Abstract 1122‐000124: Dural Arteriovenous Fistula and Implications in Aneurysmal Genesis
Authors: la Garza Carlos De , Shastri Ravi 
Published: December 2021

Introduction
: There is a reported association of cerebral arteriovenous malformations and aneurysms, however, data regarding patients presenting with dural arteriovenous fistulas (dAVF) and aneurysms is limited. Here, we present a patient who was incidentally diagnosed with 2 aneurysms in addition to a dAVF; and her treatment course. Previous to her diagnosis, she denied any and all symptomatology that would prompt further evaluation.

Methods
: Case description: 60‐year‐old female with history of hypertension, hypothyroidism and gastroesophageal reflux disease who initially presented to an outside hospital after a motor vehicle collision in 2016, at that time she reports being diagnosed with multiple aneurysms; but was lost to follow up. In 2020 she was referred to interventional neuroradiology and underwent diagnostic digital cerebral angiogram. Which reported a 13 × 12 × 13.3 mm left para‐ophthalmic internal carotid artery (ICA) aneurysm with a 7 mm neck. A 5.7 × 7.7 × 6.1 mm basilar tip artery aneurysm with a 5.6 mm neck and a right Cognard type four occipital dAVF, with feeding vessels from the right posterior cerebral artery and right occipital artery and anterograde drainage to the dural sinuses. From the time of diagnosis to the initiation of interventions, patient denied any concerning symptomatology. Treatment was initiated 4 months after diagnostic angiogram. She received 5 days of Dual Antiplatelet therapy (DAPT) with aspirin and Plavix previous to the deployment of a woven endobridge device (WEB™ 8‐3mm) into the basilar tip aneurysm; as this was felt to be the aneurysm with highest probability of rupture. Post‐operative course was unremarkable and DAPT was discontinued. Three months after WEB™ deployment, the patient underwent embolization of the right occipital dAVF with a liquid embolic agent (onyx™). Post operatively, she developed decreased peripheral vision in her left eye, though the rest of her hospitalization was unremarkable. 3 months after embolization, she underwent left para‐ophthalmic artery aneurysm flow diversion with a pipeline™ (4‐18mm) flow diverter, with an uncomplicated admission. She was subsequently evaluated by neuro‐ophthalmology who has reported a stable peripheral left eye left inferior quadrantic defect along with a supertemporal defect in her right eye.

Results
: Discussion: Interestingly, the patient presented 2 aneurysms, one in the anterior circulation and the most concerning, located in the posterior circulation. One could draw conclusions that the dAVF was associated with the basilar aneurysm. As dAVFs are acquired lesions, it is feasible to assume that there may be an association between both types of lesions, perhaps due to flow or pressure being exerted on weakened vessel walls, thus leading to aneurysmal formation.

Conclusions
: Conclusion: Because a potential for implication in the flow dynamics of the dAVF in aneurysmal formation. We have opted to use computational fluid dynamics to analyze said flow within the dAVF to better understand the causal relationship between aneurysms and dural fistulae. In the long run research into genesis of aneurysms secondary to coexisting vascular lesions could further elucidate the mechanisms by which aneurysms develop.