Abstract 333: Multiple Dural AV fistulas ‐ patient tailored approach and importance of vigilant monitoring
Authors: Maryala S. , Rubinowicz G. , Shah S. , Bakir D. , Lingam S. , Muehle C. 
Published: January 2025

Introduction
Dural AV fistulas (AVFs) are a type of heterogeneous vascular malformations accounting for 10‐15% of cerebral vascular malformations. They tend to bleed, grow and compress. The risk of neurological deficits is associated with their drainage. Cognard and Bogden grading uses such characteristics. Decision to treat is dependent on grading of AVF and symptomatology. The aetiology of the AV fistulas is likely secondary to thrombosis, trauma, inflammation or can be idiopathic. It occurs between 40‐60 years of age with no gender predisposition. Here we describe a patient who presented with multiple dural AVFs that required frequent monitoring and treatment.

Patient course
A 72 year old male patient with a past medical history of treated Renal Cancer, Myocardial infarction, Hepatic cysts, treated prostate cancer presents to the clinic with pulsatile tinnitus. Patient underwent MR angiogram that revealed left skull base dural AVF. A coil pack in the right ophthalmic artery was also found. He endorsed a history of protrusion and redness of the right eye which was treated at Barnes Jewish Hospital. Based on the records, concern was of a possible carotid‐cavernous fistula(CCF) on the right side. Patient opted for non‐invasive monitoring of the skull base AVF. 3 months later, patient presented with worsening tinnitus and proceeded with a diagnostic cerebral angiogram(DCA). DCA through the right internal carotid artery(ICA) revealed prominent meningohypophyseal arteries, pointing to remnants of the possible CCF. Right external carotid artery(ECA) revealed Cognard grade 1 grade AVF between the occipital and middle meningeal arteries with antegrade drainage into the transverse sinus. Left ICA was normal. Left ECA revealed a grade 1 AVF between the occipital artery and the inferior petrosal and cavernous sinuses with retrograde flow into the superior ophthalmic vein. Left vertebral artery was normal whereas the right vertebral artery revealed a subtle AVF from the posterior meningeal artery without any cortical vein involvement. 1 month later, symptoms worsened with throbbing, red and watery left eye with double vision. DCA was performed with plan to treat. Bilateral approach was planned due to concern for increasing the pressure on the right side. Patient underwent bilateral arterial embolization and was observed postoperatively overnight. Patient had some remnants of middle meningeal arteries feeding into the cavernous sinus, which were not treated. He endorsed no improvement in ophthalmological symptoms. In 6 weeks, he continued to have diplopia with injection. DCA was performed with the aim of endovenous embolization but was unsuccessful. Hence, endoarterial embolization of the cavernous branches of the MMA was performed, resulting in symptom resolution in 6 weeks.

Conclusion
Dural AV fistulas are vascular malformations that present themselves either incidentally or with occult and insidious progression of subtle symptoms which can also be fatal. Early acknowledgement of incidental findings, consideration for deeper investigation in case of incidental cases can help monitor the growth of the fistula and make planned decisions on their treatment whilst reducing the risk of sudden neurological injury that can lead to devastating disabilities and also death.