CT-derived adrenal-to-spleen ratio as a predictor of massive transfusion and mortality in emergency transcatheter arterial embolization of active bleeding

PURPOSE: In cases of severe shock, the adrenal gland undergoes hyperperfusion to ensure adequate circulation of stress hormones. Concurrently, the spleen experiences hypoperfusion in order to maintain optimal central blood pressure. The objective of this study was to identify the associations between adrenal and spleen parameters on computed tomography (CT) scans and patient outcomes in individuals with active bleeding who underwent transcatheter arterial embolization (TAE). METHODS: A single-center retrospective analysis was conducted on consecutive patients who underwent TAE due to bleeding from various anatomical sites following CT imaging over a five-year period (2018-2022). The initial CT scan for the detection of the bleeding site was used to determine the mean adrenal gland and spleen radiodensities, and the adrenal-to-spleen ratio. The CT-parameters were then incorporated into multivariable logistic regression models to detect associations with the primary outcome of all-cause 30-day mortality and secondary outcome massive transfusion. RESULTS: The study cohort included 126 patients (62.7% male), with a median age of 67.4 years. The 30-day mortality rate was 28.6%, and 24.6% of patients received a massive transfusion. In multivariable analysis, the adrenal-to-spleen ratio was found to be independently associated with 30-day mortality (odds ratio 15.7, 95% confidence interval 2.55-99.09, p = 0.003) and massive transfusion (odds ratio 49.69, 95% confidence interval 6.29-392.30, p < 0.001). CONCLUSION: The results suggest that the adrenal-to-spleen ratio may be associated with 30-day mortality and the need for massive transfusion in patients undergoing TAE. Further studies with more homogenous patient cohorts and higher sample sizes are needed to confirm these results.