Intracranial aneurysms in sickle cell disease are associated with hemodynamic stress and anemia

Although hemodynamic stress plays a key role in aneurysm formation outside of sickle cell disease (SCD), its role is understudied in patients with SCD. We hypothesized that tissue-based markers of hemodynamic stress are associated with aneurysm presence in a prospective SCD cohort. Children and adults with SCD, with and without aneurysms, underwent longitudinal brain magnetic resonance imaging/magnetic resonance angiography (MRA) to assess cerebral blood flow (CBF) and oxygen extraction fraction (OEF). Baseline characteristics were recorded. In the subgroup of adults, stepwise mixed-effect logistic regression examined clinical variables, CBF, and OEF as predictors of aneurysm presence. Cumulative rates of new aneurysm formation were estimated using Kaplan-Meier analyses. Forty-three aneurysms were found in 27 of 155 patients (17%). Most aneurysms were ≤3 mm and in the intracranial internal carotid artery. On univariate analysis, older age (P = .07), lower hemoglobin (P = .002), higher CBF (P = .03), and higher OEF (P = .02) were associated with aneurysm presence. On multivariable analysis, age and CBF remained independently associated with aneurysm presence. Seventy-six patients (49% of enrollment) received follow-up MRAs (median, 3.5 years). No aneurysm grew or ruptured, however, 7 new aneurysms developed in 6 patients. The 3-year cumulative rate of aneurysm formation was 3.5%. In 155 patients with SCD, 17% had intracranial aneurysms. Three-year aneurysm formation rate was 3.5%, although limited by small longitudinal sample size and short follow-up duration. Aneurysm presence was associated with elevated CBF in adults, as a tissue-based marker of cerebral hemodynamic stress. Future studies may examine the predictive role of CBF in aneurysm development in SCD.