Onyx as an adjunctive embolic material for transvenous embolization of cavernous sinus dural arteriovenous fistula after coiling.

BACKGROUND

Transvenous coil embolization (TVCE) is a common and effective treatment for cavernous sinus dural arteriovenous fistulas (CSDAVFs). However, some patients may experience residual fistulas or worsening visual symptoms after the procedure. This study aimed to compare the effectiveness of transvenous coil and Onyx embolization (TVCOE) with TVCE in treating CSDAVFs.

METHODS

The study included 207 patients with 222 CSDAVFs referred for TVCE, all of whom had complete angiographic follow-up over 9 years. Ninety patients (mean age, 65.3 years) with 97 CSDAVFs underwent TVCOE after coiling. Clinical data, angioarchitecture, and outcomes were retrospectively assessed and compared to 125 CSDAVFs treated with TVCE.

RESULTS

Key reasons for selecting TVCOE included improvement in immediate complete obliteration of CSDAVFs (n = 47, 48.5%), presence of cranial nerve palsy (n = 26, 26.8%), residual fistula with persistent pial venous reflux (n = 22, 22.7%), and redirection of fistula flow to pial venous reflux (n = 2, 2.1%). The average volume of Onyx used in TVCOE was 1.7 mL per CSDAVF. The mean coil lengths for TVCOE and TVCE were 143 and 228 cm, respectively, with a statistically significant difference ( p < 0.05). Immediate digital subtraction angiography showed complete obliteration or nearly complete obliteration of CSDAVFs in TVCOE and TVCE at rates of 97.9% and 76.8%, respectively, indicating statistical significance in immediate complete obliteration ( p < 0.05). Transient hemodynamic instability occurred in 81 (90.0%) patients due to Onyx toxicity, and one patient (1.1%) experienced hemorrhagic complications during TVCOE.

CONCLUSION

The use of a small volume of Onyx as an adjunctive embolic material in TVCOE resulted in reduced coil use and improved immediate complete obliteration. This technique is viable for patients with pial venous reflux. Aside from the transient hemodynamic instability, periprocedural complications and follow-up angiographic outcomes did not show significant differences between the two groups.