FLUID AND HEMODYNAMIC 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
ENDOTHELIAL ATTACHMENT LINES OF ZAHN THROMBUS
POSTMORTEM CLOT Formed extravascularly Postmortem ( clotting after death ) Involves only clotting factors “ currant jelly “ or “ chicken fat “ clot
POST- MORTEM CLOTS Forms perfect cast on vessel wall No attachment to Rubbery, gelatinous Forms perfect cast on vessel wall No attachment to endothelium POST- MORTEM CLOTS
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 Vasoconstriction Primary hemostatic plug Secondary hemostatic plug 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-factor b. extrinsic tissue factor- activates extrinsic clotting pathway c. Plasminogen activators inhibitors – inhibits fibrinolysis Insulation of platelets from subendothelial collagen
BLD VESSEL CONTRIBUTION Cont… Elaboration of humoral factors ( endothelin) vasoconstriction 4. Role of subendothelial collagen
BLOOD VESSEL WALL CONTRIBUTION (Cont..) 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: Formation of Io hemostatic plug A. Platelet adhesion - attachment to site of injury and exposed collagen - needs vWF to bridge platelet and collagen
PLATELET ROLE (cont..) Platelet secretion and release Alpha granules Dense bodies - fibrinogen - ADP - fibronectin - Ca - PDGF - histamine - PF4 - serotonin
PLATELET ROLE (cont..) Platelet aggregation ( platelet to platelet interaction ) - formation of temporary ( primary ) hemostatic plug - stimulated by ADP, TXA2 thrombin
PLATELET ROLE (cont..) 4. Platelet contraction formation of secondary viscous metamorphosis formation of secondary hemostatic plug mediated by octomyosin
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 INJURY TO ENDOTHELIUM ALTERATION IN NORMAL BLOOD FLOW ALTERATION IN THE BLOOD ( hypercoagulable state )
Endothelial Injury : Acute Myocardial Infarction Atherosclerosis Cigarette smoking Vasculitis Hypertension Hypercholesterolemia
Alterations in blood flow Stasis Aneurysm Valvular stenosis / regurgitation Vascular obstructions
Hypercoagulability Immobilization Malignancy APAS DIC Nephrotic syndrome Oral contraceptive use
THROMBUS : Morphology Endothelial wall attachments Gross and microscopic laminations ( LINES OF ZAHN ) Compositions : laminated platelets, fibrin, RBC and WBC
ENDOTHELIAL ATTACHMENT THROMBUS
ENDOTHELIAL ATTACHMENT W/ RBC , PLT , FIBRIN
THROMBUS : LINES OF ZAHN
2 1 LINES OF ZAHN
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 : Mural thrombus Vegetations Arterial / occlusive / white or conglutination thrombi Venous/phlebothrombosi/ red or coagulative thrombi
MURAL THROMBUS
MURAL THROMBUS
MURAL THROMBUS
MURAL THROMBUS
ENDOCARDIAL THROMBOTIC VEGETATION
THROMBUS VALVE
ARTERIAL / OCCLUSIVE THROMBUS
ARTERIAL THROMBUS
ARTERIAL THROMBUS , RECENT , OCCLUSIVE
THROMBOSIS WITH ORGANIZATION
THROMBUS RENAL ARTERY
Thrombi Morphology: Venous Venous thrombi Usually occlusive Red (because they form in stasis syndrome and have more associated enmeshed RBCs) Long - forming a cast of vein with markings on them from venous valves Red blood cells alternating with peripheral areas of fibrin
Venous Thrombi: Clinical Lab test: D- dimer test
ARTERIAL VENOUS THROMBI THROMBI Occur at site of stasis Forward propagation Occlusion and fragmentation Red , stasis thrombi More RBC content Occur site injury/ turbulence Retrograde growth Prone to occlusion Gray white thrombi More PLT and fibrin, less RBC
THROMBUS : CLINICAL SIGNIFICANCE 1. Obstruction of blood flow ischemia and infarction 2. Source of thrombo-emboli
CAROTID ARTERY ANGIOGRAM- ARTERIAL OCCLUSION
GANGRENE SECONDARY TO ARTERIAL OBSTRUCTION
THROMBO-EMBOLISM
THROMBUS : OUTCOME 1. Propagation 2. Lysis and resolution 3. Embolization 4. Organization
THROMBO-EMBOLISM RIGHT VENTRICLE AND PULM ART
RECANALIZED THROMBUS ORGANIZED 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
MICROTHROMBOSIS DIC
MICROTHROMBOSIS