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

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.

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.

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.

Angioarchitecture and prognosis of pediatric intracranial pial arteriovenous fistula

OBJECTIVE

Pial arteriovenous fistulas (PAVFs) are rare and mostly observed in children. However, the overall angioarchitecture, clinical features, treatments and long-term prognosis for pediatric patients remain unclear.

METHODS

Clinical data of consecutive 42 pediatric PAVFs were documented and analysed. According to the differences of age distribution and clinical features, they were split into a younger group (≤3 years old; 20 cases) and an older group (3-14 years old; 22 cases).

RESULTS

Their mean age was 4.9±3.9 years, and the mean preoperative modified Rankin Scale (mRS) score was 1.64±1.57. Fourteen patients (33.3%) were asymptomatic, followed by epilepsy (21.4%), intracranial haemorrhage (16.7%), hydrocephalus (9.5%), developmental delay (7.1%), intermittent headache (7.1%) and congestive heart failure (4.8%). Annual bleeding rate and rebleeding rate before treatment reached 3.86% and 3.17%. Poor venous drainage including sinus dynamic obstruction (21 cases, 50.0%) and sinus occlusion (17 cases, 40.48%) were found with high frequency among these patients. Finally, 33 cases were cured (78.57%), and 4 cases faced surgery-related complications (9.52%). During 24-140 months' follow-up, the mean mRS score reduced to 0.57±0.40. However, only 22 cases (52.38%) recovered to absolutely normal, and poor venous drainage was the risk factor for patients' incomplete recovery (p=0.028, Exp(B)=14.692, 95% CI 1.346 to 160.392). Compared with the older group, younger group showed more chronic symptoms, more secondary pathological changes, more times treatment and worse prognosis (p=0.013, 0.002, 0.000 and 0.032, respectively).

CONCLUSIONS

Pediatric PAVF has different angioarchitectures, clinical features and prognoses in different age groups. Poor venous drainage is an important factor leading to poor prognosis, and it accounts for incomplete recovery in nearly half of patients.

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.

A case of craniocervical junction pial arteriovenous fistula causing postoperative medullary and spinal cord edema

OBJECTIVES

Pial arteriovenous fistulas (pAVFs) are direct connections between the pial artery and vein without an intervening nidus. We report a rare case of craniocervical junction (CCJ) pAVF causing medullary and spinal cord edema resulting from surgical removal of the varix with remnant shunt after coil embolization.

CASE DESCRIPTION

A 16-year-old man presented with subarachnoid hemorrhage. Digital subtraction angiography revealed a CCJ pAVF with multiple fistulas at the 2 varices (varix A and varix B), which was fed by the bilateral lateral spinal arteries and anterior spinal artery (ASA), and drained into the median posterior vermian vein with varix (varix C) and anterior spinal vein (ASV). Varices A and B were embolized using coils, but the shunts remained in varix C. Then, varix C was surgically removed. After this operation, medullary and spinal cord edema occurred. Digital subtraction angiography showed the ASV drainage responsible for edema. Finally, surgical removal of varices A and B was performed. However, arteriovenous shunts, supplied by the ASA and drained into the ASV via the intrinsic vein, were found in the medulla oblongata and coagulated, resulting in disappearance of edema.

CONCLUSIONS

Edema was probably caused by concentration of drainage from the arteriovenous shunt in the medulla oblongata into the ASV by surgical removal of varix C acting as another draining route. High flow AVF can induce angiogenesis and secondary arteriovenous shunt. Precise analysis of the angioarchitecture is important to treat such cases without complications.

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.

Analysis of the Pial Arterial Supply as a Cause of Intraprocedural Hemorrhage During Transarterial Liquid Embolization of Tentorial Dural Arteriovenous Fistulas

OBJECTIVE

Tentorial dural arteriovenous fistulas (AVFs) are bridging vein shunts, and are therefore sometimes supplied by the pial artery as well as the dural artery. Recently, intraprocedural hemorrhage from the pial artery was reported, and we experienced 2 tentorial dural AVFs with the same complication. Pure pial artery has a glomus-like structure and forms direct shunts along the draining vein, and is likely to bleed after restriction of the draining vein caused by the transarterial embolization. This study investigated the characteristics of the pial arterial supply as a cause of hemorrhage.

METHODS

Twenty-six tentorial dural AVFs in 25 patients treated in our institute were retrospectively investigated and the characteristics of the pial feeders responsible for bleeding were analyzed.

RESULTS

Thirteen pial arterial feeders (pure pial feeder in 7, dilated dural branch of the pial artery in 4, and undefined in 2) were identified in 10 of the 26 tentorial dural AVFs. Pure pial feeders were responsible for bleeding in 2 tentorial dural AVFs.

CONCLUSIONS

To prevent intraprocedural hemorrhage, differentiation of the pure pial supply from the dural branch of the pial artery is important. The infratentorial artery will supply supratentorial fistula as the dural branch after passing through the tentorium. In contrast, the supratentorial artery can supply supratentorial fistula not only as a dural branch but also as a pure pial feeder. Therefore, attribution of the fistula and the pial supply, supratentorial or infratentorial, is useful in identifying pure pial supply.

SARS-CoV-2: its potential neurological manifestations and plausible mechanism: a review article

Coronavirus disease (COVID-19) was first identified in late December 2019. The disease began in Wuhan, Hubei province in China and since then it has spread quickly to many countries all over the world. COVID-19 is caused by a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The virus was majorly seen to overwhelm the respiratory system with mild to severe acute respiratory syndrome considered pathognomic for the disease. However, with time a plethora of symptoms was observed in the patients infected with COVID-19 including strong evidence for neurological symptoms. Evidence suggests that the virus has both central and peripheral nervous system manifestations. Patients, particularly those who suffer from a severe illness, have a central nervous system (CNS) involvement and neurological manifestations. There is precise and targeted documentation of neurological symptoms with details of clinical, neurological, and electrophysiological findings. This review article thus gives an insight into the neuro-invasive potential of COVID-19 and discusses the possible pathogenesis.