Pediatric intracranial nongalenic pial arteriovenous fistulas: clinical features, angioarchitecture, and outcomes

Evolving indications for pediatric neurointerventional radiology: A single institutional 25-year experience in infants less than one year of age and a brief historical review

Background and PurposePediatric neurointerventional radiology is an evolving subspecialty with growing indications and technological advancement such as miniaturization of devices and decreased radiation dose. The ability to perform these procedures is continuously balanced with necessity given the inherently higher risks of radiation and cerebrovascular injury in infants. The purpose of this study is to review our institution's neurointerventional experience in infants less than one year of age to elucidate trends in this patient population.MethodsWe retrospectively identified 132 patients from a neurointerventional database spanning 25 years (1997-2022) who underwent 226 procedures. Treatment type, indication, and location as well as patient demographics were extracted from the medical record.ResultsNeurointerventional procedures were performed as early as day of life 0 in a patient with an arteriovenous shunting malformation. Average age of intervention in the first year of life is 5.9 months. Thirty-eight of 226 procedures were completed in neonates. Intra-arterial chemotherapy (IAC) for the treatment of retinoblastoma comprised 36% of neurointerventional procedures completed in infants less than one year of age followed by low flow vascular malformations (21.2%), vein of Galen malformations (11.5%), and dural arteriovenous fistulas (AVF) (9.3%). Less frequent indications include non-Galenic pial AVF (4.4%) and tumor embolization (3.0%). The total number of interventions has increased secondary to the onset of retinoblastoma treatment in 2010 at our institution.ConclusionThe introduction of IAC for the treatment of retinoblastoma in the last decade is the primary driver for the increased trend in neurointerventional procedures completed in infants from 1997 to 2022.

Pial arteriovenous fistula with a large intraparenchymal hemorrhage in a 9-year-old child: a case report and case-based mini review

BACKGROUND

Pial arteriovenous fistulas are rare cerebrovascular malformations, predominantly occurring in the pediatric population. The spectrum of symptoms is broad, ranging from incidental findings to intracranial hemorrhage. However, accurate diagnosis and optimal treatment require, among other factors, dynamic imaging modalities and interdisciplinary management.

CASE PRESENTATION

We describe a case of a 9-year-old patient presenting with acute spontaneous headache and apathy. MRI revealed a right temporal intraparenchymal hemorrhage, without signs of an underlying vascular pathology. Cerebral angiography was performed, revealing a suspected pial arteriovenous fistula. The patient was scheduled for surgical hematoma removal and resection of the pial fistula, with intraoperative angiographic control. After hematoma removal and resection of the pial fistula, intraoperative cerebral angiography revealed an additional fistula point that had not been appreciated on the initial preoperative angiography. The craniotomy was extended and the remaining fistula was resected. Final intraoperative angiography confirmed complete resection of the pial fistula.

CONCLUSION

Pediatric pial arteriovenous fistulas are rare, complex, and challenging arteriovenous lesions. Accurate diagnosis and an interdisciplinary management are essential. However, consensus on the diagnostic workflow and treatment approach remains lacking. Therefore, we report our case and propose a diagnostic and therapeutic workup for ruptured vascular intracranial anomalies in children.

High flow pial arteriovenous fistula with dural sinus malformation of the posterior circulation

Posterior fossa congenital pial arteriovenous fistulas are rare vascular anomalies associated with high morbidity. These anomalies often present challenges to neurointerventionists due to their complex morphological features. We successfully treated two technically challenging, infratentorial large pial arteriovenous fistulas (AVFs) associated with complete flow steal in the basilar artery. The first case involved an 18-year-old male with a posterior fossa single-hole AVF characterized by dilated venous pouches and retrograde venous reflux. After an unsuccessful initial coiling attempt, this patient was treated using a double microcatheter coiling technique, supported by a large balloon for flow control. The second case involved a 9-month-old infant with a complex two-hole posterior fossa pial AVF and a large venous sac. This patient was treated with coil embolization of the fistula and with balloon protection of the vertebrobasilar junction. Both patients recovered without postoperative complications and showed significant improvement on follow-up. These cases provide valuable insights into the management and characteristics of pial arteriovenous fistulas.

Neurovascular Malformations in the Fetus and Neonate

Vein of Galen malformations are the most common congenital neurovascular malformation and are a type of choroidal arteriovenous fistula involving the midline primitive choroidal venous circulation. The arteriovenous shunt zone of a VOGM may directly involve the embryonic precursor of the vein of Galen and/or its tributaries within the 3rd ventricle tela choroidea. Dural sinus malformations are characterized by dilated intracranial dural venous sinuses, some of which acquire multifocal arteriovenous shunts within the dural walls of these overgrown venous sinuses.Pial arteriovenous fistulae are high-flow shunts representing direct arterial to venous communication of pial blood vessels, with no definable nidus.

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.

Endovascular management of pediatric pial arteriovenous fistulas with hereditary GDF2 mutation: illustrative case

BACKGROUND

Intracranial pial arteriovenous fistulas (PAVFs) are uncommon neurovascular anomalies that primarily affect the pediatric population. PAVFs are often linked to hereditary hemorrhagic telangiectasia, yet the specific genetic mutations remain unidentified. While endovascular embolization is the preferred treatment for PAVFs, complications like hydrocephalus and sinus thrombosis pose challenges in management.

OBSERVATIONS

The authors present a rare case of PAVF in a 6-month-old male neonate with a hereditary GDF2 mutation, where the fistula was supplied by the posterior inferior cerebellar artery and drained directly into the sigmoid sinus. The PAVF was effectively treated with endovascular embolization using coils and Onyx. Furthermore, the authors describe the successful use of rivaroxaban in managing subsequent sinus thrombosis after the embolization of PAVFs. Additionally, the authors review treatment strategies and complications following fistula disconnection.

LESSONS

Endovascular embolization is the primary treatment choice for the majority of pediatric PAVFs, while a hereditary GDF2 mutation is considered a potential contributing factor to the formation of these malformations in children. Rivaroxaban has shown promise as an effective therapeutic option for pediatric sinus thrombosis, supported by its established safety profile. https://thejns.org/doi/10.3171/CASE24182.

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.

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.

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.

Diagnostic Pitfalls of Macrocephaly and Intracranial Dural Arteriovenous Fistulas: Connecting the Dots With the Red Flags

Macrocephaly is defined as an abnormal increase in head circumference greater than two standard deviations above the mean for a given age and sex. We present the case of a 16-month-old boy with congenital progressive macrocephaly, who was referred to our hospital for a ventriculoperitoneal shunt placement for external hydrocephalus diagnosed at 13 months of age. The patient had a febrile seizure 12 hours after the shunt was placed and the emergency CT exam revealed collapsed ventricles and a right frontal subdural collection, suggestive of an over-drainage and intracranial hypotension. A subsequent electroencephalogram (EEG) revealed some anomalies, but the patient was discharged two days later due to having no neurological symptoms after being placed on anticonvulsants. The patient returned to the hospital one week later due to recurrent seizures. Further clinical examination revealed prominent and tortuous veins of the skull, palpated in the left occipital region. A thrill and a left carotid murmur were heard during auscultation. A subsequent brain MRI with MR arteriography and venography was performed in search of an explanation for hydrocephaly. The sequences were suggestive of a dural arteriovenous fistula, which was confirmed and then treated using coils during an interventional angiography. A second procedure was performed two months later to complete the embolization, with subsequent imaging follow-ups showing the procedure to have been successful. The measurement of the cranial circumference, its regular evaluation, and its evolution allow a hierarchical diagnosis strategy by distinguishing primary and secondary macrocephaly, progressive or not. Dural arteriovenous fistulas (DAVF) are an under-appreciated cause of macrocephaly, with which they are associated in 35% of cases. Intracranial DAVFs are pathologic shunts between dural arteries and dural venous sinuses, meningeal veins, or cortical veins. Patients with DAVFs may be completely asymptomatic. Symptoms, when present, may range from neurological deficits, seizures, and hydrocephaly to fatal hemorrhage. The symptoms depend on the location and venous and drainage patterns of the DAVF. They can be difficult to identify on routine MRIs unless specifically searched for, especially in cases of technically suboptimal examinations. We aim to give a practical approach to identify the clinical clues that warrant further investigation. Several specific protocols exist regarding the management of macrocephaly and should be followed carefully once a diagnosis has been reached, but further studies are needed to integrate more clinical and neuroimaging findings to permit an early diagnosis.

Pial arteriovenous fistula resembling the vein of Galen aneurysmal malformation, treated with staged endovascular embolization: a case report

A 41-month-old boy was presented to our hospital because of an intracranial mass suspected of cerebrovascular malformation. He was admitted and received cerebral angiography. The angiography result confirmed the intracranial mass was the dilated vein of Galen resulting from a pial arteriovenous fistula, which quite resembling the vein of Galen aneurysmal malformation. Considering one-time embolization of the fistula may greatly change the distribution of intracranial blood flow, we decided to perform staged embolization. In the first stage, we partially embolized the fistula, resulting in a sharp decrease in blood flow to the lesion. The second intervention was performed one month later, and completely embolized the fistula. The boy recoverd well and returned to normal childhood without any neurological deficits. Follow-up MR images obtained at 10 months after the last procedure showing total obliteration of the pAVF, gradually shrinking of the varix, and remodeling of the vein of Galen.

Neonatal high-flow anterior circulation dural arteriovenous fistulae successfully treated with subtotal endovascular embolization; A case report

High-flow grade-III dural arteriovenous fistulae(dAVF) represent rare abnormal vascular connections with a high risk of rupture. Management involves obliteration of both the fistulous connection as well as the draining venous network with preservation of normal vasculature. We describe and multiple neonatal dAVFs inducing cardiomyopathy via high-flow grade III shunting in the anterior circulation successfully treated via transvenous and transarterial embolization.

A Systematic Review of Non-Galenic Pial Arteriovenous Fistulas

OBJECTIVE

Non-galenic pial arteriovenous fistulas (NGPAVFs) are rare cerebrovascular pathologies accounting for only 1.6%-4.8% of all brain vascular malformations. We performed a comprehensive review of NGPAVF cases reported in the literature to further characterize their clinical patterns of presentation, angiographic features, management, clinical outcomes, and complications.

METHODS

We searched PubMed, Google Scholar, and Embase from each database's earliest records to April 2022 for all relevant English language articles. A total of 3280 articles were screened to identify those that met prespecified inclusion criteria. Differences in clinical outcomes between children (≤18 years old) and adults (>18 years old) and those articles in which NGPAVFs were associated with the presence of a varix or a hemorrhage were statistically examined.

RESULTS

A total of 242 patients in 86 articles were included. The mean patient age was 18.51 ± 18.80 years. The male-to-female ratio was 1.44:1. Headache was the most common initial presentation (42.6%) in the study cohort. Hemorrhage occurred at a significantly higher frequency in adults (P = 0.004), whereas more children presented with congestive heart failure (P < 0.001). Surgical, endovascular, and combination therapy led to comparable rates of complete NGPAVF obliteration (86.8%, 85.2%, and 88.5%, respectively). Fifty-nine patients (24.4%) experienced a complication, ranging from minor neurological deficit to severe hemorrhage. The mortality rate for the overall cohort was 3.3%, and all deceased patients had a varix associated with their fistulas.

CONCLUSIONS

To our knowledge, we report the largest literature review describing the clinical course and characteristics of NGPAVFs. All treatment approaches resulted in favorable obliteration rates and overall patient outcomes.

Huge cerebral pial arteriovenous fistula in a newborn: illustrative case

BACKGROUND

Pediatric arteriovenous malformations (AVMs) and pial/dural arteriovenous fistulas (AVFs) are rare but life-threatening complications that can lead to congestive heart failure and hemorrhagic stroke in newborns and pediatric patients. The pronounced shunting in these conditions is associated with early complications and necessitates aggressive surgical management. Here, the authors describe endovascular treatment of an atypical cerebral pial AVF in a newborn.

OBSERVATIONS

This AVF formed direct communication between a major cerebral artery (basilar artery) and a large draining vein (dilated deep cerebral vein). The authors performed earlier subtotal embolization of the AVF using 0.020-inch coils, which led to progressive thrombosis of the fistula with restoration of normal arterial blood flow. The patient was discharged 18 days after surgery, examination at 1.5 and 6 months showed magnetic resonance imaging signs of blood flow absence through the fistula and satisfactory condition of the infant without physical and mental developmental delay.

LESSONS

Subtotal coiling of a high-flow pial AVF in a newborn can result in a good clinical outcome.

Combined transarterial and transvenous embolization of multi-hole pial arteriovenous fistula with large varix

BACKGROUND

Pial arteriovenous fistula (AVF) is a vascular fistulous disease in which the cerebral pial artery and vein are directly connected without the intervening nidus within a sub-pial space. Multi-hole pial AVFs, wherein multiple feeders flow into one drainer, are usually formed with complex angioarchitecture and are difficult to treat.

METHODS

A rare case of an adult patient with hereditary hemorrhagic telangiectasia and multi-hole pial AVF was described. A 23-year-old woman was referred to our hospital. She was previously diagnosed with left cerebellar pial AVF with multiple feeders (bilateral superior cerebellar artery and common trunk of the left anterior inferior cerebellar artery and posterior inferior cerebellar) and large varix that had been untreated for 9 years. The enlargement of the large varix with the new second varix formation was revealed by angiography. Although asymptomatic, considered to be a risk for future hemorrhage was the continuous high hemodynamic stress.

RESULTS

Endovascular embolization was performed by securing safe transarterial n-butyl-2-cyanoacrylate injection by transarterial and transvenous coil placement to the shunt points and feeders, resulting in total occlusion of the fistula without any complications. Extensive transvenous coil placement inside the varix allowed safe embolization of the entire fistula with multiple high-flow feeders. Moreover, bidirectional (transarterial and transvenous) retrograde coil embolization enabled firm obliteration of the shunt points.

CONCLUSIONS

Performing combined transarterial and transvenous embolization in a well-balanced manner was considered to treat multi-hole pial AVF to provide a safe and effective embolization.

Endovascular treatment in the multimodality management of brain arteriovenous malformations: report of the Society of NeuroInterventional Surgery Standards and Guidelines Committee

BACKGROUND

The purpose of this review is to summarize the data available for the role of angiography and embolization in the comprehensive multidisciplinary management of brain arteriovenous malformations (AVMs METHODS: We performed a structured literature review for studies examining the indications, efficacy, and outcomes for patients undergoing endovascular therapy in the context of brain AVM management. We graded the quality of the evidence. Recommendations were arrived at through a consensus conference of the authors, then with additional input from the full Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee and the SNIS Board of Directors.

RESULTS

The multidisciplinary evaluation and treatment of brain AVMs continues to evolve. Recommendations include: (1) Digital subtraction catheter cerebral angiography (DSA)-including 2D, 3D, and reformatted cross-sectional views when appropriate-is recommended in the pre-treatment assessment of cerebral AVMs. (I, B-NR) . (2) It is recommended that endovascular embolization of cerebral arteriovenous malformations be performed in the context of a complete multidisciplinary treatment plan aiming for obliteration of the AVM and cure. (I, B-NR) . (3) Embolization of brain AVMs before surgical resection can be useful to reduce intraoperative blood loss, morbidity, and surgical complexity. (IIa, B-NR) . (4) The role of primary curative embolization of cerebral arteriovenous malformations is uncertain, particularly as compared with microsurgery and radiosurgery with or without adjunctive embolization. Further research is needed, particularly with regard to risk for AVM recurrence. (III equivocal, C-LD) . (5) Targeted embolization of high-risk features of ruptured brain AVMs may be considered to reduce the risk for recurrent hemorrhage. (IIb, C-LD) . (6) Palliative embolization may be useful to treat symptomatic AVMs in which curative therapy is otherwise not possible. (IIb, B-NR) . (7) The role of AVM embolization as an adjunct to radiosurgery is not well-established. Further research is needed. (III equivocal, C-LD) . (8) Imaging follow-up after apparent cure of brain AVMs is recommended to assess for recurrence. Although non-invasive imaging may be used for longitudinal follow-up, DSA remains the gold standard for residual or recurrent AVM detection in patients with concerning imaging and/or clinical findings. (I, C-LD) . (9) Improved national and international reporting of patients of all ages with brain AVMs, their treatments, side effects from treatment, and their long-term outcomes would enhance the ability to perform clinical trials and improve the rigor of research into this rare condition. (I, C-EO) .

CONCLUSIONS

Although the quality of evidence is lower than for more common conditions subjected to multiple randomized controlled trials, endovascular therapy has an important role in the management of brain AVMs. Prospective studies are needed to strengthen the data supporting these recommendations.

OUP accepted manuscript

Paediatric intracranial dural arteriovenous shunts have clinical presentations and evolutions, with angiographic characteristics that differ from those described in adults. We report our experience concerning their therapeutic management, emphasizing the relevance of early diagnosis and appropriate treatment for satisfactory neurocognitive development. Using a prospective database, we reviewed the clinical and radiological data of all children with dural arteriovenous shunts managed between 2002 and 2020. Dural shunts were categorized into three types: dural sinus malformations with arteriovenous shunts; infantile dural arteriovenous shunts; and adult-type dural arteriovenous shunts. Therapeutic strategies and outcomes were analysed depending on lesional subtypes. Modified Rankin Scale for the paediatric population was assessed pre-treatment and at last follow-up. Twenty-eight patients [16 girls (57.1%); 12 boys (42.9%)] were included: 17 dural sinus malformation [10 boys (58.8%); seven girls (41.2%)], three infantile shunts [three girls (100%)], eight adult-type shunts [four girls (50%)]; four boys (50%)], with a mean age of 19.2 ± 36.6 months at presentation. Twelve (42.9%) had a modified Rankin Scale score of 0–2, four (14.3%) had a score of 3, three (10.7%) had a score of 4 and eight (28.6%) had a score of 5. Embolization was performed in 22 children [78.6%; 12 girls (54.5%); 10 boys (45.5%)]. Fifteen patients could be cured (68.2%): 11 dural sinus malformations (73.3%), four adult-type lesions (100%) but no infantile shunt. Mean post-treatment follow-up was 39.5 months (max. 139 months): 14 patients (63.6%) presented a modified Rankin Scale score of 0–2 and eight (36.4%) had a score ≥3. In the dural sinus malformation group, the modified Rankin Scale score was improved in 11 patients (73.3%) and unchanged in three (20%). Only one patient with infantile subtype (33.3%) improved clinically. In the adult-subtype group, all children (100%) improved. Of six untreated patients [four girls (66.7%); two boys (33.3%)], four with adult-subtype shunts showed uneventful evolutions, one with dural sinus malformation died, and therapeutic abortion was conducted in an antenatally diagnosed dural sinus malformation. Paediatric dural fistulas comprise different subtypes with variable clinical courses. Proper diagnosis is mandatory for optimal therapeutic strategies within appropriate therapeutic windows.

Transarterial Embolization of Intracranial Arteriovenous Fistulas with Large Venous Pouches in the Form of Venous Outlet Ectasia and Large Venous Varix or Aneurysm : Two Centers Experience

Objective

There are different types of cerebral vascular malformations. Pial arteriovenous fistulas (PAVFs) and dural arteriovenous fistulas (DAVFs) are two entities; they consist of one or more arterial connections to a single venous outlet without a true intervening nidus. The high turbulent flow of PAVFs and aggressive DAVFs with cortical venous reflux can result in venous outflow varix and aneurysmal dilatation. They pose a significant challenge to transvenous embolization (TVE), stereotactic radiosurgery, and surgical treatment. We aim to share our centers' experience with the transarterial embolization (TAE) for arteriovenous fistulas (AVFs) with large venous pouches and to report the outcome.

Methods

The authors' two institutions' databases were retrospectively reviewed from February 2017 to February 2021. All patients with intracranial high flow PAVFs and aggressive DAVFs with venous outlet ectasia and large venous varix and were treated by TAE were included.

Results

Fifteen patients harboring 11 DAVFs and four PAVFs met our inclusion criteria. All patients underwent TAE in 17 sessions. Complete angiographic obliteration was achieved after 14 sessions in 12 patients (80%). Four patients (25%) had residual after one TAE session. Technical failure was documented in one patient (6.7%). Fourteen patients (93.3%) had favorable functional outcome (modified Rankin score 0-2).

Conclusions

TAE for high flow or aggressive intracranial AVFs is a safe and considerable treatment option, especially for those associated with large venous pouches that are challenging and relatively high-risk for TVE.

Coexistence of RASA1 and COL4A2 variants caused pial arteriovenous fistula (AVF) in a patient with capillary malformation-arteriovenous malformation

Pial arteriovenous fistulas (AVFs) are rare vascular lesions; their exact pathophysiology is largely unknown. Pial AVFs have been reported to develop within capillary malformation-arteriovenous malformation (CM-AVM); however, only a few cases have been reported. Variants in the RASA1 gene have been reported as a cause of CM-AVM. We report the case of an adult patient with pial AVF, who carried variants in the RASA1 and COL4A2 genes. The patient in the current report was likely to have been affected by CM-AVM and the RASA1 variant seemed to be the primary factor in the pathogenesis of pial AVF. However, COL4A2 may have also contributed to the development of pial AVF because the COL4A2 and RASA1 variants have a common pathophysiology, wherein the patient develops lesions due to collagen type IV deficiency.

Asymptomatic rotational vertebral artery compression in a child due to head positioning for cranial surgery: illustrative case

BACKGROUND

The authors recently reported a series of children with vertebral artery (VA) compression during head turning who presented with recurrent posterior circulation stroke. Whether VA compression occurs during head positioning for cranial surgery is unknown.

OBSERVATIONS

The authors report a case of a child with incidental rotational occlusion of the VA observed during surgical head positioning for treatment of an intracranial arteriovenous fistula. Intraoperative angiography showed dynamic V₃ occlusion at the level of C2 with distal reconstitution via a muscular branch “jump” collateral, supplying reduced flow to the V₄ segment. She had no clinical history or imaging suggesting acute or prior stroke. Sequential postoperative magnetic resonance imaging scans demonstrated signal abnormality of the left rectus capitus muscle, suggesting ischemic edema.

LESSONS

This report demonstrates that rotational VA compression during neurosurgical head positioning can occur in children but may be asymptomatic due to the presence of muscular VA–VA “jump” collaterals and contralateral VA flow. Although unilateral VA compression may be tolerated by children with codominant VAs, diligence when rotating the head away from a dominant VA is prudent during patient positioning to avoid posterior circulation ischemia or thromboembolism.

Occult Brain Arteriovenous Malformation Superimposed on a Pial Arteriovenous Fistula: Case Report

INTRODUCTION

Pial arteriovenous fistulas are characterized by an abnormal connection between an intracranial artery and vein without an intervening nidus. Their predominant symptoms largely arise from mass effect, shunting, or hemorrhage. Most conservatively managed cases progress to death, but endovascular and/or surgical intervention is often successful.

CASE PRESENTATION

We present the unique case of a 15-year-old girl with spontaneous intracranial hemorrhage from a single-vessel arteriovenous fistula. Although preoperative imaging failed to show a distinct nidus, intraoperative indocyanine green angiography performed after successful clipping of the primary fistulous site revealed residual shunting from a peri-lesional arteriovenous malformation.

DISCUSSION/CONCLUSION

This case demonstrates the importance of intraoperative imaging and meticulous circumferential inspection of these lesions to detect residual vascular shunting.

Cerebral arteriovenous fistulae

Dural arteriovenous fistulae (dAVFs) are diverse, complex lesions that share the common feature of arteriovenous shunting without an intervening nidus. In this chapter, the ensuing discussion is organized by dAVF location, followed by further consideration of less common, distinct types of dAVFs-carotid cavernous fistulae, pial arteriovenous fistulae, and vein of Galen malformations. For each lesion type, epidemiology, clinical presentation, imaging findings, classification considerations, and treatment options are discussed.

Second International Guidelines for the Diagnosis and Management of Hereditary Hemorrhagic Telangiectasia

DESCRIPTION

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease with an estimated prevalence of 1 in 5000 that is characterized by the presence of vascular malformations (VMs). These result in chronic bleeding, acute hemorrhage, and complications from shunting through VMs. The goal of the Second International HHT Guidelines process was to develop evidence-based consensus guidelines for the management and prevention of HHT-related symptoms and complications.

METHODS

The guidelines were developed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) framework and GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology. The guidelines expert panel included expert physicians (clinical and genetic) in HHT from 15 countries, guidelines methodologists, health care workers, health care administrators, patient advocacy representatives, and persons with HHT. During the preconference process, the expert panel generated clinically relevant questions in 6 priority topic areas. A systematic literature search was done in June 2019, and articles meeting a priori criteria were included to generate evidence tables, which were used as the basis for recommendation development. The expert panel subsequently convened during a guidelines conference to conduct a structured consensus process, during which recommendations reaching at least 80% consensus were discussed and approved.

RECOMMENDATIONS

The expert panel generated and approved 6 new recommendations for each of the following 6 priority topic areas: epistaxis, gastrointestinal bleeding, anemia and iron deficiency, liver VMs, pediatric care, and pregnancy and delivery (36 total). The recommendations highlight new evidence in existing topics from the first International HHT Guidelines and provide guidance in 3 new areas: anemia, pediatrics, and pregnancy and delivery. These recommendations should facilitate implementation of key components of HHT care into clinical practice.

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.

Pial arteriovenous fistula: A clinical and neuro-interventional experience of outcomes in a rare entity

Purpose:

Pial arteriovenous fistulae (PAVF) are rare intracranial vascular malformations, predominantly seen in children and distinct from arteriovenous malformations and dural arteriovenous fistulae. PAVF often leads to high morbidity and mortality. The aim of our study was to describe the clinical features and endovascular management of PAVF at various intracranial locations; to analyze the use of liquid embolic agents and coils alone or in combination in the treatment of PAVF and to analyze the outcome of embolization.

Materials and Methods:

Retrospective review of diagnostic angiography and neurointerventional database of our institution identified a cohort of 15 patients with non-galenic PAVF from 2008 to 2014 out of 6750 patients. Fourteen patients were treated endovascularly with coils and liquid embolic materials in combination or alone. Patients were followed up for evaluation of prognosis.

Results:

Age of the patients ranged from 3 to 37 years. Most patients were male and most common presentation was headache followed by seizure. Most common location of fistula was frontal lobe. The most common type was single artery single hole fistula with venous varix. Satisfactory obliteration was seen in all cases. One patient developed intraparenchymal hematoma on the first post procedural day and outcome was poor.

Conclusions:

PAVF are rare intracranial vascular malformations which can effectively be managed endovascularly with liquid embolic, coils alone, or in combination. Complete occlusion of the fistula can be achieved in most cases in a single sitting with a reasonable morbidity related to the procedure, compared with the natural history of this disease.

Neurovascular disease and syndromes: Diagnosis and therapy in children

The pediatric neurovascular disease runs the chronologic spectrum with dramatic changes in the presentation, evaluation, and treatment from the prenatal, perinatal, and infant periods through childhood and adolescence. These diseases are often dynamic throughout this period and the dynamic continues throughout life. There are four major categories: high-flow arteriovenous shunting lesions, arterial aneurysms, low-flow vascular lesions, and vascular occlusive disease. The high-flow lesions can be subdivided into a vein of Galen malformation, non-Galenic arteriovenous fistula, dural sinus malformations and fistula, and arteriovenous malformation. Low-flow vascular lesions include cerebral cavernous malformation, developmental venous anomaly, and capillary telangiectasia. The cerebrovascular occlusive disease can be divided between arterial occlusive disease and cerebral venous sinus thrombosis. The presentation of each of these entities can be very similar, especially in younger children; however, imaging and laboratory analysis can establish the diagnosis leading to the most appropriate therapy. A multidisciplinary team, dedicated to treating pediatric cerebrovascular disease, is important in delivering the best outcomes in these complex diseases. Given the relative rarity of pediatric presentation of cerebrovascular disease, many apply adult concepts to children. A better understanding of the diseases and their difference from adults makes a critical difference in selecting the correct approach.

Endovascular treatment of intracranial vascular malformations in children

Paediatric intracranial vascular malformations are rare and different from adult ones in vascular anatomy, pathophysiology, and symptoms. Their impact on the brain and their symptoms will differ in the antenatal period, in neonates, infants, and children. Clinical presentation includes seizures, focal neurological deficit, haemorrhage, congestive heart failure, hydrovenous disorder, and developmental delays. These malformations are thus associated with a poor prognosis if left untreated. Therefore, aggressive management is generally recommended and must be performed by a multidisciplinary team with extensive experience. Endovascular treatment is the first-choice treatment for most paediatric intracranial vascular malformations. Indication and timing for treatment should be decided on the basis of a careful assessment of neurological symptoms, growth and development, cardiac and other systemic manifestations, and imaging of the malformation and the brain tissue. WHAT THIS PAPER ADDS: Paediatric intracranial vascular malformations are rare, but their prognosis is poor if left untreated. Improved clinical, anatomical, and pathophysiological understanding of these complex lesions has improved prognosis.

Hemorrhagic Cerebrovascular Pathology in the Pediatric Population

Hemorrhagic cerebrovascular disease in the pediatric population can have devastating and long-term effects. Progress in the fields of genetics, neuroimaging, pharmacology, and surgical techniques has led to improved diagnosis and management of pediatric cerebrovascular diseases. In this review we discuss the current etiologies and medical and surgical treatments of hemorrhagic cerebrovascular pathology affecting infants and children. A special emphasis is placed on neuroendovascular treatment options. Increased knowledge about this unique pathology and the medical and therapeutic options will empower practitioners to more quickly and accurately identify and accurately treat hemorrhagic diseases in the pediatric population.

Bilateral pediatric pial arteriovenous fistulas accompanying a giant arachnoid cyst with torticollis: A case report

RATIONALE

Pial arteriovenous fistula (PAVF) occurs when intracranial arteries communicate directly with veins. PAVFs are very rare congenital vascular lesions that are commonly seen in infants and children. Arachnoid cysts are congenital cavitation often filled with cerebrospinal fluid. We present a very rare associated occurrence of bilateral pediatric PAVF and a giant arachnoid cyst presenting as torticollis in a child. So far, this is the first case.

PATIENT CONCERNS

A 6-year-old male child was referred to our facility from a local hospital due to severe torticollis.

DIAGNOSES

An enhanced computed tomography scan revealed 2 slightly high-density masses at the anterior pontine cistern, right circumferential cistern, as well as left posterior occipital region. The same computed tomography scan revealed a giant arachnoid cyst in the left occipital as well as the temporal region with a thin cerebral cortex adjacent to the cyst.

INTERVENTIONS

Digital subtraction angiography confirmed that the 2 high-flow lesions were PAVFs. The patient was treated with a combination of detachable coils and Onyx Liquid Embolic System (Onyx HD-500) (Covidien/ev3 Neurovascular) via the transarterial endovascular route while the giant arachnoid cyst was managed conservatively.

OUTCOMES

The torticollis resolved 2 days after the procedure. He is currently well with no neurologic deficit.

LESSONS

We advocate that in cases of PAVF with accompanying cyst, the cyst should be managed conservatively if it is not associated with intracranial hemorrhage or focal neurologic deficit.

Surgical Disconnection of a Residual Pediatric Pial Arterio-Venous Fistula Following Partial Embolization: A Case Study

BACKGROUND

Pial arteriovenous fistulas (AVFs) are rare intracranial vascular lesions consisting of 1 or more feeder arteries connecting directly to a venous system without a nidus, in the subpial space. Because of the high-flow system, they are commonly associated with a large varix. They are thought to represent between 1.6% and 7.3% of all pediatric arteriovenous malformations (AVMs). Morbidity and mortality is high in this condition and surgical or endovascular treatment options are usually considered. There have been limited reports on the clinical features, treatment options, and outcomes of pial AVMs due to its rarity. We present a case study of a pediatric patient in our institution and her clinical course, focusing on her presenting clinical features and management.

CASE DESCRIPTION

A 1-year-old girl presents with progressively prominent and dilated facial veins and no other features suggestive of pial AVF. She was diagnosed with pial AVF with two feeder arteries and a large varix on imaging. Embolization was undertaken 3 times before successful surgical disconnection was done. Genetic testing for associated syndromes were all negative.

CONCLUSIONS

Prominence of facial veins could be 1 of the more uncommon presenting features of pial AVFs. Genetic testing should always be considered in the pediatric population diagnosed with AVFs because of their association to various syndromes. Despite endovascular embolization being considered the less invasive choice, decision on mode of treatment should be a multifactorial decision.

A Pial Arteriovenous Fistula in Infancy as the Presenting Manifestation of Hereditary Hemorrhagic Telangiectasia

BACKGROUND

Pial arteriovenous fistulas (PAVFs) are rare, accounting for 1.6%-4.7% of all intracranial vascular malformations. Often diagnosed in childhood, about 30% are associated with hereditary hemorrhagic telangiectasia. A case of PAVF diagnosed soon after birth and given cerebrovascular therapy 4 months after birth is reported.

CASE DESCRIPTION

The patient presented with heart failure immediately after birth. Ultrasonography of the head showed abnormal blood flow in the brain. On digital subtraction angiography performed 4 months after birth, a PAVF with a dural feeder shunt and a giant varix at the posterior temporal part was confirmed. After transarterial embolization (TAE), shunt blood flow disappeared. New shunt flow from the right posterior cerebral artery into the varix was confirmed by magnetic resonance imaging 3 months after the operation. A second TAE procedure using a liquid embolic material was performed and confirmed the complete disappearance of the shunt.

CONCLUSIONS

This report describes a case of infant PAVF with heart failure, a giant varix, hydrocephalus, and intraventricular hemorrhage treated by TAE using platinum coils and liquid embolic material.

Nationwide survey of pediatric intracranial arteriovenous shunts in Japan: Japanese Pediatric Arteriovenous Shunts Study (JPAS)

The authors performed a nationwide study in Japan to evaluate the annual detected rate of pediatric intracranial arteriovenous (AV) shunts such as brain AV malformations (BAVMs), pial AV fistulas (PAVFs), vein of Galen aneurysmal malformations (VGAMs), and dural AV fistulas (DAVFs). These rates were revealed for the first time and showed that VGAM, DAVF, and PAVF were relatively common but that BAVMs were extremely rare in neonates and infants.

Pial arteriovenous fistula of the spine in a child with hemiplegia

Pial arteriovenous fistula (AVF) is an extremely rare disease in children. When a child presents with sudden onset of hemiparesis and headache, it is very important to perform spinal magnetic resonance imaging (MRI) scanning for early diagnosis and treatment.

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.

Transarterial Balloon-Assisted Glue Embolization of Pial Arteriovenous Fistulas

OBJECTIVE

Endovascular disconnection of pial arteriovenous fistulas (AVFs) is challenging. The aim of this study was to evaluate safety and effectiveness of transarterial balloon-assisted glue embolization for treating pial AVFs.

METHODS

We retrospectively reviewed medical and imaging records of 8 patients with high-flow pial AVFs treated by transarterial balloon-assisted glue embolization from August 2011 to July 2017.

RESULTS

There were 6 male patients and 2 female patients with age range of 1-48 years. Presentation was seizure in 4 patients, headache in 3 patients, and subarachnoid hemorrhage in 1 patient. Seven lesions were located in the supratentorial region. All lesions were single-channel fistulas associated with venous varix. Five lesions had a single feeder, and 3 had multiple feeders. All lesions were obliterated completely in single-session embolization with no procedure-related complications. Two patients experienced symptomatic thrombosis of drainage venous system after embolization. One patient fully recovered on discharge, and another patient fully recovered after 8 months. With a mean clinical follow-up of 12.1 months, all patients were free of pretreatment symptoms. Follow-up angiograms revealed durable occlusion of fistulas.

CONCLUSIONS

Transarterial balloon-assisted glue embolization is a feasible and effective option for treatment of high-flow pial AVFs.

Pial fistula in infancy: Report of two cases and literature review with special emphasis on the ruptured group

Cerebral pial fistula is a rare vascular pathology with no more than 150 cases reported. Most cases reported in infancy have been published as case reports. Owing to its high flow, its occurrence in this age group carries the potential risk of heart failure, chronic venous hypertension, seizures and, less frequently, cerebral haemorrhage. We present two cases of pial fistulae in infancy treated by endovascular embolisation using N-butyl cyanoacrylate. A review of the English-language literature was performed for this age group with special emphasis on ruptured cases.

Nongalenic pial arteriovenous fistula: Prenatal diagnosis

Pial arteriovenous (AV) fistulae have rarely been diagnosed in utero. They are characterized by one or more pial arteries flowing directly into a cortical vein without any shunt or interposed capillary bed. In the fetus and the newborn up to 2 years of age, the most common clinical manifestation is heart failure resulting from fistula overload. Later on, hydrocephalus, focal neurologic deficits, headaches, seizures, and cerebral hemorrhage are the most common manifestations. We present a case of nongalenic pial AV fistula diagnosed in the 25th week of pregnancy, which resulted in intrauterine fetal death due to congestive heart failure. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:621-625, 2017.

Pial Artery Supply as an Anatomic Risk Factor for Ischemic Stroke in the Treatment of Intracranial Dural Arteriovenous Fistulas

BACKGROUND AND PURPOSE

Although intracranial dural arteriovenous fistulas are principally supplied by dural branches of the external carotid, internal carotid, and vertebral arteries, they can also be fed by pial arteries that supply the brain. We sought to determine the frequency of neurologic deficits following treatment of intracranial dural arteriovenous fistulas with and without pial artery supply.

MATERIALS AND METHODS

One hundred twenty-two consecutive patients who underwent treatment for intracranial dural arteriovenous fistulas at our hospital from 2008 to 2015 were retrospectively reviewed. Patient data were examined for posttreatment neurologic deficits; patients with such deficits were evaluated for imaging evidence of cerebral infarction. Data were analyzed with multivariable logistic regression.

RESULTS

Of 122 treated patients, 29 (23.8%) had dural arteriovenous fistulas with pial artery supply and 93 (76.2%) had dural arteriovenous fistulas without pial arterial supply. Of patients with pial artery supply, 4 (13.8%) had posttreatment neurologic deficits, compared with 2 patients (2.2%) without pial artery supply (P = .04). Imaging confirmed that 3 patients with pial artery supply (10.3%) had cerebral infarcts, compared with only 1 patient without pial artery supply (1.1%, P = .03). Increasing patient age was also positively associated with pial supply and treatment-related complications.

CONCLUSIONS

Patients with dural arteriovenous fistulas supplied by the pial arteries were more likely to experience posttreatment complications, including ischemic strokes, than patients with no pial artery supply. The approach to dural arteriovenous fistula treatment should be made on a case-by-case basis so that the risk of complications can be minimized.

Rete mirabile associated with pial arteriovenous fistula: imaging features with literature review

A rete mirabile is a vascular network of intercommunicating small arteries or arterioles that replace the definitive adult artery supplying the brain. It supplies the brain in lower mammals but is not seen in normal human embryological development. A 26-year-old man presented with worsening tinnitus that was interfering with his sleep. On CT and digital subtraction angiography he was found to have a temporal lobe pial arteriovenous fistula with bilateral carotid and vertebral rete mirabile. The patient was offered open surgical and endovascular treatment options for pial arteriovenous fistula but he refused both and opted for conservative medical management. At 6-month follow-up he continued to have pulsatile tinnitus but was otherwise neurologically normal. We present the first described association of rete mirabile with pial arteriovenous fistula and discuss its clinical presentation and imaging features, with a review of the literature for bilateral carotid and vertebral rete mirabile.

Prenatal Diagnosis and Multimodal Neonatal Treatment of a Rare Pial Arteriovenous Fistula: Case Report and Review of the Literature

BACKGROUND

Intracranial pial arteriovenous fistulas (PAVFs) are direct communications between the arterial and venous system of the brain, with the characteristic absence of a plexiform nidus, as seen in the classic cerebral arteriovenous malformations. These vascular malformations, usually occurring in the pediatric population, very rarely are diagnosed in utero, because of a lack of understanding of the condition and because they may be hard to visualize.

CASE DESCRIPTION

We report a rare case of a mass-effect PAVF diagnosed with fetal magnetic resonance imaging, involving the right cerebral hemisphere, fed by a pericallosal artery and associated with a giant venous dilatation. The PAVF initially was managed by the endovascular embolization. The recruitment of a middle cerebral artery feeder and the rapidly enlarging size of the venous pouch with mass effect required subsequent surgery.

CONCLUSIONS

The 2-stage multimodal treatment resulted in complete disappearance of the PAVF without complications.

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.

Serial Measurement of Superior Vena Cava Flow in Evaluation of the Clinical Severity of Pial Arteriovenous Fistula in an Infant

Background Pial arteriovenous fistula (AVF) is composed of one or more direct arterial feeding vessels with a single draining vein without nidus. A patient with the disease with high-flow AV shunting in the neonatal period not only suffers from high-output cardiac failure but also shows secondary neurological sequelae. In vein of Galen aneurysmal malformation, superior vena cava (SVC) flow measurements provide useful prognostic information. Case Presentation We measured serial SVC flow in a male infant with pial AVF. The term infant presented with tachypnea, a heart murmur, and a cranial bruit after birth, and cranial magnetic resonance imaging and computed tomographic angiography revealed a pial AVF on the left sylvian fissure. SVC flow was at the upper normal limit at presentation. After 1 month, SVC flow gradually increased up to fourfold. Surgical resection of the pial AVF was performed and diagnosed as pial AVF on day 62. The SVC flow immediately decreased thereafter. Conclusion SVC flow reflects the shunt volume and may be a useful parameter for evaluating the optimal timing and effectiveness of intervention in pial AVF.