Introduction
Nerve tissue is delicate, easily damaged, and has a poor capacity for repair. This is especially true of the cortex and spinal cord, and injury to these structures may obviously have devastating consequences. Therefore, it is extremely important that when you are assisting at neurosurgical operations, you handle the tissues gently, if at all.
Equipment
As in other areas of surgery, it is helpful to be familiar with the equipment you will be using. In cranial neurosurgical procedures, this equipment will often include the Mayfield skull clamp, which is a table-mounted instrument designed to hold the head firmly in position. It does so by means of three pins which are fixed to the bony skull vault. Usually the surgeon will apply the pins and then ask you to tighten the clamps in position while he or she positions the head.
The Greenberg retractor is another table-mounted instrument, commonly used in intra-cranial surgery. It can be fitted with a variety of tissue-retracting blades. If the surgeon asks you to loosen one of these blades, be very clear on which blade you are to loosen. The blade may be very near a critical structure, such as an aneurysm, which may rupture as you remove the blade.
Specialised tables are normally used for spinal surgery (e.g. the Jackson table and the Andrews table).
In some centres, the Stealth® system may be used. Briefly, this system uses complex computer imaging to localise anatomical (and pathological) structures with great accuracy–often within less than 1 mm. Obviously, it is important not to lean on the frame of such a precision instrument.