<p><b>BACKGROUND</b>Usually, cavernous dural arteriovenous fistula can be treated via transarterial approaches. However, in many complicated patients, transvenous approaches are superior to the transarterial ones because of the difficulties during a transarterial operation. In this study, we retrospectively analyzed the outcomes of 28 patients with cavernous dural arteriovenous fistula treated by transvenous embolization.</p><p><b>METHODS</b>From September 2001 to December 2005, 28 patients with 31 cavernous dural arteriovenous fistulae were treated with transvenous embolization in Beijing Tiantan Hospital. The involved cavernous sinuses were catheterized via the femoral vein-inferior petrosal sinus approach or the femoral-facial-superior ophthalmic vein approach, and embolized with coils (GDC, EDC, Matrix, Orbit or free coil) or coils plus silk. The patients were followed up for 3 to 26 months.</p><p><b>RESULTS</b>All the 31 cavernous sinuses in the 28 patients were successfully embolized. Complete angiographic obliteration of the fistulae was achieved immediately in 25 patients. Residual shunting was observed in the other 3, who had drainage through the pterygoid plexus (2 patients) or the inferior petrosal sinus (1) after the operation. Headache and vomiting were the most common symptoms after the embolization. In 3 patients, who achieved complete angiographic obliteration immediately, the left oculomotor nerve palsy remained unchanged after the operation. Transient abducens nerve palsy was encountered in 1. In 1 patient, the occular symptoms were improved after the operation, but recurred 4 days later, and then disappeared spontaneously after 5 days. During the follow-up, no patient had recurrence. Three months after the operation, angiography was performed on the 3 patients with residual shunting. Two of them had angiographic cure, the other had residual drainage through the pterygoid plexus.</p><p><b>CONCLUSIONS</b>Transvenous catheterization and embolization of the cavernous sinus is a safe and efficient way to treat complicated cavernous dural arteriovenous fistulae. It is an alternative to the patients with spontaneous cavernous dural arteriovenous fistulae or those in whom transarterial embolization failed.</p>