Low PHASES-Estimated Rupture Risk Among Patients Presenting with Ruptured Intracranial Aneurysms: A Retrospective Single-Centre Observational Study

Background/Objectives: The PHASES score is widely used to estimate the 5-year rupture risk of unruptured intracranial aneurysms, yet many patients present with aneurysmal subarachnoid haemorrhage despite low calculated risk. This study aimed to characterise the demographic and aneurysm-related profile of patients with ruptured aneurysms classified as low risk by PHASES.