Background: Transvenous coil embolization (TVCE) of cavernous sinus dural arteriovenous fistulae (CSDAVFs) is a standard method with promising results. There may have residual fistula and/or aggravate patient’s visual symptoms after coiling. Here, we reported our experience of using Onyx as adjuvant embolizer to manage CSDAVF after TVCE.
　　Method: Over an 8-year period, a total of 188 patients with 203 CSDAVFs were referred for TVCE with complete angiographic follow up. There were 86 patients (mean age: 65.5 years) with 93 CSDAVFs underwent transvenous Onyx embolization (TVOE) of CSDAVFs after coiling. We retrospectively assessed the clinical data, angioarchitecture and outcomes of all patients and compare with 102 CSDAVFs undergoing TVCE.
　　Results: The major factor for selection of TVOE was to enhance immediate complete obliteration (CO) of CSDAVFs (n=43, 46.2%), patients with cranial nerve palsy (n=26, 28.0%), residual fistula with persistent pial vein reflux (PVR, n=22, 23.7%), or redirection of fistula flow to PVR (n=2, 2.2%). The average amount of Onyx for TVOE was 1.7ml per CSDAVF. The mean coil length for TVOE and TVCE were 148cm and 234cm, respectively and showed statistical significance (p=0.03). Immediate and follow-up DSA showed near or complete CO of CSDAVFs in TVOE and TVCE were 93.5%/100% and 73.6%/ 96.4%, respectively, which showed statistical significance on immediate CO (p=0.02). Transient hemodynamic instability was found in 80 patients (93.0%) due to toxicity of Onyx. One patient (1.2%) and hemorrhagic complication in TVOE.
　　Conclusions: Small amount of Onyx as an adjuvant embolic material for TVOE had the advantage of less coil utilization and better immediate CO. This technique can be a salvageable procedure in patients with PVR. There is no statistical significance in the peri-procedural complication and follow-up angiographic outcomes in both groups.