Genetic Profile in Patients With Ruptured and Unruptured Intracranial Aneurysms: Observational Study Aimed at Identifying Genetic Variants Associated With the Risk of Intracranial Aneurysm Rupture

This observational study aims to identify potential genetic determinants associated with the risk of rupture in saccular intracranial aneurysms (sIA). The study is conducted in collaboration with three Units of the Fondazione IRCCS Istituto Neurologico Carlo Besta in Milan (Neurosurgery Unit II, Cerebrovascular Diseases Unit, Neurology Unit IV), as well as additional neurosurgical centers across Italy, particularly for the enrollment of patients with ruptured sIA who do not present to Besta due to the absence of an Emergency Department.

As an observational study, it does not involve any modification to the routine clinical management of patients with sIA at participating centers. Specifically, the decision to propose surgical or endovascular treatment for patients with ruptured or unruptured aneurysms will be made independently of the study, based on shared criteria discussed during regular multidisciplinary vascular meetings. Furthermore, no additional follow-up is planned beyond what is routinely scheduled for patients undergoing surgical or endovascular treatment for intracranial aneurysms.

Each patient will be asked to provide informed consent through a dedicated form. Once consent is obtained, each participant will be assigned a unique alphanumeric central code, used exclusively for study purposes. Throughout the duration of the project and thereafter, only the responsible physician will be able to link the code to the patient's identity.

Patients will undergo clinical evaluation at the time of enrollment, as part of standard clinical practice. Anonymized clinical data will be recorded in a centralized database and will include: sex, age, height, weight, regular use of illicit substances, alcohol consumption, smoking habits, family history of sIA, arterial hypertension, medical history with particular attention to autoimmune diseases and recent infections, general and neurological assessment, and aneurysmal characteristics (location, maximum diameter, morphology-regular or irregular).

Each patient will also undergo peripheral venous blood sampling for genomic studies. When available (e.g., during clipping procedures or lumbar puncture performed for decompression or other clinical indications), samples of aneurysm wall tissue, subcutaneous arterial wall, and/or cerebrospinal fluid (CSF) will be collected. Biological samples, along with coded clinical and genetic data, will be stored at the Fondazione IRCCS Istituto Neurologico Carlo Besta in separate containers, housed in controlled and locked environments, to establish the first Integrated Italian Biobank for Intracranial Aneurysms.