Non-galenic arteriovenous fistulas in adults: transarterial embolization and literature review

Combined transarterial and transvenous embolization of multi-hole pial arteriovenous fistula with large varix

BACKGROUND

Pial arteriovenous fistula (AVF) is a vascular fistulous disease in which the cerebral pial artery and vein are directly connected without the intervening nidus within a sub-pial space. Multi-hole pial AVFs, wherein multiple feeders flow into one drainer, are usually formed with complex angioarchitecture and are difficult to treat.

METHODS

A rare case of an adult patient with hereditary hemorrhagic telangiectasia and multi-hole pial AVF was described. A 23-year-old woman was referred to our hospital. She was previously diagnosed with left cerebellar pial AVF with multiple feeders (bilateral superior cerebellar artery and common trunk of the left anterior inferior cerebellar artery and posterior inferior cerebellar) and large varix that had been untreated for 9 years. The enlargement of the large varix with the new second varix formation was revealed by angiography. Although asymptomatic, considered to be a risk for future hemorrhage was the continuous high hemodynamic stress.

RESULTS

Endovascular embolization was performed by securing safe transarterial n-butyl-2-cyanoacrylate injection by transarterial and transvenous coil placement to the shunt points and feeders, resulting in total occlusion of the fistula without any complications. Extensive transvenous coil placement inside the varix allowed safe embolization of the entire fistula with multiple high-flow feeders. Moreover, bidirectional (transarterial and transvenous) retrograde coil embolization enabled firm obliteration of the shunt points.

CONCLUSIONS

Performing combined transarterial and transvenous embolization in a well-balanced manner was considered to treat multi-hole pial AVF to provide a safe and effective embolization.

Endovascular Management of Intracranial Pial Arteriovenous Fistula with Giant Venous Varix: Case Report and Review of Literature

Background: Intracranial pial arteriovenous fistulas (AVFs) are rare intracranial vascular malformation and their treatment is challenging because of high-flow pial supply of the lesion. We report a case of intracranial pial AVF with associated giant venous varices managed successfully by embolization.

Case Description: A 25-year-old male presented with sudden onset headache and altered sensorium. Computed tomographic scan was suggestive of frontal lobar hematoma that had dissected into the third ventricle with associated intraventricular hemorrhage. Magnetic resonance imaging revealed presence of large vascular channels with the presence of multiple flow voids in bilateral frontal location. Digital subtraction angiography revealed pial fistula with arterial supply from hypertrophied left anterior cerebral artery. Treatment was done using combined coil and onyx embolization after careful analysis of angioarchitecture of the lesion using three-dimensional rotational angiogram cross-sectional reconstructions. Postprocedure angiogram revealed closure of fistula and giant varices.

Conclusion: Pial AVFs with giant venous varix in adults are rare vascular malformation and understanding the angioarchitecture with exact identification of fistulous point is important to plan for surgical/endovascular management strategies. Combined strategy of embolization using coils and onyx is a safe option in such cases with giant varices.

Distal microcatheter placement using the Asahi Chikai TM 0.008-inch micro-guidewire for liquid embolic material delivery: A technical note

INTRODUCTION

Management of vascular malformations requires microcatheter manipulation through distal tortuous arterial feeders less than a millimetre in diameter, to permit safe and effective embolization at the fistula or nidus location. The Asahi Chikai^TM 0.008 inch micro-guidewire recently introduced in the United States was used to evaluate microcatheter torque, support and safety in distal microcatheter navigation.

METHODS

The use of the Asahi Chikai 0.008 inch micro-guidewire in conjunction with flow-guided, and over the wire microcatheters was evaluated in 25 neuroendovascular cases over a 1 year period. It involved single operator usage for endovascular microcatheter embolization of intracranial vascular malformations listed below. The study evaluated angiographic evidence of distal microcatheter positioning, subsequent obliteration of the fistula at the location and complications if any.

RESULTS

The micro-guidewire was used in microcatheter embolization of 10 vein of Galen malformations, 11 brain and head & neck arteriovenous malformations, 2 spinal and 2 cranial dural arteriovenous fistula. Good flow directed and over the wire microcatheter placement using the Asahi Chikai^TM 0.008 inch micro-guidewire was possible across the spectrum of cases achieving optimum catheterization and safe embolization in all. There were no micro-guidewire or microcatheter related vessel spasm, dissection, or perforation during their combined or individual manipulation, contrast or embolic extravasation on fluoroscopy or post- embolization angiograms CONCLUSION: The Asahi Chikai^TM 0.008 inch micro-guidewire is a safe, sturdy micro-guidewire which provides good torque in distal arterial anatomy while providing microcatheter support and maintaining tip configuration on repeated use.

Transarterial Balloon-Assisted Glue Embolization of Pial Arteriovenous Fistulas

OBJECTIVE

Endovascular disconnection of pial arteriovenous fistulas (AVFs) is challenging. The aim of this study was to evaluate safety and effectiveness of transarterial balloon-assisted glue embolization for treating pial AVFs.

METHODS

We retrospectively reviewed medical and imaging records of 8 patients with high-flow pial AVFs treated by transarterial balloon-assisted glue embolization from August 2011 to July 2017.

RESULTS

There were 6 male patients and 2 female patients with age range of 1-48 years. Presentation was seizure in 4 patients, headache in 3 patients, and subarachnoid hemorrhage in 1 patient. Seven lesions were located in the supratentorial region. All lesions were single-channel fistulas associated with venous varix. Five lesions had a single feeder, and 3 had multiple feeders. All lesions were obliterated completely in single-session embolization with no procedure-related complications. Two patients experienced symptomatic thrombosis of drainage venous system after embolization. One patient fully recovered on discharge, and another patient fully recovered after 8 months. With a mean clinical follow-up of 12.1 months, all patients were free of pretreatment symptoms. Follow-up angiograms revealed durable occlusion of fistulas.

CONCLUSIONS

Transarterial balloon-assisted glue embolization is a feasible and effective option for treatment of high-flow pial AVFs.

Intracranial non-galenic pial arteriovenous fistula: A review of the literature

An intracranial non-galenic pial arteriovenous fistula (NGPAVF) is a direct connection between the intracranial artery and vein without a nidus. NGPAVFs are clinically rare, and the current understanding of NGPAVFs is limited. This study searched PubMed for the currently available literature, and a review of the relevant publications revealed that NGPAVFs require aggressive treatment, spontaneous occlusion is uncommon, and the prognosis following conservative treatment is poor. NGPAVFs can be divided into congenital and traumatic (including iatrogenic) types. Clinically, NGPAVFs are characterized by congestive heart failure, epilepsy, hemorrhage, mass effects, and nerve function deficits. For the imaging examination of NGPAVFs, digital subtraction angiography (DSA) is still the gold standard for diagnosis, although magnetic resonance DSA (MRDSA) and 4D computed tomography angiography (CTA) can also provide hemodynamic data in a non-invasive manner. Current treatments for NGPAVFs include surgical resection and endovascular embolization, both of which can yield clinical improvements. However, potential postoperative complications should be addressed, such as fatal bleeding due to rupture and deep vein thrombosis. Some studies recommend postoperative anticoagulation to reduce postoperative thrombotic complications.