Transverse/sigmoid sinus dural arteriovenous fistulas presenting as pulsatile tinnitus.

Abstract

Transverse/sigmoid sinus dural arteriovenous fistula (TSDAVF) is a diagnostically elusive entity that is critical for the otologist to account for, when confronted by pulsatile tinnitus in the face of normal otoscopy. Left untreated, TSDAVF may result in catastrophic outcome. We have previously proposed a grading system specifically for TSDAVF based on venous restrictive disease. Our objective was to assess the validity of this grading system for clinical severity and therapeutic outcome. Through a retrospective review of 41 patients with TSDAVF, we evaluated clinical presentation, diagnostic evaluation, therapy, and outcome. Patients were classified into four grades based on the severity of venous restrictive disease as determined by superselective angiography. Our treatment algorithm combined compression therapy, transarterial embolization, and for more severe grades, surgery. Pulsatile tinnitus was the chief complaint of all the patients in this series, and of 90% of all cases of TSDAVF treated at our institution. While angiography remains the gold standard, magnetic resonance imaging/magnetic resonance arteriography is far superior to computed tomography scanning in detecting dural arteriovenous fistulas. As normal venous outflow gives way to aberrant cortical venous drainage in higher grades, there is a dramatically increased risk for adverse consequences with therapeutic intervention. Using our treatment algorithm, 82% of patients achieved clinical resolution of symptoms. Half of these patients had complete angiographic obliteration of their TSDAVF. The TSDAVF-specific grading system for the severity of venous restrictive disease is reflective of clinical presentation, fundamental in planning treatment, and predictive of therapeutic outcome.