Clinical management of isolated transverse-sigmoid sinus dural arteriovenous fistulas: a three-case illustrative series and narrative review.

INTRODUCTION AND IMPORTANCE: Isolated transverse-sigmoid sinus (TSS) dural arteriovenous fistulas (DAVFs) are uncommon. Endovascular treatment (EVT), using either transarterial embolization (TAE) or transvenous embolization (TVE), has shown efficacy. However, the EVT strategies remain incompletely elucidated. CASE PRESENTATIONS: Patient 1 was a 54-year-old man presenting with a sudden headache. Digital subtraction angiography (DSA) revealed an isolated TSS DAVF with Cognard type III. TAE via the middle meningeal artery (MMA) obliterated the fistula. Patient 2 was a 55-year-old woman who presented with intracranial hemorrhage. DSA revealed an isolated TSS DAVF with Cognard type IV. TAE via the MMA and the occipital artery (OA) obliterated the fistula. Patient 3 was a 56-year-old man presenting with seizures. DSA revealed an isolated TSS DAVF with Cognard type III. TVE was performed in the following stages: first, the occluded TSS was recanalized; subsequently, the isolated TSS was coiled; and finally, occlusion of both the OA and MMA led to obliteration of the fistula. These three patients achieved favorable outcomes after the procedure, with modified Rankin Scale scores of 0 to 1. CLINICAL DISCUSSION: Based on these three cases and a narrative review that was performed, it may be concluded that TAE can be the first-line approach for isolated TSS DAVFs with a good transarterial route. Alternatively, TVE with reopening of the TSS can be employed, depending on the fistula's angioarchitecture. CONCLUSION: For isolated TSS DAVFs with appropriate patient selection, EVT can achieve favorable outcomes.