P098 Preservation of radiopacity in ethylene-vinyl alcohol liquid embolization agents through manual agitation: a comprehensive multiparametric in-vitro study

<h3>Introduction</h3> The formation of a solid plug using Ethylene-Vinyl Alcohol liquid embolization agents (EVOH LEAs) is a standard technique in neurointerventionnal embolization procedure. This process requires a waiting-period during which the tantalum powder, which enhances radiopacity, may settle, resulting in decreased radiopacity. In daily practice, to prevent sedimentation, it is standard practice to agitate the syringe as the plug solidifies. <h3>Aim of Study</h3> The main objective of this study is to determine the sedimentation duration of tantalum and to identify the optimal method of manual agitation for maintaining satisfactory radiopacity. <h3>Methods</h3> EVOH LEA was prepared and assessed using optical imaging and fluoroscopic analysis of kinetic sedimentation. The quality of visibility, signal-to-noise ratio (SNR), and absorbance in 1mL syringes subjected to 8 agitation methods were assessed (fast or slow rotation either automated or manual, fast or slow horizontal shaking either automated or manual) at intervals of 3, 5, 7, and 10 minutes. Additionally, we tested these agitation methods at various time points during in-vitro embolization on a 3D-printed model simulating a distal intracranial artery. <h3>Results</h3> Early sedimentation resulting in a loss of radiopacity was noted under fluoroscopy within just 3 minutes after preparation in 1mL syringes. Despite varying time intervals, all agitation techniques successfully maintained satisfactory radiopacity in the syringes and throughout the embolization process. <h3>Conclusion</h3> Considering the swift sedimentation of EVOH LEA in a 1mL syringe, consistent agitation of EVOH LEA during the waiting time is recommended in clinical settings, with the choice of agitation method left to the practitioner’s discretion to ensure optimal radiopacity. <h3>Disclosure of Interest</h3> no.