Thromboembolism

1. Thromboembolism
Dr.Nafeeya
Department of Forensic Medicine &Toxicology

2. Overview
• Haemostasis
• Brief about Thrombus & Embolus
• Various types
• Pathogenesis
• Gross & Histopathology findings

3. Normal haemostasis
• Process of maintaining blood in a fluid ,clot
free state in a normal vasculature & rapidly
forming haemostatic plugs at the site of
vascular injury .
• The pathology opposite of haemostasis is
thrombosis, emboli formation

4. Thrombosis - Pathogenesis
1. Prothrombotic effect
2. Antithrombotic
effect
3. Fibrolytic effect

5. Role of endothelium in hemostasis
• Prothrombotic effects
• Vwf – secreted by endothelium
• TF (Tissue factor ) - activates extrinsic
pathway
• Pl.A – plasminogen activator

6. Fibrinolytic effect
• Plasminogen activators
convert plasminogen to
plasmin
• Plasmin lyses Fibrin (&
Fibrinogen) to degradation
products which are soluble
and are removed.
Anti thrombotic effects
PGI2 & Nitric oxide
Heparin like molecule
Thrombomodulin
TFPI –tissue factor pathway
inhibitor

7. Thrombosis - Definition
• Thrombosis refers to the formation of thrombus within a vascular lumen,
defined as an aggregate of coagulated blood containing platelets, fibrin,
and entrapped cellular elements..

8. Thrombosis - arterial
• Arterial thrombosis eg , myocardial infarction (1- cause of death).
• stroke (2- cause of death),
• or peripheral infarcts.

9. Thrombosis - High risk patients
• Tissue damage (surgery, burns)
• Prolonged immobilization
• Myocardial infarction
• Neoplasms ,Prosthetic heart valves
• DIC (also increased risk of hemorrhage)
Smokers
Pregnancy/postpartum
Oral contraceptives
Hyperlipidemia
Sickle cell disease
Atrial fibrillation

10. Thrombosis, Coronary Artery

11. Thrombosis-Lines of Zahn

12. Thrombus, Lines of Zahn

13. Endocarditic, Gross

14. Mural Thrombus, Heart, Gross

15. Mural Thrombus, Left ventricle

16. • Complications of cardiac thrombosis
– The major complication of thrombi in any location in the heart is the
– detachment of fragments and their transport to distant sites
(embolization),
– where they lodge and occlude arterial vessels.

17. Thrombosis - venous
Deep veins of the leg - most common site for
thrombosis
• Primarily due to sluggish blood flow
• Prolonged immobilization.
• This condition may cause swelling of the leg, or
may be completely asymptomatic.
• Complication - Pulmonary thromboembolism

18. Thrombosis, Femoral Vein, in situ

19. Thrombus, Femoral Vein, Recanalization

20. Coronary Artery, Recanalization

21. Thrombosis - fate of thrombi
• Propagation
• Embolization
• Dissolution (lysis by the thrombolytic system)
• Organization and re-canalization

22. Embolism - Definition
• Embolism is the passage through the venous or arterial circulations of any
material capable of lodging in a blood vessel and thereby obstructing the
lumen

23. Embolism-Types
• Thromboembolism (most common)
• Fat embolism
• Amniotic fluid embolism
• Gas embolism
• Cholesterol embolism
• Septic embolism
• Foreign body embolism
• Bone marrow embolism

24. Embolism - Pulmonary
• Source -deep leg veins - phlebothrombosis
• Fate of pulmonary thrombo-emboli
1. Massive pulmonary embolism (saddle
embolus), with ventricular fibrillation
2. Pulmonary infarction
3. Embolism without infarction
4. Paradoxical embolus- Intracardiac defect

25. Pulmonary Embolism, Gross

26. Fat Embolism
• Seen after fracture of long bones,soft tissue injury
or burns
• Fat embolism syndrome-symptomatic cases
• Pulmonary insufficiency,neurological
symptoms,anemia and thrombocytopenia
• Diffuse petechial rash

27. Atherosclerotic plaques, Aorta, Gross

28. Sudan III staining
• Frozen tissue sections
• Small blood vessels
&
Capillaries
Multiple fat emboli
Lung tissue, kidney, brain, liver and
pancreas
Fat droplets stained orange

29. H
&
E
LUNG
PANCREAS
KIDNEY
BRAIN
LIVER

30. LUNG BRAIN
KIDNEY
LIVER
PANCREAS
S
U
D
A
N
III
S
T
A
I
N

31. L
U
N
G
S

32. B
R
A
I
N

33. K
I
D
N
E
Y

34. Fat Embolism, Lung, Oil Red O

35. H
P
E

36. Amniotic fluid embolism
• Post partum complication-Condition in which amniotic fluid, fetal cells,
hair or other debris enters the maternal circulation due to tear in amnion
via placental bed.
• C/f-sudden severe dyspnoea,cyanosis and shock,neurologic impairment
• Cause-infusion of amniotic fluid into maternal circulation

37. Causes
• Criminal abortion
• 1st and 2nd trimester abortions
• Abdominal trauma
• Amniocentesis
• Immediate post partum
• Normal labour & delivery
•5-10% of maternal mortality
•Cardiac arrest
•Rapid respiratory failure.

38. Stains used
• Alcian blue – detects mucin
• H & E – routine staining
• Attwood’s stain – stains keratin red and mucus turquoise blue
• Lendrum stain ( contains Phloxine & Tartrazine ) – stains squames red
• Sudan black or oil red – detects vernix caseosa

41. Cholesterol Embolism

42. Cholesterol Embolism

43. References
• K S N Reddy 34th edition - Essentials of Forensic Medicine and Toxicology
• Anil aggrawal - Text book of Forensic Medicine and Toxicology
 Knights forensic pathology
• Robbins & cotran basis of disease pathology.
• Atlas of histology –Lippincotts williams &wikins
 Amniotic fluid embolism: Manjusha Viswanathan, International Journal of Reproduction,
Contraception, Obstetrics and Gynaecology Viswanathan M et al. Int J Reprod Contracept Obstet
Gynecol
 Forensic aspects of post-mortem histological detection of amniotic fluid embolism ,I. Sinicina , Springer-
Verlag 2009
• Fat embolism, fat embolism syndrome and the autopsy, academic forensic pathology, 2019
• Pathogenesis of non-traumatic fat embolism, Geoffrey Hulman, the lancet, 1988
• Autopsy diagnosis of fat embolism syndrome, am J forensic med pathol & volume 32, number 3,
september 2011