Post on 31-Dec-2015
FLUID ANDHEMODYNAMIC DERANGEMENTS
- PART II
SOCORRO CRUZ – YANEZ MD, FPSP
THROMBOSIS
Definition :
Formation of a solid clotted mass
( thrombus ) derived from blood elements ( vessel , platelets , CF) intravascularly in a living person.
A.K.A antemortem clot
THROMBUS
ENDOTHELIAL ATTACHMENT
LINES OF ZAHN
POSTMORTEM CLOT
• Formed extravascularly • Postmortem ( clotting after
death ) • Involves only clotting factors• “ currant jelly “ or “ chicken fat
“ clot
POST- MORTEM CLOTS
• Rubbery, gelatinous
• Forms perfect cast on vessel wall
• No attachment to endothelium
POST MORTEM CLOT
NORMAL HEMOSTASIS
Functions :1. Maintenance of blood
in a fluid, clot free state 2. Ability to produce hemostatic plug at site
of vascular injury
FACTORS OF NORMAL HEMOSTASIS
• Blood vessel/ endothelium
• Platelets
• Coagulation system
SEQUENCE OF EVENTS IN HEMOSTASIS
1.Vasoconstriction2.Primary hemostatic plug3.Secondary hemostatic
plug4.Thrombosis and anti-
thrombotic events
NORMAL HEMOSTASIS : A. VASOCONSTRICTION
•Stimulated by vascular injury
•Mediated by :a . sympathetic NS b. Endothelin secretion
BLOOD VESSEL WALL CONTRIBUTION
1. Elaboration of prothrombotic factors / substances :a. vWF- platelet binding co-factorb. extrinsic tissue factor- activates
extrinsic clotting pathwayc. Plasminogen activators
inhibitors – inhibits fibrinolysis 2. Insulation of platelets from subendothelial collagen
BLD VESSEL CONTRIBUTION Cont…
3. Elaboration of humoral factors ( endothelin) vasoconstriction
4. Role of subendothelial collagen
BLOOD VESSEL WALL CONTRIBUTION (Cont..)
5. Elaboration of anti-thrombotic substance
a. Plt aggregator inhibitors: prostacyclin , ADPase , NO
b. Anti-thrombin inhibitors : thrombomodulin, heparin
like molecule c. Fibrinolytic : t-PA
PLATELET ROLE IN HEMOSTASIS:
1. Formation of Io hemostatic plugA. Platelet adhesion
- attachment to site of injury and exposed collagen- needs vWF to bridge platelet
and collagen
2. Platelet secretion and release Alpha granules Dense bodies
- fibrinogen - ADP - fibronectin - Ca
- PDGF - histamine - PF4 - serotonin
PLATELET ROLE (cont..)
3. Platelet aggregation ( platelet to platelet interaction ) - formation of temporary
( primary ) hemostatic plug - stimulated by ADP, TXA2
thrombin
PLATELET ROLE (cont..)
4. Platelet contraction viscous metamorphosis formation of secondary
hemostatic plug mediated by octomyosin
PLATELET ROLE (cont..)
ROLE OF COAGULATION SYSTEM IN HEMOSTASIS
conversion of thrombin to fibrinogen and formation of fibrin thrombus
may be stimulated by extrinsic and intrinsic pathway
ANTI-CLOTTING MECHANISM
• Depletion of clotting factors
• Clearance of CF by liver
• Fibrinolysis : plasmin and plasminogen
• Proteases
• Anti-thrombin
THROMBOSIS : PREDISPOSING FACTORS
1. INJURY TO ENDOTHELIUM2. ALTERATION IN NORMAL
BLOOD FLOW3. ALTERATION IN THE BLOOD
( hypercoagulable state )
Endothelial Injury :
Acute Myocardial Infarction AtherosclerosisCigarette smoking Vasculitis HypertensionHypercholesterolemia
Alterations in blood flow
Stasis AneurysmValvular stenosis /
regurgitationVascular obstructions
Hypercoagulability
Immobilization MalignancyAPASDICNephrotic syndrome Oral contraceptive use
Endothelial wall attachmentsGross and microscopic
laminations ( LINES OF ZAHN )Compositions : laminated
platelets, fibrin, RBC and WBC
THROMBUS : Morphology
THROMBUS
ENDOTHELIAL ATTACHMENT
ENDOTHELIAL ATTACHMENT W/ RBC , PLT , FIBRIN
THROMBUS : LINES OF ZAHN
LINES OF ZAHN
1
2
THROMBUS : COMPONENTS OF LAYERS 1 – Pale areas( fibrin/platelets ) 2- Red areas ( RBC,WBC ,
fibrin )
THROMBUS : COMPONENTS OF LAYERS 1 – Pale areas( fibrin/platelets ) 2- Red areas ( RBC,WBC , fibrin )
THROMBUS : Morphology
TYPES OF THROMBI :1. Mural thrombus2. Vegetations 3. Arterial / occlusive / white or
conglutination thrombi 4. Venous/phlebothrombosi/
red or coagulative thrombi
MURAL THROMBUS
MURAL THROMBUS
MURAL THROMBUS
MURAL THROMBUS
ENDOCARDIAL THROMBOTIC VEGETATION
VALVE THROMBUS
ARTERIAL / OCCLUSIVE THROMBUS
ARTERIAL THROMBUS
ARTERIAL THROMBUS , RECENT , OCCLUSIVE
THROMBOSIS WITH ORGANIZATION
THROMBUS RENAL ARTERY
Thrombi Morphology: Venous•Venous thrombi
o Usually occlusiveo Red (because they form
in stasis syndrome and have more associated enmeshed RBCs)
o Long - forming a cast of vein with markings on them from venous valves
o Red blood cells alternating with peripheral areas of fibrin
Venous Thrombi: Clinical
Lab test:D- dimer test
ARTERIAL VENOUS THROMBI THROMBI Occur site
injury/ turbulence
Retrograde growth
Prone to occlusion
Gray white thrombi
More PLT and fibrin, less RBC
Occur at site of stasis
Forward propagation
Occlusion and fragmentation
Red , stasis thrombi
More RBC content
THROMBUS : CLINICAL SIGNIFICANCE
1. Obstruction of blood flow
ischemia and infarction2. Source of thrombo-emboli
CAROTID ARTERY ANGIOGRAM- ARTERIAL OCCLUSION
GANGRENE SECONDARY TO ARTERIAL OBSTRUCTION
THROMBO-EMBOLISM
THROMBUS : OUTCOME
1. Propagation2. Lysis and resolution 3. Embolization4. Organization
THROMBO-EMBOLISM RIGHT VENTRICLE AND PULM ART
ORGANIZED THROMBUS RECANALIZED THROMBUS
RECALANIZED & ORGANIZED PTE
RECANALIZED THROMBUS
RECANALIZATION OF THROMBUS
Dissiminated Intravascular
Coagulopathy ( DIC ) Definition :
An acute, subacute or chronic thrombotic disorder occurring 2o to cx of variety of clinical dis, presenting with thrombotic ischemia , consumption coagulopathy and shock.
DIC : Disseminated intravascular coagulopathy
• AKA. Defibrination syndrome Microcirculatory thromb Consumption coagulopathy• Clinical assoc : sepsis burns snake bites shock abruption placenta AFE
retained dead fetus carcinomatosis
DIC : MORPHOLOGY
•Multiple microthrombi in diff organs ( brain, heart, lungs , kidneys, adrenals )
•Assoc ischemic / hypoxic injury to tissues
•Multiple hemorrhages
DIC
MICROTHROMBOSIS
MICROTHROMBOSIS