Staged Arterial and Venous Embolizations in Treatment of Type IV Intraosseous Dural Arteriovenous Fistula

Abstract

Objective

This is a case report of an adult male with complex type IV intraosseous DAVF causing severe venous hypertension and bony destruction, presenting with severe hemotympanum, and a novel way of staged arterial and venous embolizations to treat the emergent symptoms.

Methods

First and second stages were direct selective arterial embolizations using Onyx liquid agent. Goal was to reduce flow into the fistula by embolizing the feeder branch and distal penetration of the nidus with Onyx. The third stage was performed through the venous route: the transverse sinus and the sigmoid sinus were embolized using Penumbra Ruby coils and Onyx, two microcatheters were used and two large coils were placed simultaneously to form a stable coil mass, and the entire sinus was embolized using Coils and Onyx.

Results

Patient’s venous hypertension and degree of hydrocephalus had significantly decreased after the procedure. He was able to return to work, but was instructed to avoid heavy lifting and placing anything in and around his right ear.

Conclusions

Multiple step arterial and venous embolization procedures were successful in decreasing the frequency of hemotympanum, degree of hydrocephalus, and improving quality of life of this patient.

INTRODUCTION

This is a case report of an adult male with complex type IV intraosseous DAVF causing severe venous hypertension and bony destruction presenting with severe hemotympanum and a novel way of staged arterial and venous embolizations to treat the emergent symptoms.

PRESENTING CONCERNS

A 32-year-old Hispanic male with no significant past medical history presented with chief complaint of hemorrhage from his right ear for 1-day duration. He also complained of binocular diplopia, pain, and pressure along his right side of face, disfigurement of his right side of face, and dizziness when turning to the right. He also complained of a “whooshing” sound in his ears and decreased auditory acuity of his right ear. He reported the hemorrhage from his right ear would commence when he sneezed or turned to sleep on his right side. Approximately six years prior, the right side of his face experienced a facial droop, with inability to raise eyebrow on that side, but he had not followed up with any physician for it. Three years ago, he saw physician in El Salvador and was told that there was something abnormal with his neck; however, he did not follow up. The patient worked in construction and avoided seeking medical attention, because he was a sole provider for his family.

CT and CT angiogram (CTA) of the neck and head showed findings suggestive of a large erosive vascular malformation along the right skull base temporal bone involving the middle ear cavity with massively dilated veins within the brain and the neck with hydrocephalus.

CTA showed a complex high flow dural arteriovenous malformation (AVM) involving the right skull base eroding through the temporal and mastoid bones being supplied by dural vessels from all extracranial vessels. Most of the blood supply was derived from the distal right vertebral artery and the right external carotid artery branches. There was chronic thrombosis of the sigmoid sinus jugular bulb region. Significant venous hypertension with retrograde flow through the dural sinuses was noted.

CLINICAL FINDINGS

The patient’s past medical, surgical, and family history were all noncontributory. He was not taking any medications. He reported smoking cigars occasionally but denied illicit drug or alcohol use. Review of systems was negative excepting for his presenting complaints. His neurological exam was notable for a right cranial nerve VII lower motor neuron palsy and nystagmus on saccades with overshooting.

Left vertebral artery injection showing feeders from the Right PICA and Right AICA.

A computerized tomography (CT) scan of the brain without contrast showed a destructive lesion involving the Right side of the skull base, involving the right petrous bone and mastoid segment of the temporal bone. It was causing mass effect on the cerebellum with effacement of the fourth ventricle. This was causing obstructive hydrocephalus. There was also non-obstructive hydrocephalus from severe venous hypertension causing CSF flow impediment. There was also complete opacification of the Right mastoid and of the Right-sided middle ear cavity with ossicular destruction.

AP view of the Right vertebral artery injection.

DIAGNOSTIC FOCUS AND ASSESSMENT

The patient presented with an extremely large complex intraosseous high flow type IV dural AVM involving the right skull base with bony destruction and severe venous hypertension. The venous hypertension has resulted in cortical venous drainage, aneurysmal dilatation of the veins, and compromising the CSF flow dynamics, with resultant hydrocephalus. There was massively dilated veins projection into the right External auditory canal causing hemotympanum.

Right vertebral artery angiogram shows the Right vertebral artery ending into the nidus. There is a patent right vertebrobasilar junction.

The goal was to perform multiple staged arterial and venous embolizations to decrease flow, reduce venous hypertension, and eventually try to achieve cure.

Right Internal Carotid Artery angiogram showing the dural feeders. Right External Carotid Artery.

THERAPEUTIC FOCUS AND ASSESSMENT

First and second stages were direct selective arterial embolizations using Onyx liquid agent. The goal was to reduce flow into the fistula by embolizing the feeder branch and distal penetration of the nidus with Onyx. The two stages were done one week apart.

Lateral view of the Right External Carotid injection.

Selective catheterization and embolization of multiple branches of the Right and Left external carotid arteries were performed using combination of Onyx18 and 34. The microcatheters were advanced into the distal feeder branches just proximal to the fistula. Selective angiography was performed prior to embolization.

AP view of the Right External Carotid injection.

Post embolization there was significant reduction in flow and reduction in venous hypertension.

Arterial Onyx in the Right external carotid branches after stage 1.

At this point, patient’s EAC hemorrhage resolved. There was no worsening of symptoms and no new neurologic symptoms.

AP plain film view showing arterial onyx and venous coils.

The third stage was performed through the venous route two weeks later. Two microcatheters were advanced into the transverse sinus. The transverse sinus, sigmoid sinus, was embolized using Penumbra Ruby coils and Onyx. Since there was extreme high flow in the sinuses, it was difficult to form a coil mass in the sinus with just a single catheter. Therefore, two microcatheters were used and two large coils were placed simultaneously to form a stable coil mass. Then, the entire sinus was embolized using Coils and Onyx.

Lateral view plain film.

At this point, patient’s venous hypertension had significantly decreased. There was now antegrade flow in the Superior Sagittal sinus and the Straight Sinus. The degree of hydrocephalus has markedly decreased.

FOLLOW-UP AND OUTCOMES

Patient tolerated the procedure well. He was able to return to work, but was instructed to avoid heavy lifting and placing anything in and around his right ear.

DISCUSSION

Dural AV fistulas have a potential to occur anywhere there is a dural covering in the brain, with clinical symptoms ranging from focal neurological deficits to seizures and hydrocephalus, most of which can be traced back to resulted venous hypertension [1]. Venous drainage pattern has been identified as the most important risk predictor in attempted treatment [1]. The annual risk of hemorrhage for unruptured DAVFs is reported to be 1.5%–1.8% [2, 3]. Patients who present with hemorrhage experience increased mortality [4]. Similarly, when intracranial venous hypertension is present, it serves as a sign of poor long-term prognosis [5]. Leptomeningeal venous drainage or presence of a varix also signifies a poor prognosis [6], and this type of DAVF is common to present with hemorrhage and focal neurological deficits. Such was the case in this patient. Endovascular therapy is considered to be the first line of treatment, allowing relief of symptoms and possible elimination of the lesion [1].

The patient described in this case presents with an AVM as well, which is similar to an AVF and presents as an abnormal connection between arteries and veins without a capillary bed, but that is present within soft tissue or bone [7, 8]. Intraosseous AVMs often involve the craniofacial bones [9]. This patient’s intraosseous AVM presented similarly to the common description of AVM of bones: with engorged in-flow arteries shunting blood to outflow veins, and giving symptoms of pain, CN VII palsy, disfiguring mass effect, and hemorrhage from the ear [10].

This complex case will require multiple stepwise embolization procedures, aimed at decreasing symptoms, such as pain in the Right side of the head, pulsatile tinnitus in Right ear, decreasing risk of hemorrhage, and improving quality of life. The first staged procedure allowed for the patient to return back to work and relieved the occurrence of frequent bleeding from the Right ear.

Informed Consent: The patient provided informed consent for this case report.