Intracranial dural arteriovenous fistula presenting with tetraparesis due to cervicomedullary junction compression. A case report

Watch brain circulation in unexplained progressive myelopathy: a review of Cognard type V arterio-venous fistulas

BACKGROUND

Intracranial dural arterio-venous fistulas are pathological anastomoses between arteries and veins located within dural sheets and whose clinical manifestations depend on location and hemodynamic features. They can sometimes display perimedullary venous drainage (Cognard type V fistulas-CVFs) and present as a progressive myelopathy. Our review aims at describing CVFs' variety of clinical presentation, investigating a possible association between diagnostic delay and outcome and assessing whether there is a correlation between clinical and/or radiological signs and clinical outcomes.

METHODS

We conducted a systematic search on Pubmed, looking for articles describing patients with CVFs complicated with myelopathy.

RESULTS

A total of 72 articles for an overall of 100 patients were selected. The mean age was 56.20 ± 14.07, 72% of patients were man, and 58% received an initial misdiagnosis. CVFs showed a progressive onset in 65% of cases, beginning with motor symptoms in 79% of cases. As for the MRI, 81% presented spinal flow voids. The median time from symptoms' onset to diagnosis was 5 months with longer delays for patients experiencing worse outcomes. Finally, 67.1% of patients showed poor outcomes while the remaining 32.9% obtained a partial-to-full recovery.

CONCLUSIONS

We confirmed CVFs' broad clinical spectrum of presentation and found that the outcome is not associated with the severity of the clinical picture at onset, but it has a negative correlation with the length of diagnostic delay. We furthermore underlined the importance of cervico-dorsal perimedullary T1/T2 flow voids as a reliable MRI parameter to orient the diagnosis and distinguish CVFs from most of their mimics.

Clinical features, angio-architectural phenotypes, and treatment strategy of foramen magnum dural arteriovenous fistulas: a retrospective case series study

Background

The rarity and complex angioarchitecture of foramen magnum dural arteriovenous fistulas (DAVFs) make its treatment difficult and controversial. We aimed to describe their clinical features, angio-architectural phenotypes, and treatments, through a case series study.

Methods

We first retrospectively studied cases of foramen magnum DAVFs treated in our Cerebrovascular Center, and then reviewed the published cases on Pubmed. The clinical characteristics, angioarchitecture, and treatments were analyzed.

Results

A total of 55 patients were confirmed with foramen magnum DAVFs, which included 50 men and 5 women, with a mean age of 52.8 years. Most patients presented with subarachnoid hemorrhage (SAH) (21/55) or myelopathy (30/55), depending on the venous drainage pattern. In this group, 21 DAVFs were supplied by only the vertebral artery (VA), three by only the occipital artery (OA), three by only the ascending pharyngeal artery (APA), and the remaining 28 DAVFs were supplied by two or three of these feeding arteries. Most cases (30/55) were treated with only endovascular embolization, 18 cases (18/55) with only surgical disconnection, five cases (5/55) with combined therapy, and two cases rejected treatment. The angiographic outcome of complete obliteration was achieved in most patients (50/55). In addition, two cases of foramen magnum DAVFs were treated by us in a Hybrid Angio-Surgical Suite (HASS) with good outcomes.

Conclusions

Foramen magnum DAVFs are rare and their angio-architectural features are complicated. The treatment option (microsurgical disconnection or endovascular embolization) should be weighed carefully, and combined therapy in HASS could be a more feasible and less invasive treatment option.

Subarachnoid hemorrhage due to a craniocervical junction arteriovenous fistula associated with thrombus formation in the internal jugular vein: illustrative case

BACKGROUND

A craniocervical junction arteriovenous fistula (CCJAVF) is a rare vascular malformation, and its etiology remains unclear. Here, to the best of the authors' knowledge, they present the first case of CCJAVF associated with thrombus formation in the ipsilateral internal jugular vein.

OBSERVATIONS

An 80-year-old man presented with a sudden occipital headache. Computed tomography revealed a subarachnoid hemorrhage surrounding the brainstem and upper cervical cord. Digital subtraction angiography showed a CCJAVF fed by the left C2 radiculomeningeal artery with ascending intracranial drainage and epidural plexus. After endovascular treatment, the authors retrospectively found that his ipsilateral internal jugular vein and innominate vein were occluded with a huge thrombus at admission.

LESSONS

This case suggested a restricted antegrade venous flow due to thrombus-induced progressive retrograde intracranial drainage causing hemorrhage. Venous hypertension should be considered one of the causes of hemorrhage due to CCJAVF as well as intracranial arteriovenous fistulas.

Surgical disconnection of a hypoglossal canal dural arteriovenous fistula demonstrating rapid progression of medulla oblongata disturbance: illustrative case

BACKGROUND

Dural arteriovenous fistulas of the hypoglossal canal (HCDAVFs) with dominant drainage to perimedullary veins are extremely rare. These patients are prone to develop slow and progressive myelopathy, however, their clinical course has not been fully elucidated. We report an unusual case of HCDAVF in which the patient demonstrated rapid progression of hemiplegia and respiratory insufficiency.

OBSERVATIONS

An 82-year-old woman demonstrated motor weakness of the left extremities. T2-weighted magnetic resonance imaging showed a high intensity area in the right medulla oblongata and angiography revealed HCDAVF with dominant drainage to the anterior medullary vein through the anterior condylar vein. Within 3 days, her hemiparesis and respiratory function worsened, and she needed mechanical ventilation. Considering that venous congestion in the medulla oblongata could cause the symptoms, we immediately performed surgical obliteration of the anterior condylar vein. The disappearance of HCDAVF was confirmed by angiography and the patient was weaned from mechanical ventilation 3 days postoperatively. Her left hemiplegia gradually resolved and she was independent in daily life 8 months after the operation.

LESSONS

HCDAVFs with dominant drainage to the perimedullary veins can demonstrate rapid progression of medulla oblongata disturbance. Early disconnection should be considered to provide an opportunity for substantial recovery.

Retrograde leptomeningeal venous approach for dural arteriovenous fistulas at foramen magnum

A 72-year-old man presented with sudden right homonymous hemianopsia. Work-up imaging revealed a left occipital haematoma and an arteriovenous fistula supplied by the meningeal branches to the clivus from the left vertebral artery (VA) with a rostral venous reflux into cortical veins. A microcatheter was advanced through brainstem veins into the venous collector. A compliant balloon was placed in the left VA facing the origin of feeders. The balloon was inflated to protect the vertebrobasilar circulation from embolic migration. Onyx was injected by the transvenous catheter. Control angiogram revealed exclusion of the lesion. Informed consent was obtained from the patient.

Dural arteriovenous fistulas of the hypoglossal canal: systematic review on imaging anatomy, clinical findings, and endovascular management

Dural arteriovenous fistulas (DAVFs) of the hypoglossal canal (HCDAVFs) are rare and display a complex angiographic anatomy. Hitherto, they have been referred to as various entities (for example, “marginal sinus DAVFs”) solely described in case reports or small series. In this in-depth review of HCDAVF, the authors describe clinical and imaging findings, as well as treatment strategies and subsequent outcomes, based on a systematic literature review supplemented by their own cases (120 cases total). Further, the involved craniocervical venous anatomy with variable venous anastomoses is summarized. Hypoglossal canal DAVFs consist of a fistulous pouch involving the anterior condylar confluence and/or anterior condylar vein with a variable intraosseous component. Three major types of venous drainage are associated with distinct clinical patterns: Type 1, with anterograde drainage (62.5%), mostly presents with pulsatile tinnitus; Type 2, with retrograde drainage to the cavernous sinus and/or orbital veins (23.3%), is associated with ocular symptoms and may mimic cavernous sinus DAVF; and Type 3, with cortical and/or perimedullary drainage (14.2%), presents with either hemorrhage or cervical myelopathy. For Types 1 and 2 HCDAVF, transvenous embolization demonstrates high safety and efficacy (2.9% morbidity, 92.7% total occlusion). Understanding the complex venous anatomy is crucial for planning alternative approaches if standard transjugular access is impossible. Transarterial embolization or surgical disconnection (morbidity 13.3%–16.7%) should be reserved for Type 3 HCDAVFs or lesions with poor venous access. A conservative strategy could be appropriate in Type 1 HCDAVF for which spontaneous regression (5.8%) may be observed.