Endocrinological remission will be determined by an endocrinologist. The criteria for acromegaly control will be normalisation of serum insulin-like growth factor and suppression of the nadir serum growth hormone level after oral glucose tolerance test. The criteria for Cushing's disease control will be normalisation of early morning serum cortisol and suppression of serum cortisol after low dose dexamethasone suppression test. The criteria for prolactinoma control will be normalisation of serum prolactin.

Postoperative complications will include death, cerebrospinal fluid leak, meningitis, vascular complications, visual complications, diabetes insipidus transient and permanent, hypopituitarism, and cranial nerve injury. Vascular complications will include carotid or other vessel injury, or symptomatic haematoma. Venous bleeding from the cavernous sinus will be considered a vascular complication only if it prevents completion of the surgical procedure. Epistaxis will only be considered a vascular complication if it warrants return to the operating room. Cerebrospinal fluid leaks will include all postoperative leaks, and all patients who develop an intraoperative leak requiring lumbar drainage. Patients with Cushing's disease receiving postoperative cortisol, or in whom a hypophysectomy was carried out will also not be included as surgical complications.