A Systematic Review of Non-Galenic Pial Arteriovenous Fistulas

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.

Imaging of Hemorrhagic Stroke in Children

Hemorrhagic stroke (HS) is an important cause of neurologic morbidity and mortality in children and is more common than ischemic stroke between the ages of 1 and 14 years, a notable contradistinction relative to adult stroke epidemiology. Rapid neuroimaging is of the utmost importance in making the diagnosis of HS, identifying a likely etiology, and directing acute care. Computed tomography and MR imaging with flow-sensitive MR imaging and other noninvasive vascular imaging studies play a primary role in the initial diagnostic evaluation. Catheter-directed digital subtraction angiography is critical for definitive diagnosis and treatment planning.

Management of pediatric pial arteriovenous fistulas with a single connection: two illustrative cases

Pediatric arteriovenous fistulas (PAVFs) are rare, representing only 7.3-17.2% of all pediatric shunts.1 2 In a number of cases they can lead to life-threatening venous hypertension, hydrocephalus and macrocrania,3 heart failure,1 hemorrhagic stroke,4 5 seizures,3 and cognitive developmental issues.1-3 In selected circumstances, early and aggressive treatment is recommended.We present two cases of single-connection, high-flow PAVFs. Case 1 represents a mid-basilar PAVF treated through a transarterial approach, while case 2 represents a quadrigeminal cistern PAVF treated with several transarterial sessions followed by a final transvenous session. The procedures are shown in video 1neurintsurg;jnis-2024-021955v1/V1F1V1Video 1 Clinical cases demonstrating endovascular treatment of pediatric pial arteriovenous fistulas.

Pediatric non-galenic pial arteriovenous fistula's characteristics and outcomes: a systematic review

INTRODUCTION

Pediatric non-galenic pial arteriovenous fistulas (pAVFs) are rare vascular malformations that are characterized by a pial arterial-venous connection without an intervening capillary bed. Outcomes and treatment strategies for pAVFs are highly individualized, owing to the rarity of the disease and lack of large-scale data guiding optimal treatment approaches.

METHODS

We performed a systematic review of pediatric patients (< 18 years at diagnosis) diagnosed with a pAVF by digital subtraction angiogram (DSA). The demographics, treatment modalities, and outcomes were documented for each patient and clinical outcome data was collected. Descriptive information stratified by outcome scores were classified as follows: 1 = excellent (no deficit and full premorbid activity), 2 = good (mild deficit and full premorbid activity), 3 = fair (moderate deficit and impaired activity), 4 = poor (severe deficit and dependent on others), 5 = death.

RESULTS

A total of 87 studies involving 231 patients were identified. Median age at diagnosis was 3 years (neonates to 18 years). There was slight male preponderance (55.4%), and 150 subjects (81.1%*) experienced excellent outcomes after treatment. Of the 189 patients treated using endovascular approaches, 80.3% experienced excellent outcomes and of the 15 patients surgically treated subjects 75% had an excellent outcome. The highest rate of excellent outcomes was achieved in patients treated with Onyx (95.2%) and other forms of EvOH (100%). High output heart failure and comorbid vascular lesions tended to result in worse outcomes, with only 54.2% and 68% of subjects experiencing an excellent outcome, respectively. *Outcomes were reported in only 185 patients.

CONCLUSION

pAVFs are rare lesions, necessitating aggregation of patient data to inform natural history and optimal treatment strategies. This review summarizes the current literature on pAVF in children, where children presenting with heart failure as a result of high flow through the lesion were less likely to experience an excellent outcome. Prospective, large-scale studies would further characterize pediatric pAVFs and enable quantitative analysis of outcomes to inform best treatment practices.

Spontaneous thrombosis of high flow pediatric arteriovenous fistulae: Case series of two patients and a comprehensive literature review

Pediatric pial arteriovenous shunts in the brain and spine are challenging to understand because of low incidence, variable presentation, and associations with genetic syndromes. What is known about their natural history comes from reviews of small series. To better understand the natural history and role for intervention, two cases are presented followed by a review of the literature. In the first case, an infant with a prior history of intracranial hemorrhage from a ruptured pial fistula returns for elective embolization for a second pial fistula which was found to be spontaneously thrombosed 2 weeks later. In the second case, a 5-year-old with a vertebro-vertebral fistula, identified on work up for a heart murmur and documented with diagnostic angiography, is brought for elective embolization 6 weeks later where spontaneous thrombosis is identified. In reviewing the literature on pediatric single-hole fistulae of the brain and spine, the authors offer some morphologic considerations for identifying which high-flow fistulae may undergo spontaneous thrombosis to decrease the potentially unnecessary risk associated with interventions in small children.

The role of surgical disconnection for posterior fossa pial arteriovenous fistulas and dural fistulas with pial supply: an illustrative case series

BACKGROUND

Pial arteriovenous fistulas (pAVFs) are rare vascular malformations characterized by high-flow arteriovenous shunting involving a cortical arterial supply directly connecting to venous drainage without an intermediate nidus. Dural arteriovenous fistulas (dAVFs) can infrequently involve additional pial feeders which can introduce higher flow shunting and increase the associated treatment risk. In the posterior fossa, arteriovenous fistula (AVF) angioarchitecture tends to be particularly complex, involving either multiple arterial feeders-sometimes from both dural and pial origins-or small caliber vessels that are difficult to catheterize and tend to be intimately involved with functionally critical brainstem or upper cervical cord structures. Given their rarity, published experience on microsurgical or endovascular treatment strategies for posterior fossa pAVFs and dAVFs with pial supply remains limited.

METHODS

Retrospective chart review from 2019-2023 at a high-volume center identified six adult patients with posterior fossa pAVFs that were unable to be fully treated endovascularly and required microsurgical disconnection. These cases are individually presented with a technical emphasis and supported by comprehensive angiographic and intraoperative images.

RESULTS

One vermian (Case 1), three cerebellopontine angle (Cases 2-4) and two craniovertebral junction (Cases 5-6) posterior fossa pAVFs or dAVFs with pial supply are presented. Three cases involved mixed dural and pial arterial supply (Cases 1, 4, and 6), and one case involved a concomitant microAVM (Case 2). Endovascular embolization was attempted in four cases (Cases 1-4): The small caliber and tortuosity of the main arterial feeder prevented catheterization in two cases (Cases 1 and 3). Partial embolization was achieved in Cases 2 and 4. In Cases 5 and 6, involvement of the lateral spinal artery or anterior spinal artery created a prohibitive risk for endovascular embolization, and surgical clip ligation was pursued as primary management. In all cases, microsurgical disconnection resulted in complete fistula obliteration without evidence of recurrence on follow-up imaging (mean follow-up 27.1 months). Two patients experienced persistent post-treatment sensory deficits without significant functional limitation.

CONCLUSIONS

This illustrative case series highlights the technical difficulties and anatomical limitations of endovascular management for posterior fossa pAVFs and dAVFs with pial supply and emphasizes the relative safety and utility of microsurgical disconnection in this context. A combined approach involving partial preoperative embolization-when the angioarchitecture is permissive-can potentially decrease surgical morbidity. Larger studies are warranted to better define the role for multimodal intervention and to assess associated long-term AVF obliteration rates in the setting of pial arterial involvement.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.