Approach to an Infratentorial Dural Arteriovenous Fistula - The Third time is the charm !

CLINICAL DETAILS

• 62-year-old man with history of remote electrocution, traumatic brain injury, chronic tinnitus and essential tremor, followed by neurology for several years, treated with Pramipexole and Propranolol. Previous diagnosis of an AVM with no caractherization or treatment
• After 6-8 months of progressive gait deterioration and imbalance (2022-2023), a brain MRI and head MRA were obtained, and the patient was referred to the neurointerventional clinic
• Patient’s wife noticed constant “draggin”of his left foot, tendency to fall, reluctance to walk without the assistance of walker
• Family history: Unremarkable
• Medical History: Psoriasis, electrocution and burns to his arms, traumatic brain injury

PHYSICAL EXAM

• General: Knee and elbow’s psoriatic plaques in resolution
• HEENT: No audible bruit or palpable thrill
• Neurological examination:
  • Higher functions intact
  • CN 2-12 intact
  • Motor: 5/5 strength bilateral UE and LE
  • Sensation : Intact
• Cerebellar:
  • Left arm dysmetria on finger-to-nose test, notable ataxia on execution
  • Left leg ataxia on heel-to-shin test
  • Truncal ataxia
  • Left lateropulsion sitting and standing
  • Ataxic gait

MRI BRAIN (03/2023)

 T1 FLAIR

T1 FLAIR

T2 FLAIR

T2

First Diagnostic Angio in June 14 2023

Left Vertebral Artery

Left Vertebral (Left oblique)

Right ICA

Right Ascending Pharyngeal Artery

Cone-Beam CT

3D Rotational Angio

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Left Vertebral Artery (Left oblique)

Left Vertebral Artery (Posterior View)

Right ECA

Left CCA

Diagnosis / Assessment

• Posterior Fossa Dural Arteriovenous Fistula
  • Infratentorial venous drainage to the inferior vermian vein and ultimately, anastomosing to the torcula – transverse sinus
  • Cognard Type IV
    • Direct drainage into cortical veins 
    • Venous ecstasies
    • High annual risk of intracranial hemorrhage
• Arterial Supply:
  • Right Posterior meningeal artery
    • Jugular branch of the R. ascending pharyngeal artery
  • Left Occipital Artery
    • Trans-osseal branches
• Venous drainage
  • Ectatic Inferior vermian vein – Torcula – Left transverse sinus

Transarterial embolization (07/2023)

1st Stage

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FISTULOGRAM

Left Occipital Artery

Post-Onyx embolization

One arterial feeder out
Minimal venous penetration…
Some more to go

Transarterial embolization (10/2023)

Right Ascending Pharyngeal Artery

One more feeder out
Some work to do…

Transarterial embolization (11/2023)

Onyx venous penetration

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The third time is the charm !

Left Occipital Artery - Final

Left ICA - Final

Right Ascending Pharyngeal - Final

Clinical course

• Maintained on IV heparin 48 hrs post embolization (3rd)
  • Aspirin 81 mg daily
• Tinnitus improved after second embolization
  • “It was not that loud”
  • Resolved after 3rd Embolization
• Ongoing, improving stance while standing, less unsteady
• Improved hand coordination (Improving ataxia)
• Improved truncal coordination and ability to get up

Discussion

• Approx., 20% to 33% of patients with symptomatic dAVFs present with an ICH. This is encountered in lesions involving the floor of the anterior cranial fossa or the tentorium cerebelli; however, it may occur in any case associated with cortical venous drainage, particularly in the presence of significant cerebral venous ectasia
  • Aneurysmal venous ectasia may cause symptomatic mechanical compression of adjacent neurologic structures, most commonly in dAVFs draining into pial veins
  • Rerouting of drainage into the supratentorial cortical venous compartment may be associated with the development of focal neurologic deficit or seizures
  • Neurosurg Clin N Am 20 (2009) 431–439
• Onyx Embolization demonstrates safety and clinical efficacy
  • A series of 260 dAVFs treated via endovascular approaches, obliteration was achieved in 80% of nonethmomidal dAVF cases in the era of Onyx, with a complication rate of 8%. Symptomatic improvement from tinnitus or ocular symptoms was also 80%
    • J Neurosurg. 2017;126:1884-1893
  • Another case series and meta-analysis incorporatng 425 patients cited a similar occlusion rate of 82%. Procedural morbidity in this review was 3%.
    • Neurosurgery. 2018;854- 863

Take-home messages

References

• C Cognard, A C Januel, N A Silva Jr, P Tall. Endovascular treatment of intracranial dural arteriovenous fistulas with cortical venous drainage: new management using Onyx. AJNR Am J Neuroradiol 2008 Feb;29(2):235-41. doi: 10.3174/ajnr.A0817
• Douglas M Choo, Jai Jai Shiva Shankar. Onyx versus nBCA and coils in the treatment of intracranial dural arteriovenous fistulas. Interv Neuroradiol. 2016 Apr;22(2):212-6. doi: 10.1177/1591019915622170