SAT-075 Introduction of a Single Radiologist Improves the Performance of Adrenal Vein Sampling for Primary Aldosteronism, but Does Not Ameliorate Suboptimal Selection of Patients for Surgery

Context: Adrenal vein sampling (AVS) should be performed in most patients with primary aldosteronism (PA) who want to pursue surgical cure. Objective: We aimed to compare the success rate of AVS at our center after the introduction of a single dedicated radiologist in 2012 to the period before that. We tried also to find out the percentage of patients with proven unilateral PA who ultimately had surgery. Patients and methods: A retrospective diagnostic cross-sectional study conducted at Slovenian national referral center included all patients with PA who underwent AVS after its introduction in 2004 until the end of 2017. AVS was performed sequentially during continuous Synacthen stimulation. When the selectivity index, calculated as the ratio of concentrations of cortisol from an adrenal vein and the infra-adrenal inferior vena cava, was at least 5, AVS was considered successful. Lateralization index, defined as the ratio of the higher over the lower cortisol-corrected aldosterone ratio, of more than 4 indicated unilateral aldosterone excess. The data were analyzed using descriptive statistics, t-test, exact Mann-Whitney test and Fisher's exact test for group comparison, and Cohen's kappa for assessing agreement. The study was approved by the National Medical Ethics Committee. Results: Data from 214 patients were examined (152 men and 62 women; age 32-73, median 57 years; BMI 18-48, median 30 kg/m(2)). The average number of AVS procedures performed per year increased significantly from 7 in the 2004-2011 period to 30 in the 2012-2017 period (p<0.001). AVS was successful in 85% of the patients; AVS had to be repeated in 11% of the cases; 89% of all AVS procedures were successful. The proportion of patients with successful AVS (91% vs. 66%, p<0.001) and of successful AVS procedures (80% vs. 61%, p=0.007) was significantly higher in the recent period. Adrenal hemorrhage due to vein rupture occurred during two procedures (0.83%), both resolved conservatively. Among the patients with successful AVS, 41% had unilateral disease; among them, only 83% underwent surgery. Main reason for not having surgery was patient’s reluctance (n=8). One patient was diagnosed with liver cirrhosis and was rejected by the surgeon, two patients were lost to follow-up and three patients were still on the waiting list. The proportion of patients with unilateral disease undergoing surgery did not differ significantly between the periods (89% vs. 81%, p=0.718). Conclusions: The introduction of a single, dedicated radiologist in 2012 expanded and improved the AVS performance at our center. A substantial number of patients with proven unilateral PA did not proceed to surgery, pointing to suboptimal selection of candidates for AVS.