RT Journal Article SR Electronic T1 O-028 Long-term outcomes of endovascular treatment of indirect carotid cavernous fistulae: superior efficacy, safety, and durability of transvenous coiling over other techniques JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP A19 OP A19 DO 10.1136/neurintsurg-2018-SNIS.28 VO 10 IS Suppl 2 A1 Alexander, M A1 Halbach, V A1 Hallam, D A1 Cooke, D A1 Meyers, P YR 2018 UL http://jnis.bmj.com/content/10/Suppl_2/A19.1.abstract AB Introduction Endovascular surgery became the first line modality for treatment of indirect cavernous carotid fistulae (CCFs) as neurointerventional radiology matured in the 1980s. For approximately thirty years transvenous coiling of the cavernous sinus has been considered the safest and most efficacious technique. This retrospective multicenter review examines treatment results and long-term outcomes among patients undergoing endovascular treatment of indirect CCFs in light of newly available techniques and embolic agents.Materials and Methods Prospectively maintained procedure logs were retrospectively queried from four academic medical centers with high volume neurointerventional services. Patients undergoing endovascular treatment of indirect CCFs were identified. Patient demographics, symptoms and lesion characteristics were noted, including feeding arteries, drainage patterns, and presence of cortical venous reflux. Treatment approach and materials were recorded, as were any immediate complications. Medical records were reviewed for changes in symptoms following treatment, delayed complications, and angiographically-proven recurrence. Two-way chi-square tests were used, defining statistical significance as p<0.05.Results Records sufficient for inclusion were available for 267 patients treated at the four centers between January 1987 and December 2016. Fistula obliteration was achieved in 86.5% patients, occurring in 86.9% of transvenous treatments and 79.5% of other treatments. Among 68 (25.5%) patients with bilateral inferior petrosal sinus (IPS) occlusion, transvenous embolization was successfully performed in 95.6%. Among patients with unilateral IPS occlusion, transvenous embolization was successful in 96.9%. Obliteration rates were highest following transvenous embolization using coils compared to all other materials (LR 5.0 p=0.024).Complications were less common with coil embolization compared to other materials (LR 0.070, p<0.001). Embolization with liquid embolics resulted in higher complication rates (LR 10.2, p=0.002). Angiographically confirmed recurrence was more common following embolization with PVA (LR 9.9, p=0.004) and when multiple embolic agents were used (LR 6.6, p=0.018). A nonsignificant trend was noted toward recurrence following embolization with nBCA (66.7% vs. 1.3%, p=0.057). Delayed development of symptoms following embolization was less common following embolization with coils (LR 0.20, p=0.030) and more common following embolization with liquids (LR 6.5, p=0.014).Conclusion Among the options available for endovascular treatment of CCFs, transvenous coil embolization via the IPS, even if occluded, is the safest and most effective technique. Embolization with liquid embolic agents is less effective and associated with higher rates of complications and should be avoided except for unusual circumstances in which their use should be carefully considered.Disclosures M. Alexander: None. V. Halbach: None. D. Hallam: None. D. Cooke: None. P. Meyers: None.