Assessing rupture risk by hemodynamics, morphology and plasma concentrations of the soluble form of tyrosine kinase receptor Axl in unruptured intracranial aneurysms.

OBJECTIVE

This study investigated the relationship between morphology, hemodynamic parameters, and plasma concentrations of the soluble form of tyrosine kinase receptor Axl (sAxl) and their potential role in assessing the intracranial aneurysm rupture risk.

METHODS

Thirty-nine patients were retrospectively recruited and these patients were divided into low and high rupture risk groups based on the PHASES score. Plasma levels of sAxl were measured using an enzyme-linked immunosorbent assay-based method. Computational fluid dynamics were used to calculate the morphological and hemodynamic parameters. Differences between clinical data, morphological-hemodynamic parameters and sAxl level were initially determined using univariate analysis. The variables (p ＜ 0.05) were included in a logistic regression model, and the specificity and sensitivity of the selected parameters were evaluated both graphically and statistically using receiver operating characteristic (ROC) curve methods.

RESULTS

Aneurysm size ratio (p = 0.023), and normalized wall shear stress (WSS) (p = 0.02) showed significant differences between the two groups. Plasma concentrations of sAXL with a high rupture risk were significantly higher than the low rupture risk (8.47 ± 4.43 ng/ml vs. 5.37 ± 3.21 ng/ml; p = 0.016). Binary logistic regression analysis indicated that the concentration of sAxl was an independent determinant of high rupture risk (odds ratio=1.41, 95%CI=1.08-1.83, p = 0.011). The combination of sAxl + size ration (SR) + WSS achieved the highest area under the curve (0.849) for predicting rupture risk.

CONCLUSIONS

Unruptured intracranial aneurysms with a higher rupture risk had a larger SR, lower WSS, and higher plasma sAxl concentration. Combining sAxl, SR, and WSS could help estimate the rupture risk of intracranial saccular aneurysm.