CONDITIONS TREATED
Stereotaxis and neuronavigation
Stereotactic neurosurgery is a technique which uses CT, MRI or angiogram images to guide the surgeon to a specific site within in the brain. The concept is a straightforward one and the theory behind it has been known for some considerable time, but its use depends on extremely sophisticated computer software which has only been available relatively recently.
The advantage of stereotactic neurosurgery is that it requires a smaller craniotomy than traditional "open" surgery and, because it is so accurate, minimises trauma to the surrounding brain tissue. This can often result in much shorter stays in hospital for the patient.
Stereotaxis may be frame-based or frameless.
Frame-Based Stereotactic Surgery
This technique is mainly used to perform a biopsy of the brain and in functional neurosurgery.
A patient undergoing such an operation is anaesthetised and a titanium frame attached to their head. A scan is then taken so that the position and shape of the target can be calculated in three dimensions, relative to the frame. Special surgical instruments are then attached to the frame to enable the surgeon to reach the target with extreme accuracy.
Frameless Stereotaxy
Also known as neuronavigation, frameless stereotaxy does away with the need to attach a frame directly to the patient's head. It involves attaching markers to the scalp, followed by highly sophisticated MRI scanning techniques which build up a 3D reconstruction of the head. This enables the surgeon to view, through his operating microscope, both the actual brain and the 3D image of his target.
This technique is particularly useful for the removal of certain specific small tumours.