Abstract 183: Characteristics and Outcomes of Treated and Untreated Mycotic Aneurysms: A Single Center Study

Introduction Infectious intracranial aneurysms (IIAs), commonly referred to as mycotic aneurysms, are a common sequela of infective endocarditis (IE). The morbidity rate is known to be about 80% in ruptured IIAs. Over the last decade, we have seen a rise in the utilization of endovascular therapies over conservative management for the treatment of IIAs with promising results. We present a single‐center experience describing the characteristics and outcomes of treated and untreated IIAs. Methods This is a single‐center retrospective observational study of patients admitted with IE who developed IIAs and were admitted at our institute from 2016 to 2022. Descriptive statistics were performed using SAS statistical software and Microsoft Excel. Results Out of a total of 862 patients with IE, 25 patients (3.0%) were identified to have 41 IIAs (single aneurysm in 18 patients and multiple aneurysms in 7 patients). The median (IQR) age of our population was 45 (27‐65) years, with 28/41 (68.3%) male patients. The overall mean (minimum‐maximum) size of all IIAs was 2.8 (0.2‐11) mm. The number of treated IIAs was 14/41 (34.1%) while 27/41 (65.9%) of IIAs were not intervened on. Among those IIAs treated, 92.8% were treated with an endovascular approach; 50% underwent onyx embolization, 28.6% underwent n‐BCA embolization, 14.2% underwent coil embolization, and 7.2% (n=1) underwent surgical intervention. The average (minimum‐maximum; mm) size of ruptured IIAs was 4.4 (1‐11) whereas the size of untreated IIAs was 2.0 (0.2‐9); (P=0.002). Among the treated group of IIAs, the majority were discharged home (21.4%) or discharged to facilities (78.6%). There was no in‐hospital mortality observed among the treated group. No IIAs were found to re‐rupture following embolization, and there was no change in any patient’s baseline neurologic examination following the embolization procedure. Conclusion Endovascular therapy is overall safe and effective in the management of IIAs and may be considered among patients with ruptured IIAs while accounting for their underlying comorbidities. Patients with secured IIAs are less likely to have in‐hospital mortality and are more likely to have better outcomes upon discharge. However, this may be influenced by case selection bias. Additional large center observational studies are warranted to confirm our findings.