A.J. Hauer Intracranial dural arteriovenous fistulae

Transcription

1 A.J. Hauer Intracranial dural arteriovenous fistulae

2 Dural arteriovenous fistulae (davfs) epidemiology Pathological anastomoses (within the dural leaflets) between meningeal arteries and dural venous sinuses or leptomeningeal/cortical veins (no parenchymal nidus). Age-standardized crude detection rate: 0.16 (95% CI, 0.08 to 0.27) per adults per year. Accounting for 7% of all incident intracranial vascular malformations (but up to a third infratentorial). Multiplicity in up to 7-8%. Slight female preponderance; males more often haemorrhagic presentation. Most frequent in middle-aged adults (40-65 years of age). davf location: 1) Transverse/sigmoid sinus 25-60% 2) Cavernous sinus 25-40% 3) Superior sagittal sinus 10% 4) Tentorial incisura < 10% 5) Anterior fossa < 10% 6) Other 10-35% Al-Shahi R. Stroke. 2003;34: Gandhi D. AJNR Am J Neuroradiol. 2012;33: Reynolds MR.. Stroke. 2017;48:

3 Dural blood supply Anterior cranial fossa: Meningeal branches of anterior and posterior ethmoidal artery, the ophthalmic artery, and the frontal branch of the middle meningeal artery. Middle cranial fossa: Frontal and parietal branches of the middle meningeal artery, the accessory meningeal artery, ascending pharyngeal artery, and branches directly from the internal carotid artery. Posterior cranial fossa: The vertebral artery, occipital artery, and ascending pharyngeal artery.

4 Cerebral venous system

5 Pathophysiology current hypotheses Acquired. Idiopathic. Inconclusive evidence for a causative role of infection, hypercoagulable state, venous sinus thrombosis, tumours, trauma, or surgery in davf aetiology thus far, though associations have been reported. Genetic contribution? Inflammatory response (as a common pathway following a (subclinical) trigger?) à (progressive) venous outflow obstruction à (local) venous hypertension à fistulous connections between meningeal/scalp arteries and the dural sinus or cortical veins by: 1) enlargement of pre-existing (physiologic) AV shunts and/or 2) de novo formation due to neoangiogenesis (VEGF) à complex network of (fragile) venous tributaries under arterial pressure. Flow haemodynamics may change over time ( angiographic conversion ) à altering clinical behaviour! Venous hypertension/congestion à risk of (remote) intracranial haemorrhage (ICH), venous infarction, non-haemorrhagic focal deficits (NHFD), vasogenic edema, and encephalopathy à possibly due to impaired arterial delivery of O2 and removal of toxic waste products. Reynolds MR. Stroke. 2017;48: Cognard C. J Neurol Neurosurg Psychiatry. 1998;65: Tsai LK. J Neurol Neurosurg Psychiatry. 2004;75:

6 Borden Shucart classification Borden Shucart classification à based on direction of venous flow & presence of cortical venous reflux (CVR): a) Dural venous sinus drainage without CVR; b) Dural venous sinus drainage with CVR; c) Only CVR. Modification of Borden Shucart classification according to Zipfel: Further specification of Borden Shucart type II and type III davfs into symptomatic vs. asymptomatic lesions. Borden JA.. J Neurosurg. 1995;82:

7 Cognard classification Cognard classification (includes sinus drainage, direction of sinus flow, cortical venous reflux (CVR), and presence of venous ectasia): Type I: Dural venous sinus drainage with antegrade sinus flow; Type IIa: Dural venous sinus drainage with retrograde sinus flow; Type IIb: Dural venous sinus drainage with antegrade sinus flow and CVR; Type IIa+b: Dural venous sinus drainage with retrograde sinus flow and CVR; Cognard C.. Radiology. 1995;194: Type III: Only CVR; Type IV: Only CVR, and presence of venous ectasia; Type V: Spinal perimedullary venous drainage.

8 Barrow classification carotid-cavernous fistulae Carotid-cavernous fistulae: Type A: direct fistulae (high flow) between the intracavernous internal carotid artery (ICA) and the cavernous sinus (CS); Type B: indirect fistulae (low flow) between meningeal branches of the intracavernous ICA and the CS; Type C: indirect fistulae (low flow) between meningeal branches of the external carotid artery (ECA) and the CS; Type D: indirect fistulae (low flow) between both meningeal branches of the intracavernous ICA and meningeal branches of the ECA and the CS. Reynolds MR.. Stroke. 2017;48:

9 Clinical manifestations & imaging modalities Clinical manifestations may vary widely, depending on 1) davf location and 2) angiographic presence of CVR. Mode of presentation: Incidental (asymptomatic) Benign symptoms: 1) Anterior cranial fossa: visual deterioration, proptosis, chemosis, retro-orbital pain, cranial nerve palsies. 2) Middle cranial fossa: pulsatile tinnitus. ICH (parenchymal, subarachnoid, subdural) à rupture of delicate, arterialized leptomeningeal veins or haemorrhagic transformation of cortical venous congestion. NFHD: seizures, focal cortical deficits, cranial nerve palsies, thalamic or cortical dementia, Parkinsonism, cerebellar dysfunction, myelopathy, quadriparesis, aphasia, symptoms related to ICP, including headache, nausea, vomiting, and papilledema. Imaging features: CT/CTA à davf-related ICH and vasogenic edema. MRI/MRA à flow voids? Presence of dilated leptomeningeal & medullary vessels? Venous ectasia? Parenchymal enhancement? Venous sinus thrombosis? Microhemorrhages? DSA à early venous filling. Angioarchitecture: configuration arterial feeders? Number of fistulae? Presence of CVD? Dural sinus stenosis/occlusion? Venous ectasia? Reynolds MR. Stroke. 2017;48: Miller TR. Stroke. 2015;46:

10 Clinical manifestations & imaging features C (A) Bithalamic edema as a result of venous hypertension in a patient with rapidly progressive dementia. (B) DSA shows (C) Another davf supplied via ethmoidal branches from a hypertrophic a davf fed by the occipital artery (arrowhead) with early arteriovenous shunting into the vein of Galen (asterisk). ophthalmic artery (white arrowheads) and draining into a cortical frontal Resolution of clinical symptoms was achieved after complete davf obliteration by endovascular embolization. vein causing venous ectasia (asterisks). Early filling of the superior sagittal sinus is also seen (black arrowheads). Reynolds MR. Stroke. 2017;48:

11 Clinical manifestations & imaging features T2-weighted MRI (A&B) showing large vascular flow voids (arrowheads) near the left anterior fossa floor. DSA (C) shows a davf fed by ethmoidal branches from the ophthalmic artery and draining into enlarged, arterialized cortical frontal veins with an associated venous ectasia (asterisks). Reynolds MR. Stroke. 2017;48:

12 Natural disease course Spontaneous davf resolution Conversion to davf with CVR davfs without cortical venous reflux ( benign ): Annual risk of ICH, NHFD or mortality: < 1%. Annual rate of conversion to davf with CVR: 1-2%; à change (deterioration or improvement) of symptoms warrants prompt (angiographic) reassessment! Spontaneous davf thrombosis/resolution: 12.5%; à most often davfs near the cavernous or transverse sinus. Transverse/sigmoid & cavernous davfs à mostly a benign clinical course. davfs with cortical venous reflux ( aggressive ): Annual risk of ICH or NHFD: 7-20%; annual risk of mortality: up to 5%-10%. Annual risk of ICH after haemorrhage: up to 45%. Annual risk of ICH or NHFD in case of asymptomatic CVR: 1.5%. Venous ectasia vs. no ectasia: incidence risk ratio 6.1 (95% CI, ) Anterior fossa, petrosal & tentorial incisura davfs à mostly an aggressive clinical course. Gross BA. Neurosurgery. 2012;71: ; discussion 602. Kim DJ. Stroke. 2010;41: van Dijk JM. Stroke. 2002;33: Reynolds MR. Stroke. 2017;48:

13 Management Observation: davfs without CVR, and tolerable symptoms, severe comorbidity, short life-expectancy. Embolization (transarterial and/or transvenous): davfs with CVR (asymptomatic davfs in an elective fashion). In case of intolerable symptoms due to flow (e.g. pulsatile tinnitus): palliation à partial embolisation & flow reduction. Transarterial à distal microcatheterization of arterial feeders à embolisation with liquid embolic agents. Transvenous à distal microcatheterization of the proximal draining vein or involved dural sinus à embolisation with liquid embolic agents or coils. Combined approaches (balloon). Reynolds MR. Stroke. 2017;48: Miller TR.. Stroke. 2015;46:

14 Management Microsurgical treatment: Selective disconnection of affected cortical veins showing reflux coagulation of dural feeding arteries preservation of adjacent non-arterialized cortical veins to prevent venous infarction! Difficult venous and/or arterial access for embolisation recanalization of embolised vessels incomplete embolisation anterior fossa floor superior sagittal sinus tentorial region involvement of eloquent feeders. Stereotactic radiosurgery: Controversial. Only for davfs without CVR, severe comorbidity or complex davf anatomy cavernous and the transverse/sigmoid sinuses dose 20 to 30 Gy latency period ( 1-3 years) for fistula obliteration. Complete davf obliteration is a conditio sine qua non to eliminate the risk of future ICH! Reynolds MR. Stroke. 2017;48: Miller TR.. Stroke. 2015;46:

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16 References Reynolds MR, Lanzino G, Zipfel GJ. Intracranial Dural Arteriovenous Fistulae. Stroke. 2017;48: Miller TR, Gandhi D. Intracranial Dural Arteriovenous Fistulae: Clinical Presentation and Management Strategies. Stroke. 2015;46: Al-Shahi R, Bhattacharya JJ, Currie DG, et al. Prospective, population-based detection of intracranial vascular malformations in adults: the Scottish Intracranial Vascular Malformation Study (SIVMS). Stroke. 2003;34: Cognard C, Gobin YP, Pierot L, et al. Cerebral dural arteriovenous fistulas: clinical and angiographic correlation with a revised classification of venous drainage. Radiology. 1995;194: Borden JA, Wu JK, Shucart WA. A proposed classification for spinal and cranial dural arteriovenous fistulous malformations and implications for treatment. J Neurosurg. 1995;82: van Dijk JM, terbrugge KG, Willinsky RA, et al. Clinical course of cranial dural arteriovenous fistulas with long-term persistent cortical venous reflux. Stroke. 2002;33: Gross BA, Du R. The natural history of cerebral dural arteriovenous fistulae. Neurosurgery. 2012;71: ; discussion 602. Cognard C, Casasco A, Toevi M, et al. Dural arteriovenous fistulas as a cause of intracranial hypertension due to impairment of cranial venous outflow. J Neurol Neurosurg Psychiatry. 1998;65: Tsai LK, Jeng JS, Liu HM, et al. Intracranial dural arteriovenous fistulas with or without cerebral sinus thrombosis: analysis of 69 patients. J Neurol Neurosurg Psychiatry. 2004;75: Kim DJ, terbrugge K, Krings T, et al. Spontaneous angiographic conversion of intracranial dural arteriovenous shunt: long-term follow-up in nontreated patients. Stroke. 2010;41: Gandhi D, Chen J, Pearl M, et al. Intracranial dural arteriovenous fistulas: classification, imaging findings, and treatment. AJNR Am J Neuroradiol. 2012;33:

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