Adrenal Surgery 

Updated: Aug 12, 2016
Author: Brian J Miles, MD, FACS; Chief Editor: Bradley Fields Schwartz, DO, FACS 

Overview

Background

Tumors of the adrenal cortex are reported in 2% of all autopsies, with the most common lesion being a benign adenoma (see the first image below). The common major pathologic entities of the adrenal gland that require surgical intervention are primary hyperaldosteronism (ie, Conn syndrome, see the second image below), 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.

Homogeneous, well-defined, 7-HU ovoid mass is seen Homogeneous, well-defined, 7-HU ovoid mass is seen in the right adrenal gland; this finding is diagnostic of a benign adrenal adenoma.
Magnetic resonance imaging (MRI) scan in a patient Magnetic resonance imaging (MRI) scan in a patient with Conn syndrome showing a left adrenal adenoma.

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

Table. TNM Staging System for Neoplastic Lesions of the Adrenal Gland (Open Table in a new window)

Stage

TNM

Stage I

T1, N0, M0

Stage II

T2, N0, M0

Stage III

T3, N0, M0 or T1-2, N1, M0

Stage IV

Any T, N, M1, or T3-4, N1, M0

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[1] and remained relatively unchanged until the 1960s, when Crout et al elucidated the biochemical pathways and diagnostic catecholamine studies, allowing diagnostic ability prior to exploration.[2]

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%.[3] 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.

Myelolipoma

Adrenal myelolipomas are rare benign masses that consist of fat and hematopoietic cells. They are hormonally inactive. These masses are typically asymptomatic, but some are associated with flank or abdominal pain. Adrenal myelolipomas can often be diagnosed with imaging studies. On CT scans, myelolipomas appear as well-circumscribed massed with a negative attenuation consistent with fat. Should the diagnosis still be in doubt, obtaining an image-guided needle biopsy can be helpful. As myelolipomas are benign lesions with no hormonal activity, most physicians recommend observation unless symptoms occur or the tumor begins to grow during observation.

Adrenocortical carcinoma

Adrenocortical carcinoma is a rare disease with a poor prognosis. Up to 80% of adrenal carcinomas are functional and secrete multiple hormones.

Epidemiology

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.

Cushing syndrome

See Cushing syndrome in Pathophysiology.

Pheochromocytoma

See Pheochromocytoma in Pathophysiology.

Neuroblastoma

Neuroblastomas arise from sympathetic neuroblasts and occur almost exclusively in the pediatric population. Approximately one third of neuroblastomas arise in the adrenal gland.

Myelolipoma

Many theories have been proposed as to the etiology of myelolipomas. The most widely accepted theory is adrenocortical cell metaplasia and growth due to an insult to the adrenal gland (eg, infection, ischemia).

Adrenocortical carcinoma

See Adrenocortical carcinoma in Pathophysiology.

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.

Presentation

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.

Lesions metastatic to the adrenal gland

Adrenal masses thought to arise from distant metastases include melanoma, lung cancer, renal cell carcinoma, and breast cancer. These should be discussed with the primary service taking care of these lesions, but these adrenal masses are often amenable to laparoscopic adrenalectomy.

Indications

In deciding whether adrenalectomy is indicated for a newly discovered adrenal mass, one must ascertain whether the mass is functional and if it has signs of malignancy. Except for bilateral adrenal hyperplasia, which can be treated medically with spironolactone, most functional masses should be surgically removed.

Signs of malignancy are based on tumor size, radiographic findings, and history of carcinoma.

  • Tumor size: Studies have shown that adrenal masses larger than 6 cm have a much greater chance of malignancy. Because CT scans tend to underestimate the size of the tumor by more than 20%, the cutoff on CT scan for an adrenal mass should be 4-6 cm. Therefore, adrenal masses larger than 4-6 cm on CT scan are considered high risk for cancer and should be surgically removed.

  • Radiographic findings: Adrenocortical carcinomas and pheochromocytomas have been shown to be hyperintense on MRI T2–weighted images. If the intensity of the adrenal lesion relative to the liver or spleen on an MRI T2–weighted image is less than 80%, the lesion is more likely to be a cortical adenoma. CT scan findings suggestive of an adrenocortical carcinoma include lesions that have irregular margins, are heterogeneous, and have high densities on noncontrast images. Necrosis and calcification are also more commonly associated with adrenal carcinoma. Most adenomas are lipid rich and have densities of less than 10 Hounsfield units. Furthermore, the density of adenomas on delayed contrast images is reduced by at least 60%, unlike adrenocortical carcinomas. Finally, nuclear scans such as metaiodobenzylguanidine (MIBG) and NP-59 (131-6-β-iodomethylnorcholesterol) can help to identify pheochromocytomas and adrenocorticalcarcinomas, respectively.

  • History of carcinoma: Patients with a history of carcinoma and a newly discovered adrenal mass have a 32%-73% chance of having metastasis to the adrenal gland. The most common cancers that metastasize to the adrenal glands are melanoma, lung cancer, breast cancer, and renal cancer. Biopsy of an adrenal lesion is appropriate in a patient with a history of cancer. If the biopsy sample is positive for metastasis, the decision of whether to give chemotherapy, with or without adrenalectomy, should be further explored. In most settings, adrenalectomy would not be indicated in the presence of metastases.

Attention must be given to the increasing diagnosis of the adrenal incidentaloma, which refers to a clinically inapparent adrenal mass that is discovered with some form of imaging study performed for an indication not related to adrenal disease. Estimates of the prevalence of adrenal incidentalomas range from 0.1%-4.3%. Current National Institutes of Health (NIH) recommendations dictate that patients with such a diagnosis should undergo hormonal evaluation, including an overnight dexamethasone suppression test, plasma-free metanephrine study, and a study of plasma aldosterone level–plasma renin activity ratio.[4] In general, adrenal incidentalomas associated with abnormal hormonal findings should undergo surgical adrenalectomy. Masses larger than 6 cm are associated with a 25% risk of malignancy, and these should also be treated surgically.

If a mass is nonfunctional and has no signs of malignancy (ie, >6 cm), the patient can be monitored and observed. The patient should undergo CT scanning every 6 months and an annual endocrine evaluation for 4 years. If the mass grows or affects endocrine function, it should be removed. Some clinicians now believe that if the mass is stable as revealed by CT scan at 3 and 12 months and is not functional, routine follow-up is not required.

Relevant Anatomy

Before describing surgical technique, understanding the anatomy of the adrenal glands is essential. The adrenal glands, also known as suprarenal glands, belong to the endocrine system. They are a pair of triangular-shaped glands, each about 2 in. long and 1 in. wide. The suprarenal glands are responsible for the release of hormones that regulate metabolism, immune system function, and the salt-water balance in the bloodstream; they also aid in the body’s response to stress.

Both adrenals are located on the superior posterior aspect of the kidneys in the retroperitoneum. The right adrenal is covered anteriorly by the liver and has a short vein typically draining directly into the inferior vena cava (IVC). The left adrenal is covered anteriorly by the pancreas and spleen. In general, the surgical approach is dependent on the primary adrenal lesion, the size of the lesion, the side of the lesion, and the habitus and health of the patient, as well as surgeon preference and familiarity.

For more information about the relevant anatomy, see Suprarenal (Adrenal) Gland Anatomy.

Contraindications

Metastatic disease, unless part of research protocol, is a contraindication to adrenal surgery.

 

Workup

Laboratory Studies

See the list below:

  • Serum

    • Electrolyte levels

    • Cortisol levels

    • Androgen levels

    • Free metanephrine levels (most sensitive test for pheochromocytoma)

  • Urine

    • 24-hour catecholamine levels

    • 24-hour metanephrine levels (most specific test for pheochromocytoma)

    • 24-hour free cortisol levels

    • 17-ketosteroids and 17-hydroxycorticosteroids levels

  • If a pheochromocytoma is suspected, a clonidine suppression test or glucagon stimulation test can be performed to confirm the diagnosis.

Imaging Studies

See the list below:

  • CT scan has become the criterion standard. Other imaging studies often are used in conjunction with the CT scan in diagnosis of adrenal masses.

  • MRI frequently is useful in delineating lesions. In the case of adrenocortical carcinoma, regardless of size or function, if T2-weighted images from an MRI reveal a high-intensity signal, this finding is strongly suggestive of a malignancy, and exploration is warranted.

  • Nuclear scans such as an MIBG scan or NP-59 scan can also help delineate between malignant and benign lesions. An MIBG scan may be helpful with pheochromocytomas because MIBG is taken up in the norepinephrine pathway and suggests function. NP-59 is taken up by the adrenal cortex and by adenomas. Space-occupying lesions, such as adrenocortical carcinoma, do not take up the tracer.

Other Tests

See the list below:

  • Blood pressure

  • Serum potassium levels (for aldosteronoma)

Diagnostic Procedures

See the list below:

  • See Surgical therapy.

Histologic Findings

A detailed discussion of the histologic findings is beyond the scope of this surgical article.

 

Treatment

Medical Therapy

Primary hyperaldosteronism

The management of bilateral adrenal hyperplasia is centered on medical therapy. Spironolactone, an aldosterone antagonist, is used to normalize serum potassium levels and blood pressure. The major side effect of this drug is painful gynecomastia. Unilateral adrenal adenomas are generally treated surgically.

Cushing syndrome

Bilateral adrenalectomy was the suggested treatment for patients with micronodular or macronodular hyperplasia, incurable pituitary Cushing syndrome, or an unknown source of ACTH. Today, with the advancements in localization, Cushing disease is treated with bilateral adrenalectomy only when ablation of the pituitary through radiation or surgery has failed or when medical therapy does not control secretion. The major role for surgery in this patient population occurs with primary adrenal hypercorticalism either due to adenomas or to adrenal carcinomas. The first line of therapy for unilateral hypercorticalism is unilateral adrenalectomy.

Pheochromocytoma

The medical and surgical management of the pheochromocytoma was first described in the United States by Mayo,[1] and it remained relatively unchanged until the 1960s, when Crout et al[2] elucidated the biochemical pathways and diagnostic catecholamine studies. Preoperative management of pheochromocytoma is aimed at control of the catecholamine secretion and its cardiovascular sequelae. Hypertension is usually alleviated with preoperative alpha-adrenergic blockade, and most authors recommend preoperative fluid loading to prevent rapid onset of hypotension after the alpha-adrenergic secretion is stopped. Some centers also recommend beta-adrenergic blockade; however, its definitive use remains unclear.

Neuroblastoma

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 neuroblastoma, with a reported 2-year survival rate of 89%. Reviews regarding safety reveal a low complication rate, most 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

Chemotherapy largely has been unsuccessful in treating adrenocortical carcinoma. The most common chemotherapeutic agent used is mitotane. In a review of 551 cases of adrenocortical carcinoma, mitotane induced a tumor response in 35% of patients. However, mitotane has thus far shown no increase in survival benefit.[5]

Surgical Therapy

The basic principle for all adrenal excisions is to handle the adrenal gland as little as possible, or to dissect the patient away from the tumor, because the adrenal is an extremely fragile organ. Gentle traction can be obtained by using the kidney as a handle. Typically, posterior, modified posterior, or laparoscopic approaches are used with smaller tumors. Larger tumors may require flank, transabdominal, or thoracoabdominal approaches, but they also have been removed successfully with laparoscopic approaches. The right adrenal vein is short and enters the IVC posteriorly. Therefore, a right adrenalectomy is best approached through a posterior or modified posterior incision. The left adrenal gland is in close contact with the upper pole of the left kidney. Therefore, for large left adrenal lesions, a flank approach or thoracoabdominal approach offers the best exposure. The laparoscopic approach is now considered the criterion standard for most adrenal surgery.

Posterior approach

The posterior approach typically is used for small tumors and in the past was recommended for bilateral exploration in bilateral hyperaldosteronism. Today, localization studies are mandatory prior to bilateral exploration for adenomas. The posterior approach to the adrenal was first described by Young in 1936.

Generally, incisions are made over the 11th or 12th ribs with the patient in a prone position or in a face down jackknife position. After rib resection for better exposure, the Gerota fascia is swept away, revealing an open space superior to the adrenal. The liver or spleen is taken off the anterior surface of the adrenal, and cranial blood supplies are ligated. The dissection then is carried medially to the IVC, which is followed inferiorly until the short adrenal vein is visualized and ligated. The adrenal gland can be drawn caudally by traction on the kidney, and the medial arterial blood supply then can be ligated. Care must be taken to avoid accessory renal artery branches to the upper pole of the kidney. The remaining portion of the adrenal then can be dissected off the kidney and removed.

Modified posterior approach

The posterior approach may be modified in a number of different manners. One may use a true posterior approach in a more cephalad manner and gain transthoracic access to the adrenals. Another modified posterior approach is aimed at decreasing the drawbacks of the jackknife positioning. The primary advantage of the posterior approach is that of obtaining rapid exposure to the adrenal gland as well as excellent exposure and control of the short right adrenal vein.

However, the jackknife position can lead to high pulmonary ventilation pressures, high intraperitoneal pressures, and poor visualization in larger patients. Vaughan and associates (1987) reasoned that a modified prone position could be used without the morbidity of the jackknife position. Vaughan recommends a slight rolling of the thorax with less flexion, which should reduce intra-abdominal compression. An incision then is carried posteriorly along the 11th or 12th rib, avoiding the pleura. The pleura and peritoneum are dissected away, the hepatic attachments are divided, the adrenal is exposed at the base of this incision, and the multiple arteries are ligated. The IVC then is be exposed, and the short adrenal vein is in plain view for ligation.

Flank approach

An extraperitoneal, extrapleural 11th or 12th rib flank approach as used for a radical nephrectomy provides excellent exposure for right or left adrenalectomy. The Gerota fascia is exposed in a typical fashion, and, with this approach, the kidney is used as a means of traction on the adrenal gland. The superior vasculature to the Gerota (and to the adrenal gland) is ligated and divided, providing exposure to the medial edge and main vasculature to the adrenal gland. Patients with large malignancies might require en bloc nephrectomy with the adrenal specimen for cancer control.

Transabdominal approach

Numerous transabdominal approaches for adrenalectomy have been suggested. Typically, transabdominal approaches are used in the pediatric population and for patients with large malignancies. Transverse, chevron, subcostal, and midline approaches are the most common. The midline approach commonly is used if suspicion of a paraganglionoma (ie, extra-adrenal pheochromocytoma) exists. After entering the peritoneal cavity, the abdomen is explored for evidence of metastasis, and the colonic reflection is taken down, exposing the great vessels and retroperitoneum.

As with the flank approach, the kidney is used for retraction, and the superior attachments are divided, providing exposure. On the right side, this may necessitate ligation of the accessory hepatic veins for sufficient exposure of the vena cava and the (posteriorly located) short adrenal vein. After exposure of the IVC, the vein is ligated and then the multiple adrenal arteries are taken. The adrenal gland is removed from the kidney. On the left side, the renal vein is exposed first, providing exposure to the adrenal vein. After ligation, the dissection proceeds medially along the vascular pedicle where the multiple arteries are taken.

Thoracoabdominal approach

The thoracoabdominal approach via the eighth, ninth, or 10th intercostal space is the incision of choice for large adrenal tumors, especially right-sided pheochromocytomas. The incision is made along the appropriate intercostal space and carried medially along the space, across the costal margin to the midline, and then extended caudally, as needed, for exposure. With the division of the diaphragm, the superior dissection of large adrenal tumors, as well as cephalad access to the IVC, is made easier. The colon then is reflected, allowing the great vessels and retroperitoneum to be exposed. As in the flank incision, the kidney may be used for gentle traction. The posterior and superior attachments are divided, leaving the adrenal gland attached to the kidney for traction. The posteromedial vein can be divided first, and then, proceeding caudally, the multiple adrenal arteries can be ligated.

Laparoscopic approach

Little debate exists in the literature that laparoscopic approaches decrease operative morbidity. The laparoscopic approach typically is used for smaller adrenal tumors. At many laparoscopic centers, the laparoscopic adrenalectomy has become the criterion standard. Although case reports of laparoscopy used with large tumors have occurred, most centers recommend laparoscopy in tumors smaller than 6 cm. Laparoscopy should be avoided in patients with bowel obstruction, severe cardiopulmonary disease, or hypovolemic shock because of increased morbidity. Adhesions represent a relative contraindication that greatly depends on the surgeon's skills.

Trocar placement is variable, but usually a minimum of 3, and typically 4, ports are used under the costal margin. The surgery proceeds much as through a transabdominal approach, dissecting the colonic flexure into the retroperitoneum. On the right after dissecting under the liver, the liver is retracted cephalad and the superior pole of the kidney again is used as a handle. With gentle traction on the kidney, a plane of dissection along the IVC allows the surgeon to "walk up" the IVC and identify the short right adrenal vein, which can be clipped. The superior and anterior aspects, as well as arterial supply, also may be taken using clips. The inferior aspect of the adrenal abutting the kidney is dissected last; then, the adrenal is placed in an entrapment sack and removed.

Multiple centers have attempted to emphasize a particular approach or laparoscopic method, and, regardless of which approach is advocated, one point remains applicable across the board: cure rate and operative morbidity are similar for laparoscopic and open adrenalectomy (in small tumors).

No method is best for all patients, and, in general, using the approach based on patient and tumor characteristics combined with surgeon approach familiarity yields the best results.

Hirano et al reported their experience with laparoscopic adrenalectomy, including retroperitoneoscopic adrenalectomy via a single large port (RASLP) and conventional laparoscopic adrenalectomy, in the treatment of adrenal tumors in 134 patients since 1992. Complications were graded according to the modified Clavien system. The mean operation time for RASLP was 166 minutes; for conventional laparoscopic adrenalectomy, 205 minutes. Intraoperative estimated blood loss was significantly lower for the patients who underwent conventional adrenalectomy (85 vs 247 mL). Conversion to open surgery was required in 3 patients (5%) in the RASLP group and in 5 patients (7%) in the conventional adrenalectomy group. Grade 1 postoperative complications occurred in 3 patients in who underwent RASLP and in 1 patient who underwent conventional laparoscopic adrenalectomy. The authors concluded that conventional laparoscopic adrenalectomy is preferable to RASLP for patients with adrenal tumors.[6]

Partial adrenalectomy

Traditionally, the standard treatment for patients with adrenal lesions has been total adrenalectomy. Recently, successful treatment of these lesions with partial adrenalectomy has been reported. A study that compared partial versus total adrenalectomy for the treatment of primary hyperaldosteronism found that both approaches were equally effective. In fact, at 5-year follow-up, the partial adrenalectomy group demonstrated greater improvement in returning to normal physiologic renin and aldosterone levels. Another study that compared 100 patients with partial adrenalectomy versus 225 patients with total adrenalectomy found that no recurrences occurred in the partial adrenalectomy group, while local recurrence was noted in 6 patients after total adrenalectomy. The adrenocortical function in 14 of 15 patients with bilateral diseases was preserved.[7] Consider patients with bilateral disease for partial adrenalectomy.

Janetschek et al reported the first laparoscopic partial adrenalectomy in 1997.[8] Since then, many other successful laparoscopic partial adrenal resections have been reported. Because of the vascular nature of the adrenal gland, the surgeon must obtain excellent hemostasis when performing a partial adrenalectomy.

A study by Castinetti et al suggested that adrenal-sparing surgery should be the surgical approach of choice in patients with multiple endocrine neoplasia type 2 (MEN2) and bilateral pheochromocytoma. In the study, 438 (79%) of 552 operated patients were treated by adrenalectomy and 114 (21%) had adrenal-sparing surgery. Pheochromocytoma recurrence occurred in 3% (four of 153) of the operated glands following adrenal-sparing surgery with a follow-up of 6 to 13 years, compared with 2% (11 of 717) of glands removed by adrenalectomy. The authors cautioned that after approximately 20 years, nearly all patients who have adrenal-sparing surgery would have recurrence of pheochromocytoma so patients need a prolonged follow-up after 10 years.[9, 10]

Cryosurgery and other ablative techniques of adrenal masses

Although cryoablation has gained popularity in the treatment of tumors such as prostate, liver, lung and brain tumors, very limited reports exist of successful use with adrenal tumors. In 2003, Munver et al described the first case of adrenal cryosurgery in a patient with primary hyperaldosteronism secondary to bilateral adrenal hyperplasia.[11] Schulsinger et al demonstrated that cryoablation was successful in destroying adrenal tissue in a canine model.[12] More studies are needed to assess the long-term efficacy of this procedure.

Successful ablation of adrenal masses has been described using selective arterial infusion of ethanol. In a study of 33 cases of primary hyperaldosteronism, this technique was successful in 27 cases (82%).[13] Few reports exist of radiofrequency ablation (RFA) of adrenal masses.[11] Most of these reports have involved patients with metastatic adrenocortical carcinoma. Currently, RFA is used primarily for palliation in patients with metastatic disease for whom conventional treatment with surgery or chemotherapy is not possible.

Preoperative Details

Primary hyperaldosteronism

The preoperative management for primary hyperaldosteronism is aimed at achieving blood pressure control with spironolactone. Typically, the causative agent is a unilateral adenoma or adrenocortical carcinoma.

Pheochromocytoma

Preoperative management of pheochromocytoma is aimed at control of the catecholamine secretion and its cardiovascular sequelae. Hypertension usually is alleviated with preoperative alpha-adrenergic blockade. Patients undergo alpha-adrenergic blockade with agents such as phenoxybenzamine for a minimum of 2 weeks preoperatively, and they maintain adequate hydration. Preoperative beta-blockers (ie, propranolol) are administered after alpha-blockers to help control arrhythmias. Administer alpha-blockers first; otherwise, hypertension may be exacerbated. Some centers now administer long-acting calcium-channel blockers (ie, verapamil SR, nifedipine XL) as preoperative monotherapy, which control both hypertension and arrhythmias.

Most authors recommend preoperative fluid loading to prevent rapid onset of hypotension after the alpha-adrenergic secretion is stopped.

Adrenocortical carcinoma

No special preoperative evaluation exists, other than the determination of whether the lesion functions or not.

Intraoperative Details

See the list below:

  • Primary hyperaldosteronism: As long as the tumor or gland is small, a posterior, modified posterior, or laparoscopic approach is suggested.

  • Cushing syndrome: As long as the tumor or gland is small, a posterior, modified posterior, or laparoscopic approach is suggested.

  • Pheochromocytoma: The operative management of the pheochromocytoma is different from other adrenal tumors in that, primarily, clear communication between the surgical and anesthesia teams must occur due to the cardiovascular lability. Secondly, the surgical approaches are aimed at early control of the adrenal vein. After it is ligated, a marked hypotensive episode often occurs. Several centers have reported laparoscopic approaches as well as partial adrenalectomies. Other reviews reexamined the role of calcium channel blockers instead of alpha blockade and still found low complication rates and determined that adrenalectomy is safe. Patients with multiple endocrine adenopathy or a family history of pheochromocytoma should be considered at high risk for multiple lesions, and a thorough abdominal exploration should be performed during surgery.

  • Neuroblastoma: 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 neuroblastoma, with a reported 2-year survival rate of 89%. Reviews regarding safety reveal a low complication rate, most 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: The adrenocortical carcinoma typically is a large lesion, and, for that reason, a flank, thoracoabdominal, or, in rare cases, laparoscopic approach has been advocated.

Postoperative Details

Adequate hydration is necessary for patients with pheochromocytoma, and meticulous follow-up is necessary for patients with malignancy. Patients with cortisol-producing tumors require glucocorticoid replacement throughout the surgical procedure and postoperatively until the function of the contralateral adrenal gland is regained.

Follow-up

Postoperative follow-up is routine, with wound checks and close follow-up for malignant disease that is aimed at detecting early evidence of metastases.

Complications

The keys to adrenal surgery are exposure and dissecting the body away from the tumor. Most preventable complications arise from failure to strictly adhere to these principles. Certainly, the most troublesome complication occurs from avulsion of the short right adrenal vein. Manual compression and good exposure allow the avulsed area of the cava to be partially occluded with sponge sticks, and the vein stump may be grasped with an Allis forceps and subsequently suture ligated. In addition, on the right side, the accessory hepatic veins can be avulsed and are handled using a similar manner of vascular control and then ligation.

On the left side, complications typically involve splenic laceration or damage to the tail of the pancreas. Dissection superiorly on either adrenal involves the possibility of entering the pleura, with subsequent pneumothorax. Finally, being aware of the possible need for postoperative supplementation of glucocorticoids and mineralocorticoids in the patient with complex and/or bilateral disease is essential.

Outcome and Prognosis

See the list below:

  • Primary hyperaldosteronism: The surgical removal of the adrenal gland and adenoma provides excellent results, with most patients being cured.

  • Pheochromocytoma: Long-term cures are rare in cases of malignant pheochromocytomas. In cases of metastatic disease, 5-year survival rates as high as 36% have been reported.

  • Neuroblastoma: Surgery of neuroblastoma is an important element in diagnosis, staging, and treatment of children with neuroblastoma. Surgery is curative therapy for people 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, most 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: At presentation, 19% of patients had IVC involvement and 32% had metastases. The median time of survival was 17 months, and evaluation of factors affecting survival reveal benefit to the following characteristics: age younger than 54 years, absence of metastasis, and nonfunctional tumors.[14] Another study at Memorial Sloan-Kettering reviewed 115 patients and revealed overall median survival to be 38 months, with a 5-year survival rate of 37%. Patients with stage I or II disease fared better, with a 5-year survival rate of 60%, while patients with stage III and IV disease had a 5-year survival rate of 10%.

Future and Controversies

Laparoscopic approach

Little debate exists in the literature that laparoscopic approaches decrease operative morbidity. The laparoscopic approach typically is used for smaller adrenal tumors. At many laparoscopic centers, the laparoscopic adrenalectomy has become the criterion standard. Multiple centers have attempted to emphasize a particular approach or laparoscopic method, and regardless of which approach is advocated, one point remains applicable across the board: cure rate and operative morbidity are similar for laparoscopic and open adrenalectomy (in small tumors). No method is for all patients, and, in general, selecting the approach based on patient and tumor characteristics and with consideration of surgeon approach familiarity yields the best results.