Dural arteriovenous malformations of the transverse/sigmoid sinus acquired from dominant sinus occlusion by a tumor: report of two cases.

OBJECTIVE AND IMPORTANCE: Debate continues regarding the pathogenesis of dural arteriovenous malformations (dAVMs). The prevailing theory is that dAVMs are acquired lesions that occur after thrombosis of the dural venous sinus. CLINICAL
PRESENTATION: We report unique cases of two patients having different tumors (one meningioma and one glomus jugulare paraganglioma) that occluded the ipsilateral transverse and sigmoid sinuses, respectively, and were associated with dAVMs. In each patient, the occluded venous sinus was the dominant sinus.
CONCLUSION: Our experience with these patients supports the hypothesis that dAVMs are acquired and induced lesions that may occur after sinus occlusion. We suggest that the occlusion of the dominant transverse/ sigmoid sinus is a major contributing factor to the development of dAVMs because of the inability of the contralateral (nondominant) sinus to handle the venous flow from the obstructed (dominant) side.