Bilateral direct carotid-cavernous fistulas of traumatic and spontaneous origin: two case reports.

In the present paper we discuss two cases with bilaterally located carotid-cavernous fistulas: one of traumatic origin and the other occurring spontaneously. Most traumatic fistulas are direct, unilateral and of a high flow type. In our first case we deal with traumatic bilateral direct fistulas with a low flow, a combination which must be considered rare and is not reported in the literature so far. In our second case there are bilaterally located fistulas, occurring spontaneously. Peculiarly they are direct, instead of indirect as is to be expected in spontaneously developing fistulas, and of a low flow type. This combination too must be considered extremely rare. In both cases conservative therapy was successful, despite their difference in etiology. It appears that neither the anatomy nor the manner of onset determines the success of conservative therapy, but the fact that a fistula is of a high- or low flow type.