Coil-based endovascular treatment of single-hole cerebral arteriovenous fistulae: experiences in 11 patients

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.

Traumatic dissecting pathology of posterior cerebral artery: a report of two cases-aneurysm and pial arteriovenous fistula

We present two cases of 17-year-old man and 10-year-old boy presenting with subarachnoid haemorrhage and a history of road traffic accident. One patient had dissecting aneurysm of the posterior cerebral artery (PCA), and the other patient had partially thrombosed aneurysm on CT angiography. On digital subtraction angiography of the second patient, there was formation of PCA pontomesencephalic vein pial arteriovenous fistula (PAVF). Both the patients underwent endovascular treatment: stent-assisted coiling for aneurysm and coiling with parent vessel occlusion for PAVF. There were no procedural complications. Follow-up angiography showed no residual aneurysm or fistula. Trauma is one of the recognised causes of dissection, and intracranial dissections can present as stenotic lesions, aneurysms or fistulas, depending on the pathology. Traumatic dissecting PCA aneurysm has been reported in only two case reports previously, and post-traumatic PAVF in PCA has not been reported.

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.

Trigeminal neuralgia associated with cerebellar pial arteriovenous fistula: A case report

RATIONALE

Trigeminal neuralgia (TN) is frequently associated with compression at the root entry zone of the trigeminal nerve by an aberrant loop of an artery, tributaries of the petrosal vein, tumors, aneurysm, and vascular malformation. TN associated with a cerebellar pial arteriovenous fistula (PAVF) has not been described previously.

PATIENT CONCERNS

A 65-year-old man presented with right-sided TN. Cerebral angiography revealed a right cerebellar PAVF and magnetic resonance imaging demonstrated a mixed compression of the petrous vein complex and anterior inferior cerebellar artery at the right trigeminal nerve.

DIAGNOSIS

Due to the patient's symptoms, radiographic findings, he was diagnosed with TN and PAVF.

INTERVENTIONS

Coiling combined with use of the liquid embolic agent Onyx was used for the complete embolization of the fistula.

OUTCOMES

Complete relief of the pain was achieved 3 months after endovascular treatment, and the patient has remained pain-free during 2 years of follow-up.

CONCLUSIONS

Endovascular treatment with a combination of coils and Onyx embolization is an effective approach for complete resolution of rarely occurring TN caused by mixed venous and arterial compressions associated with cerebellar PAVF.

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.

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.

Adjunct to Embolize the High-Flow Fistula Part of Arteriovenous Malformation Using a Double-Lumen Balloon Catheter

OBJECTIVE

The purpose of this study is to report our initial experience of Onyx embolization of the high-flow fistula part of arteriovenous malformation (AVM) using a double-lumen balloon catheter.

METHODS

A Scepter C balloon catheter was used in 2 patients with AVMs associated with high-flow fistulas. The fistulas were located in the anterior cerebral artery and the middle cerebral artery.

RESULTS

Onyx embolization was successful in 2 cases, resulting in elimination of the high-flow fistula part of the AVM. There were no treatment-related events.

CONCLUSIONS

The double-lumen Scepter balloon appears to be a safe and convenient device for Onyx embolization of high-flow fistulas.

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.

Onyx Embolization of Intracranial Pial Arteriovenous Fistula

Intracranial pial arteriovenous fistulas (AVFs) are rare cerebrovascular lesions consisting of one or more arterial connections to a single venous channel without an intervening nidus. Because of the location and high flow dynamics of these lesions, neurosurgeons may have a difficulty deciding between endovascular treatment and open surgical treatment. We report on a patient who underwent endovascular treatment with liquid embolic agent. A 50-year-old man with a decreased mental state and a tonic seizure event was brought to our hospital. Computed tomography (CT) of the brain showed a subcortical hematoma in the right temporoparietal lobe. On three-dimensional cerebral artery CT, there was no evidence of definite cerebrovascular abnormality. Cerebral angiography showed a pial AVF supplied by the right middle cerebral artery with early drainage into the right superior cerebral vein. The patient was treated with Onyx embolization for definitive closure of the fistula. The patient was transferred to the department of rehabilitation medicine two weeks later with grade 4 left hemiparesis. The application of advanced equipment, such as the latest angiography and endovascular tools, will facilitate the correct diagnosis and delicate treatment of pial AVF.

Radiculo-pial spinal arteriovenous fistulas treated with coils: Report of two cases

Spinal pial arteriovenous fistulas (SPAVFs) are rare lesions that present more frequently in young patients. Lesions located on radiculo-pial arteries without involvement of the anterior spinal artery are even rarer. SPAVFs may present with mass effect, venous congestion or hemorrhage. Most often, treatment is performed either by surgery or endovascularly with fluid embolic material. Use of microcoils has not been reported for this condition.We present two cases of radiculo-pial high-flow SPAVFs in two patients in their early 30 s. One patient presented with abrupt headache without proof of hemorrhage and the other one with trigeminal neuralgia resulting from dilated posterior fossa draining veins remote from the fistula. Both patients were successfully treated with endovascular shunt closure using microcoils with resolution of symptoms and disappearance of the dilated veins at follow-up.With recent advances in microcatheter technology, distal navigation and microcoil embolization offers another option for these cases that may be safer than fluid embolic material.

Anchor coil technique for arteriovenous fistula embolization. A technical note

We describe a case of arteriovenous fistula (AVF) successfully treated by coil embolization with an anchor coil inserted in the varix to facilitate dense packing at the shunting site. AVF of the left anterior choroidal artery (AChoA) draining into the ipsilateral basal vein of Rosenthal was incidentally found in a newborn female. A single detachable coil was inserted as an anchor into the varix adjacent to the shunt, and the microcatheter was pulled back to the shunting point. Three more detachable coils were delivered at the shunting point without migration under the support of the anchor coil, and the AVF was successfully obliterated with preservation of AChoA blood flow. The anchor coil technique can reduce the risk of coil migration and the number of coils required.

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.

Balloon-assisted Onyx embolization of cerebral single-channel pial arteriovenous fistulas

OBJECT

Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risks of hemorrhage and neurological deficit. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. The authors describe a novel endovascular treatment strategy that was used successfully to treat 2 pediatric patients with a pial AVF, and they discuss the technical nuances specific to their treatment strategy.

METHODS

A single-channel high-flow pial AVF was diagnosed in 2 male patients (6 and 17 years of age). Both patients were treated with endovascular flow arrest using a highly conformable balloon followed by Onyx infusion for definitive closure of the fistula.

RESULTS

Neither patient suffered a complication as a result of the procedure. At the 6-month follow-up in both cases, the simple discontinuation of blood flow had resulted in durable obliteration of the fistula and stable or improved neurological function.

CONCLUSIONS

Onyx can be delivered successfully into high-flow lesions after flow arrest to allow a minimally invasive and durable treatment for pial AVFs.