There are three ways to monitor pressure in the skull (intracranial pressure).
The intraventricular catheter is thought to be the most accurate method.
To insert an intraventricular catheter, a burr hole is drilled through the skull. The catheter is inserted through the brain into the lateral ventricle. This area usually contains liquid (cerebrospinal fluid or CSF) that protects the brain and spinal cord.
The intracranial pressure (ICP) can be monitored this way. The ICP also can be lowered by draining cerebral spinal fluid (CSF) out through the catheter.
The catheter may be hard to get into place when the intracranial pressure is high.
This method is used if the patient needs to be monitored right away. A subdural screw or bolt is a hollow screw that is inserted through a hole drilled in the skull. It is placed through the membrane that protects the brain and spinal cord (dura mater). This allows the sensor to record from inside the subdural space.
If an epidural sensor is used, it is inserted between the skull and dural tissue. The epidural sensor is placed through a burr hole drilled in the skull. This procedure is less invasive than other methods, but it cannot remove excess CSF.
Lidocaine or another local anesthetic will be injected at the site where the cut will be made. You will most likely get a sedative to help you relax.
- First the area is shaved and cleansed with antiseptic.
- After the area is dry, a surgical cut is made. The skin is pulled back until the skull is seen.
- A drill is then used to cut through the bone.