.

Question 2

Outline thrombus development

Answer 2

1.Cause of denudation of intima - turbulent blood flow due to atheroma, endothelial injury
“dumping”/aggregation of platelets and fibrin

2. Denudation exposes collagen, allows aggregation of fibrin/platelets forming mesh network, traps RBC’s, forming lines of Zahn.
3. Further turbulent flow and propagation.

Question 3

Outcomes of thrombosis

Answer 3

Resolution
Recanalisation
ischemia/infarction
Embolism

Question 4

List the different types of embolism

Answer 4

Thrombo-embolism from artery (ie. atheroma) or DVT
Septic emboli - rupture of abscess, bronchiectasis, IVDA
Vegetative emboli from heart valve
Air emboli/gas emboli - result of injection, or “the bends”
Fat/marrow emboli - result of major trauma or fracture
Tumour - invasion
Foreign body - cannula, stitches
Amniotic fluid - sudden MI/massive PE during/after childbirth

Question 5

List risk factors for thrombosis and embolism

Answer 5

hypertension, atherosclerosis, 
stasis due to aneurysm or bed ridden
Trauma - surgery, severe burns, major fracture
Use of OC
IVDA
Previous DVT or MI
Malignancy
Severe infection - pneumonia, bronchiectasis, TB.