====== Posterior fossa dural arteriovenous fistula ======

[[Dural arteriovenous fistula]] of the [[posterior fossa]] are defined as [[intracranial]] direct [[shunt]]s involving the [[tentorium]] and the [[dura]] that covers the remainder of the [[posterior fossa]]
((Newton TH, Weidner W, Greitz T. Dural arteriovenous malformation in the posterior fossa. Radiology. 1968 Jan;90(1):27-35. doi: 10.1148/90.1.27. PMID: 5635134.)).

On the basis of their drainage, dAVFs of the posterior fossa can be divided into 2 entities: benign fistulas,
((Pierot L, Chiras J, Meder JF, Rose M, Rivierez M, Marsault C. Dural arteriovenous fistulas of the posterior fossa draining into subarachnoid veins. AJNR Am J Neuroradiol. 1992 Jan-Feb;13(1):315-23. PMID: 1595468.))
draining into a [[sinus]], and those with a high risk of bleeding, with a subarachnoid venous drainage. If one excluded shunts of the transverse and [[sigmoid sinus]]es, posterior fossa [[fistula]]s are the most dangerous fistulas due to their cortical drainage at risk of rupture and their [[eloquent]] location
((Pierot L, Chiras J, Meder JF, Rose M, Rivierez M, Marsault C. Dural arteriovenous fistulas of the posterior fossa draining into subarachnoid veins. AJNR Am J Neuroradiol. 1992 Jan-Feb;13(1):315-23. PMID: 1595468.))
((Zhou LF, Chen L, Song DL, Gu YX, Leng B. [[Tentorial dural arteriovenous fistula]]s. Surg Neurol. 2007 May;67(5):472-81; discussion 481-2. doi: 10.1016/j.surneu.2006.08.078. PMID: 17445607.))

Posterior fossa [[dural arteriovenous fistula]]s (dAVFs) presenting clinically as a [[carotid-cavernous fistula]] (CCF) are rarely encountered in clinical practice.

Common locations:

1. transverse/sigmoid: the most common
((Graeb DA, Dolman CL. Radiological and
Pathological Aspects of Dural Arteriovenous
Fistulas. J Neurosurg. 1986; 64:962–967))
(63% of cases) with a slight left-sided predominance,
((Arnautovic KI, Krisht AF. Transverse-Sigmoid Sinus
Dural Arteriovenous Malformations. Contemp
Neurosurg. 2000; 21:1–6))
with the epicenter of these almost invariably at the junction of the transverse and [[sigmoid sinus]]es

Common locations:

1. transverse/sigmoid: the most common
((Graeb DA, Dolman CL. Radiological and
Pathological Aspects of Dural Arteriovenous
Fistulas. J Neurosurg. 1986; 64:962–967))
(63% of cases) with a slight left-sided predominance,
((Arnautovic KI, Krisht AF. Transverse-Sigmoid Sinus
Dural Arteriovenous Malformations. Contemp
Neurosurg. 2000; 21:1–6))
with the epicenter of these almost invariably at the junction of the transverse and [[sigmoid sinus]]es

Tentorial/petrosal
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[[Foramen Magnum Dural Arteriovenous Fistula]]

===== Treatment =====
When intervention is indicated, the cornerstone of dAVF treatment is the disconnection of the vein foot. Proximal draining veins must be occluded at the end of the treatment
((Maimon S, Nossek E, Strauss I, Blumenthal D, Frolov V, Ram Z. Transarterial treatment with Onyx of intracranial dural arteriovenous fistula with cortical drainage in 17 patients. AJNR Am J Neuroradiol. 2011 Dec;32(11):2180-4. doi: 10.3174/ajnr.A2728. Epub 2011 Oct 13. PMID: 21998110; PMCID: PMC7964375.)).
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Due to their rarity, endovascular treatment of posterior fossa dAVFs has been less often described. Nevertheless, the arterial approach is the most common one even if a transvenous or combined approach can be a safe and effective option
((Lee SK, Hetts SW, Halbach V, terBrugge K, Ansari SA, Albani B, Abruzzo T, Arthur A, Alexander MJ, Albuquerque FC, Baxter B, Bulsara KR, Chen M, Delgado Almandoz JE, Fraser JF, Frei D, Gandhi CD, Heck D, Hussain MS, Kelly M, Klucznik R, Leslie-Mazwi T, McTaggart RA, Meyers PM, Patsalides A, Prestigiacomo C, Pride GL, Starke R, Sunenshine P, Rasmussen P, Jayaraman MV; Standard and Guidelines Committee for the Society of Neurointerventional Surgery. Standard and Guidelines: Intracranial Dural Arteriovenous Shunts. J Neurointerv Surg. 2017 May;9(5):516-523. doi: 10.1136/neurintsurg-2015-012116. Epub 2015 Nov 27. PMID: 26614491.))
((Wong GK, Poon WS, Yu SC, Zhu CX. Transvenous embolization for dural transverse sinus fistulas with occluded sigmoid sinus. Acta Neurochir (Wien). 2007;149(9):929-35; discussion 935-6. doi: 10.1007/s00701-007-1264-4. Epub 2007 Aug 13. PMID: 17700989.)).