Adrenalectomy

The Adrenal Cortex
Adrenocortical tumour treatment
Adrenal medulla tumour treatment
Methods
Complications
Specific complications

Adrenalectomy involves the surgical excision of the adrenal gland(s), which are located on top of the upper poles of the kidneys. The adrenal gland has two distinct components, which derive from different types of cells during foetal development; the cortex and the medulla. These two areas produce a variety of hormones, with different effects on the body. Tumours can arise from either area and can be benign, malignant, functioning or non-functioning. The decision to surgically remove these tumours depends on various factors, such as if the tumour is secreting hormones affecting the body's function, or if the tumour appears to be cancerous (malignant). Adrenalectomy can be performed through keyhole surgery with a camera (laparoscopically) or as an open procedure. The method chosen depends on the size or the tumour and whether it is malignant. Laparoscopic procedures are best for small benign tumours, and are associated with reduced post-operative pain and earlier discharge from hospital. Open procedures can be more appropriate for large tumours, and can be performed via an anterior approach or extraperitoneal (posterior through the bed of the 12th rib or postero-laterally).

The Adrenal Cortex

Adrenalectomy involves the surgical excision of the adrenal gland(s), which are located on top of the upper poles of the kidneys. The adrenal gland has two distinct components, which derive from different types of cells during foetal development; the cortex and the medulla.

The adrenal cortex produces glucocorticoids (cortisol, corticosterone), mineralocorticoids (aldosterone) and sex steroids (oestrogen, testosterone, DHEA). The release of these hormones is under the control of the hypothalamus (an area of the brain), which releases corticotrophin-releasing factor (CRF) that stimulates the secretion of adrenocorticotropic hormone (ACTH) from the pituitary (a small gland attached to the base of the brain). ACTH then stimulates the production of hormones from the adrenal cortex. The adrenal medulla, which arises from neural crest cells and therefore under the control of the sympathetic nervous system, produces catecholamines (adrenaline, noradrenaline, dopamine). Tumours can arise from either area and can be benign, malignant, functioning or non-functioning. The decision to surgically excise these tumours depends on various factors, such as if the tumour is secreting hormones affecting the body's function, or the likelihood or definitive diagnosis of the tumour being malignant.

Adrenocortical tumour treatment

Glucocorticoid-producing tumours: Treatment involves adrenalectomy. This is usually cures benign tumours (adrenal adenomas) but is rarely curative for carcinomas (malignant tumours). Radiotherapy and medical treatment may therefore be necessary in this case. To the right is an x-ray image of an adrenal carcinoma.

Aldosterone-producing adenomas: Treatment involves adrenalectomy, plus spironolactone (a medication which blocks the effect of aldosterone) for 4 weeks preoperatively to avoid suppression of the non-affected adrenal gland.

Adrenal medulla tumour treatment

Pheochromocytoma: Treatment involves adrenalectomy plus prevention of intraoperative and postoperative complications (see below).

Methods

Adrenalectomy can be performed through keyhole surgery with a camera (laparoscopically) or as an open procedure. The method chosen depends on the size or the tumour and whether or not it is malignant. Laparoscopic procedures are best for small benign tumours, and are associated with reduced post-operative pain and earlier discharge from hospital. This is usually the treatment of choice for aldosterone-producing tumours (in Conn's syndrome), as these are almost always small (<1cm) and benign, and is now frequently used in the management of pheochromocytomas (catecholamine-producing tumours). This approach should not be used for large carcinomas of adrenocortical origin. Open procedures can be more appropriate for large tumours. Most open procedures are via an extraperitoneal approach, either posteriorly (especially for bilateral lesions) through the bed of the 12th rib or postero-laterally. This approach is associated with reduced pain and discomfort and fewer post-operative complications. An anterior approach is generally only used for large and probably malignant tumours and involves excision through the peritoneal cavity.

Complications

Complications from adrenalectomy arise from the surgery itself or are specific to the type of tumour removed. General complications of open abdominal or laparoscopic surgery include those of general anaesthetia (nausea, vomiting, headache and rarely serious complications such as aspiration pneumonia, anaphylaxis or death), and those of the procedure (damage to the surrounding bowel causing leakage of bowel fluid, haemorrhage, infection, ileus, adhesions within the abdomen and weakness of the wound leading to bursting or herniae).

Specific complications include:

Phaeochromocytoma:

intraoperative increased blood pressure (hypertensive crisis), due to the massive release of catecholamines upon handling of the tumour.
postoperative decreased blood pressure (hypotension) and massive fluid requirements following the fluid shifts that follow catecholamine control.
These are avoided by careful preoperative preparation with administration of alpha-adrenergic blocking agents.

Adrenal Cortex Tumour

Addisonian crisis (decreased adrenal cortical function) can occur after the removal of a glucocorticoid-secreting tumour. This is due to the suppression of the non-affected adrenal gland by negative feedback from the prior excess steroid production.
This can be prevented by the administration of steroids until the remaining gland recovers. This can take up to 4-6 weeks.

Reference

[1] Health Department of Queensland â€“ Consent Forms and Guidelines. [2] Longmore, M et al (2001), Oxford Handbook of Clinical Medicine 5th Edition, Oxford University Press, Oxford. [3] Tjandra, J, Clunie, G and Thomas, R (2001), Textbook of Surgery, Blackwell Publishing, Australia.