Definition and Overview
Hypophysectomy refers to pituitary gland removal surgery performed mainly to treat benign or malignant tumours. It can be performed using traditional or open method surgery or using a minimally invasive technique.
The pituitary gland, which is also called hypophysis, is located at the base of the brain, just up in the inside of the nose. Although it’s small, it’s referred to as a master gland since it controls many functions such as growth, metabolism, and sexual reproduction.
Because of the several serious risks involved, surgical procedures like hypophysectomy aren't always the first line of treatment for conditions that affect the pituitary gland. Non-invasive treatment such as medications and therapies are first recommended before a patient is referred to a neurosurgeon for the surgical procedure.
Who Should Undergo and Expected Results
One of the foremost reasons for a pituitary gland removal procedure is a tumour, which can be either malignant or benign. Benign tumours are not cancerous but they require the surgery just the same as they have the potential to continue to grow and press on the gland and the brain, causing severe headaches and possibly life-threatening neurological or vascular problems. If the tumour is malignant (cancerous), the procedure is performed mainly to prevent the spread of cancer to other parts of the body. Some of these tumors can also be hormone secreting, which can then affect the way the body works. So far, most of the reported pituitary tumors are benign.
The procedure may also be necessary if the pituitary gland releases over- or underactive hormones despite other interventions like medications. A good example is the treatment of Cushing’s syndrome, which leads to a range of symptoms triggered by excess amount of cortisol in the bloodstream. Cortisol is produced by the adrenal glands, but it is stimulated by adrenocorticotropic hormone (ACTH) created by the pituitary gland. If there’s a high level of cortisol, the person becomes prone to hypertension and cardiovascular disease. Women, who are more commonly affected, can experience fertility and metabolic problems like insulin resistance.
Once the pituitary gland is removed, the patient may have to take hormone replacements for life, which can have adverse effects like hyperlipidemia, an abnormally high concentration of fats or lipids in the blood.
How Does the Procedure Work?
Before the surgery, the neurosurgeon goes over the patient’s medical records and requests for tests to check the patient’s condition and neurological health to properly plan for the surgery. Just like other major surgical procedures, hypophysectomy requires certain preparations. This includes reviewing the patient’s medications. If he or she is taking blood thinners, the surgeon will advise him or her to stop taking them at least a week prior to the procedure as these can increase risks and complications during and after surgery. The patient is also most likely to be advised to stay in the hospital overnight for close observation.
When it comes to the techniques that can be used, the neurosurgeon has two options: transsphenoidal pituitary hypophysectomy and the conventional method. Transsphenoidal pituitary hypophysectomy is a minimally invasive procedure that involves the use of an endoscope, a long rigid telescope that is introduced into the nasal cavity. It is equipped with a camera that provides real-time visuals of the inside of the nose and light so the surgeon can see the targeted site and its surroundings.
During this procedure, the surgeon makes an incision in the upper palate inside the mouth or inserts the scope directly into the nose. It’s also possible to bore a hole in the skull and insert the endoscope behind the nose or in the sphenoid sinus. Using microsurgical instruments, the sinus is incised to allow the scope to proceed farther.
Once it reaches the back wall, another opening is made to access the pituitary gland and the tumour is removed. Depending on the size of the tumor, it may be removed piece by piece.
In a traditional surgical method, the surgeon accesses the gland through the skull by creating a small hole and removing a part of the bone to access and remove the tumour.
Both surgical approaches, which could take at least an hour to complete, are performed under general anaesthesia.
Possible Risks and Complications
The pituitary gland removal is a very risky procedure. That’s why the neurosurgeon has to take great lengths to ensure the patient fully understands what it entails. Initial complications can include bleeding of the nose, internal cranial hemorrhage, and leaking of the cerebrospinal fluid. There’s also a risk that some part of the brain gets damaged if the surgeon encounters difficulty reaching the gland during the procedure.
Melmed S, Kleinberg D. Pituitary masses and tumors. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 9.
Molitch ME. Anterior pituitary. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 231.