Angioarchitectural characterization of transdural supply in brain arteriovenous malformations: a multicenter retrospective study.

PURPOSE: Transdural supply (TDS) is a recognized angioarchitectural feature of brain arteriovenous malformations (bAVMs). We aimed to systematically characterize the angioarchitecture of TDS in bAVMs, focusing on whether transdural feeders terminated within the nidus or connected directly to the draining vein. TDS prevalence and its associated clinical features were also investigated. METHODS: This retrospective study enrolled 521 patients (524 bAVMs) from 16 centers who underwent systematic six-vessel digital subtraction angiography. bAVMs were classified as nidus- or fistula-dominant. Angiography was evaluated with specific focus on the presence of TDS and the termination site of transdural feeders. TDS was classified as TDS-Nidus (fistulous point within the nidus) or TDS-DV (fistulous point at the draining vein wall). RESULTS: TDS was identified in 88 bAVMs (16.8%). The fistula-dominant type was more frequent in bAVMs with TDS (P < 0.01). Among TDS cases, 25 (28.4%) demonstrated TDS-DV. Fistula-dominant morphology was the only independent predictor of TDS-DV (P < 0.01). No significant differences in complete occlusion rates or modified Rankin Scale score after treatment were observed between the TDS-Nidus and TDS-DV groups. Older age (odds ratio [OR]: 1.04; 95% confidence interval [CI]: 1.02-1.06), larger nidus size (OR: 1.95; 95% CI: 1.60-2.42), occipital location (OR: 3.12; 95% CI: 1.28-7.62), eloquent area involvement (OR: 3.23; 95% CI: 1.61-6.50), and headache (OR: 2.85; 95% CI: 1.26-6.44) were independently associated with TDS. CONCLUSION: TDS-DV was identified in 28% of bAVMs with TDS and was strongly associated with fistula-dominant morphology. Recognition of this angioarchitectural pattern may facilitate angiographic characterization of bAVMs with TDS.