Hypophysectomy is the surgical removal of the hypophysis (pituitary gland). It is most commonly performed to treat tumors, especially
craniopharyngioma
A craniopharyngioma is a rare type of brain tumor derived from pituitary gland embryonic tissue that occurs most commonly in children, but also affects adults. It may present at any age, even in the prenatal and neonatal periods, but peak incidence ...
tumors. Sometimes it is used to treat
Cushing's syndrome
Cushing's syndrome is a collection of signs and symptoms due to prolonged exposure to glucocorticoids such as cortisol. Signs and symptoms may include high blood pressure, abdominal obesity but with thin arms and legs, reddish stretch marks, a ...
due to
pituitary adenoma
Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.Simmond's disease It is also applied in
neuroscience
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...
s (in experiments with lab animals) to understand the functioning of hypophysis. There are various ways a hypophysectomy can be carried out. These methods include transsphenoidal hypophysectomy, open craniotomy, and stereotactic radiosurgery.
Medications that are given as
hormone replacement therapy
Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. These symptoms can include hot flashes, vaginal ...
following a complete hypophysectomy (removal of the pituitary gland) are often
glucocorticoids
Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebr ...
. Secondary Addison's and hyperlipidemia can occur. Thyroid hormone is useful in controlling cholesterol metabolism that has been affected by pituitary deletion.
Methods of hypophysectomy
Hypophysectomies can be performed in three ways. These include transsphenoidal hypophysectomy, open craniotomy, and stereotactic radiosurgery. Each of these methods differ in the method in which the pituitary gland is removed.
Transsphenoidal hypophysectomy
In a transsphenoidal hypophysectomy, the pituitary gland or section of the pituitary gland is removed through the
sphenoid sinus
The sphenoid sinus is a paired paranasal sinus occurring within the within the body of the sphenoid bone. It represents one pair of the four paired paranasal sinuses.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012 ...
and out through the nose.
Open craniotomy
In an open
craniotomy
A craniotomy is a surgical operation in which a bone flap is temporarily removed from the skull to access the brain. Craniotomies are often critical operations, performed on patients who are suffering from brain lesions, such as tumors, blood clot ...
, a cavity is opened within the skull to reach the pituitary gland. Once the cavity is open, the pituitary gland is removed through the cavity.
Stereotactic radiosurgery
in stereotactic radiosurgery, a headframe is applied to a patient.
MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...
or CT scans are then administered on the patient to allow a map of the head/brain to be formed. This map will then be used as a guide to allow correct orientation of the lasers administering radiation to specifically destroy the pituitary gland or part of the pituitary gland.
Complications
Hypophysectomy performed at any age causes atrophy of the
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
and
adrenal gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex whic ...
s as well as
asthenia
Weakness is a symptom of a number of different conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, i ...
and
cachexia
Cachexia () is a complex syndrome associated with an underlying illness, causing ongoing muscle loss that is not entirely reversed with nutritional supplementation. A range of diseases can cause cachexia, most commonly cancer, congestive heart ...
. When the procedure is performed before sexual maturity, the reproductive tract remains undeveloped and non-functional. There is also a general lack of growth. If performed after sexual maturity, there will be a loss of reproductive function along with atrophy of gonads and accessory reproductive structures.
There is a risk of cerebral spinal fluid leak due to penetration of the basal skull and risk of increased cerebral spinal fluid pressure that may lead to central nervous system changes. Post surgery, patients may have a severely altered
self-image
Self-image is the mental picture, generally of a kind that is quite resistant to change, that depicts not only details that are potentially available to an objective investigation by others (height, weight, hair color, etc.), but also items that h ...
that may lead to an increased risk of suicide. There is also an increased risk of hemorrhage and infection secondary to the surgical procedure.Swearingers. Manuel of medical surgical nursing: A care planning Resource. 7th Edition
See also
*
List of surgeries by type
Many surgical procedure names can be broken into parts to indicate the meaning. For example, in gastrectomy, "ectomy" is a suffix meaning the removal of a part of the body. "Gastro-" means stomach. Thus, ''gastrectomy'' refers to the surgical remo ...