Current best practice in the management of patients after pituitary surgery

Abstract

Sellar and parasellar masses are a common finding, and most of them are treated surgically via transsphenoidal approach. This type of surgery has revolutionized the approach to several hypothalamic-pituitary diseases and is usually effective, and well-tolerated by the patient. However, given the complex anatomy and high density of glandular, neurological and vascular structures in a confined space, transsphenoidal surgery harbors a substantial risk of complications. Hypopituitarism is one of the most frequent sequelae, with central adrenal insufficiency being the deficit that requires a timely diagnosis and treatment. The perioperative management of AI is influenced by the preoperative status of the hypothalamic-pituitary-adrenal axis. Disorders of water metabolism are another common complication, and they can span from diabetes insipidus, to the syndrome of inappropriate antidiuretic hormone secretion, up to the rare cerebral salt-wasting syndrome. These abnormalities are often transient, but require careful monitoring and management in order to avoid abrupt variations of blood sodium levels. Cerebrospinal fluid leaks, damage to neurological structures such as the optic chiasm, and vascular complications can worsen the postoperative course after transsphenoidal surgery as well. Finally, long-term follow up after surgery varies depending on the underlying pathology, and is most challenging in patients with acromegaly and Cushing disease, in whom failure of primary pituitary surgery is a major concern. When these pituitary functioning adenomas persist or relapse after neurosurgery other treatment options are considered, including repeated surgery, radiotherapy, and medical therapy.

Keywords: Cushing disease; diabetes insipidus; hypopituitarism; hypothalamic hormones; hypothalamic neoplasms; hypothalamo-hypophyseal system; pituitary hormones; pituitary neoplasms.

Figure 1.

Physiology of ADH release and action. ADH is synthetized in the magnocellular neurons of the paraventricular and supraoptic nuclei, transported along the axons of hypothalamic neurons, and stored in the posterior pituitary. Its release has two major stimuli, a raise in plasma osmolality and a decrease in blood pressure and circulating blood volume. After ADH is secreted in the circulation, it acts both on kidneys (by promoting water reabsorption at the renal collecting duct) and on blood vessels (by stimulating vasoconstriction). ADH, antidiuretic hormone.

Figure 2.

Pathophysiology and management of water metabolism imbalance after pituitary surgery. bid, twice a day; ADH, antidiuretic hormone (vasopressin); AVP, arginine vasopressin; DDAVP, desmopressin; IM, intramuscular injection; SC, subcutaneous injection; SIADH, syndrome of inappropriate ADH secretion; tid, three times a day.

Figure 3.

Cured, persistent and recurrent CD. ‘Cured’ CD means that the patient has gone into persistent remission, defined as normalization of the HPAA after surgery. ‘Persistent’ CD is defined as sustained hypercortisolism after pituitary surgery. The term ‘recurrent’ CD refers to hypercortisolism occurring after transient resolution (up to several years) of the abnormal cortisol secretion. Residual corticotroph tumor cells within the pituitary gland or surrounding structures are responsible for both persistent and recurrent CD. ACTH, adrenocorticotropic hormone; CD, Cushing disease; HPAA, hypothalamic–pituitary–adrenal axis.

Figure 4.

Management of patients with CD. Possible scenarios during management of patients with CD. Lifelong follow up is mandatory for patients in persistent remission after first or repeated pituitary surgery, as they can develop disease relapse many years after surgical treatment. CD, Cushing disease.