thromboembolisms

1. THROMBOSIS, EMBOLISm AND
surgical treatment

2. Normal Haemostasis
 Process of maintaining blood in a fluid, clot – free
state in normal vasculature
and
rapidly forming a localized haemostatic plug at
the site of vascular injury
 The pathologic opposite of haemostasis is
thrombosis

4. Thrombosis
 Formation of solid mass in circulation from the
constituents of flowing blood with intact
cardiovascular tree during life

5. RUDOLF VIRCHOW
Coined the terms“THROMBOSIS” and “EMBOLISM”

6. Virchow Triad

7. Endothelial Injury
 Main cause for thrombus formation in the heart
and the arterial circulation
 These are platelet – rich clots
 Inflammation
 Infection
 Toxins from cigarette smoking
 Hypercholesterolemia

8. Laminar blood flow

9. Abnormal blood flow
Turbulence
• Arterial thrombosis
• Atherosclerotic plaque
Stasis
• Venous thrombosis
• Aortic aneurysm
• Post MI – cardiac mural
thrombi
• Rheumatic mitral valve
stenosis
• Hype
Poly
rviscosity –
cythemia vera

10. Hypercoagulability
 Thrombophilia
 Any disorder of blood that predisposes to
thrombosis
 Hypercoagulable states are associated with
VENOUS THROMBOSIS

11. Hypercoagulable states
GENETIC
 Factor V mutation
 Increased levels of
factor VIII, IX, XI
or Fibrinogen
ACQUIRED
 Pregnancy and
 Prolonged bed rest or
immobilization
 Disseminated Cancer
 Prosthetic cardiac valves
 Disseminated intravascular
coagulation
 Oral contraceptive use
post partum

12. Arterial thrombi Venous thrombi
Arteries and heart veins
Aorta, coronary, cerebral etc
Superficial varicose veins,
deep leg veins
Endothelial cell injury
Causes-atherosclerosis,
vasculitis, trauma
Venous stasis
Usually mural, not occluding
lumen
Invariably occlusive
Grey- white, friable with lines of
zahn
Red-blue with fibrin strands
with line of zahn
Grows retrogrde
Grows in the direction of
blood flow
Meshwork of platelets, fibrin, red
cells and degenerating
leucocytes
More enmeshed RBC s and
few platelets(red or stasis
thrombi)

13. Antemortem thrombus Postmortem clot
Adherent to wall Not adherent to vessel wall
Red in colour
Fibrin with red cells and
leucocytes in a haphazard
network (gelatinous)
Upper layer resembling
chicken fat
Lines of zahn present
No lines of zahn – bland and
non – laminated

14. Lines of zahn

15. Mural thrombi

16. Vegetations – Thrombi on heart
valves

17. Arterial thrombosis

18. Fate of thrombus
 Propagation
 Embolization – thrombi dislodges and travels
to other sites in vasculature
 Dissolution – by fibrinolysis
 Organisation and recanalization
Older thrombi become organised by
ingrowth of endothelial cells, smooth muscle
cells and fibroblasts. Capillary channels
reestablish continuity of lumen

20. Embolism
 An embolus is a detached intravascular solid,
liquid or gaseous mass that is carried by the
blood to a site distant from origin.

21. Classification
 Thromboembolism (most common)
 Fat embolism
 Air embolism
 Amniotic fluid embolism

22. Pulmonary embolism
Embolus lodges in the lungs
(most common from deep vein
thrombosis)
Systemic embolism
extremities,
kidneys,
Brain, lower
intestines,
spleen(arterial emboli from
valvular
intracardiac mural or
thrombi, aortic aneurysms,
atherosclerotic plaques)

23. Pulmonary thromboembolism
 Cause from venous emboli
from deep leg veins
 Common in hospitalisedand
bed ridden patients
 Large thrombus gets
impacted at
bifurcation of pulmonary artery-
saddle embolus
 Multiple emboli
 Paradoxical embolism

24. PULMONARY ARTERYEMBOLUS

25. Fat embolism
 Obstruction of arterioles and capillaries by fat
globules
 Fractures of long bones
 Trauma to soft tissue eg., adipose tissue
Clinical features
 Pulmonary insufficiency - tachypnea, dyspnea,
tachycardia
 Neurologic symptoms - irritability, restlessness to
delirium and coma
 Thrombocytopenia

26. Fat embolism

27. Air embolism
 Gas bubbles within the circulation can
coalesce to form frothy masses and obstruct
vascular flow
 Large volume of air (more than 100 cc) is
necessary to produce effect in pulmonary
circulation
 Small volume of air trapped in coronary artery
during bypass surgery
 Chest wall injury
 Obstetric or laproscopy procedures

28. Decompression sickness
• Bends - formation of gas
bubbles in skeletal muscles
and joints producing pain
- edema,
focal
• In lungs
hemorrhages,
atelectasis
Caissons disease (chronic
decompression sickness) -
gas emboli in heads of femur,
tibia and humeri.

29. Amniotic fluid embolism
partum
 During labour or immediate post
period
 Dyspnea, cyanosis, hypotensive shock,
seizure and coma
 Infusion of amniotic fluid or fetal tissue into
maternal circulation via tear in placental
membranes or rupture of uterine veins

30. Methods of surgical treatment:
• Surgery. Types of surgery to treat arterial thrombosis if it is
blocking an artery to the heart include coronary artery bypass
and carotid endarterectomy. In coronary artery bypass
surgery, surgeons take a blood vessel from another part of the
body to bypass the block.
• injections of a medicine called a thrombolytic which can
dissolve some blood clots. an operation to remove the clot
(embolectomy) an operation to widen the affected artery – for
example, an angioplasty (where a hollow tube is placed inside
the artery to hold it open)

31. Surgical procedure to remove a blood
vessel?
• Thrombectomy and embolectomy can be performed using
the following methods: non- invasive (no incisions required /
small puncture / low to moderate sedation), minimally-invasive
(small incisions of 2–3 inches long / general anesthesia), or
through open-surgery (large incisions of 8-10 inches long /
general anesthesia).