| Adrenal
Surgery:
|
The
adrenal glands are
golden-yellow triangle or crescent
shaped glands which are attached to
the top of each of your two kidneys.
They are normally about 3 x 5 x 1
cm in size. Each gland had a cortex
which surrounds the medulla. Each
region of the gland is responsible
for hormone production such as cortisol
and aldosterone in the cortex and
norepinephrine and epinephrine (adrenaline)
in the medulla. The adrenal gland
also manufactures some of the sex
hormones. |
WHEN IS ADRENAL
SURGERY NEEDED?
Surgical
removal of the adrenal gland (adrenalectomy)
may be recommended in situations of hormone
overproduction or if there is a concern
that a mass of the adrenal gland may be
a cancer.Three
main situations exist where hormone overproduction
is an indication to have an adrenalectomy.
The first is Cushing's Syndrome in which
excess steroid production (cortisol) is
caused by a tumor of the adrenal cortex.
The second is Conn's Syndrome in which a
tumor of the same area produces excess aldosterone
which may cause problems with high blood
pressure and blood potassium levels. The
third is a tumor of the medulla which is
called a pheochromocytoma. This tumor may
manufacture excess adrenaline and cause
problems such as high blood pressure, excess
sweating, tremor, and anxiety.
Sometimes
an adrenal tumor is found incidentally during
an ultrasound or CAT scan of the abdomen.
Even if these tumors do not overproduce
hormones and cause any of the problems above,
adrenalectomy may be recommended due to
the size or other characteristics of the
mass. This is because of concern that the
mass may be a cancer of the adrenal gland.
Adrenal cancer is very rare, but adrenalectomy
may be the only chance to cure the cancer.
If the tumor is a cancer that has spread
from another organ to the adrenal gland,
that is not a good reason for adrenalectomy
(with very few exceptions).
HOW IS ADRENAL
SURGERY USUALLY PERFORMED?
Adrenalectomy may be performed in two main
fashions - an open procedure or a laparoscopic
procedure. Open operations may be performed
through the back (sometimes requiring partial
removal of a rib), the flank, or the abdomen.
Laparoscopic procedures use small telescopes
and long instruments to remove the adrenal
gland through a series of small incisions.
Typically, patients having laparoscopic
procedures have less pain and a more rapid
recovery. The
method by which the adrenalectomy is performed
depends on many factors including the specific
disorder, tumor size, and general patient
health. Laparoscopic adrenalectomy is not
an appropriate operation if there is strong
evidence that the tumor is an adrenal cancer.We
have included a short video (1.4 mg / .mpg
file) of an adrenalectomy for you to view.
You may click here to begin.
Tumors
of the adrenal cortex are reported in 2%
of all autopsies, with the most common lesion
being a benign adenoma. The common major
pathologic entities of the adrenal gland
that require surgical intervention are primary
hyperaldosteronism (ie, Conn syndrome),
Cushing syndrome, pheochromocytoma, neuroblastoma,
and adrenocortical carcinoma. However, many
adrenal glands are removed en bloc as part
of a radical nephrectomy for renal cell
carcinoma. Frequently, lesions metastatic
to the adrenal gland necessitate adrenalectomy,
and reports exist of adrenal excision for
symptomatic adrenal cysts. The workup of
adrenal disorders requiring surgical intervention
has undergone a revolution with the tremendous
advances in hormonal research, as well as
in radiographic techniques and localization.
In general, neoplastic lesions of the adrenal
gland may be classified with the tumor,
node, metastases (TNM) staging system.
Tumor
- T1 - Tumor confined
to adrenal gland and less than 5 cm
- T2 - Tumor confined
to adrenal gland and greater than 5 cm
- T3 - Tumor invasion
into periadrenal fat
- T4 - Tumor invasion
of adjacent organs
Node
- N0 - Negative
lymph nodes
- N1 - Positive
lymph nodes
Metastases
- M0 - No metastases
- M1 - Distant metastases
History
of the Procedure: The adrenal gland is crucial
to endocrine homeostasis, and maladies associated
with it result in several recognized syndromes.
Understanding of the adrenal glands began
in 1805, when Currier first delineated the
anatomic structure of the medulla and cortex.
Addison later described the clinical effects
of adrenal insufficiency in 1855. Thomas
Addison first described the association
of hypertensive episodes with adrenal tumors
in 1886. Medical and surgical management
of pheochromocytoma was first described
in the United States by Mayo and remained
relatively unchanged until the 1960s, when
Crout elucidated the biochemical pathways
and diagnostic catecholamine studies, allowing
diagnostic ability prior to exploration.
Problem:
Primary
hyperaldosteronism
First
described in 1955 by Jerome Conn, the hallmarks
of primary hyperaldosteronism are hypertension,
hypokalemia, hypernatremia, and elevated
urine aldosterone levels (with salt repletion),
as well as decreased renin activity and
alkalosis with increased urinary potassium
excretion. Primary hyperaldosteronism can
be secondary to an adrenal adenoma or secondary
to bilateral adrenal hyperplasia. Differentiating
between these two disease processes is important
because they can be treated differently.
The patient's renin level should also be
checked to rule out causes of secondary
hyperaldosteronism, such as renal artery
stenosis. The renin level is elevated in
persons with renal artery stenosis, while
the renin level is suppressed in those with
primary hyperaldosteronism.
Cushing
syndrome
The
diagnosis of Cushing syndrome is made based
on abnormalities of urinary and plasma cortisol
and/or adrenocorticotropic hormone (ACTH).
The syndrome typically is attributed to
central, hypothalamic, or pituitary excess
secretion of ACTH (Cushing disease), primary
adrenal hypercorticalism, or ectopic secretion
of ACTH.
Pheochromocytoma
These
tumors arise from chromaffin cells of the
adrenal medulla. Ten percent of cases may
be familial, and 10% might be bilateral
or in extra-adrenal locations. If the tumor
arises from a site other than the adrenal,
it is termed a paraganglionoma. Paraganglionomas
have been reported in locations from the
neck to the pelvis. While pheochromocytoma
follows the "rule of 10s," with
only 10% of cases involving malignant tumors,
50% of cases of paraganglionomas have reported
malignancies. Pheochromocytomas also can
be a part of an endocrine syndrome such
as multiple endocrine neoplasia (MEN) IIa,
MEN IIb, von Hippel-Lindau disease, or von
Recklinghausen disease.
Neuroblastoma
Neuroblastomas
arise from sympathetic neuroblasts and occur
almost exclusively in the pediatric population.
Neuroblastoma represents the most common
extracranial solid tumor in children, and
approximately one third of neuroblastomas
arise in the adrenal gland. Surgery of neuroblastoma
is an important element in diagnosis, staging,
and treatment of children with neuroblastoma.
Surgery is curative therapy for patients
with stage I and early stage II disease,
with a reported 2-year survival rate of
89%. Reviews regarding safety reveal a low
complication rate, commonly less than 10%.
Advanced-stage tumors usually require a
combination of surgery, chemotherapy, and/or
radiation therapy to provide a complete
response.
Adrenocortical
carcinoma
Adrenocortical
carcinoma is a rare disease with a poor
prognosis. Up to 80% of adrenal carcinomas
are functional and secrete multiple hormones.
Frequency:
In the United States, tumors of the adrenal
cortex are reported in 2% of all autopsies,
with the most common lesion being a benign
adenoma. The incidence of adrenal carcinoma
is estimated to be 1 case per 1.7 million,
and it accounts for 0.02% of all cancers.
Etiology:
Primary
hyperaldosteronism
The
most common causes of aldosterone overproduction
are idiopathic adrenal hyperplasia, followed
by adenomas, and then (rarely) adrenal carcinoma.
Of the benign adenomas, approximately 60%
are unilateral (and typically managed surgically),
while 40% are bilateral lesions.
Neuroblastoma
Neuroblastomas
arise from sympathetic neuroblasts and occur
almost exclusively in the pediatric population.
Approximately one third of neuroblastomas
arise in the adrenal gland.
Pathophysiology:
Primary
hyperaldosteronism
The
hallmarks of primary hyperaldosteronism
are hypertension, hypokalemia, hypernatremia,
and elevated urine aldosterone levels (with
salt repletion), as well as decreased renin
activity and alkalosis with increased urinary
potassium excretion. The most common causes
of aldosterone overproduction are idiopathic
adrenal hyperplasia, followed by adenomas,
and then (rarely) adrenal carcinoma. Of
the benign adenomas, approximately 60% are
unilateral (typically managed surgically),
while 40% are bilateral lesions that are
treated medically with spironolactone, unless
marked asymmetry of aldosterone production
is present. In this case, the dominant gland
often is excised, unless bilateral disease
that is uncontrollable by medical therapy
exists.
Cushing
syndrome
The
syndrome typically is attributed to central,
hypothalamic, or pituitary excess secretion
of ACTH (Cushing disease), primary adrenal
hypercorticalism, or ectopic secretion of
ACTH.
Pheochromocytoma
These
tumors arise from chromaffin cells of the
adrenal medulla. Presentation of the pheochromocytoma
varies with the production of active metabolites.
Most commonly, episodic alpha-adrenergic
hypersecretion leads to intermittent malignant
hypertension.
Neuroblastoma
Neuroblastomas
arise from sympathetic neuroblasts and occur
almost exclusively in the pediatric population.
Neuroblastoma represents the most common
extracranial solid tumor in children, and
approximately one third of neuroblastomas
arise in the adrenal gland. They are rapidly
growing tumors and may be metabolically
active; however, the more common presentation
is from mass effect.
Adrenocortical carcinoma
As
the name implies, adrenocortical carcinoma
arises from the cortex. The adrenal cortex
in made up of 3 distinct zones: glomerulosa
(outer), fasciculata (middle), and reticularis
(inner). These 3 zones are responsible for
aldosterone, cortisol, and sex steroid production,
respectively. Up to 80% of adrenal carcinomas
are functional and secrete multiple hormones.
The most common hormones secreted are glucosteroids,
followed by androgens, estradiol, and, finally,
aldosterone. Adrenal carcinomas can be subclassified
according to their ability to produce adrenal
hormones.
Clinical:
Primary
hyperaldosteronism
Presentation
of primary hyperaldosteronism includes hypertension,
hypokalemia, hypernatremia, and elevated
urine aldosterone levels (with salt repletion),
as well as decreased renin activity and
alkalosis with increased urinary potassium
excretion.
Cushing
syndrome
The
clinical presentation of Cushing syndrome
is hypertension, moon facies, abdominal
striae, buffalo hump, muscle weakness, amenorrhea,
decreased libido, osteoporosis, fatigue,
hirsutism, and obesity.
Pheochromocytoma
Presentation
of the pheochromocytoma varies with the
production of active metabolites. Pheochromocytoma
most often develops in young–to–middle-aged
adults. The classic triad is episodic headache,
tachycardia, and diaphoresis. The most common
clinical sign of pheochromocytoma is hypertension.
Persons with this condition may experience
sustained hypertension, paroxysmal hypertension,
or sustained hypertension with superimposed
paroxysms. Other common signs are palpitations,
anxiety, tremulousness, chest pain, and
nausea and vomiting. A small group of these
patients experience induced myocardiopathy
due to sustained catecholamine release.
They present with decreased cardiac function
and congestive heart failure. Generally,
the cardiomyopathy is reversible with the
use of antiadrenergic blocking agents and
alpha-methylparatyrosine, a catecholamine
synthesis inhibitor.
Neuroblastoma
Neuroblastomas
arise from sympathetic neuroblasts and occur
almost exclusively in the pediatric population.
Neuroblastoma represents the most common
extracranial solid tumor in children, and
approximately one third of neuroblastomas
arise in the adrenal gland. They are rapidly
growing tumors and may be metabolically
active; however, the more common presentation
is from mass effect.
Adrenocortical
carcinoma
These
patients present with constitutional symptoms
such as weight loss, fever, and malaise.
Up to 80% of adrenocortical carcinomas are
functional, and patients with these present
with clinical signs of Cushing syndrome.
An increase in sex steroid levels can result
in oligomenorrhea, virilization, or feminization.The
most common presentation of adrenocortical
carcinoma is that of an incidentaloma. At
presentation, 19% have inferior vena cava
(IVC) involvement and 32% have metastases.
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