The preoperative assessment involves an endocrinological investigation, a vision test and an MR image of the hypophysis. In the event of hormone failure the patient should preferably be placed on hormone replacement therapy before the procedure.
The majority of hypophyseal tumors can be operated on using transsphenoidal access through the nose. In extreme circumstances, the largest tumors must be operated by craniotomy with subfrontal access in order to preserve vision.
The patient will be informed that further growth of the tumor and the operation itself can result in hypophyseal failure. If hypophysis function is normal before the operation, it is relatively rare for the patient to suffer hypophyseal failure as a result of the procedure.
The operation takes place under general anesthesia. An endoscope or operation microscope is used to provide good illumination and magnification, and X-ray examination is used to simplify orientation with regard to anatomic landmarks. The operative access is long and narrow, which hampers instrumentation. The consistency of the tumor and the extent of its growth outside the sella turcica (hypophyseal cavity) are of significance regarding how much of the tumor that can be removed. Most hypophyseal adenomas are soft. The tumor capsule is left to prevent spinal fluid leak.
The method of operation is gentle for the brain and achieves good results with a low risk of complications in the majority of cases.
Tumors (with the exception of prolactinomas) that lift and compress the sensory organs
Hormone-producing tumors (growth hormone - acromegaloidism/gigantism, ACTH - Cushing, thyroxin)
Prolactinomas that do not shrink with drug therapy
Relieve the optic nerves and optic nerve junction
Preserve hypophysis function