Ogilvy, Christopher S.

OBJECTIVE While the relationship between smoking and subarachnoid hemorrhage is well established, data regarding the probability of detecting unruptured intracranial aneurysms (UIAs) in smokers remain sparse. The aim of this systematic review and meta-analysis is to provide a comprehensive understanding of the relationship between smoking and the likelihood of identifying UIAs in healthy asymptomatic patients who underwent brain imaging for indications unrelated to UIAs. METHODS A systematic review was conducted following the PRISMA guidelines. The PubMed and Scopus databases were searched for studies published before March 2024 that reported on the presence of UIAs in healthy asymptomatic patients who had undergone brain imaging for indications unrelated to UIAs. Three independent reviewers assessed the eligibility of all retrieved studies. Risk of bias for the included observational studies was assessed using the methodological index for non-randomized studies. Data on UIA prevalence, smoking status, and patient and aneurysm characteristics were extracted. The association between smoking and the presence of UIA was studied. A prevalence proportional meta-analysis was conducted across the included studies. A meta-analysis was performed with a random-effects model by using summary statistics from the included studies. RESULTS Six studies involving 47,788 patients who had undergone brain imaging were identified for quantitative analysis. The pooled UIA prevalence in the sample was 3.07% (95% CI 2.27%–4.16%). Patients who smoked had higher rates of aneurysm detection than the patients who did not smoke (pooled prevalence of 2.96%, 95% CI 2.68%–3.27% vs 2.23%, 95% CI 2.08%–2.39%). Although the relation between the two was not statistically significant (p = 0.06), smoking was associated with higher odds for UIA detection, yielding an OR of 1.34 (95% CI 1.07–1.67) with an I 2 value of 53%. CONCLUSIONS This study suggests a potentially higher risk of UIAs in patients who smoked than in those who never smoked. However, the results of this meta-analysis revealed that smoking was not statistically associated with higher UIA detection. This result could be explained by the limited number of studies published on this topic. If these findings reach statistical significance in future larger studies, it could justify revising guidelines to include cigarette smokers in intracranial aneurysm screening.

OBJECTIVE Endovascular intracranial aneurysm (IA) management has significantly evolved over the last 2 decades. Despite these advancements, the aneurysm recanalization rate after coil embolization remains a concern. Statins have been found to affect vascular repair and remodeling; therefore, the authors hypothesized that patients receiving statin therapy at the time of coil embolization would have lower aneurysm recurrence and retreatment rates compared with patients not receiving statin therapy. METHODS A post hoc analysis was conducted of the primary data from patients enrolled in the Hydrogel Endovascular Aneurysm Treatment Trial focusing on the impact of statin use on the recurrence rates of 3- to 14-mm IAs after endovascular coiling. The primary outcome measured included aneurysm recurrence over 18–24 months using the Raymond-Roy Occlusion Classification. Secondary outcomes included major and minor recurrence rates and retreatment rates. Propensity score matching based on patient and aneurysm characteristics was performed to mitigate selection bias. RESULTS A total of 577 patients with data on statin use were eligible for this analysis. Of these, 178 (30.8%) patients were using statins and 399 (69.2%) were not. After propensity score matching, 156 (39.2%) patients were included in the statin group and 242 (60.8%) in the nonstatin group. The recurrence rate was 3.8% (6/156) in the statin group and 10.7% (26/242) in the nonstatin group (p = 0.013). In a subgroup analysis, statin use significantly reduced recurrence in patients with unruptured aneurysms (1.6% vs 9.7%, p = 0.005), but not in those with ruptured aneurysms (12.5% vs 13.6%, p = 0.876). CONCLUSIONS Statin use was associated with a reduced rate of aneurysm recurrence in patients who underwent endovascular coiling for IAs with a decreased rate of retreatment during the follow-up period. Statins are a relatively low-risk treatment and may be an effective therapy to reduce recanalization of IAs, although further prospective studies are warranted to validate these findings.