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.

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.

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.

Brain Arteriovenous Malformation Recurrence After Apparent Microsurgical Cure: Increased Risk in Children Who Present With Arteriovenous Malformation Rupture.

BACKGROUND AND PURPOSE: Do children have an increased risk for brain arteriovenous malformation (AVM) recurrence compared with adults and does this risk vary depending on initial presentation with AVM rupture? METHODS: We retrospectively studied 115 patients initially presenting with brain AVM under age 25 years who underwent complete surgical resection of the AVM as documented by digital subtraction angiography (DSA) and had delayed follow-up DSA to evaluate for AVM recurrence after apparent initial cure. RESULTS: The mean time from baseline DSA to follow-up DSA was 2.3 years, ranging from 0 to 15 years. Twelve patients (10.4% of the 115 patient cohort and 16.7% of 72 patients with hemorrhage at initial presentation) demonstrated AVM recurrence on follow-up DSA. All patients with recurrence initially presented with intracranial hemorrhage, and intracranial hemorrhage was a significant predictor of recurrence (log rank P=0.037). Among patients with initial hemorrhage, the 5-year recurrence rate was 17.8% (95% CI, 8.3%-35.7%). All recurrences occurred in patients who were children at the time of their initial presentation; the oldest was 15 years of age at the time of initial AVM surgery. The 5-year recurrence rate for children (0-18 years of age) with an initial presentation of hemorrhage was 21.4% (95% CI, 10.1%-41.9%). Using Cox regression, we found the risk of AVM recurrence decreased by 14% per each year increase in age at the time of initial surgical resection (hazard ratio=0.86 [95% CI, 0.75-0.99]; P=0.031). CONCLUSIONS: There is a high rate of recurrence of apparently cured brain AVMs in children who initially present with AVM rupture. Imaging follow-up is warranted to prevent re-rupture.

Normalization of Congenital Venous Stasis Retinopathy Following Sclerotherapy of a Macrocystic Lymphatic Malformation.

The authors describe, for the first time to their knowledge, a case of a congenital macrocystic lymphatic malformation of the orbit with associated venous stasis retinopathy that acutely normalized after drainage and sclerotherapy of the lesion. Prenatal ultrasound revealed prominence of the left orbital soft tissue, and at birth, the patient was noted to have unilateral proptosis, tortuous retinal vessels, and intraretinal hemorrhages in all 4 quadrants in the left eye. MRI demonstrated a primarily intraconal, multiloculated, T2-hyperintense mass consistent with a lymphatic malformation. Ultrasound-guided cyst aspiration and sclerotherapy was performed, with subsequent improvement of the proptosis and resolution of the vessel tortuosity and intraretinal hemorrhages. Although venous stasis retinopathy is usually related to central retinal vein occlusion or carotid artery occlusive disease, any entity that increases orbital venous resistance can generate retinal venous dilation and intraretinal hemorrhages, including an orbital lymphatic malformation.

MRI phenotypes of localized intravascular coagulopathy in venous malformations.

BACKGROUND: The incidence of localized intravascular coagulopathy (LIC) in venous malformations varies with lesion size and location, as well as the presence of palpable phleboliths. The development of LIC can cause pain and hemorrhage and can progress to disseminated intravascular coagulopathy (DIC) and thromboembolic disease resulting in death in some cases. Early recognition of LIC can relieve symptoms and prevent progression to life-threatening complications. OBJECTIVE: The aim of this work was to identify MRI features of venous malformation associated with LIC. We hypothesized that venous malformations with larger capacitance, slower flow and less physiological compression (greater stasis) were more likely to be associated with LIC. MATERIALS AND METHODS: In this HIPAA-compliant and IRB-approved study, we retrospectively reviewed clinical records and MRI for consecutive patients undergoing evaluation of venous malformations at our multidisciplinary Birthmarks and Vascular Anomalies Center between 2003 and 2013. Inclusion required consensus diagnosis of venous malformation and availability of laboratory data and MRI; patients on anticoagulation or those previously undergoing surgical or endovascular treatment were excluded. LIC was diagnosed when D-dimer exceeded 1,000 ng/mL and/or fibrinogen was less than 200 mg/dL. Two board-certified radiologists assessed the following MRI features for each lesion: morphology (spongiform vs. phlebectatic), presence of phleboliths, size, location (truncal vs. extremity), and tissue type(s) involved (subcutis, muscle, bone and viscera). Univariate logistic regression analyses were used to test associations between LIC and MRI findings, and stepwise regression was applied to assess the significance of the individual imaging predictors. RESULTS: Seventy patients, 37 with LIC, met inclusion criteria during the 10-year study period (age: 14.5 +/- 13.6 years [mean +/- standard deviation]; 30 male, 40 female). Both elevated D-dimer and low fibrinogen were associated with the presence of phleboliths, larger lesion sizes and visceral involvement on MRI (all P < 0.05). In stepwise regressions, lesion size (P < 0.001), the presence of phleboliths (P = 0.005) and lesion morphology (P = 0.006) were all significant predictors of LIC. CONCLUSION: LIC is associated with larger lesion size, visualized phleboliths, truncal location and spongiform morphology on MRI in venous malformations, suggesting that lesions with larger capacitance, slower flow and less physiological compression are more likely to be associated with coagulopathy.

Atypical MRI features in soft-tissue arteriovenous malformation: a novel imaging appearance with radiologic-pathologic correlation.

BACKGROUND: The absence of a discrete mass, surrounding signal abnormality and solid enhancement are imaging features that have traditionally been used to differentiate soft-tissue arteriovenous malformations from vascular tumors on MRI. We have observed that these findings are not uncommon in arteriovenous malformations, which may lead to misdiagnosis or inappropriate treatment. OBJECTIVE: To estimate the frequency of atypical MRI features in soft-tissue arteriovenous malformations and assess their relationship to lesion size, location, tissue type involved and vascular architecture. MATERIALS AND METHODS: Medical records, MRI and histopathology were reviewed in consecutive patients with soft-tissue arteriovenous malformations in a multidisciplinary vascular anomalies clinic. Arteriovenous malformations were divided into those with and without atypical MRI findings (perilesional T2 signal abnormality, enhancement and/or a soft-tissue mass). Lesion location, size, tissue involved and vascular architecture were also compared between groups. Tissue stains were reviewed in available biopsy or resection specimens to assess relationships between MRI findings and histopathology. RESULTS: Thirty patients with treatment-naïve arteriovenous malformations were included. Fifteen lesions demonstrated atypical MRI. There was no difference in age, gender, lesion size or involved body part between the groups. However, more than half of the atypical lesions demonstrated multicompartmental involvement, and tiny intralesional flow voids were more common in atypical arteriovenous malformations. Histopathology also differed in atypical cases, showing densely packed endothelial cells with connective tissue architectural distortion and edema. CONCLUSION: Arteriovenous malformations may exhibit features of a vascular tumor on MRI, particularly when multicompartmental and/or containing tiny internal vessels. These features are important to consider in suspected fast-flow vascular malformations and may have implications with respect to their treatment.

Cavernous and inferior petrosal sinus sampling and dynamic magnetic resonance imaging in the preoperative evaluation of Cushing's disease.

The surgical management of Cushing's disease is often complicated by difficulties detecting corticotropic adenomas. Various diagnostic modalities are used when conventional magnetic resonance imaging (MRI) is negative or inconclusive. We sought to analyze our use of two such modalities in the surgical management of Cushing's disease: (1) cavernous/inferior petrosal sinus sampling (central venous sampling, CVS) for adrenocorticotropic hormone and (2) dynamic MRI (dMRI). We conducted a single-center, retrospective review of all patients with Cushing's disease treated by a single neurosurgeon with endonasal transsphenoidal surgery. Accuracy of adenoma localization with CVS and dMRI was analyzed. Ninety-one consecutive patients were included. Pathology confirmed an adenoma in 66. Preoperative dMRI and CVS were performed in 40 and 37 patients, respectively, with 20 undergoing both studies. Surgical pathology was positive for adenoma in 31 dMRI patients, 25 CVS patients, and 13 who underwent both. Among patients with pathology confirming an adenoma, dMRI identified a lesion in 96.8% and correctly lateralized the lesion in 89.7%, while CVS correctly lateralized in 52.2-65.2% (depending on location of sampling). Among patients with both studies, dMRI and CVS correctly lateralized in 76.9 and 61.5-69.2%, respectively. Accuracy of CVS improved if only patients with symmetric venous drainage were considered. In this mixed population of Cushing's disease patients, dMRI was more accurate than CVS at localizing adenomas, supporting the use of advance MRI techniques in the work-up of Cushing's disease. CVS, however, remains an important tool in the workup of Cushing's syndrome.

Aspirin therapy in venous malformation: a retrospective cohort study of benefits, side effects, and patient experiences.

Venous malformations (VMs) are often painful and may enlarge over time. Chronic coagulopathy is common in VMs and may contribute to phleboliths and potentially to disease progression. Few studies have examined the effects of anticoagulation on VMs and to our knowledge none have examined the use of aspirin therapy. A survey was administered to patients and parents of patients with VMs who attended the University of California at San Francisco Vascular Anomalies Center over a 4-year period (2008-2012) to whom aspirin had been recommended. They were surveyed regarding whether they were taking aspirin and, if yes, whether aspirin had resulted in any appreciable benefit. Sixty-five letters were sent to potential subjects: 38 participated and 27 declined to participate or could not be contacted. Twenty-eight of the 38 had begun aspirin and 22 reported current use. Seventeen reported some benefit, including less aching (n = 2), less shooting pain (n = 15), less fullness and swelling (n = 13), and shrinking of the VM (n = 1). Discontinuation of aspirin was associated with worsening VM symptoms in five of six patients. Side effects were reported in 6 of 28 patients, including five episodes of minor bleeding or excessive bruising and one of nausea and vomiting. This study suggests that aspirin may be a beneficial treatment for VM, with a reduction in pain and soft tissue swelling and an acceptable side-effect profile, but the retrospective nature of the study and the small size of the cohort limited our conclusions. Larger prospective studies of aspirin for VM using clinical and laboratory outcome measures are needed to confirm these observations.

Density of thrombus on admission CT predicts revascularization efficacy in large vessel occlusion acute ischemic stroke.

BACKGROUND AND PURPOSE: Can lysability of large vessel thrombi in acute ischemic stroke be predicted by measuring clot density on admission nonenhanced CT (NECT), postcontrast enhanced CT, or CT angiogram (CTA)? METHODS: We retrospectively studied 90 patients with acute large vessel ischemic strokes treated with intravenous (IV) tPA, intra-arterial (IA) tPA, and/or mechanical thrombectomy devices. Clot density [in Hounsfield unit (HU)] was measured on NECT, postcontrast enhanced CT, and CTA. Recanalization was assessed by the Thrombolysis in Cerebral Infarction grading system (TICI) on digital subtraction angiography. RESULTS: Thrombus density on preintervention NECT correlated with postintervention TICI grade regardless of pharmacological (IV tPA r=0.69, IA tPA r=0.72, P<0.0001) or mechanical treatment (r=0.73, P<0.0001). Patients with TICI≥2 demonstrated higher HU on NECT (mean corrected HU IV tPA=1.58, IA tPA=1.66, mechanical treatment=1.7) compared with patients with TICI<2 (IV tPA=1.39, IA tPA=1.4, mechanical treatment=1.3) (P=0.01, 0.006, <0.0001 respectively). There was no association between recanalization and age, sex, baseline National Institute of Health Stroke Scale, treatment method, time to treatment, or clot volume. CONCLUSIONS: Thrombi with lower HU on NECT appear to be more resistant to pharmacological lysis and mechanical thrombectomy. Measuring thrombus density on admission NECT provides a rapid method to analyze clot composition, a potentially useful discriminator in selecting the most appropriate reperfusion strategy for an individual patient.

Early versus later presentations of venous malformations: where and why?

Venous malformations (VMs) are congenital anomalies of the venous vasculature, but not all are evident at birth. The factors that lead to presentation later in life are not well understood. The objective of this retrospective cohort study of patients with VMs evaluated at the University of California at San Francisco Birthmarks and Vascular Anomalies Center from 2005 to 2009 was to investigate the clinical presentation of VMs and correlate these features with different types of tissues (e.g., skin, subcutis, intramuscular). Main outcomes included the age at which lesions were first noticed, tissue type involved, presenting signs and symptoms, aggravating factors, and morbidities. A total of 115 subjects was included. The mean age when VM was first noted was 6.7 ± 0.9 years. Tissue types involved included skin/subcutaneous (46%); intramuscular (40%); and bone, tendon, or joint (14%). Presenting signs/symptoms included soft tissue swelling (44%), discrete mass (34%), pain (33%), and skin discoloration (26%). When compared with VMs limited to the skin or subcutis, those restricted to the intramuscular compartment were less likely to present at birth (27% vs 53%, p < 0.05) but were more frequently painful (79% vs 60%, p < 0.05) and contained more phleboliths (28% vs 11%, p < 0.05), and were associated with more exercise limitation (35% vs 16%, p < 0.05). VMs differ in age of onset, clinical features, and complications based on differing tissues and sites of involvement, with isolated intramuscular involvement associated with later presentation and greater morbidity.

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 .

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.

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.

Brain arteriovenous malformation multiplicity predicts the diagnosis of hereditary hemorrhagic telangiectasia: quantitative assessment.

BACKGROUND AND PURPOSE: The purpose of this study was to quantitatively estimate the relationship between multiplicity of brain arteriovenous malformations (bAVMs) and the diagnosis of hereditary hemorrhagic telangiectasia (HHT). METHODS: We combined databases from 2 large North American bAVM referral centers, including demographics, clinical presentation, and angiographic characteristics, and compared patients with HHT with non-HHT patients. Logistic regression analysis was performed to quantify the association between bAVM multiplicity and odds of HHT diagnosis. Sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ratios were calculated to determine accuracy of bAVM multiplicity for screening HHT. RESULTS: Prevalence of HHT was 2.8% in the combined group. bAVM multiplicity was present in 39% of patients with HHT and was highly associated with diagnosis of HHT in univariate (OR, 83; 95% CI, 40-173; P<0.0001) and multivariable (OR, 86; 95% CI, 38-195; P<0.001) models adjusting for age at presentation (P=0.013), symptomatic presentation (P=0.029), and cohort site (P=0.021). bAVM multiplicity alone was associated with high specificity (99.2%; 95% CI, 98.7%-99.6%) and negative predictive value (98.3%; 95% CI, 97.6%-98.8%) and low sensitivity (39.3%; 95% CI, 26.5%-53.2%) and positive predictive value (59.5%; 95% CI, 42.1%-75.2%). Positive and negative likelihood ratio was 51 and 0.61, respectively, for diagnosis of HHT. HHT bAVMs were also more often smaller in size (<3 cm), noneloquent in location, and associated with superficial venous drainage compared with non-HHT bAVMs. CONCLUSIONS: Multiplicity of bAVMs is highly predictive of the diagnosis of HHT. The presence of multiple bAVMs should alert the clinician to the high probability of HHT and lead to comprehensive investigation for this diagnosis.

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.