PT - JOURNAL ARTICLE AU - Yakes, W TI - E-072 Efficacy of a modern AVM classification system that directs curative endovascular therapies accurately AID - 10.1136/jnis-2023-SNIS.172 DP - 2023 Jul 01 TA - Journal of NeuroInterventional Surgery PG - A119--A119 VI - 15 IP - Suppl 1 4099 - http://jnis.bmj.com/content/15/Suppl_1/A119.1.short 4100 - http://jnis.bmj.com/content/15/Suppl_1/A119.1.full SO - J NeuroIntervent Surg2023 Jul 01; 15 AB - Purpose To determine if AVM angioarchitecture characteristics that can be predictive and direct specific curative endovascular procedures accurately and consistently to cure high-flow malformations in all anatomic locations.Material and Methods Angiographic analysis of high-flow AVMs determined 4 major angioarchitectures. Type I: Direct arterial/arteriolar to vein/venule connection; e.g., as commonly seen in pulmonary AVF, congenital renal AVF, etc. Type II: Arterial/arteriolar connections to a ‘nidus’ that then have several out-flow veins with no intervening capillary beds in any of the vascular interconnections. Type IIIa: Arterial/arteriolar connections to an aneurysmal vein (‘nidus’ is the vein wall) that drains into a dominant out-flow vein with no intervening capillary bed in these connections. Type IIIb: Same angioarchitecture as Type IIIa, except that there are more than one (several) out-flow veins. Type IV: ‘Infiltrative’ form of AVM whereby innumerable micro-arteriolar branches fistulize through a tissue (e.g., ear AVMs) totally infiltrating it, shunting into multiple out-flow veins. Capillary beds also exist in the tissue and are admixed with the innumerable AVFs. Without the capillaries the tissue could not be viable, therefore must be present.Results Type I: Can be effectively treated with mechanical devices; e.g., coils, Amplatzer Plugs, etc.Type II: Can be effectively treated with ethanol embolization; trans-cath and direct puncture. Type IIIa: Can be effectively treated by transcatheter ethanol, retrograde vein catheter access or direct puncture access of the aneurysmal vein and treatment with ethanol and coils, or even by coils alone. Type IIIb: Can be effectively treated as above, but can be more challenging by the vein route as more veins (not a single out-flow vein) require closure. Type IV: Can be effectively treated by transcatheter or direct puncture of the innumerable microfistulous AVFs by embolization with 50% -50% ethanol non-ionic contrast mixture.Conclusions This newly reported AVM Classification system has a direct impact on determining the curative endovascular and direct puncture embolization procedures and also determines the embolic agents that will successfully treat and cure complex AVMS in all anatomies.Disclosures W. Yakes: None.