Objective: Adrenal vein sampling (AVS) is recognised by Endocrine Society guidelines as the only reliable mean to distinguish between aldosterone producing adenomas and bilateral adrenal hyperplasia, the two most common subtypes of primary aldosteronism (PA). However, AVS protocols are not standardised and vary between centres. The objective of the present study was to assess whether the presence or absence of contralateral adrenal (CL) suppression has an impact on the postoperative clinical and biochemical parameters in patients who underwent unilateral adrenalectomy for PA.
Design and methods: The study was retrospectively carried out in eight referral hypertension centres in Italy, Germany, and Japan. Screening and subtype differentiation were performed according to the Japan Endocrine Society and the Endocrine Society guidelines and a total of 234 AVS procedures were included in the study. CL suppression was defined as aldosterone/cortisolnondominantadrenalvein/aldosterone/cortisolperipheralvein <1.
Results: Overall, 82% of patients displayed CL suppression at AVS, with no statistically significant differences among centres. This percentage was significantly higher in ACTH-stimulated compared with basal procedures (90% vs 77%). The CL ratio was inversely correlated with the aldosterone level at diagnosis and, among AVS parameters, with the lateralisation index (P<0.02 and P<0.01 respectively). To investigate whether the presence of CL suppression was correlated with response to adrenalectomy, we analysed the CL suppression status with regard to the patients clinical and biochemical postoperative parameters. No differences were observed between the two groups for the main clinical and biochemical parameters (systolic and diastolic blood pressures, aldosterone, PRA, PRC, K+, number of drugs, reduction of blood pressure levels, and the number of classes of drugs assumed), but patients with CL suppression underwent a significantly larger reduction in aldosterone levels after adrenalectomy.
Conclusions: For patients with lateralisation indices of >4, CL suppression should not be required to refer patients to adrenalectomy because it is not associated with a larger blood pressure reduction and might exclude patients from curative surgery.