The adrenal glands are small, triangular-shaped organs situated atop each kidney, functioning as part of the endocrine system. They produce hormones that regulate metabolism, blood pressure, and the body’s response to stress. When a medical condition requires the removal of only one gland, the procedure is called a unilateral adrenalectomy. This surgery is typically performed to resolve hormone imbalances or remove tumors.
Reasons for Removing a Single Adrenal Gland
The decision to perform a unilateral adrenalectomy is most often driven by the presence of a tumor, which may be benign or malignant. A common reason is the discovery of an adenoma, a non-cancerous growth that causes hormone overproduction. Specific hypersecretion syndromes require removal, such as primary hyperaldosteronism, often caused by an aldosteronoma. This condition leads to high blood pressure and low potassium levels.
Another frequent cause is a pheochromocytoma, a tumor originating in the adrenal medulla that releases excessive catecholamines, such as adrenaline and noradrenaline. The procedure is also performed for unilateral Cushing’s syndrome, caused by a cortisol-producing adenoma. Additionally, removal may be necessary for large tumors, even if non-functional, or for adrenocortical carcinoma, a rare form of cancer.
Compensation: How the Body Maintains Hormone Balance
The body is generally capable of maintaining normal hormone levels with only one gland after a unilateral adrenalectomy. This adaptation is achieved because the remaining, healthy adrenal gland possesses a functional reserve, allowing it to increase its production capacity. This process is sometimes referred to as compensatory hypertrophy, where the remaining gland effectively takes over the hormone-producing role.
The body tightly regulates cortisol production through the hypothalamic-pituitary-adrenal (HPA) axis. When one gland is removed, the pituitary gland detects the potential drop in cortisol and releases more adrenocorticotropic hormone (ACTH). This hormone stimulates the remaining gland to increase production. This feedback loop ensures that a single healthy gland can meet the body’s full need for cortisol, a hormone vital for metabolism and the stress response.
The remaining gland maintains the balance of mineralocorticoids, such as aldosterone, which controls blood pressure and salt balance. If the removed gland was a source of hormone overproduction, the contralateral gland may have been suppressed and temporarily dormant. In cases of cortisol-secreting tumors, the HPA axis may be severely suppressed, requiring the remaining gland to recover function over time. This recovery can range from a few months to over a year, depending on the severity of the initial hormone excess.
Post-Surgical Recovery and Long-Term Health
Recovery from a unilateral adrenalectomy depends on the surgical approach and the reason for the procedure. The majority of these surgeries are performed laparoscopically, a minimally invasive technique involving small incisions. This method typically results in a shorter hospital stay, allowing most patients to resume normal activity within two to four weeks.
An open adrenalectomy, which involves a larger incision, is reserved for very large tumors or suspected malignancy. This requires a longer recovery period, often four to six weeks. Following surgery for a cortisol-producing tumor, temporary steroid support may be administered while the suppressed remaining gland recovers its ability to produce adequate cortisol. The need for medication is carefully monitored using blood tests.
The long-term prognosis for most patients is highly favorable, with the single remaining gland providing sufficient hormone levels for a normal life. Regular follow-up testing, including blood work to check hormone levels, is standard practice to confirm the optimal function of the remaining gland. Patients who had pheochromocytoma or aldosteronoma removed often experience significant improvement or resolution of their associated high blood pressure.