Parathyroid Surgery

As a qualified breast and endocrine surgeon, Dr Murugappan specialises in the surgical treatment of parathyroid disease. The information provided here is intended to give a general and basic understanding of the role of the parathyroid glands, and insight into parathyroid conditions and the role for surgical management. We recommend talking to your medical practitioner to determine which information is relevant to you and to clarify any questions you may have. During your appointment with us, Dr Murugappan will discuss your specific case and treatment options. If you have any questions related to this material or your individual case, please do not hesitate to ask.

The parathyroid glands are four small glands located in your neck behind the thyroid gland. They play an important role in controlling the level of calcium in your bloodstream and in regulating the use of calcium in the body.

They do this by producing a hormone called “Parathyroid Hormone”, also known as PTH. PTH works to increase the level of calcium in the blood stream by; breaking down bone, increasing absorption of calcium from food, and reducing loss of calcium in the urine.

When the levels of PTH are too high, the level of calcium in the blood rises. This can cause problems as calcium is involved in many aspects of normal bodily function. Specifically, effects may include;

• Mood disturbance
• Fatigue
• Abdominal Pains
• Bowel dysfunction
• Kidney Stones
• Kidney injury
• Increased urination
• Muscle weakness and muscle aches.
• Heart beat irregularities

In addition, because elevated levels of PTH increase bone breakdown, this can lead to osteoporosis and increased risk of bone fracture.

While some patients with elevated calcium may not show any symptoms, if calcium levels in the blood become high enough, the effects can prove fatal.

What causes elevated PTH?

An elevated level of parathyroid hormone is also referred to as “Hyperparathyroidism”. This condition is generally broken up into three types; primary, secondary and tertiary.

Primary Hyperparathyroidism is due to excess parathyroid hormone secretion from an overactive gland or glands. This is most commonly due to a single overactive gland called a parathyroid adenoma. This is a non-cancerous condition whereby one gland has become enlarged and has begun to excessively excrete hormone. Less commonly, it can also be the result of; multiple adenomas – where 2 or more of the parathyroid glands are involved, hyperplasia – generalised enlargement of all glands, or parathyroid cancer.

Parathyroid cancer accounts for less than 1% of all cases of Primary Hyperparathyroidism.

Secondary Hyperparathyroidism is a result of low calcium levels, most commonly observed in Vitamin D deficiency or in renal disease. Because of the low calcium levels, the body tries to compensate by increasing PTH production.

When secondary hyperparathyroidism is prolonged, the increased PTH production can cause enlargement of the parathyroid glands, and they may begin to excrete PTH irrespective of blood calcium levels. This condition is termed Tertiary Hyperparathyroidism.

There are a number of investigations your doctor will arrange when they have a suspicion of parathyroid disease. These are likely to include;

Pathology Tests

• Parathyroid Hormone Level – with be elevated in hyperparathyroidism.
• Calcium Level – May be elevated to varying degrees in primary and tertiary hyperparathyroidism, or even normal in secondary hyperparathyroidism.
• Vitamin D level – needs to be checked to assess for an easily reversible cause of secondary hyperparathyroidism
• Urinary Calcium Creatinine Ratio – performed by testing a urine sample collected over 24 hours. This is done to help evaluate the possibility of a condition called Familial Hypocalciuric Hypercalcemia – a rare genetic condition which may mimic primary hyperparathyroidism but does not require surgery.
• Thyroid Function Tests – checked to exclude any co-existing pathology that may need to be considered at the time of surgery.

Imaging

Imaging is performed to assess the anatomy of your neck and to try and locate which gland or glands may be enlarged or overactive.

• Neck Ultrasound Scan – performed to locate the enlarged gland or glands
• Sestamibi Scan – a special type of imaging scan where a mild radioactive agent is injected into your blood stream. This is more readily absorbed by overactive parathyroid glands. Imaging shows areas where uptake is high and therefore is helpful in locating an overactive gland.
• CT scan may be performed if abnormal anatomy is suspected e.g. if an abnormal gland has not been located using either of the two methods above.

Surgical treatment of hyperparathyroidism involves removal of the involved glands.

Primary Hyperparathyroidism

In the case of a single parathyroid adenoma, what surgery you will need depends on whether or not the abnormal gland has been identified. Typically, you have four parathyroid glands, two on the right and two on the left. An ultrasound and a sestamibi scan is commonly all that is required to determine which gland is enlarged and overactive. With enough certainty on imaging, a MIPS procedure can be performed.

MIPS, or Minimally Invasive Parathyroid Surgery, involves making a small incision in the neck, carefully dissecting around important structures to locate the parathyroid gland identified in the imaging, and removing it. The benefit of being able to undergo a MIPS procedure is that the incision in the neck is generally smaller and less tissues are disturbed. If the gland located during a MIPS procedure does not look abnormal, then it is important to convert to a bilateral neck exploration to exclude to possibility of a parathyroid adenoma at a different site.

A Bilateral Neck Exploration means, literally, exploring both sides of the neck. This procedure is performed when testing confirms the diagnosis of primary hyperparathyroidism, but the imaging is unable to identify the location of the abnormal gland.

This procedure involves making an incision in the neck and carefully dissecting around the surrounding tissues to locate all four parathyroid glands. The glands are inspected and any abnormal glands are removed.

Secondary and Tertiary Hyperparathyroidism

In tertiary or secondary hyperparathyroidism, where normal calcium levels are unable to be effectively controlled medically, you may be referred for parathyroid surgery. Because all four glands are involved, this surgery typically requires a bilateral neck exploration with removal of all four glands, followed by gland re-implantation. With re-implantation, a portion of one of your removed glands is dissected and then injected into a neck muscle.

Re-implantation is necessary because without your body producing enough parathyroid hormone, your blood calcium levels drop dangerously low. The re-implanted parathyroid gland develops new blood supply and will start working to produce parathyroid hormone again, to help maintain normal calcium levels.

Hospital Stay

• Regardless of whether you undergo a MIPS or a bilateral neck exploration, both operations require a general anaesthetic and the minimum of an overnight stay in hospital.
• Patients with secondary or tertiary hyperparathyroidism who have four gland removal and re-implantation will typically need a longer stay in hospital while their calcium levels normalise. This is likely to involve an ICU (Intensive Care Unit) stay where calcium levels can be monitored more closely and intravenous calcium replacement can be given more easily if needed.

How will you feel

• After waking from your anaesthetic it is very common to have a stiff sore neck. This is from a combination of your neck positioning during surgery, the operation itself, and the tube placed in your airway to assist your breathing during the operation.
• In most cases, after you are sufficiently awake following your anaesthetic, patients can eat a full diet.
• Some people do feel nauseous or even vomit after an anaesthetic. If this is the case for you, rest assured that we can give you some medication to assist and that this feeling will improve as you recover from your anaesthetic.

Wound Care

• Your incision will be stitched with dissolvable sutures, meaning that you will not need to get any sutures removed. It will then be covered with a simple dressing. We ask that you keep your dressing in place until your next outpatient appointment with Dr Murugappan.
• In all cases, Dr Murugappan will endeavour to make the incision within an existing neck crease as this will result in the best cosmetic outcome. It is normal to experience some swelling around the incision site which will continue to improve in the days and weeks following surgery.
• With any incision there is always a risk of bruising and scarring. A minority of patients may be prone to excessive scarring (keloid scarring).
• In the case of difficult or extensive dissection, it is possible that a drain may be placed in the operative site. This is a precautionary measure used to alleviate pressure in the unlikely event of any bleeding after the operation. If you have a drain placed, it will be removed following surgery before you are discharged from the hospital.

Calcium and PTH Levels

• After your operation, your calcium and PTH levels will be checked. Your body requires only ½ to 1 parathyroid gland to maintain normal calcium levels, however after the sudden loss of excessive production from an abnormal gland, it can take a while for calcium and PTH levels to normalise. This may mean that you need to take Calcium and Vitamin D supplements in order to maintain normal calcium levels. In some cases, especially in the case of a bilateral neck exploration, PTH levels may not return to normal and patients may need to take lifelong calcium and vitamin D supplementation.

Voice Changes

Most patients following parathyroid gland surgery will wake up with either a normal or slightly hoarse voice due to the breathing tube used while asleep. A small percentage of patients may experience longer-term voice hoarseness due to damage to the recurrent laryngeal nerve, a nerve which helps to control the vocal cords.

Because of the close relationship of this nerve to the thyroid and parathyroid glands, the nerve may be manipulated or bruised during your operation, causing a temporary voice hoarseness. This typically resolves over a few weeks to months.

For parathyroid surgery there is a less than 1% risk of transection of the recurrent laryngeal nerve, resulting in permanent voice hoarseness.

Operative Success and Results

In primary hyperparathyroidism, most cases (over 90%) are cured in a single operation – the success rate being higher if the adenoma has been well localised on imaging prior to surgery. Once removed, the parathyroid gland is sent to a pathology lab and examined microscopically where the diagnosis of a parathyroid adenoma can be confirmed. Your follow-up blood tests are also used to check that calcium and PTH levels return to normal.

The diagnosis of cancer, known as parathyroid carcinoma, is extremely rare and accounts for less than 1% of cases of primary hyperparathyroidism. The pathologist will look for features of parathyroid carcinoma when examining the gland microscopically.

In some circumstances the adenoma cannot be identified during the operation. Occasionally this may be due to an abnormally positioned gland or the presence of an additional parathyroid gland. If the abnormal gland cannot by identified, the next step is to undergo further imaging and investigation. Further surgery may be required.

There is also a small risk that despite a gland appearing abnormal and being removed during surgery, the PTH and calcium levels do not return to normal. Whilst rare, this may be due to the presence of more than one parathyroid adenoma. If PTH and calcium levels remain elevated post-surgery, further investigation and possibly further surgery is required.

Many of the risks of parathyroid surgery are discussed above. These include;

• Swelling
• Bruising, scarring
• Neck stiffness/soreness
• Wound infection
• Bleeding
• Recurrent Laryngeal Nerve Injury
• Permanent Hypoparathyroidism i.e. permanent low calcium levels and need for lifelong calcium and vitamin D supplementation.
• Need for repeat operation due to multiple adenoma or inability to locate adenoma.