Hemodynamic modulation of transnidal pressure during transvenous arteriovenous malformation embolization: an experimental porcine model

BACKGROUND: Optimization of transvenous embolization of brain arteriovenous malformations (AVMs) depends on effective modulation of the transnidal pressure gradient. Pharmacologic flow arrest with adenosine has been proposed as an adjunct, but its hemodynamic equivalence to purely mechanical strategies remains unclear. METHODS: End-to-end carotid-jugular fistula AVM models were created in 10 pigs. Hemodynamic measurements were obtained with pressure-sensing fractional flow reserve guidewires placed in the feeding artery and draining vein. Measurements included feeding artery mean pressure (MAfF), draining vein mean pressure (MVP), and transnidal pressure gradient (MAfP-MVP). Interventions were performed sequentially and included arterial balloon occlusion, venous coiling, combined arterial-venous strategies, venous balloon occlusion, systemic hypotension (-20%), and adenosine-induced transient cardiac arrest. RESULTS: The model was successfully established in all 10 animals and provided stable hemodynamic measurements throughout the protocol. Baseline mean venous pressure (MVP) was 47.1±14.3 mmHg, and baseline transnidal pressure gradient was 18.1±8.96 mmHg. Significant reductions in MVP were observed with arterial balloon occlusion, combined arterial-venous mechanical strategies, and adenosine-induced transient cardiac arrest. Arterial inflow control consistently produced greater reductions than venous-only interventions and systemic hypotension. Significant reductions in the transnidal pressure gradient were achieved with arterial balloon occlusion and simultaneous arterial-venous balloon occlusion. Adenosine produced hemodynamic effects comparable with the most effective mechanical strategies. CONCLUSIONS: Mechanical flow-control strategies replicate the hemodynamic effects of adenosine-mediated flow arrest without systemic exposure. These findings support the use of localized endovascular approaches for gradient modulation and may inform safer procedural strategies for transvenous AVM embolization.