Adrenal Surgery in Brisbane by Dr. Green

What is the adrenal gland?

The adrenal gland is a small endocrine gland that secretes various important hormones. You have two adrenal glands in your body. They both sit on top of your kidneys.

The adrenal gland secretes various hormones that are important for normal body functions.

  • Catecholamine – Adrenaline and Noradrenaline – increase blood pressure and heart rate.
  • Aldosterone – Affects the kidney to reabsorb sodium and water resulting in elevated blood pressure.
  • Cortisol – Released in response to stress to increase metabolism and sugar levels.
  • Androgens – Hormones that are the building blocks for development of sex hormones responsible for maintaining male sexual characteristics (testosterone).

Normally the adrenal glands are very small and only weigh 5-10grams.

What is an adrenal incedentaloma?

An adrenal incedentaloma is a term given to any lesion or growth of the adrenal gland that is found accidentally.

Adrenal problems are regularly found accidentally when a patient is having a scan for another reason.

Most patients are unaware of any symptoms or may become aware of symptoms when questioned.

The next step once an incedentaloma is found is to determine if it is overactive or possibly a cancerous growth.

Is an incedentaloma an adrenal cancer?

Very rarely is an adrenal incidentaloma turn out to be a cancer of the adrenal gland. The overwhelming majority are due to a benign (not dangerous) tumour of the adrenal called an adenoma.

An adenoma can either be inactive or can be overactive and releasing an excess of adrenal hormones. This is then called a functional adenoma.

A CT scan will be done to assess the adrenal gland and tumour more closely. Size is an important feature. Cancer is very rare in tumours less than 3cm. Tumours that are small and not overactive will often be observed. Once a tumour is over 5cm in size the risk of cancer increase quite substantially and surgery is recommended in case there is a small cancer developing.

What is a functioning tumour? (phaeochrmocytoma, Conns and Cushing’s tumour)

When an adrenal tumour called an adenoma is secreting excess hormones it is referred to as a functional adrenal adenoma. These tumours that produce excess hormones often have a specific name depending on the hormone that is produced:

  • Phaeochrmocytoma – excess catecholamine (adrenaline and noradrenaline).
  • Cushing’s tumour – excess cortisol production.
  • Conn’s tumour – excess Aldosterone.

Each of these tumours results in a different set of side effects and potential long-lasting problems on the rest of the body.

Phaeochromocytoma

Is a tumour that secretes an excess of catecholamine (adrenaline and noradrenaline). These hormones normally increase heart rate and blood pressure. Patients with a phaeochromocytoma (phaeo) usually have very high blood pressure that is difficult to control with medication. Patients also complain of sweating, tremors, palpitations (irregular heart eats) and headaches. These tumours can be very dangerous if left untreated. Prior to surgery you will be required to take a powerful blood pressure medication called phenoxybenzamine to lower your blood pressure enough to make surgery safe.

A phaeo can also be due to an inherited genetic disorder that results in multiple endocrine tumours developing. This syndrome is called MEN-1(multiple endocrine neoplasia type 1).

Cushing’s tumour

is a tumour that secretes and excess of cortisol. Patients with a Cushing’s tumour have symptoms and signs that are due to an excess cortisol. This is called Cushing’s syndrome and causes the following signs and symptoms:

  • High blood pressure
  • Bruised skin
  • Weak muscles
  • Increase central body fat
  • Moon shaped face
  • Excessive sweating
  • Stretch marks
  • Acute psychosis

Conn’s Tumour

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Is the result of an adrenal tumour that secretes excessive Aldosterone. The aldosterone acts on the kidneys causing them to reabsorb Sodium and water to raise blood pressure. It does this by secreting Potassium in the urine instead of the sodium. The result is a patient who has a high blood pressure and a low potassium level.

If this is determined, patients will undergo a test called adrenal vein sampling to confirm the high aldosterone is due to a tumour and not due to general hyperplasia of the adrenal glands which would not require adrenal surgery.

What tests do I need to have done?

Tests are broken into two categories:

  • Imaging to define the anatomy and size.
  • Functional tests to determine if hormones are being secreted excessively.

Imaging studies

These are performed to locate the tumour or to assess the anatomy and surrounding structures to aid the removal. The common imaging studies performed include:

  • CT scan – Most common, allows assessment of the density, invasion into surrounding organs (if cancer is suspected) and identification of the blood vessels and size. Will be performed on all patients.
  • Ultrasound – Usually not performed to aid surgery. Can be used for follow up of a small tumour to see if it is growing. Done to avoid further CT scans and the associated radiation.
  • MRI scan – Not a common first line scan. Usually only done when there is a possibility that the tumour is a benign fat tumour that may not need surgery called a myelolipoma. May be performed when a CT is not possible.

Functional studies

Depending on the type of tumour that is suspected a series of functional test may be ordered. Initially a screening set of test will be conducted to see if a tumour is functioning and secreting excess hormones.

  • Cortisol Level – elevated in Cushing’s tumours.
  • Renin to aldosterone ratio – elevated in Conn’s tumours.
  • Plasma catecholamine and metanephrines – elevated in phaeo.
  • 24hr urinary cortisol, catecholamine and metanephrine collection.

Once the likely type of tumour is determined further test will be arranged to confirm the result.

MIBG scan

A phaeochromocytoma will take up a fluorescent protein. When scanned the adrenal gland will glow bright conforming a phaeo. This will also confirm only a single gland is involved and that there is not extra-adrenal disease.

Dexamethasone suppression test (DST)

This is a blood test to assess your cortisol levels before and after being given a dose of dexamethasone. Normally your cortisol will be supressed by the dexamethasone. If a tumour producing excess is present the cortisol will remain elevated. The first blood test is done in evening followed by the dexamethasone. The second blood test is performed at 8am the following morning.

Adrenal vein sampling

Is only performed when a Conn’s tumour secreting an excess of aldosterone is suspected. This test requires an invasive procedure called an angiogram where a catheter is passed via a vein in your leg to the adrenal glands. Samples are taken to measure the aldosterone level. If a Conn’s tumour is present then the side with the tumour should be greatly increased.

Do all tumours need adrenal surgery?

Not all tumours need to be removed by an adrenal surgeon. However, there are guidelines that determine what lesions need removal and which ones can be observed.

Non-functioning tumours / adenomas

  • >5cm – Should be removed due the potential cancer risk.
  • 3 to 5cm – Remove if suspicious features are present.
    • Very dense tissue on CT scan.
    • Increase size on follow up CT.
    • Irregular margins and possible invasion.
  • <3cm – No need to remove unless concern over cancer.

Functioning tumours / adenomas

All need removing due the secondary effects on the body, no matter what size.

How is the surgery performed?

Traditionally adrenal surgery has been performed via a keyhole approach through the front of your abdomen. Dr Green is now routinely performing what is referred to as a retroperitoneal laparoscopic approach. This is still a keyhole approach that removes the adrenal gland through your back.

There are a number of benefits to this type of adrenal surgery. The most beneficial improvement is a faster recovery time. Patients are usually up and about the same evening after the surgery and nearly all are ready to go home the next day. This results in a faster return to normal activities and less time away from work.

In the previous older approach from the front of your abdomen not all patients where suitable for a keyhole operation. If you have had previous abdominal surgery the keyhole approach is often not suitable or possible and a large cut was needed. This results in a prolonged hospital stay and lengthy painful recovery. The approach through the back that is performed by Dr Green can still be performed even if you have had previous abdominal surgery. Therefore, people who may not be offered keyhole surgery if having a front approach will now be suitable for a keyhole approach.