Emerging Potential of Microwave Ablation for Primary Aldosteronism Resulting From Unilateral Aldosterone-producing Adenoma

Primary aldosteronism (PA) is the most prevalent form of secondary hypertension and is most commonly caused by an adrenal adenoma or bilateral adrenal hyperplasia. Minimally invasive adrenalectomy is the treatment of choice for unilateral disease. Here, we report the case of a 57-year-old man with previous bladder cancer who was referred for evaluation of resistant hypertension and hypokalemia. Diagnostic workup indicated PA with computed tomography imaging revealing a left adrenal adenoma and adrenal venous sampling lateralizing to the left adrenal. He was therefore referred for a left adrenalectomy using a retroperitoneoscopic approach. However, surgery was complicated by significant perinephritis related to previous bladder cancer immunotherapy and, in view of an identifiable adrenal adenoma, a partial adrenalectomy was performed. Despite histology confirming removal of an adrenal adenoma, he remained hypertensive and hypokalemic with persistent PA. He underwent a computed tomography-guided percutaneous thermal (microwave) ablation of the residual adrenal nodule with immediate biochemical reversal of PA. Six years postprocedure, he remains biochemically and clinically cured from PA. This article presents the details of the case and reviews the literature on long-term outcomes for patients undergoing thermal ablation and adrenalectomy, suggesting that thermal ablation may be a viable alternative for selected patients.