1.
Haemostasis in neurosurgery
By
Tijani Sadiq

2.
Outline
• Introduction
• Surgical importance
• Physiology of haemostasis
• Preoperative assessment
• Intraoperative techniques
• Postoperative techniques
• Conclusion
• References

3.
Introduction
• Haemo and stasis
• Refers to the process of terminating blood loss
from an injured vessel
• In surgery there is a fine balance between
bleeding and thrombosis
• Although the haemostatic process helps to
halt excessive blood loss it might, in a
prothrombotic milieu become pathological
and lead to thrombosis

4.
Introduction
• In the management of surgical patients, it is
essential to minimise the risk of complications
from bleeding.
• Neurosurgery is unique in that postoperative
bleeding can be devastating and result in
death or disability.
• As a consequence absolute haemostasis is
essential

5.
Introduction
• Technical advances such as the operating
microscope and bipolar coagulation allow the
accurate control of bleeding from fine cortical
vessels.
• Chemical haemostasis also plays a part in the
control of bleeding from capillaries and veins.
• However unlike his colleagues in other specialties
the neurosurgeon can rarely rely on drains to an
operative site or use monopolar coagulation

6.
Surgical importance
• Adequate surgical haemostasis reduces
morbidity and mortality in postop patients by;
• Minimising blood loss and anemia
• Attenuating metabolic response to trauma
• Reducing infection
• Improving wound healing

7.
Physiology of haemostasis
• Involves three interdependent processes:
• Initial vasoconstriction
• Platelet plug formation
• Coagulation formation and fibrinolysis

8.
vasoconstriction
• Initial vascular response to injury
• Dependent on local contraction of smooth
muscles
• Vasoconstrictors: 5-HT,TXA2, bradykinins,
fibrinopeptides

9.
Platelet plug formation
• Platelets become sticky when exposed to sub-
endothelial collagen to which they become
adherent
• VWF is necessary for platelet collagen
adherence
• The adherent platelets initiate a reaction to
recruit other platelets which aggregate to
form a loose platelet plug

10.
Coagulation formation
• Aim is to convert prothrombin to thrombin
• Thrombin cleaves fibrinogen molecules to
insoluble fibrin
• Fibrin provides stability to the platelet plug
• Involves two pathways;
• Extrinsic factors XII,XI,IX,X,II
• Intrinsic factors;VII,X,II

11.
Clotting cascade

12.
Preoperative assessment
• History
• Physical examination
• Investigation

13.
History
• Easy bruisability
• Mucosal bleeds
• Epistaxis
• Menorrhagia
• Bleeding after surgical procedure or dental extractions
• History of comorbid conditions such as hypertension,
CLD.
• Alcohol consumption
• Family history of bleeding disorders
• Drug history; anticoagulants, antiplatelets and NSAIDS

14.
Examination
• General examination; Pallor, Jaundice
Anasarca, asterixis
• Skin; Petechae, Ecchymosis
• Abdomen: hepatomegaly, splenomegaly

15.
General Investigations
• Liver function tests
• Urea electrolytes and creatinine
• Abdominal USS

16.
Specific investigations
• Full blood count and differentials
• Bleeding time (1-9minutes)
• Prothrombin time (9.6-11.8seconds)
• Activated partial thromboplastin time (APTT) (20-
36seconds)
• Thrombin time (15-19seconds)
• INR
• Clothing factor assays
• Group and crossmatch blood

17.
Intraoperative techniques
• Anaesthetic techniques
• Surgical techniques
• Pharmacological techniques
• Topical agents
• Mechanical factors
• Blood products

18.
Anaesthetic techniques
• Posture/position
• Permissive hypotension
• Normothermia
• Combined GA + regional
anaesthesia e.g with
xylocaine and
adrenaline

19.
Surgical techniques
• Appropriate dissection
• Minimal access surgery
• Use of clamps
• Intraluminal balloons
• Artery ligation
• Bipolar diathemy

20.
Surgical techniques

21.
Topical agents
• Bone wax
• Surgicell
• Gelfoam
• Avitene
• Topical thrombin
• Fibrin sealants
• Platelet sealants

22.
Pharmacological techniques
• Trenexamic acid
• Aminocaproic acid
• Aprotinin
• Recombinant factor VIIa
• Vitamin K

23.
Mechanical factors
• Digital pressure
• Pressure packing
• Sutures
• Staples
• Local application of gauzes and sponges
• Head elevation

24.
Blood products
• Fresh frozen plasma
• Platelet concentrates
• Factor concentrates

25.
Post op management
• Antbiotics
• Wound care
• Elevation

26.
Conclusion
• It is the responsibility of the neurosurgeon to
preempt surgically important haemorrhage,
employ multiple modalities to prevent it and
arrest it when it occurs

27.
References
• Koh MB, Hunt BJ. (2003). The management of
perioperative bleeding. Blood Rev 17(3): 179--
185.
• Powner DJ, Hartwell EA, Hoots WK. (2005).
Counteracting the effects of anticoagulants
and antiplatelet agents during neurosurgical
emergencies.

28.
References
• Schwartz principles of surgery