Abstract Body: Object:
The introduction of antiplatelet agents is essential in stent-assisted coil embolization (SACE) for the treatment of intracranial aneurysms, and preoperative drug efficacy assessment is important in reducing the risk of ischemic complications. Light Transmission Aggregometry (LTA) is used in our institution to assess drug efficacy, and we analyzed the association between patient background factors, including preoperative LTA values, and perioperative complications in patients who underwent SACE in a retrospective analysis.

Methods:
Patients who underwent SACE for unruptured cerebral aneurysms from 1 March 2017 to 30 June 2024 were included. Two antiplatelet drugs (aspirin 100 mg and clopidogrel 75 mg /or prasugrel 3.75 mg) were administered 7 days prior to the procedure, and LTA measurements were performed on the day of surgery. The association of each patient's background factors with ischemic complications during the hospitalization period (≥1 mRS drop) and DWI and SWI positivity rates on the day after surgery was analyzed. To investigate whether LTA value affect DWI positive rate, propensity score-matched analysis was employed to control for age, sex, alcohol consumption, smoking, family history, medical history, aneurysm shape, multiple aneurysms, symptomatic aneurysms, maximum diameter, neck diameter, aneurysm site, left or right, first treatment or not, stent type, number of stents, clopidogrel or prasugrel.

Results.
During the observation period, 1021 unruptured cerebral aneurysms received endovascular treatment, of which 548 (453 Neuroform Atlas, 17 Enterprise, 78 LVIS) underwent coil embolization with stenting. The mean LTA value on the day of surgery was 44.2 (20-74). Symptomatic ischemic complications were present in two patients (0.4%), but no associated factors were found. Propensity score matching was successful for pairs of 184 aneurysms in the DWI negative group and 184 aneurysms in the DWI positive group. LTA value was still significantly higher in DWI positive group than in DWI negative group (46.96 vs 42.14, p<0.001). The cut off value of LTA for DWI positivity was 46.0 ( AUC 0.613, 95% CI 0.566 - 0.66).

Conclusion.
Pre-operative LTA values correlated with the post-operative DWI positivity rate; confirming and adjusting preoperative LTA values may contribute to reducing the DWI positivity rate and further reducing perioperative ischemic complications.