Intracerebral atypical calcification in nongalenic pial arteriovenous fistula: a case report

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.

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.

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.

Pial arteriovenous fistula with giant varices: report of two cases with good surgical outcome

Pial arteriovenous fistulas (pAVF) are rare vascular lesions consisting of one or more arterial connections to a single venous channel without any intervening nidus of vessels or capillaries. Case 1: A 65-year-old woman with a complaint of headache and left hand paresthesia was referred to us. Magnetic resonance imaging showed a large saccular lesion with signal void in the posterior part of the right sylvian fissure and catheter angiography showed a giant venous aneurysm fed by one branch of the middle cerebral artery (MCA) and draining into the vein of Trolard. Case 2: A 12-year-old boy was transferred to our hospital with a history of sudden loss of consciousness and hemiplegia. Brain computed tomography revealed a massive hemorrhagic mass in the right hemisphere and cerebral angiography showed a pAVF with a large aneurysmal varix, which was fed by multiple branches of the right MCA and draining into the superior sagittal sinus. Both patients underwent craniotomy and after ligation of vascular connections, aneurysmal varices were removed completely. Surgical resection can be a safe method for treatment of pAVFs, particularly in those with large varices.

An institutional series and literature review of pial arteriovenous fistulas in the pediatric population: clinical article

OBJECT

Pial arteriovenous fistulas (PAVFs) are a rare form of cerebrovascular disease that tend to be overrepresented in the pediatric population. There have been limited studies of the clinical features and outcomes in this group of patients. Here, the authors attempt to better delineate this clinical entity with institutional cases and a review of the literature.

METHODS

A retrospective review of cases at our institution was performed to identify all pediatric patients treated for a PAVF between 2000 and 2012.

RESULTS

Five patients treated for a PAVF were identified. Patients had a mean age of 1.9 years at diagnosis, and the most common presenting symptoms were seizure and macrocephaly. Patients were treated primarily with embolization, and 3 patients required both N-butyl cyanoacrylate (NBCA) glue and coiling. Four of the patients had complete obliteration of the PAVF and had a pediatric overall performance category score of either 1 (n = 3) or 2 (n = 1) at follow-up. There was 1 death due to heart failure. Analysis of the literature review suggested that a younger age or presence of intracerebral hemorrhage (ICH) or congestive heart failure (CHF) at presentation likely predicts a worse prognosis. Older patients presented more often with ICH, whereas younger patients presented significantly more often in CHF. The majority of pediatric patients reported on in the literature were treated with endovascular embolization, most commonly with NBCA glue alone. Most patients (65.4%) in the literature had an excellent outcome without neurological deficit.

CONCLUSIONS

Pial AVFs represent a serious yet rare form of cerebrovascular disease. Pediatric patients with ICH or CHF at presentation or those who are very young are likely to have a worse prognosis. Endovascular management of these patients has greatly changed the natural history of this disease, but the complication and mortality rates suggest the need for continued insights and advances in treatment.

[Endovascular treatment of non-galenic pial arteriovenous fistulas]

INTRODUCTION AND OBJECTIVES

Pial arteriovenous fistulas are infrequent vascular malformations. They are generally congenital and their natural history is ominous. The objective of this work is to describe our experience in their endovascular management and to review the existing literature.

PATIENTS AND METHODS

This is a retrospective and descriptive study of patients treated by endovascular approach during 3 years at 3 Latin-American hospitals.

RESULTS

The study included 6 patients with a mean age of 22 years. One case was caused by cranial trauma. In total, 50% suffered intracranial haemorrhage and 66% developed symptoms attributable to volume effect or retrograde blood flow. Intracranial varices were identified by CT and MRI scans in 83% of cases. Digital subtraction angiography showed arteriovenous fistulas from anterior circulation in 67% of cases and deep venous drainage in 50%. One endovascular procedure was performed in 5 cases (83%), while 2 procedures were required in one case. A single embolic agent was used to occlude fistulas in 67% of cases; whilst 33% required a combination. Coils were used in 4 cases (67%) and onyx was injected in another 4 (67%). One case required stent and balloon deployment. The fistulas were uneventfully occluded in all cases. The follow-up period was one year in 5 cases and 6 months in one case. All patients remained symptom-free.

CONCLUSIONS

Endovascular management can be considered as the treatment of choice. It consists in the embolisation of arterial pedicles with one or more embolic agents and should be performed as close as possible to the drainage vein, avoiding migration of the embolic agent towards the venous side.

Endovascular treatment of a pial arteriovenous fistula with occipital remodeling secondary to giant torcular dilation

Intracranial arteriovenous fistulas are vascular malformations in which clinical suspicion and prompt diagnosis, with a subsequent appropriate therapeutic approach, are crucial to avoid the development of irreversible neurological damage or even patient death because these lesions can be associated with heavy bleeding and high mortality rates. The authors present the case of a direct pial arteriovenous fistula in an infant and its unusual presentation as a large occipital protuberance with hard consistency and an audible murmur that produced bone remodeling. The patient was successfully treated by endovascular therapy, with complete regression of the occipital protuberance during follow-up.