A craniotomy is a surgical procedure that allows access to the brain and other tissues within the skull in order to treat various conditions and disorders. Some conditions that may call for the procedure include benign and cancerous brain tumors, cerebral aneurysm, and hydrocephalus.
A craniotomy involves removing a section of bone from the skull. At the end of the procedure, the bone is put back in place and eventually fuses with the bones of the skull.
First, an incision is made in the scalp covering the skull near the tumor or disorder. A series of small burr holes in the skull are made to roughly mark the edges of the bone to be removed. The bone “flap” is then created by cutting between the burr holes until it can be removed from the surrounding skull bone. The membranes covering the brain are then cut away to reveal the area of the brain to be treated.
After the treatment is completed, the brain membranes are sutured (or replaced and sewn shut), and finally the bone flap is restored to the skull and anchored with wire sutures, plates or screws. Burr holes may be covered with small plates. Finally, the scalp is sewn back together. The patient is admitted to the intensive care unit and given antibiotics to prevent infection.
A craniectomy is a similar procedure in which a portion of bone is removed from the skull, but not put back in place. For example, the bone may not be replaced over an area of the skull that is covered by muscle, or a tumor may have invaded that section of bone. A prosthetic plate may replace skull bone that is not put back in place.