Objective: Transarterial Onyx embolization is the mainstay of intracranial non-cavernous dural arteriovenous fistulas (dAVFs) treatment. Although the dural arterial supply varies depending on the location, the impact of arterial access on treatment outcomes has remained unclear. The aim of this study was to characterize factors as sociated with complete obliteration following transarterial Onyx embolization, with a special focus on arterial access routes and dAVF location.

Methods: A retrospective analysis of the patients who underwent transarterial Onyx embolization for intracranial dAVFs at two academic institutions was performed. Patients with angiographic follow-up were considered eligible to investigate the impact of the arterial access on achieving complete obliteration.

Results: Sixty-eight patients underwent transarterial Onyx embolization of intracranial dAVFs. Complete obliteration was achieved in 65% of all treated patients and in 75% of those with cortical venous reflux. Multivariable analysis identified middle meningeal artery (MMA) access to be a significant independent predictive factor for complete obliteration (OR, 2.32; 95% CI, 1.06-5.06; p=0.034). Subgroup analysis showed that supratentorial and lateral cerebellar convexity dAVFs (OR, 5.72, 95% CI, 1.89-17.33, p=0.002), and Borden type III classification at pre-treatment (OR, 3.13, 95% CI, 1.05- 9.35, p=0.041), were independent predictive factors for complete obliteration following embolization through the MMA.

Conclusions: MMA access is an independent predictive factor for complete obliteration following transarterial Onyx embolization for intracranial non-cavernous dAVFs. It is particularly effective for supratentorial and lateral cerebellar convexity dAVFs and those that are Borden type III.