The presence of cortical or medullary tumors of either a malignant or benign adenomatous nature is a well-established indication for unilateral adrenalectomy. The indication for bilateral adrenalectomy is much less common. It is occasionally performed to control complex endocrine states after partial or unilateral adrenalectomy has failed to alleviate hyperaldosteronism or hypercortisolism, as in Cushing’s syndrome from bilateral macronodular adrenal hyperplasia or hereditary pheochromocytomas as in multiple endocrine neoplasia type 2 syndrome. Synchronous bilateral adrenalectomy indications include adrenocorticotropic hormone (ACTH)–dependent Cushing’s refractory to other therapy, hereditary pheochromocytomas, or malignancy.
The most important preoperative procedure is to establish a firm diagnosis. Clinical findings often indicate altered pathophysiology, but extensive endocrine studies are necessary not only to establish the disorder within the adrenals but also to rule out associated disorders in other endocrine glands. Accordingly, the reader should refer to current texts on diagnostic endocrinology to confirm the diagnosis. Computed tomography scan is usually the preferred imaging modality, but magnetic resonance imaging also can be very useful. When adrenalectomy is decided on, the surgeon should investigate and, if possible, correct many of the secondary systemic and metabolic effects that are the direct result of the altered adrenal function. Management of hypertension and its cardiovascular sequelae is a major problem with pheochromocytomas. Problems associated with hypercortisolism include hypokalemia with alkalosis, hypertension, polycythemia, musculoskeletal depletion with osteoporosis and hypercalcemia, abnormal glucose tolerance, multiple areas of skin furunculosis, and finally, poor wound healing. Thus the surgeon must be aware that many organ systems and their responses to surgery are profoundly affected by adrenal malfunction.
Preoperative consultation and communication among endocrinologist, surgeon, and anesthesiologist are necessary. The anesthesiologist must be prepared for adequate blood and endocrine replacement and occasionally for a prolonged procedure that may be extended into the chest. Electrolytes should be in optimal condition. Parenteral steroids need to be available at the time of surgery for hypercortisolism or bilateral adrenalectomy. Adequate blood must be available because hypertension plus increased vascularity and fragile veins around the adrenals all tend to increase blood loss.
General anesthesia with endotracheal intubation is preferred. Patients with pheochromocytomas should have adequate preoperative preparation with a long-acting adrenergic (alpha receptor) blocking agent such as phenoxybenzamine hydrochloride (Dibenzyline) or doxazosin (Cardura) for an extended period of time, if possible. Administering intravenous fluids the day and evening prior to surgery helps alleviate the dehydration associated with pheochromocytomas. To minimize wide fluctuations of blood pressure, an intra-arterial line should be placed and hypertension controlled with an intravenous infusion of sodium nitroprusside (Nipride). After ensuring that adequate fluid and blood replacement has been accomplished, an infusion of norepinephrine (Levophed) may be necessary to treat hypotension. A beta-blocker and lidocaine hydrochloride (Xylocaine) may be needed to control tachycardia and cardiac arrhythmias. Once the tumor is out, norepinephrine may be needed with gradual tapering as tolerated.