Therapeutic progress in pediatric intracranial dural arteriovenous shunts: A review

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

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

Anticoagulation helps shrink giant venous lakes and arteriovenous fistulas in dural sinus malformation

BACKGROUND

Dural sinus malformations (DSMs) associated with high flow arteriovenous shunts are a challenging disease in babies that can lead to severe neurological damage or death. We report our treatment strategy in seven consecutive DSMs.

METHODS

We performed a retrospective analysis of seven consecutive patients from four centres, treated with transarterial embolization and anticoagulants.

RESULTS

Mean clinical and imaging follow-up was 2.8 years (IQR1-3 1.8-5.3). At baseline, the median size of the dilated venous pouch (giant lake) was 35 mm (IQR1-3 24-41) that decreased to a normal or near normal venous collector diameter of median size 11.5 mm (IQR1-3 8.5-13.8). This was achieved after a median of two embolization sessions targeted on dural feeders (IQR1-3 1.5-2.5), leaving associated pial feeders untreated. There were no cerebral hemorrhagic complications during the anticoagulation treatment. Median percentage of shunt remaining after embolization was 30% (IQR1-3 12-30), which spontaneously decreased with anticoagulation and even after discontinuation of anticoagulation, in parallel with the reduction in diameter of the dilated sinus, up to healing (or near healing). At the last clinical assessment, the modified Rankin Scale score was 0 in four patients, 1 in one patient, and 3 in two patients.

CONCLUSIONS

Anticoagulants may help to potentiate transarterial embolization in DSMs in babies by decreasing venous dilatation and reducing the remaining arteriovenous shunt, particularly the pial feeders. We did not observe recurrence of arteriovenous shunts after treatment, especially during anticoagulation treatment. Further studies are needed to support our findings.

Dural arteriovenous fistula of the torcular herophili presenting with hydrocephalus and venous congestion in an 8-month-old child: A case report

Dural arteriovenous fistulas (DAVFs) are direct communication between the dural arterial and venous systems. They are more common in adults. In children, they are relatively rare. Hydrocephalus is a common problem in pediatrics with a variety of causes. However, very few cases of hydrocephalus as a complication of DAVF have been reported in the literature. This case describes an 8-month-old male child with a large DAVF at the torcular herophili who presented with regression of milestones and hydrocephalus. Magnetic resonance imaging (MRI) on admission showed triventricular hydrocephalus and a massively dilated torcular with a compressed fourth ventricle. Angiography confirmed the presence of a DAVF at the torcula with arterial feeders from the posterior circulation. Endovascular embolization was performed with >80% embolization of the fistula with no complications. Control MRI immediately postoperative was acceptable. No cerebrospinal fluid (CSF) diversion was performed. At a 3-month follow-up, the child had attained all developmental milestones for age. MRI showed normal CSF dynamics and a further reduction in the size of the torcula. Despite being rare, DAVFs should be considered as a possible cause of pediatric hydrocephalus, and treating them can lead to a resolution of the mechanisms inducing hydrocephalus. CSF shunting should be reserved for those cases with persistent hydrocephalus and raised intracranial pressure despite endovascular treatment.

Cerebral neurovascular embryology, anatomic variations, and congenital brain arteriovenous lesions

Cerebral neurovascular development is a complex and coordinated process driven by the changing spatial and temporal metabolic demands of the developing brain. Familiarity with the process is helpful in understanding neurovascular anatomic variants and congenital arteriovenous shunting lesions encountered in endovascular neuroradiological practice. Herein, the processes of vasculogenesis and angiogenesis are reviewed, followed by examination of the morphogenesis of the cerebral arterial and venous systems. Common arterial anatomic variants are reviewed with an emphasis on their development. Finally, endothelial genetic mutations affecting angiogenesis are examined to consider their probable role in the development of three types of congenital brain arteriovenous fistulas: vein of Galen malformations, pial arteriovenous fistulas, and dural sinus malformations.

Brain arteriovenous malformations and dural arteriovenous fistulas with extensive venous congestive encephalopathy

In brain arteriovenous malformations (BAVMs) and dural arteriovenous fistulas (DAVFs), when too much blood is drained into the venous system, extensive venous congestive encephalopathy (EVCE) can appear. EVCE in BAVMs and DAVFs can be divided into acute and chronic stages. BAVMs and DAVFs have their own classification systems, but EVCE is not considered in these classification systems and needs to be emphasized. EVCE in BAVMs and DAVFs has unique clinical and imaging features. The clinical presentations usually consist of headache, cognitive impairment, and focal deficits. EVCE in BAVMs and DAVFs has several imaging features, and the venous congestion seen on computed tomography angiography and magnetic resonance angiography can present with the angiographic features of venous reflux and pseudophlebitic pattern. Digital subtraction angiography is the gold standard for the diagnosis. Delayed circulation time is observed. Tortuous, dilated, and engorged veins can be seen. For EVCE from BAVMs and DAVFs, prompt treatment is warranted due to the impairment of extensive brain tissue. Treatments include endovascular treatment (EVT), open surgery, and radiosurgery. EVT is often the primary treatment. Complete elimination in one stage is often difficult. Most of the time, staged treatment has to be chosen. No matter at the acute or chronic stage, aggressive treatment is recommended.

Development of bilateral subdural hematoma after endovascular embolization of a dural sinus malformation

INTRODUCTION

Dural sinus malformation is a rare congenital malformation characterized by a remarkable dilated dural sinus pouch. We described the development of bilateral subdural hematoma after endovascular embolization of a dural sinus malformation in an infant.

CASE DESCRIPTION

A 32-day male infant was observed to have a fever and enlarged head circumference. A dural sinus malformation with giant dural sinus pouch thrombosis was established by magnetic resonance imaging and digital subtraction angiography. The patient developed bilateral subdural hematoma after endovascular embolization of the dural fistula. His neurological outcome was normal at 3-year follow-up.

CONCLUSION

We report a case of development of bilateral subdural hematoma after endovascular embolization of a dural sinus malformation and had a normal neurological outcome.

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.

Endovascular management of torcular dural sinus malformations in children: the role of straight sinus occlusion

BACKGROUND

Torcular dural sinus malformations (tDSMs) with arteriovenous shunts are rare congenital intracranial vascular malformations that carry a high rate of neurologic impairment and death in the neonatal, infant and young pediatric population. Their impact on brain venous drainage, especially the deep venous system, is one of the key factors in the clinical prognosis and natural history of the disease. We describe our therapeutic strategy for tDSMs, disconnecting the reflux into the deep venous system by performing an endovascular straight sinus occlusion.

METHODS

Among all children with dural sinus malformations seen between 2002 and 2020, we retrospectively reviewed those with tDSM in whom straight sinus occlusion had been performed.

RESULTS

Our databank included nine patients with tDSM that were embolized. Mean age at the clinical onset was 8.9±9.6 months (min-max=0-31). Five patients presented a significant reflux in the straight sinus on digital subtraction angiography. Those patients were initially clinically worse (mean modified Rankin Scale (mRS) 3.8) than those who did not present with reflux (mean mRS 2.25), this reflux being responsible for intraventricular hemorrhage in three patients. The reflux was suppressed by transarterial embolization in one patient and by transvenous straight sinus occlusion in four patients. Staged endovascular treatment resulted in a complete cure in six patients without complications, and clinical improvement in all patients.

CONCLUSION

Straight sinus occlusion is a feasible technique that needs to be considered in the treatment strategy for tDSM with deep venous reflux in order to avoid or minimize brain damage.

Multiple Cranial Dural and Pial Arteriovenous Fistulas with Occlusion of All After Embolization of Primary Superior Sagittal Sinus Dural Fistula

BACKGROUND

We present a rare case of multiple intracranial arteriovenous fistulas (AVFs). A young female presented with headache and a left eyelid pulsatile swelling.

CASE DESCRIPTION

Magnetic resonance imaging demonstrated numerous dilated cortical veins, along with a prominent left superior ophthalmic vein. A diagnostic cerebral angiogram revealed 5 distinct AVFs including 4 dural AVFs (dAVFs) and a pial AVF (pAVF). The largest dAVF was at the superior sagittal sinus. The others included bilateral ethmoidal, torcular, and a pAVF arising of the right pericallosal artery. She was treated by endovascular transarterial Onyx embolization. Only the superior sagittal sinus fistula was treated via middle meningeal artery feeders with complete occlusion. Immediate follow-up angiogram also showed complete spontaneous occlusion of the untreated dAVFs and pial AVF.

CONCLUSIONS

This case is exceedingly unique considering the multiplicity of AVFs, concurrent presence of pial and dural AVF, and spontaneous occlusion of all untreated AVFs after embolizing the largest shunting fistula.

Pediatric intracranial arteriovenous shunts: Advances in diagnosis and treatment

Pediatric intracranial arteriovenous shunts (IAVSs) comprise a wide range of lesions, including pial arteriovenous malformation (AVM) and arteriovenous fistula (AVF), dural arteriovenous fistula (DAVF) and vein of Galen aneurysmal malformation (VGAM). We provide an overview of pediatric IAVSs, encompassing both diagnosis and endovascular treatment. We include references from pertinent literature and representative cases from our hospital. Pediatric IAVS are frequently associated two broader conditions, such as capillary malformation-arteriovenous malformation (CM-AVM) and hereditary hemorrhagic telangiectasia (HHT). These conditions and the associated genetic mutations have only recently been described. Their impact on the brain will be different in the prenatal period, in neonates, in infants, and in children, with variable symptoms according to each age group and the current strategies of endovascular treatment in the management of these vascular lesions will be discussed. This review could improve the understanding of pediatric IAVSs and their diagnosis and treatment.

The prospects and pitfalls in the endovascular treatment of moyamoya disease-associated intracranial aneurysms

Moyamoya disease (MMD) is characterized by progressive stenosis or occlusion of the distal internal carotid artery and simultaneous formation of collateral vasculature. The fragile alteration and increased hemodynamic stress in the intra- and extracranial vasculature would conjointly result in the formation of intracranial aneurysms in MMD patients. According to our classification, the MMD-associated aneurysms are divided into the major artery aneurysms (MAAs) and non-MAAs. The non-MAAs are further subdivided into the distal choroidal artery aneurysms, moyamoya vessel aneurysms, transdural collateral aneurysms, and anastomosis aneurysms. Currently, endovascular treatment (EVT) has become the main stream for the MMD-associated aneurysms. There is no difference to EVT for the MMD-associated MAAs of the non-stenosed major arteries with that in the non-MMD patients. While it is a big challenge to perform EVT for MMD-associated aneurysms in the stenosed arteries. Generally speaking, the parent arteries of the non-MAAs are slim, and super-selective catheterization is technically difficult. Most of the times, parent artery occlusion with liquid embolic agents or coils can only be performed. The vasculature in MMD patients is fragile; perioperative management and meticulous intraoperative manipulation are also very important to avoid complications during EVT. In spites of the complications, the EVT can bring good outcome in selected cases of MMD-associated aneurysms.

Clinical importance of the posterior meningeal artery: a review of the literature

The posterior meningeal artery, which arises from the vertebral artery, is a critical artery in neurological lesions. However, a comprehensive review of the importance of the posterior meningeal artery is currently lacking. In this study, we used the PubMed database to perform a review of the literature on the posterior meningeal artery to increase our understanding of its role in vascular lesions. The posterior meningeal artery provides the main blood supply to the paramedial and medial portions of the dura covering the cerebellar convexity. The posterior meningeal artery is often involved in dural arteriovenous fistulas occurring near the posterior fossa, and the posterior meningeal artery can be the path for transarterial embolisation or a path through which to monitor the degree of dural arteriovenous fistula embolisation. In posterior circulation ischaemia and moyamoya disease, the posterior meningeal artery can form transdural anastomoses with pial arteries at the surface of the brain, and these can help prevent ischemia. The posterior meningeal artery can also develop aneurysms, most of which are traumatic pseudoaneurysms; patients should therefore be treated in a timely manner or followed up carefully in cases of rebleeding. In addition, during a craniotomy, the posterior meningeal artery should be protected intraoperatively to avoid damaging any transdural anastomosis that may be present. In addition, when the posterior meningeal artery is the main feeding artery of an intracranial tumour, that artery is a satisfactory path for preoperative embolisation. Briefly, the posterior meningeal artery is a very important artery in neurosurgery.

Current status of endovascular treatment for dural arteriovenous fistulae in the anterior cranial fossa: A systematic literature review

Anterior cranial fossa (ACF) dural arteriovenous fistulae (DAVFs) are rare, and a systematic review of the literature is lacking. Such a review is necessary, however, so a systematic PubMed search of related studies was performed. Twenty-four studies were identified, reporting on 48 patients, of whom 39 had definite age and sex information and 33 (84.6%, 33/39) were male. The afflicted patients were between 37 and 80 years old (mean 55.6). Among the 48 patients, 28 (58.3%, 28/48) primarily presented with intracranial hemorrhage, 47 (97.9%, 47/48) had feeding arteries from the anterior ethmoidal artery (AEA) of the ophthalmic artery (OA), and 40 (83.3%, 40/48) had bilateral feeding arteries. All of the cases had high-grade Cognard classifications (III-IV). Among the 48 patients, 43 (89.6%, 43/48) had drainage into the superior sagittal sinus (SSS). In addition, 36 (75%, 36/48) patients were treated via transarterial embolization (TAE). Of these patients, 28 (77.8%, 28/36) were managed via the AEA of the OA. Another 12 (25%, 12/48) patients were treated via transvenous embolization (TVE), 11 of whom (91.7%, 11/12) were treated with the trans-SSS approach. Complete angiographic cure was achieved in 44 (91.7%, 44/48) patients, with 4 (8.3%, 4/48) patients suffering from postprocedural complications. All 48 patients had clear descriptions of follow-up outcomes, with 45 (93.8%, 45/48) patients having a good outcome. Thus, when treating ACF DAVFs, endovascular treatment (EVT) can completely obliterate the fistula point and correct the venous shunting. EVT is therefore an effective treatment for ACF DAVF. Although many complications can occur, this approach achieves good outcomes in most cases.

Coil and Onyx embolization of a torcular herophili dural arteriovenous fistula in a full-term neonate with advanced heart failure using a transumbilical approach

Neonatal dural arteriovenous fistulas (DAVFs) are rare, but if left untreated will advance to life-threatening neurological and cardiovascular compromise. Endovascular treatment is the preferred treatment modality for DAVFs. The goal of endovascular therapy is to obliterate feeding vasculature and prevent secondary complications. Endovascular access can be difficult to obtain in a neonate. The authors present the case of a full-term, normal birth weight neonate with severe congestive heart failure secondary to a congenital DAVF of the torcular herophili that was successfully treated with transumbilical arterial coil embolization and a liquid embolic agent.

Dural arteriovenous fistula of the lateral foramen magnum region: A review

The lateral foramen magnum region is defined as the bilateral occipital area that runs laterally up to the jugular foramen. The critical vasculatures of this region are not completely understood. Dural arteriovenous fistulas that occur in this region are rare and difficult to treat. Therefore, we searched PubMed to identify all relevant previously published English language articles about lateral foramen magnum dural arteriovenous fistulas, and we performed a review of this literature to increase understanding about these fistulas. Four types of dural arteriovenous fistulas occur in the lateral foramen magnum region. These include anterior condylar confluence and anterior condylar vein dural arteriovenous fistulas, posterior condylar canal dural arteriovenous fistulas, marginal sinus dural arteriovenous fistulas, and jugular foramen dural arteriovenous fistulas. These dural arteriovenous fistulas share similar angioarchitectures and clinical characteristics. The clinical presentations of lateral foramen magnum dural arteriovenous fistulas include pulsatile tinnitus, intracranial hemorrhage, myelopathy, orbital symptoms, and cranial nerve palsy. Currently, head computed tomography, computed tomography angiography, magnetic resonance imaging, magnetic resonance angiography and digital subtraction angiography (DSA) are useful for diagnosing dural arteriovenous fistulas, and of these, DSA remains the "gold standard." Most lateral foramen magnum dural arteriovenous fistulas need to be treated due to their aggressive symptoms, and transvenous embolization presents the best options. During treatment, it is critical to accurately place the microcatheter into the fistula point, and intraoperative integrated computed tomography and DSA data are very helpful. Other treatments, such as transarterial embolization, microsurgery or conservative treatment, can also be chosen. After appropriate treatment, most patients with lateral foramen magnum dural arteriovenous fistulas achieve satisfactory outcomes.

Progress in research on intracranial multiple dural arteriovenous fistulas

Intracranial multiple dural arteriovenous fistulas (MDAVFs) are rare lesions that are difficult to treat. The key factors involved in the development of MDAVFs remain unknown. At present, the majority of reports on intracranial MDAVFs are confined to case reports and small case series, and thus understanding of MDAVFs is limited. The current review assesses the available literature to date with the aim of reviewing the progress in research on intracranial MDAVFs. Intracranial MDAVFs may be divided into two types: Synchronous and metachronous. While the exact pathogenesis of MDAVFs is unknown, a number of possible mechanisms are considered relevant. The first is that MDAVFs develop following recanalization of a large sinus thrombosis that involves several sinuses. The second possibility is that a pre-existing DAVF may induce sinus thrombosis or venous hypertension, resulting in a new MDAVF. The third is that MDAVFs are caused by increased angiogenic activity, which may induce the development of MDAVFs. Intracranial MDAVFs have a malignant clinical course, and their symptoms generally rapidly progress following onset. It is therefore important to identify intracranial MDAVFs at an early stage. A number of imaging technologies, including computed tomography (CT), magnetic resonance imaging (MRI), digital subtraction angiography (DSA) and single-photon emission computed tomography (SPECT), may be used to detect MDAVFs. Of these, CT and MRI provide information on brain morphology, SPECT provides brain blood flow information, and DSA is the gold standard that may be used to identify angioarchitecture and hemodynamics. MDAVFs require timely and aggressive treatment, which may include endovascular embolization, surgical resection, radiosurgery and conservative treatment, and in some cases, combined treatments are required. Appropriate and aggressive treatment regimens can markedly improve neurological deficits and cognitive function in patients with MDAVFs.