Transvenous Embolization of Dural Arteriovenous Fistula of the Anterior Condylar Confluence via the Intercavernous Sinus Assisted by Bone Subtraction Computed Tomography Angiography

Classification and Management Considerations for Intraosseous Dural Arteriovenous Fistulae

BACKGROUND

Intraosseous dural arteriovenous fistulas (IODAVFs) are rare DAVFs that communicate with marrow. Given their infrequency, common nomenclature is nonexistent. Patients may present with benign symptoms, such as tinnitus, or venous hypertension symptoms including hemorrhage depending on the venous outflow pattern.

OBJECTIVE

To describe all available cases of IODAVF in the literature, in addition to our cases, to better define presentation, and treatment outcomes. To advance a classification system to develop common language for these lesions for clinicians and researchers.

METHODS

Neurointerventional procedure logs at 2 high-volume neurovascular centers were reviewed for all cases of IODAVFs, as was the English-based literature available in PubMed. The angioarchitecture, symptoms, management, and demographics were reviewed and summarized.

RESULTS

Four institutional cases were identified, 2 of which had shunting within the marrow (clival or petrous), with venous drainage toward the heart. One case involved the dorsum sella with drainage into the superior petrosal sinus with reflux into the anterior and posterior spinal venous plexuses, and one involved the left petroclival junction, resulting in communication with the cavernous sinus with retrograde drainage into the superior ophthalmic veins. Two patients were managed by observation, one was treated with radiosurgery and one with microsurgical skeletonization. Twenty additional cases from the literature are summarized.

CONCLUSION

IODAVFs of the cerebrocranial vasculature may present incidentally, with tinnitus, or with symptoms related to mass effect or venous hypertension. We propose a classification which accounts for drainage patterns. Further study is needed for these rare lesions.

Alternative route to a hypoglossal canal dural arteriovenous fistula in case of failed jugular vein approach

Hypoglossal canal dural arteriovenous fistulas (HC-DAVF) involve the anterior condylar vein (ACV) and anterior condylar confluence (ACC). They often present with tinnitus, bruit, and hypoglossal nerve palsy. The most common treatment in HC-DAVFs is transvenous embolization using coils and the most direct transvenous route is the trans-internal jugular vein access. When this approach is not feasible, a treatment attempt is possible through alternative routes. We report 2 patients with DAVFs involving the anterior condylar confluence. The first patient presented with pulsatile tinnitus and hypoglossal nerve palsy, and was treated by a standard transjugular approach. The second patient presented with pulse-synchronous bruit. Following an unsuccessful attempt of the transjugular approach, the fistulous point was reached via the deep cervical vein and complete occlusion was achieved by coil deployment. Both patients had complete regression of symptoms. Endovascular therapy is the elective treatment for HC-DAVFs and the transjugular approach is the most commonly used. The deep cervical vein (DCV) can be an alternative transvenous route when the transjugular approach fails.