P166 Magnetic resonance imaging changes in spinal arterio-venous fistulae treated by endovascular means: are they really reliable to predict complete cure of the fistula?

<h3>Introduction</h3> Regression or disappearance of MRI abnormalities is usually observed after treatment of spinal arterio-venous fistulae (sDAVF). <h3>Aim of Study</h3> We aimed to assess the correlation between MRI changes with sDAVF exclusion and clinical outcome. <h3>Methods</h3> Imaging data of patients treated with endovascular embolization for sDAVF between 2007 and 2023 were retrospectively analyzed. Spinal cord edema and perimedullary flow voids at baseline and 3 month follow-up were compared between patients with and without sDAVF stable exclusion and clinical improvement on the Aminoff and Logue scale. <h3>Results</h3> Twenty-five patients were included in this study. At 3-month follow-up, a regression of spinal cord edema was significantly associated with sDAVF stable exclusion (p=0.038). The combination of edema and flow voids regression was significantly associated with higher odds of cured sDAVF (p&lt;0.001) and clinical improvement (p&lt;0.01). The latter association presented high sensitivity (100% (CI95%; 78.20% - 100%)) and negative predictive values value (100% (CI95%; 47.82% – 100%)) for the detection of cured sDAVF in comparison to DSA. <h3>Conclusion</h3> Patients with both spinal cord edema and flow voids regression at 3 months were more likely to present with a stable exclusion of sDAVF and clinical improvement after endovascular embolization. Patients without MRI improvement should be referred to DSA to seek recurrence of sDAVF.