Intracranial pial fistulas in pediatric population. Clinical features and treatment modalities

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.

Curative transvenous embolization for congenital multi-hole pial arteriovenous fistula

OBJECTIVE

Congenital intracranial pial arteriovenous fistula (PAVF) is a rare cerebral vascular pathology characterized by a direct shunt between one or more pial feeding arteries and a cortical draining vein. Transarterial endovascular embolization (TAE) is widely considered first line therapy. Curative TAE may not be achievable in the multihole variant due to the potential to harbor innumerable small feeding arteries. Transvenous embolization (TVE) may be considered to target the final common outlet of the lesion. Here, we present a series of four patients with complex multi-hole congenital PAVF treated with staged TAE followed by TVE.

METHODS

A retrospective review was conducted on patients who underwent treatment for congenital, multi-hole PAVFs treated by a combined TAE/TVE approach at our institution since 2013.

RESULTS

We identified four patients with multi-hole PAVF treated by a combined TAE/TVE. Median age was 5.2 (0-14.7) years. Median follow-up of 8 (1-15) months by catheter angiography and 38 (23-53) months by MRI/MRA was obtained. TVE achieved complete occlusion in three patients that proved durable on radiographic follow-up and demonstrated excellent clinical outcomes with a modified Rankin Score (mRS) of 0 or 1. Complete occlusion of the draining vein was not achieved by TVE in one case. This patient is graded as pediatric mRS=5 three years post-procedure.

CONCLUSIONS

With thorough technical considerations, our series indicates that TVE of multi-hole PAVF that are refractory to TAE is feasible and effective in arresting the consequences of chronic, high-flow AV shunting produced by this pathology.

Use of greyscale and Doppler ultrasound in initial evaluation and follow-up of neurovascular malformations in children

Pediatric intracranial arteriovenous shunts are rare vascular malformations that can be diagnosed prenatally or postnatally, as an incidental finding or due to complications. We propose a review of cerebral vascular malformations in newborns and infants with special emphasis on neurosonography and Doppler ultrasound as the first diagnostic method. Sonography can thus contribute in the planning of further studies that are always necessary, and in post-therapy follow-up.

Intracranial arteriovenous shunts in infants: A decade of experience from a quaternary pediatric center

BACKGROUND AND PURPOSE

Intracranial arteriovenous shunts (IAVS) are rare vascular diseases in infants. They can be categorized into vein of Galen aneurysmal malformation (VGAM), pial arteriovenous fistula (PAVF), and dural arteriovenous fistula associated with dural sinus malformation (DAVF/DSM). We sought to review the clinical presentation, imaging characteristics, endovascular treatment (EVT), and outcomes of IAVS in infants presenting to a quaternary pediatric referral center over one decade.

METHODS

A retrospective review of a prospectively maintained database was performed of all infants diagnosed with IAVS between January 2011 and January 2021 in a quaternary pediatric referral center. For each patient, demographic data, clinical presentation, imaging findings, management strategies, and outcomes were reviewed and discussed.

RESULTS

Over the study period, 38 consecutive infants were diagnosed with IAVS. Patients with VGAM (23/38, 60.5%) presented with congenital heart failure (CHF) (14/23), hydrocephalus (4/23), and seizures (2/23), and three patients were asymptomatic. Eighteen patients with VGAM underwent EVT. Among those, 13 patients (72.2%) were successfully treated with an angiographic cure and three patients (3/18, 17%) died. Patients with PAVF (9/38, 23.7%) presented with CHF (5/9), intracranial hemorrhage (2/9), and seizures (2/9), and all of them were successfully treated endovascularly. Patients with Type I DAVF/DSM (4/6, 66.6%) presented with mass effect (2/4), cerebral venous hypertension (1/4), CHF (1/4), and cerebrofacial venous metameric syndrome (1/4). Patients with type II DAVF/DSM (2/6, 33.3%) presented with a thrill behind the ear. Patients with DAVF/DSM were treated endovascularly, five patients were cured, and one with type I DAVF/DSM died.

CONCLUSION

Intracranial arteriovenous shunts are rare but potentially life-threatening neurovascular pathologies in infants. Endovascular treatment is challenging but feasible in carefully selected patients.

Pediatric Interventional Neuroradiology

Pediatric neurovascular disorders can lead to substantial mortality and morbidity if not diagnosed early and adequately managed. Children with neurovascular diseases cannot be treated as small adults as the vascular and central nervous system anatomy, physiology, and pathologies in children differ greatly from those of adults. In addition, some neurovascular pathologies are seen exclusively in children such as aneurysmal malformation of the vein of Galen, pial fistulas, and dural fistulas in the context of dural sinus disease. In this review, we aim to present an overview of the common pediatric neurovascular diseases along with their endovascular management.

Adult Infratentorial Pial Arteriovenous Fistula Treated with Detachable Coils: A Case Report and a Review of Literature

An appropriate therapeutic option for pial arteriovenous fistula (PAVF) can vary according to the angioarchtecture of the lesion. We present a case of adult infratentorial PAVF treated by transarterial coil embolization. A 26-year-old man was referred to our institution for an asymptomatic intracranial vascular lesion. Cerebral angiograms revealed PAVF fed by three arteries in the right cerebellomedullary cistern. The feeding arteries were accurately identified by three-dimensional rotational angiography and were successfully embolized using coils while normal arterial flow was preserved. This case report suggests that stepwise transarterial coil embolization can cure PAVF under detailed evaluation of its angioarchitecture.

Role of endovascular embolisation for curative treatment of intracranial non-Galenic pial arteriovenous fistula

Background and purpose

The safety and effectiveness of endovascular treatment for non-Galenic pial arteriovenous fistula (NGPAVF) is inadequately known. The aim of this study is to explore the role of endovascular embolisation for curative treatment of NGPAVF.

Materials and methods

Patients with NGPAVF underwent endovascular treatment from January 2011 to November 2019 in our institution were retrospectively reviewed. Demographics, clinical information, treatment details and clinical outcomes were collected. Factors associated with clinical outcomes were statistically analysed.

Results

Twenty patients were included, with a total of 22 (2 patients have 2 fistulas) lesions. A total of 25 procedures were performed and 5 patients underwent 2 procedures. Follow-up ranged from 3 to 84 months (mean=34.5 months). Thirteen (59.1%) lesions in 12 (60.0%) patients acquired immediate occlusion after initial treatment (immediately occluded group) and follow-up confirmed the complete obliteration. A total of 17 (77.3%) lesions in 15 (75.0%) patients were cured at last follow-up. The maximal diameter of feeding arteries (p=0.04) and the maximal diameter of the varix (p=0.01) in immediately occluded group was smaller than non-immediately occluded group. The number of feeding artery (p=0.004) and the maximal diameter of the varix (p<0.001) were much smaller in curative group than non-curative group. Seven patients suffered procedure-related complications. No patients had an increased Modified Rankin Scale (mRS) and all patients had favourable clinical outcome (mRS ≥2) at last follow-up.

Conclusions

Endovascular therapy plays an important role in curative treatment of NGPAVF. Patients with less feeding arteries and small varix may be easier to be cured by endovascular embolisation.

Hydrocephalus in a patient with an unruptured pial arteriovenous fistula: hydrodynamic considerations, endovascular treatment, and clinical course

Intracranial pial arteriovenous fistulas, also known as nongalenic fistulas, are rare vascular malformations affecting predominantly the pediatric population. Hydrocephalus is an unusual presentation in which the exact pathophysiology is not fully understood. The aim of treatment in these cases is occlusion of the fistula prior to considering ventricular shunting. Here, the authors describe the hydrodynamic considerations of the paravascular pathway and the resolution of hydrocephalus with endovascular treatment of the fistula.

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.