THROMBOEMBOLISM

Dr Priyal Jain

P G in Forensic Medicine

UCMS Delhi

Embolism

It is a detached intravascular solid/ liquid or gaseous mass that is carried by the blood to a site distant from it`s point of origin.

Thromboembolism

Virchow`s Triad 1856

Vessel Injury

Platelet Adhesion

Aggregation

Risk Factors

Acquire

Strong◦Surgery◦Trauma◦Central venous catheters◦Metastasized cancersModerate◦APLS◦Peurperium◦Prolonged bed rest◦Non metastasized cancers

Risk Factors

Mild◦Pregnancy◦OCP◦HRT◦Obesity ◦Long haul air travel◦Age

Risk Factors

Inherited◦Anti-thrombin deficiency◦Protein C deficiency◦Protein S deficiency◦Factor V leiden◦Prothrombin 20210A◦Non O blood group◦Dysfibrinogenimia

Risk Factors

Mixed / Unknown◦High Levels of factor viii◦High Levels of factor ix◦High Levels of factor xi◦High Levels of fibrinogen◦High Levels of TAFI◦Low Levels of TFPI

Clinical Features

Lung ◦Dyspnea.◦Tachypnea.◦Hemoptysis.◦Tachycardia.◦Hypoxemia.◦Sudden death.

Clinical Features

Heart◦Myocardial infarction

Brain

Cerebral Infarction

Kidney

Renal Infarction

Pulmonary EmbolismANTE-MORTEMPOST MORTEM

Pulmonary Infarct

Bowden cable

Ageing of Trombus

Hemolysis of RBCs and amorphous mass formation----------------------- 24-48 hrs

PTAH Staining

Purplish fibrin strands ------ 1 dayMeshwork of strand and sheets-- 4 daysDeeply purple strand--------- 2 wks

Ageing of Thrombus

Endothelial proliferation bud – 2nd dayCovering by endothelium starts 24 hrsCovering by endothelium finish 24-72

hrAnchoring thrombus 4th day

Ageing of Thrombus

Fibroblast starts 1 wkFibroblast Maximum 4 wkElastic fibers >4 wkMaximum density 2

month

Capillary formationBegins 2nd dayContains RBCs 2nd wkCanalization 3

monthFull lumen restoration 6-12 months

Fat Embolism

Risk factors◦# of long bones/ # pelvic bones/ multiple #◦Burns◦Barotrauma◦Soft tissue injury◦Surgery (mastectomy)◦Sepsis◦Steroid◦DM◦Alcoholic fatty liver, acute pancreatitis

Micro-emboli of fat

↓ ↓

Free fatty acid occlusion of circulation

↓

↓ plt, rbc aggregation

↑ ↓

Injury to endothelium → ↑ ↓

↓

Vascular occlusion

Susceptible organs

Lung

Brain

Myocardium

Kidney

Clinical feature

Pulmonary insufficiency◦Sudden Tachypnea, Dyspnea,

tachycardia, Neurological symptoms

◦Irritability, RestlessnessAnaemiaThrombocytopenia

P M APPEARANCE

Frozen Section + staining sudan black

Skin --- petechial hemorrhages

Brain – white matter of cerebrum, cerebellum, brain stem

Heart – interfiber capillaries

Kidney – glomerulli

Eye - retina and optic nerve

Mason scale

Oil Red O Frozen Section of lung

0: no emboli seen

1: emboli found after some searching

2: emboli easily seen

3: emboli present in large amount

4: emboli present in potentially fatal No.

Air embolism

Risk Factors◦Venous air embolism

aspiration of air in neck vein

refilling of therapeutic pneumothorax

tearing of visceral pleura◦Arterial air embolism

lung laceration

baro-trauma

bends

criminal abortion

mercy killing

Post mortem procedure

Cranial cavity

↓

Thorax

↓

Abdomen

↓

Pericardial sac

Methods

Window in sternumOpen heart with clamping of

vesselsSubmerge opening or syringingAspirometer with Tween 80Pyrogallol test

◦2% , 4 ml , 2drops NaOH , yellow , brown (+)

Amniotic Fluid Embolism

Risk FactorsMultiparityAbruptionIntrauterine Fetal DeathTumultuous labourOxytocin or Prostaglandin hyper stimulationCaesarean sectionManual removal of the placenta

Pathophysiology

Probably an anaphylactoid-type reaction to the intravascular ingress of amniotic fluid

This causes widespread vasoconstriction including pulmonary and cardiac vessels

There is ↓myocardial contractility and acute left heart failure

If the mother survives the initial cardio respiratory failure then DIC and haemorrhage is inevitable

Survivors may suffer stroke due to cerebral infarction

Clinical Feature

Acute fetal distress followed quickly by maternal collapse with hypotension, dyspnoea and cyanosis.

Sudden loss of consciousness or seizure.Often proceeds or occurs immediately after

delivery.Maternal collapse during Caesarean

section.Followed by profuse post partum

haemorrhage.

P M Findings

Classical findings are presence of squamous cells shed from fetal skin, lanugo hair, fat from vernix caseosa and mucin derived from the respiratory/ GI tract.