Preoperative staging in all cases consisted of computed tomography or/and magnetic resonance imaging. Prior to surgery, a routine panel of laboratory tests was carried out. The catecholamines metabolites (metanephrine, normetanephrine, and methoxytyramine) were measured from 24-hour urine collection. All patients were preoperatively treated with phenoxybenzamine or alternative doxazosin.Additionally, beta-blockers in case of coexisting tachycardia were given. In the morning of the operation, preinduction blood pressure was measured. Pneumoperitoneum was achieved by insufflating CO2 gas to an intraperitoneal pressure of 12 mmHg. The operative method in our department was laparoscopic transperitoneal lateral total adrenalectomy. Intraoperatively SBP and diastolic blood pressure (DBP) were measured and recorded every 10 minutes. To treat hypertensive and hypotensive episodes, intravenous doses of urapidil, ephedrine, nitrates, MgSO4, norepinephrine, or ß-blockers were administered.

Hemodynamic instability was defined as an occurrence of both intraoperative episodes of systolic blood pressure above 160 mm Hg and vasoactive (vasodilators or vasoconstrictors) drugs administration. Patients were divided into two groups: one which met both above criteria, and another one without hemodynamic instability.

Data on morbidity were classified according to the Clavien-Dindo classification.