Background Endovascular interventions are now the standard of care for most intracranial aneurysms to minimize rupture risk and associated complications. Endovascular coils are placed in aneurysm sac to block the blood flow, while flow diverters are placed in the parent artery covering aneurysm neck to diverter flow away from the aneurysm. Despite their clinical effectiveness, the underlying molecular processes mediating aneurysm healing are poorly understood. The current study aimed to explore circulating miRNAs as potential biomarkers associated with treatment outcomes in patients undergoing endovascular treatment of intracranial aneurysms.

Methods Patients undergoing endovascular platinum coil embolization or intraluminal flow diverters placement for unruptured intracranial aneurysms were included. Blood samples were collected prior to endovascular intervention and at follow-up between 6-18 months post-intervention. Blood samples were pre-processed to separate plasma, from which circulating miRNAs were extracted. After miRNA sequencing and bioinformatic processing, differential miRNA analysis was performed using EdgeR to calculate log2 fold change (log2FC) with false discovery rate (FDR) correction.

Results A total of 23 patients were enrolled in the study, with 9 (39%) in the coil embolization and 14 (61%) in the flow diversion groups. Median follow-up sample collection time was 10.70 months (SEM±1.32). In the coil embolization group, miR-16-2-3p was downregulated (log2FC = -1.54, FDR=0.016) and miR-4433b-5p was upregulated (log2FC = 0.921, FDR = 0.021) at follow-up compared to pre-intervention samples. No differentially expressed miRNA were identified in patients undergoing flow diverter placement.

Conclusions Our data suggests that coil embolization leads to downregulation of miR-16-2-3p, which inhibits cellular proliferation and induces apoptosis, and upregulation of miR-4433b-5p, which promotes cellular proliferation and extracellular remodeling. These results prove the process of aneurysm healing and provide evidence for miRNAs as predictive biomarkers in aneurysm healing.

Disclosures S. Arul: None. R. Kumar: None. J. Ayers-Ringler: None. O. Mereuta: None. Y. Senol: None. A. Orscelik: None. W. Brinjikji: None. D. Kallmes: None. R. Kadirvel: None.