Angiographic features of pulmonary arteriovenous malformations: a new imaging classification system, BRAND, to guide embolisation.

Aim: To introduce a new classification system for pulmonary arteriovenous malformations (PAVMs) based on the BRanches, ANgles and Diameter of the feeding artery (BRAND), which is intended provide a better understanding of the vascular structure of PAVMs and facilitate the selection of therapeutic strategies for embolisation.

Materials And Methods: Twenty-one patients with PAVMs from 2005 to 2020 were reviewed retrospectively. According to angiographic morphology, classified the PAVMs using the BRAND classification.

Results: A total of 41 PAVMs were treated with transcatheter embolisation. Based on the BRAND classification, there were four branches (9.8%), four acute angles (9.8%), and 32 occlusion sites >4 mm in diameter (78%). A total of 30 PAVMs (73.2%) were treated with occluders and plugs while the rest were embolised with coils (26.8%). Immediate technical success was achieved in all patients. In feeding arteries with acute angles, balloon-assisted tracking and trans-septal puncture techniques were used to facilitate the advancement of delivery systems. All origins of branches were preserved. Mean SaO increased significantly from 79.5 ± 7.5% before embolisation to 92 ± 5.3% after embolisation (p<0.05). During a median follow-up of 5.4 years, two patients (9.5%) developed new PAVMs and required a second procedure. One patient (4.8%) underwent repeat embolisation due to the reperfusion of previously embolised PAVMs with coils.

Conclusions: BRAND classification is well suited to address the challenging feeding arteries of PAVMs and allow precise placement of the delivery system, leading to minimal procedural risk and high success rates.