Thromboembolism

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 Prothrombotic effect Antithrombotic effect 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 Massive pulmonary embolism (saddle embolus), with ventricular fibrillation Pulmonary infarction Embolism without infarction 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 1 st and 2 nd 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

39. Cholesterol Embolism

40. Cholesterol Embolism

41. References K S N Reddy 34 th 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