DURAL ARTERIOVENOUS-MALFORMATIONS OF THE TRANSVERSE SIGMOID SINUS ACQUIRED FROM DOMINANT SINUS OCCLUSION BY A TUMOR - REPORT OF 2 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 du ral venous sinus. CLINICAL PRESENTATION: We report unique cases of two patients having different tumors (one meningioma and one glomus jugul are paraganglioma) that occluded the ipsilateral transverse and sigmoi d sinuses, respectively, and were associated with dAVMs. In each patie nt, 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 th e inability of the contralateral (nondominant) sinus to handle the ven ous flow from the obstructed (dominant) side.