Accuracy of Adrenal Imaging and Adrenal Venous Sampling in Predicting Surgical Cure of Primary Aldosteronism

Abstract

CONTEXT: The accurate distinction between unilateral and bilateral adrenal disease in patients with primary aldosteronism (PA) guides surgical management. Adrenal venous sampling (AVS), the criterion standard localization procedure, is not readily available at many centers throughout the world. OBJECTIVE: The objective of the study was to determine factors most consistent with surgically curable PA. DESIGN: This was a retrospective observational study. SETTING: The study was conducted at the Mayo Clinic (Rochester, Minnesota), a tertiary referral center. PATIENTS: All patients who underwent unilateral adrenalectomy for treatment of PA between January 1993 and December 2011 participated in the study. INTERVENTION: The intervention in the study was unilateral adrenalectomy. MAIN OUTCOME MEASURES: Variables associated with the prediction of unilateral disease were measured. RESULTS: Over 19 years, 263 patients underwent unilateral adrenalectomy for the treatment of PA. Long-term postoperative follow-up was obtained in 143 patients (54.4%). The overall effective cure rate of PA was 95.5% in those patients sent for adrenalectomy for presumptive unilateral disease. In patients with cured PA, defined as the resolution of autonomous aldosterone secretion, hypertension was cured in 53 (41.7%) and improved in 59 (46.5%) patients. PA was not cured with unilateral adrenalectomy in six patients (4.2%). Adrenal imaging and AVS were concordant to the surgically documented side in 58.6% and 97.1% of the patients, respectively. Although there was no statistically significant difference in mean age between the inaccurate vs the accurate adrenal imaging group, we found that the minimum age in the former was 35.1 years. CONCLUSIONS: Using adrenal imaging and AVS, the effective surgical cure rate for PA was 95.5%. Although the overall accuracy of computed tomography and magnetic resonance imaging in detecting unilateral adrenal disease was poor at 58.6%, adrenal imaging performed well in those patients younger than 35 years of age.