Thrombosis - Pathophysiology

Question 1

What is virchows triad?

Answer 1

3 factors that cause a thrombus to form:

• A defect in blood vessel wall
• A change in blood constituents
• A change in the pattern of flow

The 3 are very linked and contribute to eachother. E.g. An atheroma (vessel wall change) causes turbulent flow (pattern of flow) which strips away the endothelial lining (defect in vessel wall) exposing the highly thrombolytic plaque contents (change in blood constituents).

Question 2

What are the changes in flow pattern that contribute to thrombosis?

Answer 2

Stasis or Turbulent flow

Question 3

What changes to the vessel wall lead to thrombosis?

Answer 3

A ruptured atheromatous plaque or endothelial injury

Question 4

What changes to the blood constiuents allows thrombosis?

Answer 4

Hypercoagulability (can be post traumatic)
Hyperhcholesterolaemia (often pour out of a ruptured atheroma)
Hyperviscosity

Question 5

What are lines of Zahn?

Answer 5

Alternating bands in a thrombus due to the layout of platelets fibrin and RBCs

Question 6

What are the common consequences of a thrombus?

Answer 6

An ACS
A DVT
Ischaemic Limb Disease
Stroke

Question 7

What are the 4 outcomes of thrombosis?

Answer 7

Resolution - Everything heals over as intended
Organisation - Granulation & scarring over the site of the thrombus
Death (if it blocks a particularly important artery)
Propagation (Emboli break off and block distal vessels)

Question 8

What are the common sources of an arterial thromboembolism?

Answer 8

Mural thrombus (within the heart)
Aortic Aneurysm
Atheromatous Plaque
Valvular Vegetation

Question 9

Pop Quiz Time! Can you name 11 types of emboli? You get a sweety for every one you get right! But for every one you get wrong you have to listen to a kanye song….

Answer 9

ARTERIAL/SYSTEMIC
VENOUS
AIR - head/neck wounds, surgery, Central Venous (CV) lines
GAS - Decompression Sickness, N2 bubbles lodge in capillaries
FAT - Post major fracture
TUMOUR - Method of tumour spread
TROPHOBLAST
SEPTIC MATERIAL- e.g. in infective endocarditis
AMNIOTIC FLUID - Cause of collapse +/- death in childbirth
BONE MARROW - Due to fractures, often following CPR
FOERIGN BODIES - Cannulae, sutures etc