Contralateral adrenal abnormalities in Conn's syndrome

Background During the course of evaluation for primary hyperaldosteronism, cross-sectional imaging is obtained in efforts to identify patients with an aldosterone producing adenoma (APA). A subset of these patients will have a synchronous, contralateral adrenal abnormality. Adrenal vein sampling (AVS) further guides clinical decision making by identifying unilateral (APA) versus bilateral hypersecretion. In the subset of patients with contralateral adrenal abnormalities, it is unclear how this affects the durability of an adrenalectomy for APA. This study characterizes this group of patients to assess the efficacy of surgical intervention. Methods A retrospective review of patients undergoing adrenalectomy for APA based on AVS at a university practice. Preoperative and postoperative patient characteristics, laboratory evaluations, imaging results, and final pathology were noted. Results From 2000 to 2011, 103 patients with APA underwent unilateral adrenalectomy. Eighteen patients (17%) had discordant results between AVS and imaging. Most of these patients were male (78%), and the mean age was 57 ± 13 y. Median duration of follow-up was 3.5 y [1 y, 6 y]. All patients with initial hypokalemia were rendered normokalemic after the operation. Four patients increased their antihypertensive regimen during the follow-up period. These patients all had nodular hyperplasia on final pathology. Conclusions In patients with bilateral adrenal abnormalities who have undergone unilateral adrenalectomy for primary hyperaldosteronism, patients with clear APAs on final pathology appear to have durable outcomes after resection. Conversely, nodular hyperplasia on final pathology may be a risk factor for ongoing aldosterone hypersecretion. An algorithm for biochemical surveillance in this subset of patients should be considered.