title: Microvascular anatomy of spinal dural arteriovenous fistulas: arteriovenous connections and their relationships with the dura mater.
abstract: OBJECT The microvascular anatomy of spinal dural arteriovenous fistulas (AVFs), especially the relationships of the vessels with the dura mater, has yet to be angiographically demonstrated in detail and proven histologically. METHODS From January 2012 through April 2014, a total of 7 patients with spinal dural AVFs in the thoracic region underwent open microsurgical obliteration at Tokyo Metropolitan Neurological Hospital. The microvascular anatomy of spinal dural AVFs was comprehensively assessed by using advanced microangiography, including 3D computer graphics and intraoperative indocyanine green video angiography, and by histological findings. RESULTS The 2 microangiography techniques revealed the spatial course and in vivo blood flow of the meningeal vessels and their relationships with the dura mater in sufficient detail. The meningeal branch of the intercostal artery split into multiple meningeal vessels on the outer dural surface adjacent to the root sleeve. After crossing the dura mater to the inner dural surface, these vessels gathered and joined a single intradural draining vessel. On the inner dural surface, the single draining vessel was fed by the surrounding multiple meningeal vessels, which appeared to be caput medusae. Histological findings revealed that the structure of the meningeal branch of the intercostal artery corresponded to that of a normal artery. The structure of intradural draining vessels corresponded to that of a vein modified by retrograde arterial inflow. On the inner dural surface, more than 1 meningeal artery gathered and joined with the proximal radiculomedullary vein. CONCLUSIONS Spinal dural AVFs are located on the inner dural surface, where multiple direct AV connections between more than 1 meningeal feeding artery and a single proximal radiculomedullary vein occur at the site where the vein connects to the dura mater.
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Takai
authors.affiliation: Laboratory Medicine and Pathology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Komori
authors.affiliation: Departments of 1 Neurosurgery and.
authors.forename: Makoto
authors.initials: M
authors.lastname: Taniguchi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001164:Arteriovenous Fistula / Q000000981:diagnostic imaging* / Q000473:pathology; D004388:Dura Mater / Q000098:blood supply*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007208:Indocyanine Green; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D012189:Retrospective Studies; D013131:Spine / Q000098:blood supply*; D013904:Thoracic Vertebrae
chemical_list: D007208:Indocyanine Green
keywords: AV = arteriovenous; AVF = AV fistula; ICG = indocyanine green; angioarchitecture; arteriovenous malformation; arteriovenous shunt; dural arteriovenous fistula; endovascular treatment; pathology; surgical treatment; vascular disorders