Thrombosis and embolism

Question 1

Thrombosis

Answer 1

Formation of a solid mass of blood within the circulatory system-solid mass then called a thrombus.

Question 2

clot=

Answer 2

clot= mass of blood outside the vessel wall

Question 3

virchows triad explains

Answer 3

how thrombus’ are formed

Question 4

virchows triad

Answer 4

1) hypercoagable state
2) Blood flow stasis (slowing of blood)
3) Endothelial injury

Question 5

atheroma

Question 6

what can cause endothelial damage

Answer 6

atheroma

direct injury

inflammation

Question 7

atrial thrombosis

Answer 7

• Pale
• Granular
• Lines of Zahn
• Lower cell content

Question 8

lines of zahn

Answer 8

are a characteristic of thrombi that appear particularly when formed in the heart or aorta. They have visible and microscopic alternating layers (laminations) of platelets mixed with fibrin, which appear lighter and darker layers of red blood cell

Question 9

Venous thrombus

Answer 9

• Soft
• Gelatinous
• Deep read
• Higher cell content

Question 10

outline thrombosis and fibrinolysis

Answer 10

1. fibringoen is activated to fibrin by thrombin to form platelt plug
2. plasminogen is activated by tPA (tissue plasminogen activator) to plasmin
3. plasmin disintegrates the clot
   4.

Question 11

fibrin degradation products

Answer 11

e.g. D dimers (detected in blood test)

Question 12

outcomes/ complications

Answer 12

1. Lysis
2. Propagate
3. Organise
4. Recanalize
5. embolise

Question 13

1. lysis

Answer 13

• Most likely when thrombi are small
• Complete dissolution of thrombus
• Fibrinolytic system active
• Blood flow re-established

Question 14

2. propagation

Answer 14

• Progressive spread of thrombosis
• Distally in arteries (goes out to the peripheries)
• Proximally in veins (goes more central e.g. heart)

Question 15

3. Organisation

Answer 15

• Reparative process
• Ingrowth of fibroblasts and capillaries (similar to granulation tissue)
• Lumen remains obstructed

Question 16

4. Recanilization

Answer 16

• Blood flow re-established but usually incompletely
• One or more channels formed through organising thrombus

Question 17

5. Embolism

Answer 17

• Part of thrombus breaks off
• Travels through the bloodstream
• Lodges at distant site

Question 18

affect of thrombosis on venous tissue

Answer 18

• Congestion
• Oedema
• Ischaemia
• Infarction

Question 19

Effects of thrombosis on arterial tissue

Answer 19

• ischaemia
• Infarction
• Depends on the site and collateral circulation

e.g. cerebral A, carotid A,coronary A, mesenteric A, renal A, femoral/iliac/ popliteal A

Question 20

coronary artery thrombus

Answer 20

Question 21

histological view of thrombus in coronary A

Answer 21

Question 22

coronary artery thrombus causing MI

Answer 22

Question 23

embolism

Answer 23

Blockage of a blood vessel by a solid, liquid or gas at a site distant from its origin

• >90% of emboli are thrombo-emboli

Question 24

thromboembolism- arteries and veins

Answer 24

• Passes from systemic veins to the lungs- pulmonary thromboembolic
• Pass from the heart pass via the aorta and lodge in the renal mesenteric and other arteries, resulting in bowel ischaemia and renal infarction
• Pass from atheromatous carotid artery to the brain leading to ischaemic stroke
• Pass from atheromatous abdominal aorta to the arteries of the legs leading to acute limb ischaemia

Question 25

other types of embolism

Answer 25

* Air * Amniotic fluid * Nitrogen * Medical equipment * Tumour cells * Fat, bone marrow (bost trauma)

Question 26

deep vein thrombosis

Answer 26

Question 27

histological features of PT

Answer 27

Question 28

**Predisposing factors for a DVT**

Answer 28

* Immobility/bed rest * Post- operative * Pregnancy and post-partum * Oral contraception * Severe burns * Cardiac failure * Disseminated cancer

Question 29

**Pulmonary thrombus**

Answer 29

In most cases, pulmonary embolism is caused by blood clots that travel to the lungs from deep veins in the legs or, rarely, from veins in other parts of the body (deep vein thrombosis)

Question 30

outcomes of pulmoanry thrombus

Answer 30

1) Massive coiled embolus in main pulmoanry artery  sudden death 2) Small embolus lodged in peripheral pulmonary artery Pulmonary infarct 3) Pulmonary hypertension

Question 31

saddle embolism

Answer 31

pulmonary embolism that straddles the bifurcation of the pulmonary trunk, extending into the left and right pulmonary arteries.

Question 32

thromboembolism of the foot

Answer 32

ischaemia- gangrene

Question 33

**Thromboembolism from carotid artery**

Answer 33

**- ischemic stroke**

Question 34

prophylaxis of DVT/ PE

Answer 34

* Identify high risk patient * Low molecular weight heparin sub-cutaneous * Mobilise early * Leg compressions during surgery * TED stockings * FLowt tran boots

Question 35

**Treatment of thrombus +/- thromboembolic**

Answer 35

* Clot busters * Intravenous heparin type drugs * Newer generation NOAC (noval oral anticoagulant) * Filters in inferior vena cave (devices in left atria to stop thrombus formation etc) * Embolectomy (lefs etc for acute limb ischaemia) * Oral warfarin

Question 36

clot blusters

Answer 36

Streptokinase, alteplase (recombinant tPA)

Question 37

newer geenration NOAX (noval oral anticoagulants)

Answer 37

* Dabigatran (thrombin) * Rivaroxaban (anti-factor Xa)