<unk>  is a type of surgery in which an endoscope or surgical instruments are inserted into part of the brain by going through the nose and the sphenoid bone (a butterfly-shaped bone forming the anterior inferior portion of the brain case) into the sphenoidal sinus cavity.<unk>  is used to remove tumors of the pituitary gland. (Such tumours, although within the skull, are outside the brain itself).
Transsphenoidal surgery
Head transplant
Frontal sinus trephination
Stereotactic surgery
Astragalectomy
Ablative brain surgery
Anterior temporal lobectomy
Trabeculectomy