Anticoagulation In Dental Procedures

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Anticoagulation In Dental Procedures

• Galila Zaher
• MRCPath
• KAU
• Assistant Professor

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Function of Normal Homeostasis

• Prevention of blood loss from intact vessels
• Arrest of bleeding from damaged vessels

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BLOOD CLOTTING

• Plasma protein clotting factors
• Vascular endoth

Platelets
Bleeding
Thrombosis Clotting
factors
Natural anticoagulant platelets
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Normal Hemostasis

1. Local vasoconstriction
2. Platelet release thromboxane A2
3. Prostacyclin counters effects of Thro-A2

• Vessel wall

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Normal Hemostasis

• Adhesion
• Shape change
• Aggregation
• Release Reaction

• Vessel wall
• Platelet

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Platelet Activation
Collagen
Thrombin

ADP
GpIIb/IIIa
GpIb
Adrenaline
Adhesion
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Clotting Factors
Names Factors
Fibrinogen Prothrombin Thromboplastin Calcium Labile factor Stable factor Antihemophilic factor Antihemophilic factor B Stuart-Power factor Plasma thromboplastin antecedent Hagman factor Fibrin stablizing factors I II III IV V VII VIII IX X XI XII XIII
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The Cascade, Waterfall model
APC (PC PS)
AT
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The Cascade, Waterfall model
APC (PC PS)
AT
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Normal Hemostasis
II
X
VIII/vWF
IIa
VIIIa
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Normal Hemostasis
II
X
VIII/vWF
IIa
VIIIa
V
Va
Platelet
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Normal Hemostasis
II
X
VIII/vWF
IIa
VIIIa
V
Va
Platelet
Activated Platelet
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Normal Hemostasis
II
X
VIII/vWF
IIa
VIIIa
TF
V
Va
VIIa
IX
Platelet
IXa
Activated Platelet
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Normal Hemostasis
II
X
VIII/vWF
IIa
VIIIa
TF
V
Va
VIIa
IX
Platelet
II
IXa
X
Xa
IIa
VIIIa
IXa
Va
Activated Platelet
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Normal Hemostasis
II
X
VIII/vWF
TF
VIIa
Xa
IIa
Va
VIIIa
TF-Bearing Cell
TF
V
Va
VIIa
IX
Platelet
II
IXa
X
IIa
Xa
VIIIa
IXa
Va
Activated Platelet
Hoffman et al. Blood Coagul Fibrinolysis
19989(suppl 1)S61.
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Alternative (Cell-based) Model
TF VIIa
IXa
Fibroblast
initiation phase
Xa
Prothrombin
Thrombin
Thrombin
Amplification
XIa
IXa
Xa
Prothrombin
XIa
VIIIa
Platelet
Activated platelets
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4. Fibrin threads (scanning electron
micrograph) Fibrin forms rapidly in stagnant
blood. Thrombin plays a pivotal role in the
polymerisation of the fibrin strands. Red blood
cells become trapped in the fibrin network as the
thrombus grows.
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Dental extractions

Bleeding
Thrombosis
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Bleeding complications

• Dental extractions OAC 249 Group 1
  INR(1.51.99), Group 5 INR gt3.5.
• INR among the groups did not influence
  incidence of postoperative bleeding. D. Blinderb
  Dec 2001

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Postoperative bleeding

• 214 patients divided into four groups
• Group 1 no suturing and discontinued
• Group 2 no suturing continued warfarin
• Group 3 suturing and discontinued
• Group 4 suturing and continued warfarin
• Dental extractions may be safely performed for
  patients on OAC provided the INR level lt 3.0
• Decision to suture should be made on case-by-case
  basis
• W. Becker British Dental Journal (2007)

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Thrombosis Bleeding

• Medline ,The Cochrane Collaboration database 31
  reports
• Major bleeding rare ,Thrombo-embolic events
  (1.6) Evid Based Dent. 2005
• Descriptive studies (29)1868 patients
• Thromboembolic rates were for OAC, 0.6 for D/C
  OAC
• Major bleeding was rare despite OAC

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Guidelines on oral anticoagulation (warfarin)
third edition

• Anticoagulation does not need to be stopped for
  dental extraction for patients in therapeutic
  range, i.e. INR lt3. 2005 update
• Evid Based Dent. 2005
• DATA SOURCES Medline Cochrane database
• Thrombo-embolic events (1.6) Major bleeding rare
  
• A guideline, based on the evidence available
  Certain surgical or invasive procedures can be
  undertaken with no interruption of OAC
• Nick Malden Dent Update. 2007 Nov

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Fibrin glue

• Patients OAC without interruption dental
  extraction
• Postoperatively, local hemostasis
• Group I 166 absorbable gelatin sponge and
  sutures
• Group II 154 fibrin glue
• Fibrin glue can be safely used to reduce
  postoperative bleeding TAWFIK, Egypt 2003
• Group of 250 outpatient clinic setting OAC (INR
  1.8-4) and local haemostatic measures were used.
• Difference of bleeding complications P 0.7
  ZANON 2003

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Bridging Therapy

• Long-term OAC therapy Elective surgical
  procedure.
• Retrospective analysis of either IV UH or LMWH
• The rates of adverse events (thromboembolic
  event, major and minor bleeding) NSS (p 0.67).
• Costs were significantly lower in LMWH ACCP 2004
• Large, prospective cohort studies
• Procedures with a high bleeding risk will
  necessitate temporary discontinuation of OAC.
• Bridging therapy with shorter-acting
  anticoagulants, UFH OR LMWH Curr Hematol Rep.
  2005 Alex C

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RECOMMENDATIONS

• Anticoagulation does not need to be stopped for
  patients in therapeutic range, i.e. INR lt3.
• Mechanical pressure
• Minimize trauma .
• Fibrin , Gelatin sponge
• Gauze saturated with tranexamic acid
• Tranexamic acid mouthwash
• Silk suture made on case-by-case

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• ThAnk YOu