Background A known potential source of hemorrhage of cerebral arteriovenous malformations (AVMs) arises from feeder artery aneurysms, which contributes to the 2–4% annual rupture risk of AVMs. Thus, having a better appreciation of factors leading to their development and subsequent risk of bleeding represents an important aspect in the management of AVMs.

Objective To determine risk factors associated with rupture of feeder artery aneurysms

Methods A prospectively collected, institutional database of 647 adult patients with cerebral AVMs (2007–2023) was queried. Patients with feeder artery aneurysms identified on diagnostic imaging were included for analysis. Patient characteristics, angioarchitectural information, and hemodynamic data were collected for each patient and compared between those who presented with and without hemorrhage.

Results A total of 128 patients in this dataset were found to have feeder artery aneurysms, with 71 unruptured and 57 ruptured feeder artery aneurysms. Average age, sex, and race did not differ between groups. Smoking history was not found to be a risk factor for rupture; however, hypertension was higher in those with ruptured feeder aneurysms (47.4% vs. 29.5%, p=0.046). Infratentorial location of the AVM was strongly associated with rupture (p<0.001). In this cohort, Spetzler-Martin (SM) grade was found to be associated with aneurysmal rupture; interestingly, lower SM grades were encountered more frequently in the rupture group (p=0.006). Nidal compactness, venous drainage pattern (superficial/deep and quantity of draining veins), and number of feeder arteries were not associated with aneurysm bleeding. However, the size of the feeder artery was significantly smaller in those with ruptured aneurysms (2.7 vs. 3.6 mm, p=0.003). Furthermore, in patients with available quantitative MRA data, calculated AVM flow was lower in those with aneurysmal rupture (277.5 vs. 528.7 mL/min, p=0.021).

Conclusion Hemorrhage from feeder artery aneurysms was found to be associated with several risk factors, including infratentorial location, lower AVM blood flow, and smaller feeder artery. These findings highlight the importance of hemodynamic factors in the rupture and likely development of feeder artery aneurysms.

Disclosures L. McGuire: None. T. Abou-Mrad: None. J. Hossa: None. P. Theiss: None. M. Tshibangu: None. A. Madapoosi: None. F. Charbel: None. A. Alaraj: None.