A case of two pial arteriovenous fistulas with giant venous pouches treated by endovascular coil embolization: Therapy with and without anticoagulation

Embolization of cerebellar pial arteriovenous fistula presented with congestive edema of the brainstem and cervical cord

Cerebellar pial arteriovenous fistula (PAVF) in adults presenting with congestive edema of the brainstem and cervical cord has rarely been reported. Here, we report such a case. A 59-year-old man presented with progressive weakness and numbness of the limbs and hiccups for 6 months. On physical examination, his limbs had grade III muscle strength, and he was unable to stand or walk. He also had occasional incontinence and retention. There was a positive Babinski sign in both lower limbs. Below the neck, he had hypoesthesia of the skin. Magnetic resonance imaging (MRI) showed edema of the brainstem and upper cervical cord. Digital subtraction angiography (DSA) confirmed there was a cerebellar nongalenic-type PAVF lesion; the feeding arteries were the branches of the posterior inferior cerebellar artery (PICA); and the draining vein was a single cortical vein that ultimately entered the venous systems of the brainstem and upper cervical cord. Casting Onyx-18 via the PICA obliterated the PAVF. Postoperatively, the patient recovered gradually. Two and a half months later, he could walk using a crutch and had no incontinence. Six-month follow-up MRI and DSA revealed recession of the edema of the brainstem and cervical cord and no recurrence of this PAVF. One year later, he was nearly normal. In conclusion and extremely rarely, cerebellar nongalenic-type PAVF can present with congestive edema of the brainstem and high cervical cord. This treatment by Onyx-18 embolization can resolve PAVF.

Clipping of a Pediatric Pial Arteriovenous Fistula Located at Basilar Artery Tip Using a Hybrid Trapping-Evacuation Technique

BACKGROUND

Intracranial pial arteriovenous fistulas (PAVFs) are rare cerebrovascular lesions with high mortality rates. We report a rare case of pediatric PAVF at the basilar artery tip and its treatment with surgical clipping aided by a trapping-evacuation technique in a hybrid operating room.

CASE DESCRIPTION

An 18-month-old boy was admitted with hypoevolutism and 4-month history of weakness in the left extremities. Magnetic resonance imaging showed a giant aneurysm-like malformation in the area of midbrain and pons. Angiography showed a high-flow PAVF fed by the basilar artery and bilateral P1 segments of the posterior cerebral artery, with deep draining veins into the transverse sinus and straight sinus. Given the intrinsic characteristics of the lesion, such as deep location, giant fistula and varix, and multiple feeding arteries, clipping of PAVF was performed in a hybrid operating room aided by a trapping-evacuation technique to clearly identify and block the shunting point.

CONCLUSIONS

The successful obliteration of the lesion is reported. In addition, a brief review of literature comparing endovascular embolization, surgical disconnection, and hybrid technique for treatment of PAVF is included.

Endovascular occlusion of pial arteriovenous macrofistulae, using pCANvas1 and adenosine-induced asystole to control nBCA injection

Background In large-caliber pial macrofistulae (pMF), the combination of high blood flow velocity and large efferent artery diameter makes control over the endovascular vessel occlusion difficult and may result in the inadvertent venous passage of occlusive devices or embolic agents. Case descriptions Patient 1: A 27-year-old man presented with headache and ataxia. An infratentorial pMF supplied by both superior cerebellar arteries with venous ectasia was found. The first treatment attempt using balloons and coils failed since the position of either device could not be controlled because of a distal diameter of the feeding artery of 8 mm. In a second session a pCANvas1 (phenox) was deployed at the level of the arteriovenous connection and adenosine-induced asystole allowed the controlled injection of nBCA/Lipiodol with partial occlusion of the pMF. A remaining arteriovenous shunt was occluded under asystole in a third session. The procedures were well tolerated, the patient returned to normal and DSA confirmed the occlusion of the fistula. Patient 2: A 13-year-old boy with hereditary hemorrhagic teleangiectasia presented with an intracerebral hemorrhage from an aneurysm of the left MCA. Twelve weeks after the aneurysm treatment a feeding MCA branch (diameter 4.5 mm) of a right frontal pMF was catheterized. The macrofistula was occluded by deployment of a pCANvas1, followed by the injection of nBCAl/Lipiodol under adenosine-induced asystole. Conclusion pCANvas1 and adenosine-induced asystole allow a controlled injection of nBCA/Lipiodol for the endovascular occlusion of high-flow pMF without venous passage of the embolic agent.

Pial-Dural Intracranial Arteriovenous Fistula with Flow-Associated Aneurysmal Rupture-Case Report with Review of Literature and Proposal on the Mechanism of Hemorrhage and Treatment Options

BACKGROUND

Vascular anomalies in the form of dural arteriovenous fistulas (DAVFs), arteriovenous malformations, and aneurysms are well described in the literature. Pial arteriovenous fistulas (PAVFs) are described to a lesser extent in the literature. When these anomalies are combined, diagnosis and treatment become complex.

CASE DESCRIPTION

A 55-year-old man presented with PAVF/DAVF with a ruptured flow-related aneurysm in the distal left posterior inferior cerebellar artery, which required surgical clipping and disconnection. We performed a PubMed search of all identifiable cases of PAVFs in adults. We then identified which cases had components of DAVFs and flow-related aneurysms. We identified 51 PAVF cases and identified which patients presented with hemorrhage and the treatment modalities of all cases. Of 51 cases identified, 4 were a DAVF/FRA, and 5 were a PAVF/DAVF. One case of PAVF/DAVF/FRA was identified.

CONCLUSIONS

The exact mechanism of PAVF/DAVF formation is unknown. Hemorrhage predilection of PAVF/DAVF is more difficult to predict than a sole fistula, likely secondary to the complex flow dynamics. To our knowledge, this literature review is the largest review to date regarding PAVFs in adult patients and can provide insight into decision making when evaluating treatment options.

Adjunct to Embolize the High-Flow Fistula Part of Arteriovenous Malformation Using a Double-Lumen Balloon Catheter

OBJECTIVE

The purpose of this study is to report our initial experience of Onyx embolization of the high-flow fistula part of arteriovenous malformation (AVM) using a double-lumen balloon catheter.

METHODS

A Scepter C balloon catheter was used in 2 patients with AVMs associated with high-flow fistulas. The fistulas were located in the anterior cerebral artery and the middle cerebral artery.

RESULTS

Onyx embolization was successful in 2 cases, resulting in elimination of the high-flow fistula part of the AVM. There were no treatment-related events.

CONCLUSIONS

The double-lumen Scepter balloon appears to be a safe and convenient device for Onyx embolization of high-flow fistulas.

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.