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Featured researches published by Matthew R. Amans.


American Journal of Neuroradiology | 2014

Influence of patient age on angioarchitecture of brain arteriovenous malformations.

Steven W. Hetts; Daniel L. Cooke; Jeffrey Nelson; Nalin Gupta; Heather J. Fullerton; Matthew R. Amans; Jared Narvid; Parham Moftakhar; Hugh McSwain; Christopher F. Dowd; Randall T. Higashida; Van V. Halbach; Michael T. Lawton; Helen Kim

Over 800 AVMs were retrospectively reviewed to determine if clinical and angioarchitectural features varied between children and adults. The authors found that hemorrhages and exclusively deep venous drainage were more common in children but high-risk features such as venous ectasia and feeding artery aneurysm were more common in adults. Thus, these latter high-risk features may take time to develop. BACKGROUND AND PURPOSE: The imaging characteristics and modes of presentation of brain AVMs may vary with patient age. Our aim was to determine whether clinical and angioarchitectural features of brain AVMs differ between children and adults. MATERIALS AND METHODS: A prospectively collected institutional data base of all patients diagnosed with brain AVMs since 2001 was queried. Demographic, clinical, and angioarchitecture information was summarized and analyzed with univariable and multivariable models. RESULTS: Results often differed when age was treated as a continuous variable as opposed to dividing subjects into children (18 years or younger; n = 203) versus adults (older than 18 years; n = 630). Children were more likely to present with AVM hemorrhage than adults (59% versus 41%, P < .001). Although AVMs with a larger nidus presented at younger ages (mean of 26.8 years for >6 cm compared with 37.1 years for <3 cm), this feature was not significantly different between children and adults (P = .069). Exclusively deep venous drainage was more common in younger subjects when age was treated continuously (P = .04) or dichotomized (P < .001). Venous ectasia was more common with increasing age (mean, 39.4 years with ectasia compared with 31.1 years without ectasia) and when adults were compared with children (52% versus 35%, P < .001). Patients with feeding artery aneurysms presented at a later average age (44.1 years) than those without such aneurysms (31.6 years); this observation persisted when comparing children with adults (13% versus 29%, P < .001). CONCLUSIONS: Although children with brain AVMs were more likely to come to clinical attention due to hemorrhage than adults, venous ectasia and feeding artery aneurysms were under-represented in children, suggesting that these particular high-risk features take time to develop.


Journal of NeuroInterventional Surgery | 2014

Current trends in endovascular management of traumatic cerebrovascular injury

Akash P. Kansagra; Daniel L. Cooke; Joey D. English; Ryan Sincic; Matthew R. Amans; Christopher F. Dowd; Van V. Halbach; Randall T. Higashida; Steven W. Hetts

Background The role of catheter angiography in the diagnosis and management of traumatic cerebrovascular injury has evolved rapidly with advances in CT and MR angiography and continued development of endovascular techniques. Objective To identify the modern spectrum of traumatic arterial injury encountered during catheter neuroangiography and to examine current patterns of endovascular treatment. Methods Records of trauma patients undergoing catheter neuroangiography over a 4 year period at two high volume centers were retrospectively reviewed. The sample comprised 100 separate arterial lesions that were classified according to mechanism, location, acuity, and endovascular treatment. Follow-up imaging and clinical notes were reviewed to identify procedural complications. Results Of 100 arterial lesions, 81% were related to blunt trauma. Distribution of lesions by location was 42% intracranial, 39% cervical, and 19% extracranial. The most common injuries were pseudoaneurysm (38%), fistula (29%), and dissection (19%). In total, 41% of lesions underwent endovascular treatment, with trends favoring treatment of non-acute, penetrating, non-cervical, and high grade lesions. Therapy involved coil embolization for 89% of treated lesions. There were a total of two immediate neurovascular complications and one delayed neurovascular complication; one of these resulted in a permanent neurological deficit. Conclusions Our experience in a large cohort of patients suggests that a relatively high proportion of traumatic arterial lesions identified by catheter angiography are treated by endovascular means, with a low rate of immediate and delayed neurovascular complications.


Interventional Neuroradiology | 2014

Contrast staining on CT after DSA in ischemic stroke patients progresses to infarction and rarely hemorrhages.

Matthew R. Amans; Daniel L. Cooke; Maya Vella; Christopher F. Dowd; Van V. Halbach; Randall T. Higashida; Steven W. Hetts

Contrast staining of brain parenchyma identified on non-contrast CT performed after DSA in patients with acute ischemic stroke (AIS) is an incompletely understood imaging finding. We hypothesize contrast staining to be an indicator of brain injury and suspect the fate of involved parenchyma to be cerebral infarction. Seventeen years of AIS data were retrospectively analyzed for contrast staining. Charts were reviewed and outcomes of the stained parenchyma were identified on subsequent CT and MRI. Thirty-six of 67 patients meeting inclusion criteria (53.7%) had contrast staining on CT obtained within 72 hours after DSA. Brain parenchyma with contrast staining in patients with AIS most often evolved into cerebral infarction (81%). Hemorrhagic transformation was less likely in cases with staining compared with hemorrhagic transformation in the cohort that did not have contrast staining of the parenchyma on post DSA CT (6% versus 25%, respectively, OR 0.17, 95% CI 0.017–0.98, p = 0.02). Brain parenchyma with contrast staining on CT after DSA in AIS patients was likely to infarct and unlikely to hemorrhage.


Journal of NeuroInterventional Surgery | 2013

Cerebral arteriopathy associated with Arg179His ACTA2 mutation

Matthew R. Amans; Charles Stout; Christine K. Fox; Jared Narvid; Steven W. Hetts; Daniel L. Cooke; Randall T. Higashida; Christopher F. Dowd; Hugh McSwain; Van V. Halbach

ACTA2 mutations have recently been shown to cause a multisystem smooth muscle dysfunction syndrome that may result in pediatric stroke. We report a case of ACTA2 mutation in a 3-year-old girl presenting with acute ischemic stroke and provide high resolution imaging of the cerebral arteries demonstrating novel findings of multiple tiny aneurysms (particularly in the posterior circulation), as well as the more characteristic imaging phenotype of straightened and narrowed proximal intracranial vessels, dilated cervical vessels and occlusion of the M1 MCA segment without lenticulostriate collateral formation. This newly identified disease should be added to the differential diagnosis of pediatric stroke and cerebral vasculopathy. Neuroradiologists, interventionalists, surgeons and neurologists should become familiar with this rare disease and its clinical sequelae.


American Journal of Neuroradiology | 2016

Superselective Intra-Arterial Ethanol Sclerotherapy of Feeding Artery and Nidal Aneurysms in Ruptured Cerebral Arteriovenous Malformations.

Fabio Settecase; S Hetts; A Nicholson; Matthew R. Amans; Daniel L. Cooke; Christopher F. Dowd; Randall T. Higashida; Van V. Halbach

SUMMARY: In the endovascular treatment of cerebral arteriovenous malformations, ethanol sclerotherapy is seldom used due to safety concerns. However, when limited reflux of an embolic agent is permissible or when there is a long distance to the target, ethanol may be preferable. We reviewed 10 patients with 14 cerebral AVM feeding artery aneurysms or intranidal aneurysms treated with intra-arterial ethanol sclerotherapy at our institution between 2005 and 2014. All patients presented with acute intracranial hemorrhage. Thirteen of 14 aneurysms were treated primarily with 60%–80% ethanol into the feeding artery. Complete target feeding artery and aneurysm occlusion was seen in all cases; 8/13 (62%) were occluded by using ethanol alone. No retreatments or recurrences were seen. One permanent neurologic deficit (1/13, 7.7%) and no deaths occurred. In a subset of ruptured cerebral AVMs, ethanol sclerotherapy of feeding artery aneurysms and intranidal aneurysms can be performed with a high degree of technical success and a low rate of complication.


Journal of NeuroInterventional Surgery | 2015

Radiological and clinical features of vein of Galen malformations

Maggie L. Chow; Daniel L. Cooke; Heather J. Fullerton; Matthew R. Amans; Jared Narvid; Christopher F. Dowd; Randall T. Higashida; Van V. Halbach; Steven W. Hetts

Background Vein of Galen malformations (VOGMs) are rare and complex congenital arteriovenous fistulas. The clinical and radiological features of VOGMs and their relation to clinical outcomes are not fully characterized. Objective To examine the clinical and radiological features of VOGMs and the predictors of outcome in patients. Methods We retrospectively reviewed the available imaging and medical records of all patients with VOGMs treated at the University of California, San Francisco between 1986 and 2013. Radiological and clinical features were identified. We applied the modified Rankin Scale to determine functional outcome by chart review. Predictors of outcome were assessed by χ2 analyses. Results Forty-one cases were confirmed as VOGM. Most patients (78%) had been diagnosed with VOGM in the first year of life. Age at treatment was bimodally distributed, with predominantly urgent embolization at <10 days of age and elective embolization after 1 year of age. Patients commonly presented with hydrocephalus (65.9%) and congestive heart failure (61.0%). Mixed-type (31.7%) VOGM was more common in our cohort than purely mural (29.3%) or choroidal (26.8%) types. The most common feeding arteries were the choroidal and posterior cerebral arteries. Transarterial embolization with coils was the most common technique used to treat VOGMs at our institution. Functional outcome was normal or only mildly disabled in 50% of the cases at last follow-up (median=3 years, range=0–23 years). Younger age at first diagnosis, congestive heart failure, and seizures were predictive of adverse clinical outcome. The survival rate in our sample was 78.0% and complete thrombosis of the VOGM was achieved in 62.5% of patients. Conclusions VOGMs continue to be challenging to treat and manage. Nonetheless, endovascular approaches to treatment are continuing to be refined and improved, with increasing success. The neurodevelopmental outcomes of affected children whose VOGMs are treated may be good in many cases.


Journal of Neurosurgery | 2015

Extent of collateralization predicting symptomatic cerebral vasospasm among pediatric patients: correlations among angiography, transcranial Doppler ultrasonography, and clinical findings

Parham Moftakhar; Daniel L. Cooke; Heather J. Fullerton; Nerissa U. Ko; Matthew R. Amans; Jared Narvid; Christopher F. Dowd; Randall T. Higashida; Van V. Halbach; Steven W. Hetts

OBJECT Although the development and prevalence of cerebral vasospasm (CV) has been extensively investigated in adults, little data exist on the development of CV in children. The authors hypothesized that even though children have highly vasoreactive arteries, because of a robust cerebral collateral blood flow, they rarely develop symptomatic CV. METHODS The authors retrospectively reviewed their university hospitals neurointerventional database for children (that is, patients ≤ 18 years) who were examined or treated for aneurysmal or traumatic subarachnoid hemorrhage (SAH) during the period 1990-2013. Images from digital subtraction angiography (DSA) were analyzed for the extent of CV and collateralization of the cerebral circulation. Results from transcranial Doppler (TCD) ultrasonography were correlated with those from DSA. Cerebral vasospasm on TCD ultrasonography was defined according to criteria developed for adults. Clinical outcomes of CV were assessed with the pediatric modified Rankin Scale (mRS). RESULTS Among 37 children (21 boys and 16 girls ranging in age from 8 months to 18 years) showing symptoms of an aneurysmal SAH (comprising 32 aneurysms and 5 traumatic pseudoaneurysms), 17 (46%) had CV confirmed by DSA; CV was mild in 21% of these children, moderate in 50%, and severe in 29%. Only 3 children exhibited symptomatic CV, all of whom had poor collateralization of cerebral vessels. Among the 14 asymptomatic children, 10 (71%) showed some degree of vessel collateralization. Among 16 children for whom TCD data were available that could be correlated with the DSA findings, 13 (81%) had CV according to TCD criteria. The sensitivity and specificity of TCD ultrasonography for diagnosing CV were 95% and 59%, respectively. The time to CV onset detected by TCD ultrasonography was 5 ± 3 days (range 2-10 days). Twenty-five (68%) of the children had good long-term outcomes (that is, had mRS scores of 0-2). CONCLUSIONS Children have a relatively high incidence of angiographically detectable, moderate-to-severe CV. Children rarely develop symptomatic CV and have good long-term outcomes, perhaps due to robust cerebral collateral blood flow. Criteria developed for detecting CV with TCD ultrasonography in adults overestimate the prevalence of CV in children. Larger studies are needed to define TCD ultrasonography-based CV criteria for children.


American Journal of Neuroradiology | 2015

Progressive versus Nonprogressive Intracranial Dural Arteriovenous Fistulas: Characteristics and Outcomes

Steven W. Hetts; T. Tsai; Daniel L. Cooke; Matthew R. Amans; Fabio Settecase; Parham Moftakhar; Christopher F. Dowd; Randall T. Higashida; Michael T. Lawton; Van V. Halbach

Of 579 patients with intracranial dural arteriovenous fistulas, 545 had 1 fistula and 34 (5.9%) had enlarging, de novo, multiple, or recurrent fistulas. Of those 34 patients, 19 had progressive dural arteriovenous fistulas with de novo fistulas or fistula enlargement. Angioarchitectural correlates to chronically elevated intracranial venous pressures, such as venous sinus dilation and pseudophlebitic cortical venous pattern, were more common in progressive disease. Three young patients died despite endovascular, surgical, and radiosurgical treatments. BACKGROUND AND PURPOSE: A minority of intracranial dural arteriovenous fistulas progress with time. We sought to determine features that predict progression and define outcomes of patients with progressive dural arteriovenous fistulas. MATERIALS AND METHODS: We performed a retrospective imaging and clinical record review of patients with intracranial dural arteriovenous fistula evaluated at our hospital. RESULTS: Of 579 patients with intracranial dural arteriovenous fistulas, 545 had 1 fistula (mean age, 45 ± 23 years) and 34 (5.9%) had enlarging, de novo, multiple, or recurrent fistulas (mean age, 53 ± 20 years; P = .11). Among these 34 patients, 19 had progressive dural arteriovenous fistulas with de novo fistulas or fistula enlargement with time (mean age, 36 ± 25 years; progressive group) and 15 had multiple or recurrent but nonprogressive fistulas (mean age, 57 ± 13 years; P = .0059, nonprogressive group). Whereas all 6 children had fistula progression, only 13/28 adults (P = .020) progressed. Angioarchitectural correlates to chronically elevated intracranial venous pressures, including venous sinus dilation (41% versus 7%, P = .045) and pseudophlebitic cortical venous pattern (P = .048), were more common in patients with progressive disease than in those without progression. Patients with progressive disease received more treatments than those without progression (median, 5 versus 3; P = .0068), but as a group, they did not demonstrate worse clinical outcomes (median mRS, 1 and 1; P = .39). However, 3 young patients died from intracranial venous hypertension and intracranial hemorrhage related to progression of their fistulas despite extensive endovascular, surgical, and radiosurgical treatments. CONCLUSIONS: Few patients with dural arteriovenous fistulas follow an aggressive, progressive clinical course despite treatment. Younger age at initial presentation and angioarchitectural correlates to venous hypertension may help identify these patients prospectively.


Journal of NeuroInterventional Surgery | 2016

Lesion location, stability, and pretreatment management: factors affecting outcomes of endovascular treatment for vertebrobasilar atherosclerosis

Alexander; Rebhun Jm; Steven W. Hetts; Anthony S. Kim; Jeffrey Nelson; Helen Kim; Matthew R. Amans; Fabio Settecase; Christopher F. Dowd; Van V. Halbach; Randall T. Higashida; Daniel L. Cooke

Background and purpose The proper role of endovascular treatment of cervicocerebral atherosclerosis is unclear. Posterior circulation disease has not been investigated as extensively as disease in the anterior circulation. In this study, we characterized the rates of technical success, transient ischemic attack, stroke, and death or disability, for both acute and elective endovascular treatment of atherosclerosis in the vertebrobasilar system. Methods We identified patients with atherosclerosis of the vertebrobasilar circulation who underwent endovascular intervention at our hospital through retrospective medical record review, and evaluated the association between lesion and treatment features and subsequent stroke, death, or disability at 30 days and 1 year. Results We identified 136 lesions in 122 patients, including 13 interventions for acute strokes. Technical success was achieved in 123 of 136 cases (90.4%). Elective procedures had higher rates of technical success (6.5% vs 15.4%, p=0.21) and better clinical outcomes. In multivariate analysis, intracranial lesions were associated with more disability (modified Rankin Scale score >2) at 30 days (OR 7.1, p=0.01) and 1 year (OR 10, p=0.03). Patients with non-hypoperfusion related symptoms had fewer strokes at follow-up at 1 year when treated after an asymptomatic interval of >10 days compared with those treated within 10 days of the presenting symptoms (OR 0.2, p=0.03). Statin treatment prior to intervention was associated with favorable outcomes across several examined endpoints. Preoperative antiplatelet treatment was associated with lower rates of disability at 30 days and 1 year (OR 0.1, p<0.01 and OR 0.07, p=0.01, respectively), and preoperative anticoagulation treatment was associated with higher rates of death at 30 days, particularly when prescribed for reasons other than atrial fibrillation (OR 6.4, p=0.01). Conclusions Endovascular treatment of symptomatic vertebrobasilar atherosclerosis can be performed safely and with good outcomes. Technical results were better for those with extracranial disease while clinical outcomes were more favorable in those patients with non-progressive symptoms in the subacute period and those receiving statin therapy.


Radiology Case Reports | 2013

Cerebral parenchymal cyst: A rare complication of ventriculoperitoneal shunt malfunction in an adult.

Matthew R. Amans; William P. Dillon

We report a rare complication of ventriculoperitoneal (VP) shunt malfunction: an intraparenchymal pericatheter cerebrospinal fluid (CSF) cyst. To the best of our knowledge, this is the second reported case of VP-shunt-related parenchymal CSF cyst to be reported in an adult patient, and the longest reported delay in development of this complication after shunt placement. Mass effect and edema from CSF cysts on CT and even T2 FLAIR sequences suggest the diagnosis of cerebral abscess or tumor. Comprehensive MR imaging can exclude both, and lead to proper management. While this complication is rare, clinicians treating adult patients with shunts, even shunts placed decades prior, need to be aware of it.

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Van V. Halbach

University of California

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A Nicholson

University of California

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Jared Narvid

University of California

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S Hetts

University of California

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David Saloner

University of California

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