INTRODUCTION

Adrenalectomy is performed primarily for functioning and nonfunctioning tumors of the adrenal glands. Many technical variations have evolved since the first description by Thornton in 1899. Laparoscopic adrenalectomy is now the most common type reported in the United States. Originally described by Gagner in 1992,¹ laparoscopic adrenalectomy has dramatically reduced the lengths of the hospital stay and of the postoperative recovery. This chapter discusses potential pitfalls associated with adrenalectomy. These misadventures can result from inappropriate or inadequate preoperative evaluation or a lack of technical expertise.

Evaluation of Adrenal Masses

Given the large number of available diagnostic tests, a focused and streamlined approach to preoperative testing is necessary to control cost and limit patient anxiety. Two questions are important from a surgical perspective: (1) Is the mass biochemically functional and (2) is it malignant? The detailed biochemical evaluation is beyond the scope of this chapter but has been reviewed previously.^1a The clinician must exclude common functioning adrenal tumors such as pheochromocytomas, aldosterone-producing adenomas, and cortisol-producing adenomas. A history of hypertension, unprovoked kaliuresis, palpitations or episodic “spells” associated with resistant hypertension, or unexplained weight gain or bruising is important to determine if the adrenal mass is associated with hormone hypersecretion. However, biochemical testing is the standard method of excluding hypersecretion. This should include 24-hour urinary estimation of catecholamines and their degradation products (metanephrines), cortisol, potassium, and aldosterone. The plasma aldosterone–to–renin ratio is a useful screening tool for primary hyperaldosteronism, whereas the combination of 24-hour urinary free cortisol levels and a dexamethasone suppression test can identify cortisol hypersecretion.

The diagnosis of malignancy in an adrenal mass is much more challenging because of the rarity of primary adrenal cancer,² the poor specificity of noninvasive imaging for cancer, and the lack of reliable biomarkers to diagnose adrenal cancer. Radiologic methods such as delayed contrast-enhanced computed tomography (CT) show the most promise in estimating malignancy risk.^3,⁴ Malignant tumors retain intravenous contrast dye for longer periods (e.g., there is less washout) than benign tumors. This approach has a reported sensitivity of 88% and specificity of 96% for the diagnosis of adenoma.⁵ Size is also an important factor, and many endocrine surgeons recommend adrenalectomy based on the size of adrenal tumors.⁶^–⁸ Investigators at a recent NIH consensus conference statement⁹ determined the risk of malignancy in adrenal masses to be 2% in tumors less than 2 cm, 6% in tumors 2 to 4 cm, and 25% in tumors greater than 4 cm. Based on these factors, we offer the algorithm in Figure 42-1 for the preoperative evaluation of adrenal tumors.

Figure 42-1 Algorithm for the preoperative evaluation of adrenal tumors.

INDICATIONS FOR ADRENALECTOMY

As shown in Figure 42-1, we recommend adrenalectomy for biochemically functioning lesions regardless of size and for nonfunctioning tumors larger than 4 cm or those that increase in size during observation. The choice of surgical approach depends on patient-related factors such as prior abdominal surgery, comorbid conditions, and body habitus and on tumor characteristics such as size and invasiveness.

SPECIFIC PITFALLS IN ADRENAL SURGERY

Radiologic Pitfalls

High-resolution CT and magnetic resonance imaging (MRI) studies can now identify subtle radiologic abnormalities that may mimic adrenal masses. Such findings occasionally lead to inappropriate abdominal exploration. Common mimics of adrenal tumors include renal tumors, tortuous splenic vessels and pseudoaneurysms, accessory spleens, pancreatic cysts, and gastric tumors. Figures 42-2 to 42-4 show examples of such lesions.

Figure 42-2 Gastric fundus mass can mimic adrenal tumor on computed tomography (CT) scan.

Figure 42-3 Varix mimicking adrenal tumor on CT scan.

Figure 42-4 Accessory spleen.

Biochemical Pitfalls

The full scope of biochemical evaluation of patients with adrenal masses is beyond the scope of this chapter. However, the minimal evaluation should include measurement of plasma aldosterone concentration and renin activity, plasma or 24-hour urinary metanephrines, and 24-hour urinary free cortisol.

Adequate preoperative adrenergic blockade may be the single most important factor in reducing perioperative morbidity and death during the surgical treatment of pheochromocytoma. Conversely, inadequate α-adrenergic blockade can result in perioperative cardiovascular morbidity and death. We use selective α₁-adrenergic receptor antagonists such as phenoxybenzamine and doxazosin 1 to 3 weeks prior to surgery. This may be supplemented with β-adrenergic blockade for patients who develop tachycardia or cardiac arrhythmia during α-adrenergic blockade. Intravascular volume depletion in patients with pheochromocytoma is the result of persistent vasoconstriction. Therefore, preoperative volume expansion is necessary to avoid profound perioperative hypotension.

Cortisol-Secreting Adrenal Tumors

Patients with cortisol hypersecretion have a fourfold increased risk of thromboembolic complications compared with the general population.¹⁰ Therefore, throm-bosis prophylaxis with low-dose heparin and pneumatic leg compression devices is particularly important in these patients. Perioperative steroids may be required to prevent hypotension after unilateral adrenalectomy and definitely after bilateral resection.

Nelson’s syndrome is a complication of bilateral total adrenalectomy for Cushing’s disease. It may occur in up to 30% of such patients and manifests as progressive pituitary enlargement and cutaneous pigmentation from increased adrenocorticotropic hormone (ACTH) hypersecretion. Pituitary irradiation may limit the progression of Nelson’s syndrome in selected patients.

Aldosterone-Producing Adenomas

Correction of hypokalemia with oral potassium chloride in patients with Conn’s syndrome is necessary to prevent cardiac arrhythmias during general anesthesia.

OPERATIVE APPROACHES

Operative approaches for open adrenalectomy include the anterior (transperitoneal), flank (extraperitoneal),¹¹^–¹³ posterior (retroperitoneal),¹⁴ thoracoabdominal, and transdiaphragmatic approaches. We restrict this discussion to the common approaches including anterior transperitoneal and posterior retroperitoneal operations.

Laparoscopic Anterior Transperitoneal Adrenalectomy

OPERATIVE STEPS (Table 42-1)

Step 1 Positioning

Step 2 Trocar insertion and CO₂ insufflation

Step 3 Liver mobilization (spleen and pancreas for left adrenal gland)

Step 4 Dissection of inferior vena cava (IVC)

Step 5 Identification and ligation of adrenal vein

Step 6 Dissection of arterial supply (medial) of adrenal gland

Step 7 Dissection of inferior pole of adrenal gland and superior pole of kidney

Step 8 Removal of adrenal gland and desufflation

Step 9 Closure of trocar sites

Table 42-1 Steps for Laparoscopic Anterior Transperitoneal Adrenalectomy

Step	Description
Position of the patient	Full left lateral decubitus position, lower leg flexed, cushion under left flank, table flexed to open the space between the inferior costal margin and the anterior superior iliac spine.
Trocar placement	Usually three or four trocars (one 12 mm and three 5 mm) and a 30° laparoscope are required.
Liver retraction	An atraumatic liver retractor is used to gently retract the liver superiorly and medially.
Mobilization of the liver (spleen and pancreas for left adrenal)	Using electrocautery hook, scissors, or ultrasonic shears, the subhepatic peritoneum is incised lateral to the inferior vena cava. Complete mobilization of the liver to include dissection of the right triangular ligament.
Identification of the inferior vena cava and the renal vein	Lateral border of the inferior vena cava is dissected superiorly to the level of the right crus of the diaphragm and can be dissected inferiorly to visualize the renal vein.
Identification of the main and accessory adrenal veins	Main adrenal vein is divided between surgical clips. An accessory adrenal vein may be present inferiorly.
Dissection of the arteries	Multiple adrenal arteries supply the adrenal gland from the aorta and the phrenic and renal arteries. These can usually be controlled by electrocautery or with ultrasonic shears.
Extraction of the gland	Attachments between the inferior aspect of the gland and the upper pole of the kidney are dissected. The gland is grasped with an atraumatic grasper and introduced into an extraction bag. The port site may be slightly enlarged depending on the size of the gland. Figure 42-7 shows placement of adrenal gland in an endobag.
Postoperative care	Liquid diet and ambulation on the day of surgery. Discharge home in 1 or 2 days.