Endovascular management of a hypoglossal canal dural arteriovenous fistula.

BACKGROUND

Dural arteriovenous fistulas (DAVFs) involving the hypoglossal canal are rare vascular anomalies, typically manifesting with pulsatile tinnitus or lower cranial nerve dysfunction. Treatment planning must account for their highly variable and often evolving venous drainage patterns.

CASE REPORT: We present the case of a 54-year-old male with right-sided pulsatile tinnitus and episodic headaches. Imaging revealed a DAVF centered at the right hypoglossal canal with multiple arterial feeders and dominant intracranial retrograde drainage into the inferior petrosal and cavernous sinuses. Initial transvenous embolization of the isolated inferior petrosal sinus achieved partial occlusion, with temporarily symptomatic relief. Recurrence of the bruit correlated with a major shift in venous drainage toward the cervical epidural plexus. A second embolization via the anterior epidural venous route allowed direct access to the fistulous pouch, resulting in definitive occlusion. The patient remained asymptomatic thereafter.

DISCUSSION: This case highlights the dynamic angioarchitecture of hypoglossal canal DAVFs and the challenges posed by its multiple arterial feeders and venous outlets, which can obscure the precise location of the fistulous point. In our patient, these complexities necessitated a staged and sequential endovascular approach to achieve complete fistula occlusion and resolution of symptoms.

CONCLUSION

DAVFs of the hypoglossal canal demand high-resolution imaging and adaptive treatment strategies considering its dynamic nature. Transvenous embolization via the cervical epidural venous system offers a safe and effective route for definitive fistula occlusion without neurological dysfunction.