Intracranial aneurysms in the infant population: an institutional case series and individual participant data meta-analysis

Abstract

OBJECTIVE Infantile intracranial aneurysms are exceedingly rare. The goal of this study was to evaluate an institutional case series of infantile intracranial aneurysms, as well as those reported in the contemporary literature, to determine their demographics, presentation, management, and long-term outcome. METHODS A comprehensive literature review from 1980 to 2020 was performed to identify individual cases of intracranial aneurysms in the infantile population ≤ 2 years of age. Additional cases from the authors’ institution were identified during the same time period. An individual participant data meta-analysis (IPDMA) was performed, abiding by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Patient demographic, radiographic, and clinical information was obtained. Descriptive statistical data were recorded, and multivariate logistic regression analyses were performed. RESULTS Patient data were obtained for 133 patients from 87 articles in the literature. Ten additional patients at the authors’ institution were also identified, for a total of 143 patients included in the IPDMA. The majority (72.7%) of this cohort consisted of idiopathic aneurysms, while 13.3% were posttraumatic pseudoaneurysms, 9.8% were infectious mycotic aneurysms, and 4.2% were aneurysms associated with a systemic connective tissue disorder or vasculitis. The mean age at presentation was 6.6 months. The majority of infants (97.9%) harbored only 1 aneurysm, and hemorrhage was the most common presenting feature (78.3%). The mean aneurysm size was 14.4 mm, and giant aneurysms ≥ 25 mm comprised 12.9% of the cohort. Most aneurysms occurred in the anterior circulation (80.9%), with the middle cerebral artery (MCA) being the most commonly affected vessel (51.8%). Management strategies included open surgical aneurysm ligation (54.0%), endovascular treatment (35.0%), surgical decompression without aneurysm treatment (4.4%), and medical supportive management only (13.9%). Surgical aneurysm ligation was more commonly performed for MCA and anterior cerebral artery aneurysms (p = 0.004 and p = 0.015, respectively), while endovascular techniques were favored for basilar artery aneurysms (p = 0.042). The mean follow-up period was 29.9 months; 12.4% of the cohort died, and 67.0% had a favorable outcome (Glasgow Outcome Scale score of 5). CONCLUSIONS This study is, to the authors’ knowledge, the largest analysis of infantile intracranial aneurysms to date. The majority were idiopathic aneurysms involving the anterior circulation. Surgical and endovascular techniques yielded equally favorable outcomes in this cohort. Long-term outcomes in the infantile population compared favorably to outcomes in adults.