LIQUID - Treatment of high-grade dural arteriovenous fistulas with Squid liquid embolic agent: a prospective, observational multicenter study.

BACKGROUND: Endovascular embolization is a feasible treatment for cranial dural arteriovenous fistulas (DAVFs). New embolic agents aim to improve the success of DAVF embolization. OBJECTIVE: To assess the safety, efficacy, and short-term outcome of the treatment of DAVFs using the new liquid embolic agent Squid. METHODS: The LIQUID study is a prospective, observational multicenter study on the treatment of high-grade (Cognard type ≥3) DAVFs with the embolic agent Squid. The primary outcome measures were safety (ie, morbidity and mortality), as well as the occlusion rate 90 to 180 days after treatment. RESULTS: In eight centers, 53 patients (mean age 59.8 years, 22.6% female) were treated in 55 treatment sessions. Of the DAVFs, 56.6% were Cognard type III, 41.5% type IV, and 18.9% were ruptured. Squid 18 was used in 83.6% and Squid 12 in 32.7% of the treatments. The overall rate of intraprocedural or postprocedural adverse events (AEs) was 18.2%. Procedure-related AEs resulting in permanent morbidity were observed in 3.6%. One patient (1.8%) died unrelated to the procedure due to pulmonary embolism. The final complete occlusion rate at 90 to 180 days was 93.2%. After a mean follow-up of 5.5 months, the modified Rankin Scale (mRS) score was stable or improved in 93.0%. In one of the patients, worsening of the mRS score was related to the procedure (1.8%). CONCLUSION: Squid is a safe and effective liquid embolic agent for the treatment of high-grade DAVFs.

Spinal Dural Arteriovenous Fistula in a Young Male Associated with Craniospinal Leptomeningeal Spread of a Treated High-Grade Glioma.

Spinal dural arteriovenous fistulae (SDAVF) are most commonly idiopathic in origin but may occasionally be seen secondary to surgery, trauma, or inflammation. We report a case of 27-year-old male who came with features of a myelopathy. He was found to have an SDAVF associated with leptomeningeal spread (LMS) of a previously treated high-grade cerebral glioma. Hemorrhagic presentation of gliomas, as in this case, is due to upregulation of vascular endothelial growth factor, which has also been postulated to play a role in the development of SDAVFs. This may suggest a possible mechanism of induction of secondary SDAVFs associated with such tumors. While the coexistence of intracranial neoplasms with vascular malformations has been reported previously, this is the first case report of LMS of a high-grade glioma associated with an SDAVF.

Acquired dural arteriovenous fistula after cerebellopontine angle meningioma: A case report.

RATIONALE: Intracranial brain surgeries, including ventriculostomy, burr hole, craniotomy, and craniectomy, are the most common causes of acquired dural arteriovenous fistula (dAVF). Here we report a case of acquired dAVF after a cerebellopontine angle meningioma surgery. PATIENT CONCERNS: A 51-year-old woman was diagnosed with a 40-mm cerebellopontine angle meningioma. The patient underwent surgery via a retrosigmoid suboccipital approach. A small craniotomy and an additional craniectomy were performed. At 7 months after the surgery, she presented with pulsating tinnitus and headache. DIAGNOSIS: Magnetic resonance imaging and digital subtraction angiography showed a dAVF that was fed by the occipital artery and drained into transverse and sigmoid sinuses. INTERVENTIONS: We performed Onyx® (Irvine, CA) embolization. OUTCOMES: The patient's symptoms completely improved. LESSONS: Craniectomy defects, partially exposed sinuses, and incomplete cranioplasty might be risk factors for iatrogenic dAVF after a retrosigmoid suboccipital craniotomy or craniectomy. Complete reconstructive cranioplasty is an essential procedure to prevent a direct connection between the venous sinus and the external carotid artery.

Embolization strategies for intracranial dural arteriovenous fistulas with an isolated sinus: a single-center experience in 20 patients.

BACKGROUND: Intracranial dural arteriovenous fistulas (DAVFs) draining into an isolated sinus segment constitute a specific entity within the spectrum of cranial dural AV shunts, with under-reporting of their optimal treatment. OBJECTIVE: To describe the multimodal treatment approach to isolated sinus DAVFs in a large single-center cohort. METHODS: Retrospective analysis of adult patients with an isolated sinus DAVF treated at our institution between 2004 and 2020 was performed. Cases were analyzed for demographics, clinical presentation, angiographic findings, treatment techniques, angiographic and clinical outcomes, and complications. RESULTS: Of 317 patients with DAVFs, 20 (6.3%) with an isolated sinus DAVF underwent treatment. Transarterial embolization was performed through the middle meningeal artery in 9 of 12 procedures, with a success rate of 66.7%. Transarterial glue embolization proved successful in two of five procedures (40%) and Onyx in six of seven procedures (85.7%). Transvenous embolization (TVE) with navigation via the occlusion into the isolated sinus was successful in seven out of nine procedures (77.8%). All three open TVE and one pure open surgical procedure gained complete closure of the fistula. There were two major complications. Complete occlusion of the fistula was eventually obtained in all cases (100%). CONCLUSIONS: Isolated sinus DAVFs are always aggressive and require a multimodal approach to guarantee closure of the shunt. Transarterial treatment with Onyx achieves good results. Transvenous treatment appears equally successful, navigating into the occluded segment across the occlusion or via burr hole as backup.

Iatrogenic Middle Meningeal Arteriovenous Fistula During Embolization: Two Case Reports and Literature Review.

Objective Dural arteriovenous fistulae of the middle meningeal artery are rare. There are few reports of complications associated with endovascular therapy. This report describes two cases of iatrogenic middle meningeal arteriovenous fistula due to vascular injury sustained during endovascular treatment. Case description Case 1 was that of a 46-year-old woman. She was treated for an incidentally discovered dural arteriovenous fistula of the cerebellar tentorium by transarterial embolization. During the procedure, a middle meningeal arteriovenous fistula occurred because of vessel laceration by the forced advancement of the distal access catheter (DAC). After the intervention, she developed tinnitus. Follow-up angiography revealed a middle meningeal arteriovenous fistula. The fistula was treated by coil embolization of the affected middle meningeal artery. The second case was that of a 56-year-old woman who developed a middle meningeal arteriovenous fistula from the perforation caused by the microguidewire during tumor embolization. The fistula was treated by occluding the proximal segment of the affected artery with coils. Both patients were discharged without neurological complications after the endovascular procedures. Conclusion Endovascular surgeons should be aware of the possibility of middle meningeal arteriovenous fistula as a potential complication of endovascular procedures.

Central nervous system vascular malformations: A clinical review.

CNS vascular malformation is an umbrella term that encompasses a wide variety of pathologies, with a wide range of therapeutic and diagnostic importance. This range spans lesions with a risk of devastating neurological compromise to lesions with a slow, static or benign course. Advances in neurovascular imaging along with increased utilization of these advances, have resulted in more frequent identification of these lesions. In this article, we provide an overview on definitions and classifications of CNS vascular malformations and outline the etiologic, diagnostic, prognostic, and therapeutic features for each entity. This review covers intracranial and spinal cord vascular malformations and discusses syndromes associated with CNS vascular malformations.

Dural arteriovenous fistula formation following bilateral middle meningeal artery embolization for the treatment of a chronic subdural hematoma: a case report.

Here is reported a case of dural arteriovenous fistula (DAVF) formation following middle meningeal artery (MMA) embolization. A 64-year-old male patient was operated for a bilateral CSDH by burr-hole craniostomy. Prophylactic post-operative MMA embolization was performed with 300-500-µm calibrated microparticles. The patient was admitted 3 months later for a left CSDH recurrence. Digital subtraction angiography demonstrated formation of a superior sagittal sinus DAVF fed by both superficial temporal arteries. This case highlights the possible role of local tissue hypoxia as a significant component of DAVF pathogenesis. Moreover, it has potential implications for MMA embolization as a management strategy for CSDH.

Intraosseous Arteriovenous Fistula Around the Anterior Condylar Confluence as an Occipital Bone Fracture Sequela.

BACKGROUND: Although traumatic dural arteriovenous fistula (AVF) is a rare condition, dural injury associated with skull fracture is one of the major factors for the formation of dural AVF at the skull fracture area. We report a case of de novo intraosseous AVF around the anterior condylar confluence after head injury associated with skull base fracture. CASE DESCRIPTION: A woman in her 70s presented with pulsatile tinnitus 3 months after cerebellar infarction and occipital bone fracture. The appearance of de novo intraosseous AVF was confirmed by magnetic resonance imaging and magnetic resonance angiography and treated with coil embolization, which led to symptomatic relief without recurrence on follow-up. CONCLUSIONS: There is no previous report to our knowledge of intraosseous AVF around the anterior condylar confluence proven to appear after skull fracture. This case demonstrates that head injury associated with skull base fracture could be one etiology of dural AVF around the anterior condylar confluence.

[Acute headache resulting from intracranial venous reflux due to occlusion of the brachiocephalic vein ipsilateral to a dialysis shunt].

A 72-year-old man on hemodialysis for 7 years with end-stage renal disease was admitted to our institution due to an acute headache. Physical examination revealed normal signs except for noise on the back of his neck. His head CT and brain MRI showed no abnormal findings, while his MRA demonstrated abnormal signals in the left transverse to sigmoid sinus (T-S) suggesting a left dural arteriovenous fistula. After admission, his headache persisted and left orbital numbness also occurred. His digital subtraction angiography performed on the 5th day after admission showed no vascular malformation of either the T-S or cavernous sinus (CS). However, it showed occlusion of the left brachiocephalic vein (BCV) and the origin of the left internal jugular vein (IJV) resulting in intracranial venous reflux. These findings indicated the possibility that his acute headache was caused by intracranial venous reflux and increase of intracranial pressure resulting from the occlusion of the BCV ipsilateral to a dialysis shunt. Percutaneous transluminal angioplasty (PTA) for occlusion of the left BCV was performed on the 9th day and successful dilation of the lesion with a residual stenotic ratio less than 30 percent was obtained. After the angioplasty, venous reflux to the intracranial vein was markedly reduced and his headache and orbital numbness disappeared. One day after the procedure, MRA demonstrated the disappearance of the abnormal signals of the left T-S. Twelve months after discharge, he felt discomfort in the left of his face and the re-occlusion of the left VCV was demonstrated by angiography, therefore he received re-PTA. We recommend that physicians consider occlusion of the BCV ipsilateral to a dialysis shunt and intracranial venous reflux as a cause of acute headache in patients on hemodialysis.

Spontaneous Resolution of Dural and Pial Arteriovenous Fistulae Arising After Superficial Temporal Artery to Middle Cerebral Artery Bypass for Moyamoya Disease.

BACKGROUND: Superficial temporal artery (STA)-to-middle cerebral artery bypass is frequently performed for moyamoya disease. We discuss an unusual case in a moyamoya patient complicated by the development of dural and pial arteriovenous fistulae (AVF). Both AVF then spontaneously resolved 2 years after surgery. CASE DESCRIPTION: A patient in the fifth decade of life presented after multiple strokes resulting in right-sided weakness and numbness. Magnetic resonance imaging revealed remote strokes, and angiography revealed Suzuki grade 3 moyamoya angiopathy bilaterally. With a diminutive left STA, we initially performed left-sided dual-vessel pial synangioses. After radiographic evidence of robust revascularization and improved hemispheric perfusion, a combined right STA-middle cerebral artery bypass was done. However, routine 8-month postoperative angiography identified dural and pial AVF within the prior operative field. On the 2-year surveillance cerebral angiogram, both AVF were no longer present. CONCLUSIONS: AVF as a complication of revascularization surgery is rare. Here, we discuss the possible pathophysiologic mechanisms that we theorize may have contributed and current treatment options and indications. We also review the literature surrounding this phenomenon.

Dural Arteriovenous Fistula Associated with Dental Implant.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) are characterized by pathologic shunts between meningeal arteries and venous sinuses, without nidus. Although many lesions are considered idiopathic, there may be an association with inflammatory processes, including sinus thrombosis, venous hypertension, craniotomy, trauma, and infections. CASE DESCRIPTION: A 50-year-old woman with an infectious complication of a dental implant evolved with an occipital DAVF. To our knowledge, this is the first case of a dental implant-related DAVF reported in the medical literature. CONCLUSIONS: Physicians should be aware of the possibility of DAVF formation after craniofacial infections. Better understanding of the etiopathogenesis of this type of lesion is required to avoid and treat potential complications.

Amateur Endurance Athletes: At Higher Risk of Suffering Dural Arteriovenous Fistulas? Report of 3 Cases.

BACKGROUND: The present study aims to draw attention to the fact that endurance sport could be a risk factor for dural arteriovenous fistula (DAVF) development. DAVFs have been correlated with acquired dural venous sinus anomalies owing to trauma, infection, neoplasia, or other classic risk thrombogenic factors. Here we report 3 cases of intracranial DAVF in young healthy patients who had no known thrombogenic risk factors other than amateur intensive sports practice. CASE DESCRIPTION: Three young healthy individuals not fitting into the classical clinical picture of a DAVF patient presented to our institution. One was a 40-year-old man with an acute subdural hematoma secondary to an ethmoidal DAVF. Another 41-year-old man presented with a cerebellar hematoma due to a tentorial DAVF. A third 41-year-old man presented with numbness of his right arm in relationship to a superior sagittal sinus DAVF. None of them had a relevant medical history. All the usual thrombogenic risk factors for DAVF development were ruled out. Interestingly, the 3 patients had outstanding training and practice routines for endurance sports. CONCLUSIONS: Dehydration, microfractures, muscular contractures, low heart rate, long distance travel, and high altitudes are all well documented thrombogenic risk factors affecting endurance sports amateur athletes and might represent a plausible mechanism for the development of DAVF. Despite its limitations, to our knowledge, this is the first work suggesting a possible link between such sport practice and DAVF development. Further prospective research from larger dedicated vascular centers might shed further light on this hypothetic but intriguing link.

Comparison of MRI, MRA, and DSA for Detection of Cerebral Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia.

BACKGROUND AND PURPOSE: Patients with hereditary hemorrhagic telangiectasia (HHT) have a high prevalence of brain vascular malformations, putting them at risk for brain hemorrhage and other complications. Our aim was to evaluate the relative utility of MR imaging and MRA compared with DSA in detecting cerebral AVMs in the HHT population. MATERIALS AND METHODS: Of 343 consecutive patients evaluated at the University of California, San Francisco HTT Center of Excellence, 63 met the study inclusion criteria: definite or probable hereditary hemorrhagic telangiectasia defined by meeting at least 2 Curacao criteria or positive genetic testing, as well as having at least 1 brain MR imaging and 1 DSA. MRIs were retrospectively reviewed, and the number of AVMs identified was compared with the number of AVMs identified on DSA. RESULTS: Of 63 patients, 45 (71%) had AVMs on DSA with a total of 92 AVMs identified. Of those, 24 (26%) were seen only on DSA; 68 (74%), on both DSA and MR imaging; and 5 additional lesions were seen only on MR imaging. Of the 92 lesions confirmed on DSA, 49 (53.3%) were seen on the 3D-T1 postgadolinium sequence, 52 (56.5%) were seen on the 2D-T1 postgadolinium sequence, 35 (38.0%) were seen on the SWI sequence, 24 (26.1%) were seen on T2 sequence, and 25 (27.2%) were seen on MRA. The sensitivity and specificity of MR imaging as a whole in detecting AVMs then confirmed on DSA were 80.0% and 94.4%, respectively, and the positive and negative predictive values were 97.3% and 65.4%, respectively. CONCLUSIONS: This study reinforces the use of MR imaging as a primary screening tool for cerebral AVMs in patients with hereditary hemorrhagic telangiectasia and suggests that 3D-T1 postgadolinium and 2D-T1 postgadolinium performed at 3T are the highest yield sequences.

Prevalence, risk factors and pregnancy outcomes of women with vascular brain lesions in pregnancy.

BACKGROUND: Vascular brain lesions (VBL) occur in up to 4.0% of the general population. With the increasing availability and use of sophisticated imaging techniques, there are more patients being diagnosed with asymptomatic intracranial AVMs and cavernous hemangiomas. OBJECTIVES: Here we evaluate the association between VBL in pregnancy and the maternal and fetal outcomes. STUDY DESIGN: The study cohort was identified by isolating all pregnancies from the nationwide inpatient sample (NIS), from the healthcare cost and utilization project (HCUP) over a five-year period. Within this cohort, cases with an arteriovenous malformation (AVM) or cerebral vascular malformations (CVM) were identified and their prevalence was calculated. Baseline demographic characteristics were compared and the odds ratios for various complications and outcomes were calculated. RESULTS: Amongst 4,012,396 deliveries, VBL were identified in 214 cases: a prevalence of 5.33 cases per 100,000 deliveries. Majority of VBL cases were identified in women between 25 and 35 years of age, but the proportion of women aged 35 and older was greater amongst those patients with VBL. 74% of cases were of Caucasian race and more cases with VBL had a private insurance payer (62.1%). Seizure disorders were present in 63.6% of the cases with VBL. Whilst VBL are not associated with unfavorable obstetrical complications, they are more likely to be delivered by caesarean section (CS) - 79% of VBL cases were delivered by CS compared to 33% of the patients without VBL (OR 7.03 CI 95% 4.98-9.92). Instrumental delivery was performed in 10.3% of the vaginal deliveries for index cases. Index cases were less prone to fetal growth restriction. VBL accounted for 8.4% of 166 cases of intracranial bleeding occurring during the antepartum period within the entire pregnant population. CONCLUSIONS: Presence of VBL does not appear to carry additional risk to mother or fetus during pregnancy.

Subdural hematoma from an acquired dural arteriovenous fistula following external ventricular drain placement for subarachnoid hemorrhage.

Objective: Intracranial dural arteriovenous fistulas represent pathological connections between dural arteries and dural veins, dural sinuses or meningeal veins in the absence of an intervening capillary bed. They are thought to be acquired secondary to trauma, surgery, sinus thrombosis, venous hypertension or arterial dysplasia. Methods: A 66-year-old Asian female presented with subarachnoid hemorrhage secondary to ruptured 2-mm saccular aneurysm of the left middle cerebral artery associated with fusiform dilatation. It was successfully treated with endovascular coiling. A right frontal external ventricular drain was also placed to treat her hydrocephalus. On post-bleed day 10, she became acutely unresponsive with a fixed and dilated right pupil. Head CT was obtained and revealed an acute right subdural hematoma which was emergently evacuated. Results: No obvious bleeders were identified during surgery. Patient improved and repeat catheter angiography a week later showed a new dural arteriovenous fistula fed by the anterior falcine artery and the middle meningeal artery to a cortical vein draining into the superior sagittal sinus. Conclusion: We hope that the present report will raise awareness to treating physicians to be cognizant of this unusual complication in their differential diagnosis when treating patients with an EVD in place.

Symptomatic developmental venous anomalies.

Cerebral developmental venous anomalies (DVAs) are variations of venous vascular anatomy related to an underdevelopment of either the superficial or deep venous emissary system, resulting in a dilated transmedullary vein fed by multiple smaller venous radicles responsible for drainage of normal brain parenchyma. While typically benign and found incidentally on imaging studies, DVAs can rarely be symptomatic. The radiographic appearance of DVAs, as well as their symptomatic manifestations, is diverse. Herein, we will discuss the pathophysiology of symptomatic DVAs while providing illustrative case examples depicting each of their pathogenic mechanisms.

Anomalous origin of the middle meningeal artery from the inferolateral trunk with an arterial circle around a hypoplastic internal carotid artery in an infant with a dural arteriovenous fistula.

Deviations from normal embryologic development can manifest in different anatomical variants of the ophthalmic artery. We present a case of an infant treated for a high-flow dural arteriovenous fistula of the superior sagittal sinus, in whom an arterial circle involving the ophthalmic artery, the middle meningeal artery, the inferolateral trunk and a hypoplastic segment of the internal carotid artery was found. The embryologic development is briefly reviewed with emphasis on the possible genesis of this interesting constellation.

Ruptured Posterior Inferior Cerebellar Artery Dural Fistula After Vestibular Schwannoma Resection.

A 50-year-old man with a history of left-sided retrosigmoid craniotomy for vestibular schwannoma (VS) resection 19 years prior presented with severe headache and left cerebellopontine angle subarachnoid hemorrhage (SAH). Digital subtraction angiography demonstrated a dissected, nonfunctional left posterior inferior cerebellar artery with direct fistulization at the left transverse sinus (Video 1). The lesion was treated with endovascular Onyx embolization. The patient recovered without neurologic deficit. Five additional cases of new dural arteriovenous fistula arising after VS resection have been described; we report the first such case presenting with SAH, suggesting that postoperative magnetic resonance angiography may be of value in long-term VS follow-up imaging protocols.

Supracerebellar Approach to Radiation-Induced Giant Capillary Telangiectasia Within Juvenile Pilocytic Astrocytoma of Upper Brainstem.

Radiation-induced telangiectasia of the central nervous system has been described predominantly in children, with up to 20% of patients affected after 3-41 years of radiotherapy.1,2 We present the case of a 45-year-old male with a pontine pilocytic astrocytoma treated with standard-dose radiation for 6 weeks in 1993. He developed a 3-cm multicystic, hemorrhagic brainstem lesion but was asymptomatic. The lesion caused severe brainstem mass effect, compatible with cavernous malformation or capillary telangiectasia.3 It has been reported that cavernomas and capillary telangiectasias share a similar pathologic process.4,5 The patient was surgically treated with a supracerebellar infratentorial approach to diagnose the hemorrhagic component of the lesion and ensure there was no transformation of the pilocytic astrocytoma (Video 1). He was placed in a gravity-dependent supine position with the head flexed and turned to allow for natural relaxation of the cerebellum via gravity-a technique we previously described.6 Surgical treatment proceeded with a left suboccipital craniotomy to decompress the cyst and facilitate removal of the intraaxial lesion. We took care to avoid injuring the fourth and fifth cranial nerves and branches of the superior cerebellar artery. No further lesional tissue was seen in the resection cavity. Interestingly, the final pathologic diagnosis indicated a mix of both pilocytic astrocytoma and radiation-induced capillary telangiectasia. From the surgeon's perspective, capillary telangiectasias appear similar to cavernous malformations on gross inspection, so pathologic confirmation is essential. Postoperative imaging demonstrated total resection of the lesion. The patient was discharged on postoperative day 3 with no neurologic deficit.

Galenic dural arteriovenous fistula in neurofibromatosis type 1 treated with Onyx.

Galenic dural arteriovenous fistula (GDAVF) represents a unique, hard-to-treat subgroup of tentorial dural arteriovenous fistulae. Neurofibromatosis type 1 (NF1) has been infrequently associated with different cerebrovascular conditions that may lead to either ischemic or haemorrhagic stroke. Intracranial GDAVF has not been described in NF1 patients. We present an unusual case of GDAVF in a 37-year-old man with NF1. The fistula drained directly to the vein of Galen through multiple feeders. Complete occlusion of the fistula was achieved through trans-arterial embolisation with Onyx (ethylene vinyl alcohol copolymer) in a single treatment session. Deep venous drainage remained intact, and the patient recovered well. To our knowledge, this is the first report on complete closure of GDAVF with NF1 using trans-arterial embolisation. The preservation of functioning of the straight sinus may have contributed to the success of treatment.