Alexandra Santos will present this lecture. So good afternoon. My name is Alexandra Santos. I'm from the University of Sao Paolo in Brazil. And I'm going to talk about multiple intracranial aneurysms. First of all, I'd like to thank WNS for this opportunity and thank Professor Abelval Figueiredo for his orientation. So no disclosures. Well, a brief introduction between 8% to 30% of all patients with intracranial aneurysms have more than one lesion. They are often associated with collagen defects and family history of subarachnoid hemorrhage. So multiple intracranial aneurysms are important to study because they frequently are a challenge to the neurosurgeon, often requiring two-stage surgeries or even more. One patient of our casuate was diagnosed with nine, incredible nine, intracranial aneurysms. So that's why treatment must be considered individually, taking into account some factors such as where this aneurysm is, how many aneurysms there is, the clinical manifestations associated with them, their size, et cetera. And some previous studies have found some factors that increase the risk to development of more than one intracranial aneurysm. And they are hypertension, gender, smoking cigarettes, and age. But each factor's influence is not anonymous among studies. That's why our main objective was to investigate the incidence and the risk factors associated with multiple intracranial aneurysms in a prospective study of a single Brazilian institution. Our casuistic included 1,404 patients with intracranial aneurysms between September 2009 and August 2018. Diagnosis was performed through digital subtraction and geography. And the definition of multiple intracranial aneurysms was the presence of at least two or more intracranial aneurysms. So for a statistical analysis, we used CRISPR, of course, and then logistic regression for univariate and multivariate analysis, respectively. So what we found was that the total number of intracranial aneurysms was 2,254, with 1,090 females representing 77% of our total casuistic. And the mean age was 57 years old. Well, the group of patients with multiple intracranial aneurysms was represented by 512 patients, here 36% of our casuistic, with a mean incidence of 4% per year. 440 of them were female, representing 86%, against 77% of the total casuistic. We had statistical significance for this. So the male were proportionally higher in the group of patients with multiple intracranial aneurysms, as well as presence of smoking history was also proportionally higher in this group. But we didn't observe any significant difference concerning arterial hypertension. So in this figure one, we can see that female patients were the majority of both groups with single and multiple intracranial aneurysms. But in the group of patients with more than one aneurysms, the male were proportionally higher, 86% against 77%. And on this figure, we can see that patients with more than one aneurysm were slightly older. So this table shows us the univariate analysis that we performed. So age, sex, and smoking were the factors which most influenced the incidence of multiple intracranial aneurysms. But hypertension didn't obtain any significant difference. As we can see, the proportion of the male in the group with single aneurysms was 60% against 40% of the group of patients with multiple intracranial aneurysms. Against male, male we obtained 77% and 23% of proportions, respectively. And similar results were obtained with smoking. So multivariate analysis confirmed our results and showed that what most affected the incidence of multiple intracranial aneurysms was age. Age, more than 50 years exactly, was the factor which most affected our analysis, followed by female sex and smoking. So concerning their size, multiple intracranial aneurysms have more baby aneurysms. I mean, baby minor than 3 millimeters. Here it is. So multiple aneurysms are frequently smaller. And people with one aneurysm or single aneurysm have more giant aneurysms. Here we can see aneurysms bigger than 25 millimeters. So why women are in such a higher risk to development of more than one intracranial aneurysm? Well, two previous studies have found that comparing a group of mice which received estrogen with a group of mice with lack of estrogen, they have found that the mice which received estrogen had lower risk to development of an intracranial aneurysm and lower risk to rupture of this aneurysm. But why? Well, lower levels of estrogen were associated with a higher oxidative stress and a higher inflammation of the vessel walls. And it could explain why we can see that patients, women, at postmenopausal age are in such a higher risk. But it doesn't explain why women are the majority of patients at any age with an intracranial aneurysm. So concerning arterial hypertension, there is no consensus in literature. I would like just to highlight this study, which have found an association of arterial hypertension, but just with cases with subarachnoid hemorrhage. So we point that different criteria might be responsible for their divergences found in literature concerning arterial hypertension. And maybe period living with the disease and pharmacological treatment must be considered for this analysis. And smoking, lastly smoking. So smoking was associated with the inhibition of anti-protease action, such as alpha-1 antitrypsin, and the increased of the degeneration of the components of vessel walls for disposing arteries to aneurysmous formation. So our main conclusions, multiple intracranial aneurysms representing one third of our CAS risk. Patients most affected were women at six decades of life and smokers. And arterial hypertension didn't influence the incidence of multiple intracranial aneurysms. Thank you very much. Thank you. Are there any questions or comments? We didn't study rupture in our study, but previous analysis have found that smoking is associated with rupture as well. Your next study then. Alessandra, I have one more question. So how did you identify, it said that they were admitted to the hospital and they underwent an angiogram. Were they identified as having aneurysms for some other reason? Was it incidental, a diagnosis, and then they were put into the study and admitted and had an angiogram, a formal angiogram? Well, the clinical manifestation was not included in our cases. We just included patients who were diagnosed with an aneurysm in our hospital. Oh, they were diagnosed while during their hospital stay? Yes. Okay. Thank you.

intracranial aneurysms

neurosurgeons

prospective study

risk factors

estrogen levels