Abstract No. 182 Evaluation of adjunctive collimated C-arm computed tomography in adrenal venous sampling and its effect on successful selective catheterization

Evaluation of feasibility and effect of a novel approach to adrenal venous sampling (AVS) analysis by combination of established selective cortisol and aldosterone indices with acquisition of a collimated C-arm CT (CACTColl). Overall, 100 AVS procedures in 97 consecutive patients (38f, 59m; 53 ± 8 years), performed from January 2014 to February 2020 in a single institution, were included in this retrospective study. Sequential samples of cortisol and aldosterone levels of the suspected adrenal veins and the right iliac vein were obtained and selectivity indices (SI) for both hormones computed, by dividing the central plasma cortisol/aldosterone concentration in the adrenal vein by the peripheral value in the iliac vein. Successful AVS procedures were defined either by stand-alone SICortisol and/or SIAldosterone≥2.0 as well as SICortisol and/or SIAldosterone≥1.1 in combination with positive right-sided CACTColl of the adrenals (n = 79). Radiation exposure of CACT was measured via dose area product (DAP) and weighed against an age- and weight-matched cohort of 66 patients receiving liver-directed therapy at our center. The preliminary success rate measured by either a SICortisol and/or SIAldosterone≥ 2.0 lay at 99.3% on the left and 72.6% on the right side, corresponding to sensitivity rates of 0.99 and 0.73, respectively, and could be significantly improved by addition of a positive CACTColl, adding up to a 91% success rate on the right. Sensitivity for stand-alone collimated CACT (CACTColl) could be computed at 0.93, with a total of 74 of 79 acquired CACTColl confirming selective cannulation by adrenal vein opacification. Mean DAPColl_CACT measured 2400 ± 940 μGy × m2, while mean DAPFull-FOV_CACT in the matched cohort measured 8700 ± 1900 μGy × m2 (P< 0.001). Significantly increased success rates in (right-sided) selective cannulation of AVS procedures could be achieved by combining established hormone indices with collimated CACT. This offers a successful alternative to previously published AVS analysis algorithms with lower radiation exposure as compared to a full-FOV CACT. Significantly increased success rates in (right-sided) selective cannulation of AVS procedures could be achieved by combining established hormone indices with collimated CACT. This offers a successful alternative to previously published AVS analysis algorithms with lower radiation exposure as compared to a full-FOV CACT.