Hypophysectomy: What does it involve?
The pituitary gland (also called the hypophysis) is a small, pea-sized gland in the brain behind the eyes. It produces hormones that regulate many things including body growth, metabolism, and sexual reproduction. The pituitary gland is also called the master gland.
A hypophysectomy is the removal of the pituitary gland. The operation comes with serious risks, and doctors will usually try other non-invasive options before they consider a person a candidate for surgery.
- It is the surgical removal of the pituitary gland.
- The procedure may be done for cancerous or noncancerous tumors.
- It is a risky procedure, with a long recovery time.
- The gland may be destroyed during surgery, leaving the endocrine system without regulation. If this happens, a person will require hormone replacement therapy.
Uses of a hypophysectomy
The pituitary gland.
Benign tumors are not cancerous but can grow and cause headaches. They can also cause life-threatening neurological or vascular problems, which means they may be removed as a precaution.
Cancerous tumors are removed mainly to prevent the cancer from spreading to other parts of the body. Some pituitary gland tumors produce hormones that can cause other conditions, such as Cushing's syndrome, so this may also be a reason to remove the pituitary gland.
The pituitary gland is located near the optic nerves that carry information from the eyes to the brain. Tumors of the pituitary gland can cause tunnel vision, blurred vision, or double vision.
A hypophysectomy is intended to improve or protect eyesight and in some case to correct the overproduction of hormones.
An MRI scan of the pituitary gland will determine if a hypophysectomy is necessary.
The first step is to make sure that a hypophysectomy is the most suitable course of action. A neurosurgeon will make this assessment by performing an MRI scan of the pituitary gland.
The day before surgery, a person will undergo blood tests, chest X-rays, or an electrocardiogram (ECG) to ensure that they are fit enough to have the anesthesia.
There are different ways of performing a hypophysectomy, depending on the problem that is being addressed.
It is a high-risk surgical procedure, and the approach is carefully selected to manage risk and maximize benefit. The surgery is carried out under general anesthetic, and it takes 1-2 hours to complete.
The pituitary gland can be removed through the nose, or it can be removed by opening the skull.
- To remove the pituitary gland through the nose, surgeons make an incision beneath the upper lip. They will then insert a speculum into the nasal cavity, and remove the pituitary tumor with forceps.
- Opening the skull works best if tumors have extended above the cavity in which the gland is located.
A newer method called stereotaxis involves using specialized instruments to destroy or remove tissue with pinpoint precision through tiny holes in the skull.
The hypophysectomy can take up to 2 hours. After this, the affected person will spend another 2 hours in a recovery ward before returning to the neurosurgical ward. Their nose is packed to stop bleeding, and they usually go home the next day.
Some people will require hormone replacement therapy after surgery. The most important hormone is called cortisol. Cortisol is a type of steroid, which helps your body to cope with stress. The drug most commonly used to replace cortisol is called hydrocortisone.
A follow-up appointment with a neurosurgeon and an endocrinologist (a doctor who specializes in hormone disorders) usually happens 6-8 weeks after surgery. This checkup may involve blood tests, eye checks, and a head scan.
Complications can include:
Complications of a hypophysectomy may include nosebleeds.
- nose bleeds
- internal cranial hemorrhage
- leaking of the cerebrospinal fluid
Cerebrospinal fluid (CSF) is a clear fluid which surrounds the brain and spinal cord. Leakage may require a lumbar drain in the lower back to seal the leak and prevent infection. This procedure may take 2-3 days.
Other serious complications include:
- Diabetes insipidus: This occurs when the hormone that regulates water balance (vasopressin) is affected. It causes thirst and excessive amounts of urine. If it does not settle down after a few days, doctors will prescribe hormone replacement therapy.
- Hypopituitarism: This is when the pituitary gland does not produce hormones in the right way. Pituitary gland function that has been damaged by a tumor can become worse after surgery. In his case, doctors will also prescribe hormone replacement therapy.
Sometimes it is not possible to remove all or enough of the tumor and symptoms may be the same as they were before surgery.
Other serious but rare complications may include:
- Injury to the carotid arteries: These are on either side of the pituitary gland and supply blood to the brain. Damage during surgery may lead to stroke or even death, but this happens to fewer than 1 in 100 people who have this surgery.
- Worsening of vision: Occasionally another operation will be needed to remove a small blood clot causing pressure on the optical nerves.
Typically, removal of the pituitary gland is a way of dealing with tumors that do not respond to other treatments.
Alternative non-invasive treatment options include:
- Medication: An endocrinologist may treat some pituitary tumors with medication. However, most tumors do not respond well to this type of treatment.
- Radiotherapy: X-ray treatment can control the growth of some tumors.
- Gamma knife surgery: This involves directing radiation beams at the tumor. It is effective with some small tumors.
The aim of the surgery is to remove the tumor and to try and preserve at least part of the gland. A hypophysectomy is seldom the first course of action.