1093 Outcomes in Moyamoya Disease After Revascularization: An NIS Analysis of the Impact of Preoperative Aspirin Use

INTRODUCTION: Moyamoya disease (MMD) is a rare cerebrovascular disease characterized by progressive intracranial vessel narrowing and the development of collaterals, leading to stroke. While revascularization surgery preserves perfusion and prevents strokes, the impact of preoperative aspirin use on outcomes remains unexplored. METHODS: Using the National Inpatient Sample (NIS), we identified MMD patients who underwent revascularization from 2002 to 2020. The outcomes of interest included postoperative ischemic and hemorrhagic strokes, other neurological complications, length-of-stay, non-routine discharge, and mortality. The study population was stratified by aspirin use and age. Statistical analyses included Fisher’s exact, chi-square, Spearman’s correlation, and T-tests. RESULTS: We identified 1453 patients (mean age 43.05 years; 72.75% female); 470 (32.35%) were on aspirin upon admission. Postoperatively, hemorrhagic stroke occurred in 2.89%, ischemic stroke in 24.02%, and other neurological complications in 4.06%. Most patients (75.29%) were discharged home. Patients on aspirin had a significantly lower rate of post-operative ischemic stroke at 15.95%, compared to 27.87% in the non-aspirin cohort (p<0.01). Aspirin was inversely correlated with ischemic stroke events (correlation coefficient: -0.71), particularly in the 46-55 and 66-75 age groups. Despite shorter hospital stays for the aspirin group (5.69 days vs. 7.1 days, p<0.01), their total hospital charges were higher ($184,606 vs. $154,701, p<0.01). Hemorrhagic stroke and neurological complication rates did not significantly differ between groups. CONCLUSIONS: Preoperative aspirin intake is associated with a reduced risk of postoperative ischemic stroke in MMD patients undergoing revascularization without increasing the risk of hemorrhagic complications. Aspirin users also had shorter hospital stays but incurred higher costs. These findings support considering aspirin use as a standard preoperative care for MMD patients.