# APBA Kısa Özet
A systematic review and meta-analysis of 162 studies (316,131 participants) examined the prevalence and risk factors for unruptured intracranial aneurysms (UIAs). The estimated prevalence in a hypothetical reference population (mean age 50, 50% women, no comorbidities) was 3.9%. UIA prevalence increased significantly in recent years (2016–2022 vs 2002–2015), an effect only partially explained by better imaging resolution and population aging. UIA prevalence was highest in individuals with autosomal dominant polycystic kidney disease (12.8%) and connective-tissue disorders (10.3%). Female sex, hypertension, and current smoking were associated with increased relative risk.
# Çalışma neyi araştırdı?
This systematic review and meta-analysis synthesized data from 162 studies encompassing 316,131 participants to investigate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs) across different populations, comorbidities, and time periods. The primary aim was to determine whether the observed decline in subarachnoid hemorrhage incidence is paralleled by declines in UIA prevalence. Researchers estimated age- and sex-adjusted prevalence ratios (PRs) and relative risks (RRs) for various factors, including region, comorbidities, and behavioral risk factors. The search strategy covered Embase, PubMed, and Web of Science for articles published from January 1, 2011, to December 31, 2025, and reassessed 68 previously published articles from a 2011 systematic review and meta-analysis. Studies were included if they used a cross-sectional or case-control design, provided the crude number of participants and those with UIA, reported UIA numbers separately from ruptured aneurysms, and included at least ten patients.
# Yöntem
The review searched Embase, PubMed, and Web of Science for articles published from January 1, 2011, to December 31, 2025, and reassessed 68 previously published articles from a 2011 systematic review. Studies were included if they used a cross-sectional or case-control design, provided the crude number of participants and those with UIA, reported UIA numbers separately from ruptured aneurysms, and included at least ten patients. Summary data were independently extracted by two reviewers, and conflicts were resolved by a third party. Relative risks (RRs) and prevalence ratios (PRs) were calculated using random-effects models to account for between-study heterogeneity. Heterogeneity was assessed using I² and τ² statistics, and the certainty of evidence was evaluated using GRADE. Subgroup analyses were performed based on region, study design, and imaging modality.
# Temel bulgular
The estimated overall prevalence of UIAs in a hypothetical reference population (mean age 50, 50% women, no comorbidities) was 3.9% (95% CI: 3.0–5.1). Prevalence varied significantly by region and comorbidity. For connective-tissue disorders, the UIA prevalence was 10.3%, and for autosomal dominant polycystic kidney disease (ADPKD), it was 12.8%. The study also found that the reported prevalence of UIAs increased over the past two decades, with an adjusted prevalence ratio (PR) of 1.8 (95% CI: 1.1–2.8) for 2016–2022 compared to 2002–2015. Subgroup analyses revealed higher prevalence in certain geographic regions and specific study designs. The heterogeneity statistics indicated substantial variation across included studies (τ² significant).
# Bulgular ne anlama geliyor?
The rising prevalence of UIAs, particularly in recent years, suggests that improved imaging technologies and aging populations are major contributors. However, the persistence of a significant increase even after adjustment for these factors indicates that other etiologic factors may be at play. High-prevalence groups, such as those with ADPKD or connective-tissue disorders, may benefit from targeted screening protocols. The identification of female sex, hypertension, and smoking as risk factors underscores the importance of managing these modifiable risk factors to potentially reduce UIA formation or rupture risk. Clinical guidelines may need updating to reflect these evolving epidemiological trends.
# Klinik önem
The findings highlight the need for increased awareness and potentially targeted screening for UIAs in high-risk populations, such as those with genetic connective tissue disorders or ADPKD. For the general population, the modest baseline prevalence of 3.9% in a reference group, combined with the rising trend, suggests that clinical decisions regarding screening should consider individual risk factor profiles. The study emphasizes that while imaging improvements explain part of the increase, the role of modifiable risk factors like smoking and hypertension remains critical for clinical management and prevention strategies. Early detection in high-risk groups could facilitate surgical or endovascular intervention before rupture occurs.
# Sınırlılıklar
The review acknowledges significant heterogeneity (τ²) across included studies, which limits the precision of pooled estimates. The certainty of evidence ranged from very low to moderate across outcomes under GRADE assessment. Additionally, the analysis was constrained by the observational nature of included studies, potential variations in imaging protocols and diagnostic criteria across regions, and the possibility of residual confounding. The rapid evolution of imaging technology and changes in clinical practice over the study period further complicate the interpretation of temporal trends. Language restrictions and publication bias may also affect the generalizability of the findings.