Introduction/purpose The pathogenesis of aneurysms associated with cerebral arteriovenous malformation (AVM) feeder vessels is poorly understood. We sought to determine the hemodynamic characteristics of AVM feeder vessels with and without aneurysms.

Materials and methods Patients with AVMs associated with feeder aneurysms who had flow, vessel diameter, and wall shear stress (WSS) measured before treatment using quantitative magnetic resonance angiography were retrospectively reviewed. Feeders within each AVM were classified into two groups based on presence or absence of aneurysms. Hemodynamic parameters were calculated for each arterial feeder and then compared between the two groups using the independent 2-tailed Student’s t test.

Results 11 patients had AVMs with feeder aneurysms. Cohort characteristics are summarized in Table 1. Of 35 total feeder arteries, 12 had an aneurysm and 23 feeders did not have any aneurysms. Absolute mean flow was higher (500.5 vs. 438.4 mL/min, P = 0.59) and vessel diameter was lower (3.9 vs. 4.8 mm, P = 0.22) in feeders with aneurysms but not significantly. However, WSS (95.7 vs. 28.0 dynes/cm², P = 0.04) was significantly higher in feeders with aneurysms. Exponential regression analysis demonstrated that higher flows were significantly associated with larger vessel diameter in AVM feeders with (R² = 0.52,  P = 0.01) and without aneurysms (R² = 0.46, P = 0.001). Importantly, at most flow rates feeders with aneurysms had smaller diameters and subsequently higher WSS than feeders without aneurysms (Figure 1).

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Abstract E-097 Figure 1

Flow versus diameter in feeder arteries with and without aneurysms

Conclusion WSS is significantly higher among cerebral AVM feeders harboring aneurysms. Despite similarly high flows, feeder artery diameter tended to be smaller if an aneurysm was present, suggesting that AVM feeders with aneurysms are a subgroup in which vessel remodeling cannot compensate for increased blood flow.

Disclosures S. Shakur: None. S. Amin-Hanjani: None. H. Mostafa: None. F. Charbel: None. A. Alaraj: None.