Abstract No. 89 Lateral and Inferior Emissary Vein as Real-Time Marker for Success in Adrenal Vein Sampling

This retrospective study aims to evaluate the success of right adrenal vein (RAV) sampling using lateral and/or inferior adrenal emissary vein(s) visualization as a real-time marker for successful cannulation during AVS. A retrospective study was conducted on 53 patients at a large academic center. Among these patients, 16 were found to have a right adrenal emissary vein on fluoroscopy. Inclusion criteria encompassed patients with lateral or inferior emissary veins. The study population was categorized into 2 groups: those with visualized right adrenal emissary veins (n=33) and those without such visualization (n=20). Statistical analysis was done using SPSS. Among all patients, 92% (n=49) had successful right adrenal vein cannulation. 100% of cases with a visualized right adrenal emissary vein and 80% of those without visualization had successful right adrenal vein cannulation. Both chi-square analysis and binary logistic regression analysis with omnibus test of model coefficients demonstrated statistical significance (p-value = 0.008; 0.004 respectively). The binary logistic regression model exhibited high sensitivity (100%) correctly identifying all instances of successful RAV sampling. However, this model had low predictive power for unsuccessful cannulation in those without emissary vein with four instances where, despite the model predicting successful RAV sampling, success was not achieved. Determination of success of adrenal vein sampling can be difficult due to wait times from laboratory services and anatomy of right adrenal vein. The ability to identify successful cannulation during the procedure can lead to reduced procedure times and fewer patient returns for repeat procedure, ultimately lowering costs and minimizing radiation exposure. Kohi et al. previously reported that visualization of the inferior emissary vein is a sensitive indicator of successful RAV sampling. In this study, visualization of a lateral or inferior emissary vein demonstrated a statistically significant correlation with successful RAV cannulation with high predictive power for success. However, the model demonstrated low predictive power for unsuccessful cannulation if emissary vein was not present, highlighting persistent utility of additional intra-operative confirmatory measures. Limitations include the observational, retrospective, single-operator nature of this study with lack of randomization.