Abstract
BACKGROUND AND PURPOSE: AVFs of the foramen magnum region, including fistulas of the marginal sinus and condylar veins, have complex arterial supply, venous drainage, symptoms, and risk features that are not well-defined. The purpose of this study was to present the angioarchitectural and clinical phenotypes of a foramen magnum region AVF from a large, single-center experience.
MATERIALS AND METHODS: We retrospectively reviewed cases from a 10-year neurointerventional data base. Arterial and venous angioarchitectural features and clinical presentation were extracted from the medical record. Venous drainage patterns were stratified into 4 groups as follows: type 1 = unrestricted sinus drainage, type 2 = sinus reflux (including the inferior petrosal sinus), type 3 = reflux involving sinuses and cortical veins, and type 4 = restricted cortical vein outflow or perimedullary congestion.
RESULTS: Twenty-eight patients (mean age, 57.9 years; 57.1% men) had 29 foramen magnum region AVFs. There were 11 (37.9%) type 1, nine (31.0%) type 2, six (20.7%) type 3, and 3 (10.3%) type 4 fistulas. Pulsatile tinnitus was the most frequent symptom (82.1%), followed by orbital symptoms (31.0%), subarachnoid hemorrhage (13.8%), cranial nerve XII palsy (10.3%), and other cranial nerve palsy (6.9%). The most frequent arterial supply was the ipsilateral ascending pharyngeal artery (93.1% ipsilateral, 55.5% contralateral), vertebral artery (89.7%), occipital artery (65.5%), and internal carotid artery branches (48.3%).
CONCLUSIONS: We present the largest case series of foramen magnum region AVFs to date and show that clinical features relate to angioarchitecture. Orbital symptoms are frequent when sinus reflux is present. Hemorrhage was only observed in type 3 and 4 fistulas.
ABBREVIATIONS:
- FMR
- foramen magnum region
- IJV
- internal jugular vein
Footnotes
This work was supported by National Heart Lung-Blood Institute of the National Institutes of Health under award No. R56 HL149124-01.
Paper previously presented, in part, at: Annual Meeting of the American Society of Neuroradiology, May 22–26, 2021; virtual.
Disclosures: Christopher F. Dowd—UNRELATED: Other: Stryker, Comments: Chief Adjudicator for the EVOLVE Flow Diverter Clinical Trial.* Steven W. Hetts—UNRELATED: Consultancy: Stryker Neuorovascular, Route 92, Johnson & Johnson, Siemens, Comments: Core Lab or Clinical Endpoints Committee for clinical trials, contract for angiography suite evaluation*; Stock/Stock Options: ThrombX Medical, Comments: equity in stroke device startup company. Matthew R. Amans—RELATED: Grant: National Institutes of Health; UNRELATED: Board Membership: MindRhythm Inc; Consultancy: Covidien, Stryker, MicroVention, Comments: Pipeline proctor, consultant, Precipitating Hydrophobic Injectable Liquid (PHIL), Data and Safety Monitoring Board. *Money paid to the institution.
- © 2021 by American Journal of Neuroradiology
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