Chinese Experience in Endovascular Management of Spinal Cord Vascular Malformations

Abstract

Cervical juvenile-type intramedullary AVM. Embosphere embolisation with temporary occlusion of the vertebral artery. A 23-year-old male presented with a history of acute onset of paraplegia, dyspnea, and sphincter disturbance. The patients muscle power improved two months later. A, B) Left vertebral angiograms: (A) anteroposterior and (B) lateral projections show an intramedullary AVM (3) supplied by a posterior spinal artery (2) of the posterior radiculo-medullary artery (1) originating from the left vertebral artery at the level of C2. The venous drainage is to the anterior (4) and posterior medullary veins (5). Arrowhead marks an aneurysm. C, D) Right vertebral angiograms: (C) anteroposterior and (D) lateral projections, show the anterior spinal artery (6), originating from the vertebral artery under the origin of posterior inferior cerebellar artery, also contributing to the malformation (3). E) Because the posterior radicular artery (1) was long and twisted, the Tracker-18 microcatheter (Target Co.) could not get nearer to the malformation (3). In order to prevent embolic agent migrating to the posterior cerebral circulation, a non-detachable balloon catheter (Magic Bl, Bait Co.) was introduced and temporarily occluded the vertebral artery distal to the orifice of the feeding artery with systematic heparinization. The malformation was embolised through slow injection of Embosphere (500-700 µm) with repeated control angiography until the nidus disappeared. Note the contrast media retained (open arrow) in the vertebral artery because of reflux. After embolisation, the Tracker-18 microcatheter was withdrawn and the lumen of the vertebral artery was repeatedly irrigated with saline. Then the balloon catheter the balloon inflated was gently pulled back and drove potential residual embolic agent into the subclavian artery. F-I) Left vertebral angiograms after embolisation, (F) anteroposterior and (G) lateral projections, show complete obliteration of the malformation. It is interesting that the malformation was also not opacified in the angiogram of (H) the right vertebral artery from which embolisation was not performed. The patient's symptoms have remarkably improved. I) Artist's drawing of the AVM angioarchitecture (anterior view). J-M) T8-9 intramedullary AVM with an aneurysm. A 16-year-old male presented with acute onset of paraparesis with grade 2-3 muscle power for 20 days. (J) Sagittal and (K) axial T2-weighted MR images show the intramedullary signal void at the T8-9 level. L) Selective injection of the left T10 intercostal artery in A-P view shows an AVM (3) supplied by the posterior spinal artery (2) of the posterior radiculo-medullary artery (1) with caudal venous drainage (4). Note the aneurysmal dilation (arrowhead). M) Angiogram of the left T10 intercostal artery after embolisation with Embosphere (500-700 µm) shows complete obliteration of the nidus, aneurysm and the draining vein, with preservation of the posterior spinal artery (2). N-O) Selective injections of the left T9 intercostal artery, (N) frontal and (O) lateral projections, show a radicu- lo-medullary trunk (arrow) dividing into the anterior (3) and posterior radiculo-medullary artery (1) and then the anterior spinal axis (4) and posterior spinal artery (2), contributing to the malformation (5) with the same drainage as in figure 1L (6). Because the anterior spinal axis (4) supplies the malformation in an indirect manner with its distal branch supplying the caudal part of the spinal cord, embolisation was contraindicated.P) Artist's drawing of the AVM angioarchitecture (anterior view). 1) Posterior radiculomedullary artery; 2) Posterior spinal artery; 3) Anterior radiculomedullary artery; 4) Anterior spinal artery; 5) AVM nidus; 6) Draining vein. Arrowhead: Venous pouch.