Parathyroid

There are usually 4 parathyroid glands in the neck (2 on each side) that are responsible for maintaining the normal level of calcium in the blood specifically and the body in general. 

It is simply called “parathyroid” because it is “next to” the thyroid gland (para (GREEK)=beside).  The protein it releases into the blood is called parathyroid hormone (if only all medicine were so simple!).  Parathyroid hormone causes cells in bone to release calcium into the blood, and induces gut cells to increase absorption of calcium from food.  It does this to maintain blood calcium levels within a range required for other bodily functions such as blood clotting, muscle contraction, nerve function.

 

What is an endocrine gland?

A gland in this sense is a bodily unit made of specialized cells that produce and release a specific substance into the blood.  Such glands are called  endocrine glands  (endon GREEK = within).  Thus patients with abnormalities of the parathyroid glands are often initially investigated by an endocrinologist who is a specialist physician with special expertise in disorders of all endocrine glands (e.g. pituitary, pancreas, kidney, thyroid etc).  There are other types of glands in the body that are discussed elsewhere.

What is a hormone?

The substance that an endocrine gland releases into the blood is a specialized protein (hormone) that will induce other cells to change in some way e.g. grow, multiply, secrete etc.

Where are the parathyroid glands?

There are usually 4 parathyroid glands, 2 on each side, superior (upper) and inferior (lower). They are quite small, less than the area of your little fingernail. They are closely associated with the thyroid gland, thus their name.  The superior or upper glands tend to be more constant in location being behind the upper half of the thyroid gland adjacent to the voice box (larynx).  The inferior or lower glands are more variable and may be anywhere from behind the lower half of the thyroid, within the thyroid itself or even lower down in the chest.

Normal feed-back

Normal parathyroid glands are regulated by a “feed-back” mechanism.   As the level of calcium in the blood increases, the stimulation to secrete parathyroid hormone decreases and vice versa.

When is parathyroid surgery advisable?

Parathyroid surgery is indicated when there is an elevated calcium level in the blood (hypercalcaemia) due to over-activity of one or more of the parathyroid glands (hyperparathyroidism).

Hyperparathyroidism causes osteoporosis/ kidney stones/ other symptoms

Parathyroid hormone stimulates the release of calcium from the bones which are the main store for calcium in the body.  Too much of this hormone weakens them (osteoporosis) and increases the risk of fractures particularly affecting the weight-bearing bones such as at the hip and the vertebrae.

The extra calcium appearing in the blood is excreted in the urine and this causes a slowly reduction in  the total amount of calcium in the body.  Calcium within the urine may precipitate in the kidneys themselves or within the drainage system to form“kidney stones” which are not only very painful to pass but also can damage the kidneys themselves. Abdominal discomfort may also occur due to an increased rate of stomach ulcers, inflammation of the pancreas (pancreatitis) and constipation.

Furthermore, people with hypercalcaemia often feel slightly fatigued and depressed with reduced levels of concentration.  These symptoms may be very subtle and certainly may otherwise be due to life pressures. Often it is only restrospectively after abnormal parathyroid gland(s) are removed and a patient feels rejuvenated that the chronic effects of the condition are realized.  I have seen this effect many times with my older patients.

Is surgery really necessary?

A few years ago patients were only operated on when they had obvious signs or symptoms of hyperparathyroidism such as bone fractures, kidney stones, abdominal pain or bone pains.  Now we realize that patients may have subtle symptoms such as lethargy and reduced thought clarity - the presence of which only becomes evident once the disorder is corrected. After surgery these patients simply feel better in themselves.

Also, now with bone density studies being done on post-menopausal women, more and more cases of osteoporosis and hyperparathyroidism are being diagnosed.

While some drugs can lower the level of blood calcium they are only used in the short term and surgery remains the definitive treatment.

What sort of surgery do I need? Can it be done through small incision

Surgery is basically designed to remove the abnormal gland or glands leaving sufficient parathyroid tissue to maintain blood calcium in the normal range. It involves a general anaesthetic, an incision in the lower neck, and usually an overnight stay.  An experienced parathyroid surgeon will have a success rate of at least 95% in cases of primary hyperparathyroidism.  I have been successful in 98% of cases.

 

If the abnormal gland has been localized prior to the operation, a small incision is possible together with a Rapid Parathyroid Hormone Assay when available.  With this we can demonstrate a drop in the high parathyroid hormone levels once the rogue gland(s) has been removed.  In this situation the patient usually goes home the next morning although some may be as a daystay. 

Where the rogue gland(s) has not been identified prior to surgery, a larger incision is usually required with a search on both sides of the neck.

 

 

What is hyperparathyroidism?

Adenoma/ Hyperplasia/ Primary hyperparathyroidism

Hyperparathyroidism is where one or more parathyroid glands produces too much parathyroid hormone. Usually this is because one gland has developed a benign tumour or adenoma where the cells are autonomous i.e. they don’t obey the rules, secreting regardless of the consequences.  

Much less frequently all parathyroid glands are involved due to an increase in the number of cells in each gland (hyperplasia). 

When the abnormality is due to autonomy of one or more glands (adenoma or hyperplasia) the condition is called primary hyperparathyroidism i.e. excess secretion of parathyroid hormone because of an abnormality arising in the parathyroid gland itself.

Hyperplasia involving all the glands may be associated with abnormalities in other endocrine glands, a condition known as multiple endocrine neoplasia or by the acronym “MEN”.

Secondary hyperparathyroidism

In some patients parathyroid abnormalities arise in a background of prolonged excessive parathyroid stimulation i.e. it is secondary or due to a problem elsewhere in the body.

The classic case is in chronic kidney (renal) failure.  Kidneys are involved in the metabolism of vitamin D which helps regulate absorption of calcium from the gut.  In this situation, chronically low vitamin D levels cause a tendency to low calcium levels as not enough is absorbed from the gut.  By the feed-back mechanism, this in turn causes parathyroid gland stimulation and an increase in parathyroid cells in each gland (hyperplasia) thus producing more parathyroid hormone.  The increase in parathyroid hormone causes release of calcium from the bones to maintain a normal serum calcium level. This is secondary hyperparathyroidism i.e. secondary to kidney disease.

Tertiary hyperparathyroidism

After a while, and as we see in society, a chronically bad situation can lead to autonomous and delinquent behaviour.  In this case, chronic kidney failure with prolonged parathyroid stimulation can cause the cells to become autonomous and to overproduce parathyroid hormone.  They no longer respond to the feed-back mechanism and cause high blood levels of calcium. This is called tertiary hyperparathyroidism.

What are typical parathyroid tests?

Blood tests

Usually the diagnosis is made on a blood test which will show a raised level of calcium. You will then be sent for further blood tests to demonstrate an elevated level of parathyroid hormone. Kidney function will also be checked by blood tests to rule out the possibility of secondary or tertiary hyperparathyroidism (see FAQ's). 

Urine sample

Often you will be asked to submit a sample to demonstrate an elevated amount of calcium in the urine.

Ultrasound scan

This can be useful in localising an enlarged parathyroid but will only pick up about 50%. It is dependent on the size of the adenoma and also on the size and nodularity of the overlying thyroid gland

Sestamibi scan

This is a dynamic study whereby a chemical is injected into a small vein and taken up by active parathyroid cells. A special scanner can then create an image whereby an enlarged and hyperactive parathyroid gland is seen to stand out from the rest of the neck tissues. This is very useful in planning minimal access parathyroid surgery but will only detect around 80% of adenomas. Where the abnormal gland cannot be localised, minimal access surgery cannot be done.

In the scan to the left the parathyroid adenoma is marked with a red arrow. Note how there is symmetrical uptake in the submandibular and parotid salivary glands higher up around the face.

 

When and where will the operation be done?

What must I do in the week(s) before Surgery? (insurance, hospital, family, work)

What do I do on the day of Surgery and what shall I bring into hospital?

What will happen when I go to Theatre?

What will happen when I get back on the ward following surgery?

Are there any risks of parathyroid surgery?

Complications are rare, they include:

Significant voice change

There are 2 nerves that go to each side of the voice box.  These are more at risk with thyroid than parathyroid surgery.  My incidence of a significant voice change after parathyroid surgery is less than 1%.

Low Calcium Levels

It is possible that once the abnormal gland(s) is removed that the leeched bones start to take back calcium from the blood causing a drop in the blood calcium level.  This is called “Hungry Bone Syndrome”. 

Also, if you have had high calcium levels for a long time you may feel that a normal level is too low for you.  This may last for a few days.

In both these situations one can experience tingling around the lips, fingertips and toes and also a fine tremor.  This is because calcium is important for nerve and muscle function.  Calcium tablets may be necessary for a few days or weeks until the situation normalizes.

Bleeding

Bleeding into the wound can occur in around 1% of any operation.  If this does occur it will be necessary to return to theatre to control it.

Failure

Yes it does happen.  In experienced hands rates of about 5% are quoted with primary hyperparathyroidism.  My failure rate is around 1%.

What are the costs for parathyroidectomy?

There are generally 3 costs for any procedure:  surgeon’s fee, anesthetist’s fee, hospital fee. These are given separately by the surgeon, the anaesthetist and the hospital and are to be paid separately. 

Dr McIvor’s secretary will give or post to you an estimate for all three of these costs.  It is important that you discuss this with your insurance company prior to coming into hospital. 

The hospital account is to be paid at the time of discharge from the hospital. The anaesthetic and surgeon fees should be settled on receipt of the account through the post or at the post-operative appointment?

How will I feel after the operation?

Surprisingly good is the answer.  I have had thyroid surgery so I know.  My anaesthetist Graeme Crookes also put me to sleep for my thyroid operation. He is excellent.  Once you are asleep, Graeme puts lots of local anesthetic into the neck around the operation site to reduce pain during the procedure.  That way he doesn’t have to give heavy pain-killers and as a result you have a lighter anesthetic and wake up faster.

You can eat and drink and receive visitors on the evening of surgery.  If there is a drain it is usually kept in overnight.  There may be a sensation of mucus in the throat that causes you to “ahem” a bit over the first week.  Paracetamol and maybe an anti-inflammatory for a few days is all the pain relief required. 

Despite all this you should plan a week and preferably 10 days off work as anesthetics tend to make you a bit tired.

What care do I need to take regarding my neck wound?

Keep your neck wound clean and dry.  There will be a paper tape over the wound to protect the wound.

After your skin tapes are removed at your one week appointment and the scar is healing well you can rub a small amount of unscented moisturising cream on the scar so it is less dry as it heals.  Vitamin A, Vitamin E, Bio-oil , or Aloe Vera are effective. Take care not to knock your wound and remember to keep the wound dry if it becomes wet after bathing or showering by patting it dry with a clean towel.

The pressure of rubbing the cream in will also help to soften the scar.

If your neck becomes increasingly painful, red or swollen or you notice any discharge then please seek medical advice from Dr McIvor or your GP.

Will I have a scar?

All incisions leave scars but a parathyroid incision usually heals to leave a fine scar which is not very noticeable. Providing the abnormal gland can be reliably localised before surgery a small incision of about 4cm can be employed.

What rest do I need and when should I return to work?

You will need to take it easy while your neck wound is healing. This means avoiding strenuous activity and heavy lifting for a couple of weeks. The wound area will gradually feel less stiff and you will soon be able to enjoy your normal activities.

You will probably need to take one to two weeks off work (or sometimes longer) depending on your occupation and the nature of your work.   Dr McIvor can issue you with a note for two weeks and then you should see your GP if more time is required.

What about my medications and tablets?

Please continue to take the medication you have been prescribed and ensure that you have a good supply. If you are unsure about any of the tablets you need to take, please check this with a nurse before you go home. Repeat prescriptions can be obtained from your GP.

What follow-up will there be?

Following your discharge you will need to be reviewed in the outpatient clinic to check how your wound is settling down, and how you are feeling. You will usually receive the date and time for this appointment through the post or by phone from Dr McIvor’s secretary. Please contact Dr McIvor’s secretary (09 441 3981)if you do not receive one shortly following discharge.

If you are on calcium supplements blood tests for calcium will be initially twice a week.

Most patients are not on calcium supplements but a follow-up blood test will be arranged to ensure that the calcium and parathyroid hormone levels remain in the normal range.

You will most likely have a follow-up with an endocrinologist to check that the calcium balance is restored. The endocrinologist may put you on medication to ensure adequate uptake of calium into the bones and arrangements may be made for a bone density study.