The endoscopic approach to the skull base has revolutionised surgery in this region.
Neurosurgery involves working around anatomical structures that are uniquely sensitive to
damage and manipulation and patients may be left with the potentially devastating
consequences of violating these structures. The endoscope allows the surgeon to visualise
and reach areas that were previously only accessible with large amounts of destructive
dissection. Tumours are able to be removed and aneurysms clipped without the need for
large craniotomies and bony drilling.
There are, however, drawbacks. The midline endoscopic route takes the surgeon between
the carotid arteries. It potentially violates the anterior communicating artery complex and
the basilar artery region anterior to the brainstem. These are important arteries that supply
critical structures. Damage to these, or diminution of blood flow through them, results in
profound neurological dysfunction or death.
The rate of damage to the carotid artery with these approaches ranges from 1.1-9%
depending on the specific approach and pathology. The carotid artery in this region does
not generally lend itself to suturing, clipping or direct closure methods. Currently, the gold
standard for repair is the application of crushed muscle patch to stop the bleeding and seal
the vessel. The drawbacks to this are that it takes time to harvest and control the bleed
(generally requiring 2 surgeons), and that there is a risk of pseudoaneurysm formation post
recovery. This thesis describes novel techniques that may replace the muscle patch in order that a
single surgeon may have this technique available to them immediately.
Aims:
To demonstrate the use of fibrin/thrombin/gelatin patches, fibrin/thrombin glues,
beta-chitosan patches and self-assembling peptides on a sheep model of carotid
artery haemorrhage and quantify the rate of pseudoaneurysm formation.
To show the percentage of platelets activated by crushed and uncrushed muscle,
chitosan, and fibrin and thrombin patches and gels using flow cytometry to further
delineate the mechanism of action of crushed muscle as a haemostatic agent.
To quantify the stress response in surgeons training on this sheep vascular
haemorrhage model de novo, to quantify its effect on surgeons’ teamwork and
communication skills, and determine the effect and value of training on modulation
of this stress response.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, Adelaide Medical School, 201
