Although adrenal vein sampling (AVS) is the gold standard for diagnosing subtypes of primary aldosteronism (PA), it is sometimes difficult to make correct diagnosis by conventional AVS in which only adrenal central veins are selected. We recently employed a new approach, super-selective AVS (SS-AVS). We hereby present a case of aldosterone-producing adenoma (APA) diagnosed by SS-AVS and discuss the characteristics of difficult cases.Design and method:
Case report: The 36-year-old patient with hypertension was treated with oral medication for five years, but the blood pressure control was poor. Endocrinological examinations were performed and it revealed low plasma renin activity (PRA 0.1 ng/ml/h) and high plasma aldosterone concentration (PAC 190 pg/ml). Imaging examinations showed a 13 mm-sized left adrenal mass. PA was suspected and AVS was performed subsequently to confirmation tests. However, aldosterone/cortisol ratios of both left and right adrenal central veins were lower than that of the inferior vena cava, and he failed to be diagnosed as APA. As we have employed SS-AVS since two years, we performed SS-AVS for the reevaluation for this case, and reviewed such undiagnosable cases.Results:
A microcatheter was inserted to the tributaries of the left adrenal vein. Lateralized ratio (LR) using the aldosterone value in the tributary near the mass was 25.8 and contralateral ratio (CR) was 0.50. He was diagnosed as left APA and the surgery was performed. We diagnosed 30 APAs in total, but 8 cases failed to be diagnosed by conventional AVS. Among them, 7 cases were in the left side, and none of them were with tumor size larger than 15 mm.Conclusions:
SS-AVS is useful for cases undiagnosable by conventinal AVS because a high plasma aldosterone level can be detected when a microcatheter is inserted closely to APA. It appears that such cases have much in common: a small mass in the left adrenal gland.