Sacral Dural Arteriovenous Fistulas, a Rare and Underdiagnosed Subtype of Spinal Dural Arteriovenous Fistulas: A Case Series with Review of Literature

Spinal Dural Arteriovenous Fistulas (SDAVFs) are the most common type of spinal vascular malformations with arterial feeders usually from the intercostals, vertebral, subclavian and lumbar arteries and rarely from the internal iliac arteries. Authors report three cases of SDAVFs at our institution where arterial feeders were from internal iliac artery. The endovascular embolisation of arterial feeders was done using n-BCA (n-butyl cyanoacrylate) embolic agent in one case and with Ethylene Vinyl Alcohol (Onyx) in two cases with complete obliteration of the fistula. This resulted in marked clinical improvement in all the patients. The lateral sacral arteries are not a common site of origin of arterial feeders to the SDAVFs and can be easily overlooked if thorough spinal Digital Subtraction Angiography (DSA) is not performed. Through these three cases, authors want to highlight the importance of performing complete spinal DSA.