ABSTRACT NUMBER: ESOC2026A293 ANEURYSMAL WALL PRESSURE DYNAMICS IN ARTIFICIAL VESSEL MODELS AFTER FLOW DIVERTER PLACEMENT

Abstract Background and aims Flow diverters are safe and efficient devices for treating intracranial aneurysms; however, delayed aneurysmal rupture – potentially triggered by increased intra-aneurysmal pressure – remains a rare but fatal complication. Nevertheless, peri-procedural fluctuations in aneurysmal wall pressure are still controversial. This study examined alterations in aneurysmal wall pressure before and after flow diverter placement using artificial vessel models. Methods Artificial vessel models were fabricated using 3D-printed molds and silicone. Three aneurysm configurations were prepared: two with medium (10mm) or large (20mm) aneurysms on a straight parent vessel, and one with a medium aneurysm on a tortuous parent vessel. The models were integrated into a closed-loop flow system containing a pulsatile pump and saline to simulate physiological flow and pressure. Pressures were recorded in real time at three aneurysmal dome locations (inflow, apex, and outflow) as well as at proximal and distal parent vessel sites adjacent to the aneurysm before and after flow diverter placement. Results Across all models, aneurysmal wall pressure at each dome site did not differ significantly before versus after flow diverter deployment. No significant pressure differences were observed among the three aneurysm configurations. Additionally, parent vessel pressures proximal and distal to the aneurysm also showed no significant change following device placement. Conclusions Aneurysmal wall and parent vessel pressures remained stable after flow diverter placement, regardless of aneurysm size or parent vessel geometry. These findings suggest that intra-aneurysmal hemodynamic changes alone may not fully account for delayed aneurysmal rupture after flow diverter treatment. Conflict of interest Daizo Ishii: nothing disclose, Takeshi Hara: nothing disclose, Takeshi Moriwaki: nothing disclose, Genki Nakashima: nothing disclose, Masashi Kuwabara: nothing disclose, Shingo Matsuda: nothing disclose, Nobutaka Horie: nothing disclose