Risk factors for bleeding in patients with arteriovenous malformations associated with intracranial aneurysms

Natural history of brain arteriovenous malformations (bAVMs) with associated intracranial aneurysms (IAs) reveals a higher rate of hemorrhage. We aimed to identify the prevalence and risk factors for hemorrhage in a subgroup of patients with bAVMs and associated arterial IAs.

The authors conducted an international, bicentric retrospective study of patients with ruptured and unruptured bAVMs with associated IAs treated at tertiary centers between January 2013 and December 2022. Sociodemographic data, clinical characteristics, and radiological parameters in patients with bAVM and associated IAs were analyzed.

Of 944 patients with bAVM, 137 individuals with 191 associated arterial IAs were included in the final analysis. Bleeding presentation was documented in 85 cases (62.0%). The mean size of bAVM-associated IAs was 6.8 (SD = 4.8) mm. Multiple intracranial aneurysms (MIA) were present in 35 patients (25.5%). bAVM-associated IAs were classified as nidal in 19.0%, flow-related in 73.7%, and unrelated in 7.3% of cases. Univariate analysis revealed that arterial hypertension (odds ratio 4.37 [CI 1.52-12.57]; P =.004), history of smoking (odds ratio 5.77 [CI 1.26-26.53]; P =.013), and high-grade bAVMs (grades IV/V, odds ratio 0.35 [CI 0.15-0.87]; P =.02), were associated with a bleeding risk. In the multivariable analysis, only arterial hypertension remained significantly associated with the bleeding event (adjusted odds ratio 3.37 [CI 1.07-10.58]; P =.038).

Observational data from our large bicentric cohort of patients with bAVM and associated IAs identified arterial hypertension as a risk factor associated with an increased risk of bleeding.

The study was approved by the Institutional Review Board (IRB) of the University Clinical Center of Vojvodina and the University of Duisburg-Essen (20-9288-BO).