060 - Role of Adrenal Vein Sampling in Workup of Primary Hyperaldosteronism (Conn Syndrome)
Rebecca Guan, Medical Student – Medical Student, University of Louisville School of Medicine; Nana Ohene-Baah, MD – Attending Physician, Radiology, University of Louisville School of Medicine
Purpose: Hyperaldosteronism is an under-diagnosed cause of hypertension, with an estimated prevalence of 1% of all patients with hypertension. It is typically caused by aldosterone producing adenomas (Conn Syndrome) or bilateral adrenal hyperplasia. Adrenal vein sampling (AVS) is the standard test to distinguish between unilateral adenomas and bilateral hyperplasia. Patients found to have unilateral disease may undergo surgical management, whereas patients with bilateral hyperplasia undergo medical management with aldosterone sparing antagonists such as Spironolactone.
Material and Methods: In this case series, we present three cases of patients who underwent adrenal vein sampling during evaluation of hyperaldosteronism. These three patients presented with hypertension, hypokalemia and adrenal adenomas or hyperplasia. After undergoing AVS, it was found that all patients showed unilateral derangements and underwent appropriate management.
Results: Two of the three patients were found to have left adrenal adenomas using AVS. After surgical consults, they were scheduled to undergo removal. The third patient who was found to have benign adenomatous hyperplasia on CT, had nondiagnostic findings from AVS. This patient is being medically managed with Amlodipine, Spironolactone and oral potassium supplementation with adequate control of blood pressure and symptoms.
Conclusions: AVS is the standard test for further workup of PA. However, it also has its challenges. It is a techniquely challenging procedure and can be nondiagnostic in a significant number of cases, similarly to patient 3 in this series. In a small subset of patients, cortisol can be co-secreted with aldosterone, leading to false results with the A/C ratio. In addition, variation in vasculature can result in failure to access the adrenal vein, especially on the right side. Although rare, AVS also can result in complications such as venous rupture, adrenal infarction or catheter induced venous thrombosis.
AVS should only be considered for patients in which adrenalectomy is an option, because adrenalectomy is curative for patients with a unilateral adenoma. It is important for providers to understand the indications for testing for PA and AVS because it is a reversible cause of hypertension. Patients who are found to have bilateral hyperplasia from AVS can be successfully medically managed.