A craniotomy is a surgical procedure- removal of a piece of the skull so the surgeon may get access to the brain beneath, for the treatment of a variety of neurological disorders. The cut-away part – called as bone flap – may be tiny or large, and is typically put back in place after surgery on the brain is finished and before the incision closed.
Craniotomies vary in size and complexity. Small dime-sized craniotomies are called burr holes; "keyhole" craniotomies are quarter-sized or larger. Stereotactic frames, image-guided computer systems, or endoscopes may be used to precisely place instruments through these small holes. Burr holes and keyholes are used for minimally invasive procedures to:
- insert a shunt into the ventricle to drain cerebrospinal fluid (to treat hydrocephalus)
- insert a deep brain stimulator (DBS)
- insert an intracranial pressure (ICP) monitor
- remove a sample of tissue cells (needle biopsy)
- drain a blood clot (hematoma aspiration)
- insert an endoscope to remove tumors
A cranioplasty is performed to correct a deformity or defect of the skull. The deformity/defect could be congenital, as a result of trauma or acquired such as after a previous surgery involving the skull. A craniotomy is the most commonly performed surgery for brain tumour removal. It also may be done to remove a blood clot (hematoma), to control haemorrhage from a weak, leaking blood vessel (cerebral aneurysm), to repair arteriovenous malformations (abnormal connections of blood vessels), to drain a brain abscess, to relieve pressure inside the skull, to perform a biopsy, or to inspect the brain. A cranioplasty is a surgical procedure to correct a deformity or defect of the skull, and it is usually performed following a traumatic injury to the skull or after a previous brain surgery such as a craniotomy or craniectomy. To correct the defect the physician may have to use a prosthetic or other synthetic surgical material to complete the procedure.