Vol.:(0123456789) 1 3 Eur Spine J DOI 10.1007/s00586-017-5298-x CASE REPORT Spinal dural arteriovenous fistula (SDAVF) variant with dual perimedullary and epidural drainage Philippe Gailloud 1   Received: 6 June 2017 / Revised: 1 August 2017 / Accepted: 9 September 2017 © Springer-Verlag GmbH Germany 2017 known to represent an anti-reflux mechanism. The poten- tial role played by the topographical relationship between the shunt and the anti-reflux mechanism of the RMV in the formation and clinical expression of SDAVFs is discussed. Keywords Spinal vascular malformation · Spinal angiography · Spinal venous thrombosis · Etiology Introduction While spinal dural arteriovenous fistulas (SDAVFs) were noticed long before the introduction of spinal angiography, notably in the form of dilated perimedullary veins observed during anatomical dissection or necropsies, their nature remained unclear until the introduction of selective spinal angiography in the late nineteen-sixties and the publication of two landmark contributions in the mid-nineteen-seventies. Aminoff first suggested the role of venous hypertension in the presentation of spinal malformations in 1974 [1] while Kendall and Logue identified the foraminal location of SDAVFs in 1977 [6]. It is now accepted that SDAVFs are made of a microshunt found within the dura mater surrounding the spinal nerve root in the neural foramen [3, 9]. This arteriovenous shunt establishes an abnormal connection between a radiculome- ningeal artery and a radiculomedullary vein (RMV) as the latter passes through the thecal sac. SDAVFs drain into the perimedullary venous system via the involved RMV. This retrograde drainage—combined with characteristically impaired perimedullary and radiculomedullary venous pathways [8, 10]—results in a slowly progressive venous hypertensive myelopathy that preferentially involves older men [2, 8]. While instances of spinal epidural arteriovenous fistulas wrongly considered as SDAVFs draining into the Abstract Purpose A spinal dural arteriovenous fistula (SDAVF) is an abnormal connection between a radiculomeningeal artery and a radiculomedullary vein (RMV) characteristically draining into the perimedullary venous system. We present an observation of SDAVF draining simultaneously into the perimedullary and epidural venous systems. Methods A 67-year-old man presented with lower extrem- ity weakness and sphincter dysfunction. MRI documented a longitudinally extensive myelopathy with parenchymal enhancement and flow-voids on T2-weighted images. Spi- nal angiography revealed the presence of two SDAVFs, at left T9 and right L1. Results The right L1 SDAVF was treated endovascularly. Superselective angiography of the main feeder, a right T12 radiculomeningeal branch, documented an unusual drain- age pattern, with contrast flowing both retrogradely towards the perimedullary venous system and antegradely into the epidural plexus. The meningeal branch was embolized using a liquid embolic agent with adequate penetration of the embolic material into the proximal segment of the draining vein. The left T9 SDAVF was surgically resected, as the radicular artery supplying the fistula also provided the artery of Adamkiewicz. Conclusions Dual drainage of the right L1 SDAVF into the perimedullary and epidural venous systems allowed to locate the site of the arteriovenous shunt at the point of transdural passage of the RMV, a narrowed segment also * Philippe Gailloud phg@jhmi.edu 1 Division of Interventional Neuroradiology, The Johns Hopkins Hospital, 1800 E Orleans Street, Bloomberg 7216, Baltimore, MD 21287, USA