Instrumentation For Haemostasis

Dorn Spinal Therapy

Spine Healing Therapy

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Haemostasis must be achieved in all phases of the surgery. It is important to gain haemostasis in the superficial layers before proceeding to the deeper structures. In a craniotomy plastic haemostatic "Raney" clips are first applied to the edge of the scalp. The bone edges are waxed and then the extradural space is closed with hitch sutures. The dura can then be opened and the operative field is kept clear and dry for working under the microscope. Complex cranial and spinal operations often take four hours or longer and continuous blood loss can jeopardise a patient's haemodynamic status if there is continuous oozing.

Bipolar coagulation is fundamental to neurosurgery because it enables precise coagulation ofsmall vessels without dangerous spread of the current to adjacent neural and vascular structures.13 A range of bipolar forceps of different sizes and lengths should be available. A larger tip, 2 to 3 mm, is necessary to control bleeding from the scalp margins. Finer tips, 0.3 to 1 mm, can be used on or within the dura. The bipolar forceps also need to be of different lengths. Bayonet lengths with 8 cm shafts are suitable for working on the brain surface. Blades measuring 9.5 cm are suitable for coagulation of deeper structures, such as, around the circle of Willis, and 11 cm blades may be necessary for trans-sphenoidal operations. Bipolar instruments are continually being revised. Bipolar tips can be self-irrigating, and any rise in impedance can be monitored to prevent charring and sticking of the tips of the forceps. Irrigation is essential to prevent this charring. It is important to reduce the current setting when switching from a standard bipolar to the fine tips, for microsurgery. The narrower the forceps tip, the higher will be the current density for the same amount of current flow. The interface between the forceps tips and the tissue should be wet with continual irrigation of saline. In bipolaring vessels, the tips should be kept slightly open. The forceps should not be simply closed over the vessel as this will lead to short-circuiting and no coagulation occurs (Fig. 2).14 At sites where even gentle coagulation could result in neural damage, such as around the optic or acoustic nerves, an attempt is made to control the bleeding with lightly applied haemostatic material. Surgicell (an oxidised regenerated cellulose), gel foam (a gelatinous sponge), or avitene (a microfibrillar collagen) may be used. Floseal matrix haemostatic sealant, a gelatine matrix, is expanding its range of use. It has been found to be a reliable if not expensive agent to control bleeding in both cardiac and spinal surgery.15

Cutting loops or ultrasonic aspirators are routinely used for tumour removal. They do not control bleeding although some are designed to enable coagulation to be applied through the tip. Tumours of the brain or spinal cord are often removed piecemeal unlike cancer surgery where the tumour is excised intact. The external capsule is first devascularised and then the tumour mass is emptied before the tumour is delivered. Removal of a tumour is invariably piecemeal and bipolar coagulation provides the ability to achieve precise haemostasis without causing damage to the surrounding neural structures.

Fig. 2 Forceps. The provision of properly shaped and balanced bipolar forceps has been undertaken by a number of neurosurgeons. The forceps are angled to stay out of the line of vision. There is a range of lengths and the polished tips vary in size. The bipolar forceps are used with constant saline irrigation.

Fig. 2 Forceps. The provision of properly shaped and balanced bipolar forceps has been undertaken by a number of neurosurgeons. The forceps are angled to stay out of the line of vision. There is a range of lengths and the polished tips vary in size. The bipolar forceps are used with constant saline irrigation.

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