Clarifying the clinical landscape of pediatric spinal arteriovenous shunts: an institutional experience and individual patient-data meta-analysis.

BACKGROUND: Pediatric spinal arteriovenous shunts (SAVS) are rare lesions with heterogeneous pathogenesis and clinical manifestations. OBJECTIVE: To evaluate the clinical characteristics, angioarchitecture, and technical/clinical outcomes in SAVS through a large single-center cohort analysis and meta-analysis of individual patient data. METHODS: A retrospective institutional database identified children (aged 0-21 years) who underwent digital subtraction spinal angiography (DSA) for SAVS between January 1996 and July 2021. Clinical data were recorded to evaluate angioarchitecture, generate modified Aminoff-Logue gait disturbance scores (AL) and McCormick grades (MC), and assess outcomes. We then performed a systematic literature review following PRISMA-IPD (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for individual patient data) guidelines, extracting similar data on individual patients for meta-analysis. RESULTS: The cohort consisted of 28 children (M:F=11:17) with 32 SAVS lesions, with a mean age of 12.8±1.1 years at diagnosis. At presentation, SAVS were most highly concentrated in the cervical region (40.6%). Children had a median AL=2 and MC=2, with thoracolumbar AVS carrying the greatest disability. Among treated cases, complete obliteration was achieved in 48% of cases and median AL scores and MC grades both improved by one point. Systematic literature review identified 161 children (M:F=96:65) with 166 SAVS lesions with a mean age of 8.7±0.4 years. Among studies describing symptom chronicity, 37/51 (72.5%) of children presented acutely. At presentation, children had a median AL=4 and MC=3, with thoracolumbar AVS carrying the highest MC grades. After intervention, median AL and MC both improved by one point. CONCLUSIONS: This study provides epidemiologic information on the location, onset, and presentation of the full spectrum of pediatric SAVS, highlighting the role of targeted treatment of high-risk features.

Evolving indications for pediatric neurointerventional radiology: A single institutional 25-year experience in infants less than one year of age and a brief historical review.

BACKGROUND AND PURPOSE: Pediatric neurointerventional radiology is an evolving subspecialty with growing indications and technological advancement such as miniaturization of devices and decreased radiation dose. The ability to perform these procedures is continuously balanced with necessity given the inherently higher risks of radiation and cerebrovascular injury in infants. The purpose of this study is to review our institution's neurointerventional experience in infants less than one year of age to elucidate trends in this patient population. METHODS: We retrospectively identified 132 patients from a neurointerventional database spanning 25 years (1997-2022) who underwent 226 procedures. Treatment type, indication, and location as well as patient demographics were extracted from the medical record. RESULTS: Neurointerventional procedures were performed as early as day of life 0 in a patient with an arteriovenous shunting malformation. Average age of intervention in the first year of life is 5.9 months. Thirty-eight of 226 procedures were completed in neonates. Intra-arterial chemotherapy (IAC) for the treatment of retinoblastoma comprised 36% of neurointerventional procedures completed in infants less than one year of age followed by low flow vascular malformations (21.2%), vein of Galen malformations (11.5%), and dural arteriovenous fistulas (AVF) (9.3%). Less frequent indications include non-Galenic pial AVF (4.4%) and tumor embolization (3.0%). The total number of interventions has increased secondary to the onset of retinoblastoma treatment in 2010 at our institution. CONCLUSION: The introduction of IAC for the treatment of retinoblastoma in the last decade is the primary driver for the increased trend in neurointerventional procedures completed in infants from 1997 to 2022.

Percutaneous sclerotherapy for head and neck lymphatic malformations in neonates and infants ≤12 months of age.

BACKGROUND: Percutaneous sclerotherapy is an effective treatment for lymphatic malformations (LM) of the head and neck in adults. The purpose of this study was to examine the indications and efficacy of sclerotherapy for head/neck LM in the neonate and infant population. METHODS: We retrospectively reviewed patients treated with percutaneous sclerotherapy for LM of the head/neck at age ≤12 months at a single vascular anomalies clinic. The clinical, anatomic, and technical aspects of each treatment, complications, and post-treatment clinical and imaging outcomes were analyzed. RESULTS: 22 patients underwent 36 treatments during the first year of life. Median age at first treatment was 6.2 months (range 2-320 days). Severe airway compromise was the most frequent indication for treatment (31.8%). Sclerosants included doxycycline (80.5%), sodium tetradecyl sulfate (55.5%), bleomycin (11.1%) and ethanol (2.8%). There were no immediate procedure-related complications; sclerosant-related laboratory complications included transient metabolic acidosis (8.3%) and hemolytic anemia (5.5%). Median follow-up was 3.7 years (IQR 0.6-4.8). 47.6% of patients showed >75% lesion size reduction and 19.0% showed minimal response (<25% improvement). At last follow-up, 71.4% of children were developmentally normal and asymptomatic, 23.8% had recurring symptoms, and 4.8% required permanent tracheostomy. Patients with ongoing symptoms or limited response to percutaneous sclerotherapy (33.3%) were treated with long-term sirolimus. CONCLUSIONS: Percutaneous sclerotherapy is a safe and effective treatment for symptomatic LM of the head and neck in neonates and infants. Treatment strategy and management of recurrent symptoms requires consensus from an experienced, multidisciplinary team.

Dual-agent percutaneous sclerotherapy technique for macrocystic lymphatic malformations.

Percutaneous sclerotherapy is an effective technique for treating lymphatic malformations of the head and neck, with clinical success rates exceeding 84%.1 Sodium tetradecyl, which damages lipid membranes and stimulates free radical-induced local damage, and doxycycline, which inhibits angiogenesis, have emerged as the safest and most effective of several available sclerosants.2-4 Although severe periprocedural morbidity is rare, temporary local complications are reported in 14% and skin necrosis or scarring in up to 0.8-5.8% of sclerotherapy procedures.5 As these lesions are frequently located in the face and/or neck, even minor complications can be disfiguring and must be avoided. This technical video describes a 'dual-agent' approach for percutaneous sclerotherapy of macrocystic lymphatic malformations using sodium tetradecyl as a 'primer' followed by doxycycline as a definitive sclerosant (video 1). This technique emphasizes meticulous backtable preparation and effective use of ultrasound and fluoroscopy to minimize complications. neurintsurg;15/9/931/V1F1V1Video 1 .

Pharyngo-tympano-stapedial middle meningeal artery variant supply to a falcotentorial dural arteriovenous fistula.

The pharyngo-tympano-stapedial middle meningeal artery (PTS-MMA) variant has been described in one case report and never in the setting of arterial supply to a dural arteriovenous fistula, to our knowledge. We report the case of a middle-aged patient with severe, daily headache who presented to our institution for angiography and treatment. CT angiography and MRI demonstrated an enlarged left middle meningeal artery coursing to a large venous varix in the falcotentorial region. Dural arteriovenous fistula was confirmed by subsequent cerebral angiography. Endovascular treatment was performed but without complete obliteration of the fistula. Follow-up angiography demonstrated parasitized arterial supply from a right middle meningeal artery arising from the proximal cervical internal carotid artery coursing through the middle ear consistent with a PTS-MMA variant. The fistula was then treated surgically without recurrence at the 6-month follow-up.

Endovascular Therapy for Intracranial Giant Cell Arteritis : Systematic Review, Technical Considerations and the Effect of Intra-arterial Calcium Channel Blockers.

BACKGROUND: Giant cell arteritis (GCA) is a systemic vasculitis that may cause ischemic stroke. Rarely, GCA can present with aggressive intracranial stenoses, which are refractory to medical therapy. Endovascular treatment (EVT) is a possible rescue strategy to prevent ischemic complications in intracranial GCA but the safety and efficacy of EVT in this setting are not well-described. METHODS: A systematic literature review was performed to identify case reports and series with individual patient-level data describing EVT for intracranial GCA. The clinical course, therapeutic considerations, and technique of seven endovascular treatments in a single patient from the authors' experience are presented. RESULTS: The literature review identified 9 reports of 19 treatments, including percutaneous transluminal angioplasty (PTA) with or without stenting, in 14 patients (mean age 69.6 ± 6.3 years). Out of 12 patients 8 (66.7%) with sufficient data had > 1 pre-existing cardiovascular risk factor. All patients had infarction on MRI while on glucocorticoids and 7/14 (50%) progressed despite adjuvant immunosuppressive agents. Treatment was PTA alone in 15/19 (78.9%) cases and PTA + stent in 4/19 (21.1%). Repeat treatments were performed in 4/14 (28.6%) of patients (PTA-only). Non-flow limiting dissection was reported in 2/19 (10.5%) of treatments. The indications, technical details, and results of PTA are discussed in a single illustrative case. We report the novel use of intra-arterial calcium channel blocker infusion (verapamil) as adjuvant to PTA and as monotherapy, resulting in immediate improvement in cerebral blood flow. CONCLUSION: Endovascular treatment, including PTA with or without stenting or calcium channel blocker infusion, may be effective therapies in medically refractory GCA with intracranial stenosis.

Endovascular treatment strategy, technique, and outcomes for dural arteriovenous fistulas of the marginal sinus region.

BACKGROUND: Dural arteriovenous fistulas (AVF) of the foramen magnum region (FMR) are technically challenging lesions to treat. Transvenous (TV), transarterial (TA), and surgical approaches have been described, but the optimum treatment strategy is not defined. OBJECTIVE: To report treatment strategies and outcomes for FMR-AVF at a single, high-volume referral center. METHODS: A retrospective review from January 2010 to August 2020 identified patients with FMR-AVF at a single referral center. Angiographic features, treatment (observation, endovascular, surgical), and follow-up of angiographic and clinical results were recorded. The technical aspects of TV embolization are then presented in detail. RESULTS: 29 FMR-AVF were identified in 28 patients. Of these, 24/29 (82.8%) were treated and 5/29 (17.2%) were observed. Treatment was endovascular in 21/24 (87.5%), combined (endovascular+surgical) in 2/24 (8.3%), and surgical in 1/24 (4.2%). Endovascular treatments were 76.2% TV, 14.3% TA, and 9.5% combined TV/TA. Sufficient follow-up data were available for 20/28 (71.4%) with mean follow-up of 16.8 months. No AVF recurrence was seen for TA/TV, combined endovascular/surgical, or surgical groups, and there was one recurrence (7.1%) in the TV group. Symptomatic improvement was seen in all groups: TV (71.4% complete, 28.6% partial), TA (66.7% complete, 33.3% no follow-up), TV+TA (100% partial), endovascular/surgical (100% complete), and surgical (100% partial). Minor non-neurologic complications included 1/14 (7.1%) in the TV group and 1/3 (33.3%) in the TA/TV group. CONCLUSION: Endovascular treatment is safe and effective for most FMR-AVF. TV embolization has a high cure rate with few complications.

Robotics for neuroendovascular intervention: Background and primer.

The simultaneous growth of robotic-assisted surgery and telemedicine in recent years has only been accelerated by the recent coronavirus disease 2019 pandemic. Robotic assistance for neurovascular intervention has garnered significant interest due to opportunities for tele-stroke models of care for remote underserved areas. Lessons learned from medical robots in interventional cardiology and neurosurgery have contributed to incremental but vital advances in medical robotics despite important limitations. In this article, we discuss robot types and their clinical justification and ethics, as well as a general overview on available robots in thoracic/abdominal surgery, neurosurgery, and cardiac electrophysiology. We conclude with current clinical research in neuroendovascular intervention and a perspective on future directions.

Safety and efficacy results of the Flow Redirection Endoluminal Device (FRED) stent system in the treatment of intracranial aneurysms: US pivotal trial.

OBJECTIVE: To evaluate the safety and effectiveness of the Flow Redirection Endoluminal Device (FRED) flow diverter in support of an application for Food and Drug Administration approval in the USA. METHODS: 145 patients were enrolled in a prospective, single-arm multicenter trial. Patients with aneurysms of unfavorable morphology for traditional endovascular therapies (large, wide-necked, fusiform, etc) were included. The trial was designed to demonstrate non-inferiority in both safety and effectiveness, comparing trial results with performance goals (PGs) established from peer-reviewed published literature. The primary safety endpoint was death or major stroke (National Institutes of Health Stroke Scale score ≥4 points) within 30 days of the procedure, or any major ipsilateral stroke or neurological death within the first year. The primary effectiveness endpoint was complete occlusion of the target aneurysm with ≤50% stenosis of the parent artery at 12 months after treatment, and in which an alternative treatment of the target intracranial aneurysm had not been performed. RESULTS: 145 patients underwent attempted placement of a FRED device, and one or more devices were placed in all 145 patients. 135/145 (93%) had a single device placed. Core laboratory adjudication deemed 106 (73.1%) of the aneurysms large or giant. A safety endpoint was experienced by 9/145 (6.2%) patients, successfully achieving the safety PG of <15%. The effectiveness PG of >46% aneurysm occlusion was also achieved, with the effectiveness endpoint being met in 80/139 (57.6%) CONCLUSION: As compared with historically derived performance benchmarks, the FRED flow diverter is both safe and effective for the treatment of appropriately selected intracranial aneurysms. CLINICAL REGISTRATION NUMBER: NCT01801007.

Endovascular Biopsy of Vertebrobasilar Aneurysm in Patient With Polyarteritis Nodosa.

Background and Purpose: The management of unruptured intracranial aneurysms remains controversial. The decisions to treat are heavily informed by estimated risk of bleeding. However, these estimates are imprecise, and better methods for stratifying the risk or tailoring treatment strategy are badly needed. Here, we demonstrate an initial proof-of-principle concept for endovascular biopsy to identify the key molecular pathways and gene expression changes associated with aneurysm formation. We couple this technique with single cell RNA sequencing (scRNAseq) to develop a roadmap of the pathogenic changes of a dolichoectatic vertebrobasilar aneurysm in a patient with polyarteritis nodosa. Methods: Endovascular biopsy and fluorescence activated cell sorting was used to isolate the viable endothelial cells (ECs) using the established techniques. A single cell RNA sequencing (scRNAseq) was then performed on 24 aneurysmal ECs and 23 patient-matched non-aneurysmal ECs. An integrated panel of bioinformatic tools was applied to determine the differential gene expression, enriched signaling pathways, and cell subpopulations hypothesized to drive disease pathogenesis. Results: We identify a subset of 7 (29%) aneurysm-specific ECs with a distinct gene expression signature not found in the patient-matched control ECs. A gene set enrichment analysis identified these ECs to have increased the expression of genes regulating the leukocyte-endothelial cell adhesion, major histocompatibility complex (MHC) class I, T cell receptor recycling, tumor necrosis factor alpha (TNFα) response, and interferon gamma signaling. A histopathologic analysis of a different intracranial aneurysm that was later resected yielded a diagnosis of polyarteritis nodosa and positive staining for TNFα. Conclusions: We demonstrate feasibility of applying scRNAseq to the endovascular biopsy samples and identify a subpopulation of ECs associated with cerebral aneurysm in polyarteritis nodosa. Endovascular biopsy may be a safe method for deriving insight into the disease pathogenesis and tailoring the personalized treatment approaches to intracranial aneurysms.

Radial artery access for neuroendovascular procedures: safety review and complications.

Although enthusiasm for transradial access for neurointerventional procedures has grown, a unique set of considerations bear emphasis to preserve safety and minimize complications. In the first part of this review series, we reviewed anatomical considerations for safe and easy neuroendovascular procedures from a transradial approach. In this second part of the review series, we aim to (1) summarize evidence for safety of the transradial approach, and (2) explain complications and their management.

Radial artery access anatomy: considerations for neuroendovascular procedures.

Although enthusiasm for transradial access for neurointerventional procedures has grown, a unique set of considerations bear emphasis to preserve safety and minimize complications. In the first part of this review series, we will review important anatomical considerations for safe and easy neuroendovascular procedures from a transradial approach. These include normal and variant radial artery anatomy, the anatomic snuffbox, as well as axillary, brachial, and great vessel arterial anatomy that is imperative for the neuroendovascular surgeon to be intimately familiar prior to pursuing transradial access procedures. In the next part of the review series, we will focus on safety and complications specific to a transradial approach.

Neurological manifestations of polyarteritis nodosa: a tour of the neuroaxis by case series.

BACKGROUND: Heterogenous central nervous system (CNS) neurologic manifestations of polyarteritis nodosa (PAN) are underrecognized. We review three cases of patients with PAN that illustrate a range of nervous system pathology, including the classical mononeuritis multiplex as well as uncommon brain and spinal cord vascular manifestations. CASE PRESENTATION: Case 1 presented with mononeuritis multiplex and characteristic skin findings. Case 2 presented with thunderclap headache and myelopathy due to spinal artery aneurysm rupture. Both patients experienced disease remission upon treatment. Case 3 presented with headache and bulbar symptoms due to partially thrombosed intracranial aneurysms, followed by systemic manifestations related to visceral aneurysms. She demonstrated clinical improvement with treatment, was lost to follow-up, then clinically deteriorated and entered hospice care. CONCLUSIONS: Although the peripheral manifestations of PAN are well-known, PAN association with CNS neurovascular disease is relatively underappreciated. Clinician awareness of the spectrum of neurologic disease is required to reduce diagnostic delay and promote prompt diagnosis and treatment with immunosuppressants.

Intrasaccular flow disruption (WEB) of a large wide-necked basilar apex aneurysm using PulseRider-assistance.

Large, wide-necked basilar apex aneurysms are difficult to treat. Microsurgical clipping can result in neurologic morbidity and mortality. Endovascular treatment often leaves remnants that need retreatment and/or stent placement with dual antiplatelet therapy. The Woven EndoBridge (WEB) is an intrasaccular flow disruption device that can be used without dual antiplatelet therapy. However, the WEB cannot typically be used in large or giant aneurysms > 10 mm because the largest diameter device is the 11 × 9.6 mm single layer sphere (SLS). We present a case in which we use a PulseRider aneurysm neck reconstruction device in the basilar artery to assist in WEB deployment within a 22 mm basilar apex aneurysm with 14 mm neck, thereby permitting aspirin monotherapy postoperatively.

Intracranial hemorrhage due to central venous occlusion from hemodialysis access: A case report.

Central venous stenosis in hemodialysis patients rarely causes venous hypertension and intracranial hemorrhage. A 54 year-old male with right arm arteriovenous fistula was transferred to our institution in a comatose state following right parietal venous infarction. Fistulography showed right brachiocephalic vein (BCV) occlusion with reflux into the right transverse sinus and obstruction of left internal jugular vein outflow due to the styloid process. Balloon venoplasty of the right BCV occlusion failed to improve the patient's status because of the delayed diagnosis. Headaches and neurologic symptoms in hemodialysis patients can herald intracranial hypertension due to central venous occlusion and needs prompt assessment with fistulography.

Combined Use of X-ray Angiography and Intraprocedural MRI Enables Tissue-based Decision Making Regarding Revascularization during Acute Ischemic Stroke Intervention.

Background For patients with acute ischemic stroke undergoing endovascular mechanical thrombectomy with x-ray angiography, the use of adjuncts to maintain vessel patency, such as stents or antiplatelet medications, can increase risk of periprocedural complications. Criteria for using these adjuncts are not well defined. Purpose To evaluate use of MRI to guide critical decision making by using a combined biplane x-ray neuroangiography 3.0-T MRI suite during acute ischemic stroke intervention. Materials and Methods This retrospective observational study evaluated consecutive patients undergoing endovascular intervention for acute ischemic stroke between July 2019 and May 2020 who underwent either angiography with MRI or angiography alone. Cerebral tissue viability was assessed by using MRI as the reference standard. For statistical analysis, Fisher exact test and Student t test were used to compare groups. Results Of 47 patients undergoing acute stroke intervention, 12 patients (median age, 69 years; interquartile range, 60-77 years; nine men) underwent x-ray angiography with MRI whereas the remaining 35 patients (median age, 80 years; interquartile range, 68-86 years; 22 men) underwent angiography alone. MRI results influenced clinical decision making in one of three ways: whether or not to perform initial or additional mechanical thrombectomy, whether or not to place an intracranial stent, and administration of antithrombotic or blood pressure medications. In this initial experience, decision making during endovascular acute stroke intervention in the combined angiography-MRI suite was better informed at MRI, such that therapy was guided in real time by the viability of the at-risk cerebral tissue. Conclusion Integrating intraprocedural 3.0-T MRI into acute ischemic stroke treatment was feasible and guided decisions of whether or not to continue thrombectomy, to place stents, or to administer antithrombotic medication or provide blood pressure medications. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lev and Leslie-Mazwi in this issue.

Delayed-Onset Cranial Nerve Palsy After Transvenous Embolization of Indirect Carotid Cavernous Fistulas.

BACKGROUND: Carotid cavernous fistulas (CCF) often present with diplopia secondary to cranial nerve palsy (CNP). Immediate development of postoperative CNP has been described in the literature. This study described delayed-onset of CNP after complete and reconfirmed obliteration of the CCF and resolution of initial CNP. METHODS: A retrospective analysis was performed on patients with indirect CCF between 1987 and 2006 at 4 academic endovascular centers. Details of the endovascular procedures, embolic agents used, and complications were studied. Partial or complete obliteration was determined. Immediate and delayed cranial nerve palsies were independently assessed. RESULTS: A total of 267 patients with symptomatic indirect CCF underwent transvenous endovascular treatment. Four patients (1.5%) developed delayed abducens nerve (VI) palsy after complete resolution of presenting symptoms after embolization. Delayed presentation ranged between 3 and 13 months after complete resolution of initial double vision and cranial nerve palsies. Transvenous coil embolization through the inferior petrosal sinus was performed in all 4 affected patients. All had follow-up angiography confirming durable closure of their CCF. MRI did not show new mass lesions or abnormal soft tissue enhancement. In all 4 patients, their abducens nerve (VI) palsy remained. CONCLUSIONS: Delayed CNP can develop despite complete endovascular obliteration of the CCF. The cause of delayed CNP is not yet determined, but may represent fibrosis and ischemia. Long-term follow-up is needed even after complete neurological and radiological recovery is attained in the immediate perioperative period.

Cerebral angiography: Techniques and practice.

As a refresher course on current techniques and practice of cerebral angiography, this chapter outlines the steps in effective angiography, incorporating modern quality and safety considerations. The format is step-by-step from preprocedure to intraprocedure to postprocedure for ease of reference. The chapter will serve as a framework for the fledgling angiographer, augmenting the important teaching provided by a seasoned angiographer.

Vascular anomalies: Classification and management.

Vascular anomalies are broadly classified into two major categories: vascular tumors and vascular malformations. Most vascular anomalies are caused by sporadic mosaic gene mutations, and recent genetic studies have advanced our understanding of the molecular pathways involved in their pathogenesis. These findings have suggested new therapeutic approaches to vascular anomalies, focusing on their pathogenetic mechanism. This chapter seeks to integrate an improved molecular understanding within the updated classification system of the International Society for Study of Vascular Anomalies. We emphasize the genetic, radiologic, and interventional aspects of diagnosis and management in hopes of allowing improved multidisciplinary collaboration surrounding these complex and interesting anomalies.