The road less traveled: transarterial embolization of dural arteriovenous fistulas via the ascending pharyngeal artery.

BACKGROUND: With the introduction of Onyx, transarterial embolization has become the most common endovascular approach to treating dural arteriovenous fistulas (dAVFs), often via the middle meningeal or occipital arteries. The ascending pharyngeal artery (APA) is a less frequently explored transarterial route because of its small caliber, potential anastomoses to the internal carotid and vertebral arteries, and vital supply to lower cranial nerves.

OBJECTIVE: To review our institutional experience and highlight the prevalence of APA supply to dAVFs and cases where it is a safe and effective pedicle for embolization.

METHODS: We reviewed our endovascular database (January 1, 1996 to March 1, 2016) for cranial dAVFs, evaluating dAVF characteristics and embolization results for those treated transarterially via the APA.

RESULTS: Of 267 endovascularly treated dAVFs, 68 had APA supply (25%). Of these 68 dAVFs, embolization was carried out via this pedicle in 8 (12%) and 7 were ultimately occluded. No complications, including post-treatment cranial neuropathies or radiographic evidence of non-target embolization, were found. For 5 dAVFs, the APA was selected as the initial pedicle for embolization (two marginal sinus, one distal sigmoid, one cavernous, one tentorial). In four of these five cases, dAVF occlusion was achieved via the initial APA feeding artery pedicle. In one case, near-complete, stagnant occlusion was achieved after APA embolization; complete occlusion was achieved after adjunctive embolization of a single additional middle meningeal artery pedicle. In three other cases of complex transverse/sigmoid dAVFs, the APA was used after multiple attempts via middle meningeal and occipital artery pedicles. Occlusion was not achieved transarterially; two of these three dAVFs were ultimately occluded transvenously.

CONCLUSIONS: In rare, select cases, the APA is an excellent route for transarterial embolization of cranial dAVFs.