C F Dowd

University of California, San Francisco, San Francisco, California, United States

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Publications (192)610.56 Total impact

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    ABSTRACT: Intracranial atherosclerotic disease (ICAD) is often stratified by degree of stenosis. Additional features such as patient demographics and symptom characteristics also affect lesion behavior and response to treatment. This study compares stratification by degree of narrowing to these additional features.
    Journal of Neurointerventional Surgery 07/2014; 6 Suppl 1:A7. · 2.50 Impact Factor
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    ABSTRACT: Although many intracranial dural arteriovenous fistulas (DAVFs) are straightforward to treat, de novo and rapidly progressive ("runaway" or "malignant") DAVFs are more complex, often requiring multiple treatment sessions with suboptimal results. As these are rare entities, we sought to review our experience in the treatment of de novo and progressive DAVFs in order to better understand predictors of disease progression.
    Journal of Neurointerventional Surgery 07/2014; 6 Suppl 1:A47. · 2.50 Impact Factor
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    ABSTRACT: 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.
    Pediatric Dermatology 07/2014; · 1.04 Impact Factor
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    ABSTRACT: Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms "fenestration" or "fenestrated" with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms.
    06/2014; 20(3):261-74.
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    ABSTRACT: 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. To examine the clinical and radiological features of VOGMs and the predictors of outcome in patients. 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 χ(2) analyses. 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. 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 Neurointerventional Surgery 04/2014; · 2.50 Impact Factor
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    ABSTRACT: Different types of symptomatic intracranial stenosis may respond differently to interventional therapy. We investigated symptomatic and pathophysiologic factors that may influence clinical outcomes of patients with intracranial atherosclerotic disease who were treated with stents. A retrospective analysis was performed of patients treated with stents for intracranial atherosclerosis at 4 centers. Patient demographics and comorbidities, lesion features, treatment features, and preprocedural and postprocedural functional status were noted. χ(2) univariate and multivariate logistic regression analysis was performed to assess technical results and clinical outcomes. One hundred forty-two lesions in 131 patients were analyzed. Lesions causing hypoperfusion ischemic symptoms were associated with fewer strokes by last contact [χ(2) (1, n = 63) = 5.41, P = .019]. Nonhypoperfusion lesions causing symptoms during the 14 days before treatment had more strokes by last contact [χ(2) (1, n = 136), 4.21, P = .047]. Patients treated with stents designed for intracranial deployment were more likely to have had a stroke by last contact (OR, 4.63; P = .032), and patients treated with percutaneous balloon angioplasty in addition to deployment of a self-expanding stent were less likely to be stroke free at point of last contact (OR, 0.60; P = .034). More favorable outcomes may occur after stent placement for lesions causing hypoperfusion symptoms and when delaying stent placement 7-14 days after most recent symptoms for lesions suspected to cause embolic disease or perforator ischemia. Angioplasty performed in addition to self-expanding stent deployment may lead to worse outcomes, as may use of self-expanding stents rather than balloon-mounted stents.
    American Journal of Neuroradiology 03/2014; · 3.17 Impact Factor
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    ABSTRACT: 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. 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 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). 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.
    American Journal of Neuroradiology 03/2014; · 3.17 Impact Factor
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    ABSTRACT: 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.
    Interventional Neuroradiology 02/2014; 20(1):106-15. · 0.77 Impact Factor
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    ABSTRACT: The ability of polymer-modified coils to promote stable aneurysm occlusion after endovascular treatment is not well-documented. Angiographic aneurysm recurrence is widely used as a surrogate for treatment failure, but studies documenting the correlation of angiographic recurrence with clinical failure are limited. This trial compares the effectiveness of Matrix(2) polyglycolic/polylactic acid biopolymer-modified coils with bare metal coils and correlates the angiographic findings with clinical failure (ie, target aneurysm recurrence), a composite end point that includes any incident of posttreatment aneurysm rupture, retreatment, or unexplained death. This was a multicenter randomized noninferiority trial with blinded end point adjudication. We enrolled 626 patients, divided between Matrix(2) and bare metal coil groups. The primary outcome was target aneurysm recurrence at 12 ± 3 months. At 455 days, at least 1 target aneurysm recurrence event had occurred in 14.6% of patients treated with bare metal coils and 13.3% of Matrix(2) (P = .76, log-rank test) patients; 92.8% of target aneurysm recurrence events were re-interventions for aneurysms that had not bled after treatment, and 5.8% of target aneurysm recurrence events resulted from hemorrhage or rehemorrhage, with or without retreatment. Symptomatic re-intervention occurred in only 4 (0.6%) patients. At 455 days, 95.8% of patients with unruptured aneurysms and 90.4% of those with ruptured aneurysms were independent (mRS ≤ 2). Target aneurysm recurrence was associated with incomplete initial angiographic aneurysm obliteration, presentation with rupture, and a larger aneurysmal dome and neck size. Tested Matrix(2) coils were not inferior to bare metal coils. Endovascular coiling of intracranial aneurysms was safe, and the rate of technical success was high. Target aneurysm recurrence is a promising clinical outcome measure that correlates well with established angiographic measurements.
    American Journal of Neuroradiology 01/2014; · 3.17 Impact Factor
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    ABSTRACT: 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.
    Journal of Neuro-Oncology 01/2014; · 3.12 Impact Factor
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    ABSTRACT: Retinoblastoma (RB) is a rare malignancy affecting the pediatric population. Intravenous chemotherapy is the longstanding delivery method, although intra-arterial (IA) chemotherapy is gaining popularity given the reduced side effects compared with systemic chemotherapy administration. Given the sensitivity of the target organ, patient age, and secondary tumor susceptibility, a premium has been placed on minimizing procedural related radiation exposure. To reduce patient x-ray dose during the IA infusion procedure, customized surgical methods and fluoroscopic techniques were employed. The routine fluoroscopic settings were changed from the standard 7.5 pulses/s and dose level to the detector of 36 nGy/pulse, to a pulse rate of 4 pulses/s and detector dose to 23 nGy/pulse. The angiographic dose indicators (reference point air kerma (Ka) and fluoroscopy time) for a cohort of 10 consecutive patients (12 eyes, 30 infusions) were analyzed. An additional four cases (five eyes, five infusions) were analyzed using dosimeters placed at anatomic locations to reflect scalp, eye, and thyroid dose. The mean Ka per treated eye was 20.1±11.9 mGy with a mean fluoroscopic time of 8.5±4.6 min. Dosimetric measurements demonstrated minimal dose to the lens (0.18±0.10 mGy). Measured entrance skin doses varied from 0.7 to 7.0 mGy and were 73.4±19.7% less than the indicated Ka value. Ophthalmic arterial melphalan infusion is a safe and effective means to treat RB. Modification to contemporary fluoroscopic systems combined with parsimonious fluoroscopy can minimize radiation exposure.
    Journal of Neurointerventional Surgery 01/2014; · 2.50 Impact Factor
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    ABSTRACT: Background and Purpose Endovascular sampling and characterization from patients can provide very useful information about the pathogenesis of different vascular diseases, but it has been much limited by the lack of an effective method of endothelial cell (EC)enrichment. We optimized the EC yield and enrichment from conventional guide wires by laser capture microdissection (LCM) and fluorescence activated cell sorting (FACS) techniques, and addressed the feasibility of using these enriched ECs for downstream gene expression detection. Methods Iliac artery endovascular samples from 10 patients undergoing routine catheter angiography were collected using conventional 0.038 inch J-shape guide wires. Each of the samples were equally divided into two parts, which were respectively used for EC enrichment by immunocytochemistry -coupled LCM or multiple color FACS. After RNA extraction and reverse transcription, the amplified cDNA were used for quantitative polymerase chain reaction (qPCR). Results Fixed ECs, with positive CD31 or vWF fluorescent signal and endothelial like nucleus, were successfully separated by LCM and live single ECs were sorted on FACS by a seven color staining panel. EC yields by LCM and FACS were 51 ± 22 and 149 ± 56 respectively (P < 0.001). The minimum number of fixed ECs from ICC-coupled LCM for acceptable qPCR results of endothelial marker genes was 30, while acceptable qPCR results as enriched by FACS were attainable from a single live EC. Conclusion Both LCM and FACS can be used to enrich ECs from conventional guide wires and the enriched ECs can be used for downstream gene expression detection. FACS generated a higher EC yield and the sorted live ECs may be used for single cell gene expression detection.
    Journal of Biotechnology. 01/2014;
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    ABSTRACT: The absence of safe and reliable methods to harvest vascular tissue in situ limits the discovery of the underlying genetic and pathophysiological mechanisms of many vascular disorders such as aneurysms. We investigated the feasibility and comparable efficacy of endothelial cell collection using a spectrum of endovascular coils. Nine detachable coils ranging in k coefficient (0.15-0.24), diameter (4.0 mm-16.0 mm), and length (8.0 cm-47.0 cm) were tested in pigs. All coils were deployed and retrieved within the iliac artery of pigs (three coils/pig). Collected coils were evaluated under light microscopy. The total and endothelial cells collected by each coil were quantified. The nucleated cells were identified by Wright-Giemsa and DAPI stains. Endothelial and smooth muscle cells were identified by CD31 and α-smooth muscle actin antibody staining. Coils were deployed and retrieved without technical difficulty. Light microscopy demonstrated sheets of cellular material concentrated within the coil winds. All coils collected cellular material while five of nine (55.6%) coils retrieved endothelial cells. Coils collected mean endothelial cell counts of 89.0±101.6. Regression analysis demonstrated a positive correlation between increasing coil diameter and endothelial cell counts (R(2)=0.52, p = 0.029). Conventional detachable coils can be used to harvest endothelial cells. The number of endothelial cells collected by a coil positively correlated with its diameter. Given the widespread use of coils and their well-described safety profile their potential as an endovascular biopsy device would expand the availability of tissue for cellular and molecular analysis.
    Interventional Neuroradiology 12/2013; 19(4):399-408. · 0.77 Impact Factor
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    ABSTRACT: BACKGROUND AND PURPOSE:Stent-assisted coiling may result in less aneurysm recanalization but more complications than coiling alone. We evaluated outcomes of coiling with and without stents in the multicenter Matrix and Platinum Science Trial.MATERIALS AND METHODS:All patients in the Matrix and Platinum Science Trial with unruptured intracranial aneurysms treated per protocol were included. Baseline patient and aneurysm characteristics, procedural details, neurologic outcomes, angiographic outcomes, and safety data were analyzed.RESULTS:Overall, 137 of 361 (38%) patients were treated with a stent. Stent-coiled aneurysms had wider necks (≥4 mm in 62% with stents versus 33% without, P < .0001) and lower dome-to-neck ratios (1.3 versus 1.8, P < .0001). Periprocedural serious adverse events occurred infrequently in those treated with and without stents (6.6% versus 4.5%, P = .39). At 1 year, total significant adverse events, mortality, and worsening of mRS were similar in treatment groups, but ischemic strokes were more common in stent-coiled patients than in coiled patients (8.8% versus 2.2%, P = .005). However, multivariate analysis confirmed that at 2 years after treatment, prior cerebrovascular accident (OR, 4.7; P = .0089) and aneurysm neck width ≥4 mm (OR, 4.5; P = .02) were the only independent predictors of ischemic stroke. Stent use was not an independent predictor of ischemic stroke at 2 years (OR, 1.1; P = .94). Stent use did not predict target aneurysm recurrence at 2 years, but aneurysm dome size ≥10 mm (OR, 9.94; P < .0001) did predict target aneurysm recurrence.CONCLUSIONS:Stent-coiling had similar outcomes as coiling despite stented aneurysms having more difficult morphology than coiled aneurysms. Increased ischemic events in stent-coiled aneurysms were attributable to baseline risk factors and aneurysm morphology.
    American Journal of Neuroradiology 11/2013; · 3.17 Impact Factor
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    ABSTRACT: BACKGROUND: The use of ethylene-vinyl alcohol copolymer for liquid embolization of cranial vascular lesions has resulted in microcatheter fragments entrapped in patients following endovascular procedures. Undergoing subsequent diagnostic MRI examinations poses a safety concern due to the possibility of radiofrequency heating of the metallic braid incorporated into the microcatheter. Heating of nitinol, tungsten, and polyetheretherketone (PEEK) braided microcatheters was assessed and compared using a phantom model. METHODS: Microcatheters coupled with fluoroptic temperature probes were embedded in a polyacrylamide gel within a head and torso phantom. Experiments were performed at 1.5 T and 3 T, analyzing the effects of different catheter immersion lengths, specific absorption rate (SAR) levels, short clinical scans, long clinical scans, and microcatheter fragment lengths. RESULTS: The maximal increase in temperature for the nitinol braided microcatheter during a 15 min scan was 3.06°C using the T1 fast spin echo sequence at 1.5 T and 0.45°C using the balanced steady state free precession sequence at 3 T. The same scans for fragment lengths of 9, 18, 36, and 72 cm produced maximal temperature rises of 0.68, 0.80, 1.70, and 1.07°C at 1.5 T, respectively. The temperature changes at 3 T for these fragment lengths were 0.66, 0.83, 1.07, and 0.72°C, respectively. The tungsten and PEEK braided microcatheters did not demonstrate heating. CONCLUSIONS: Substantial heating of nitinol braided microcatheters occurred and was a function of SAR level and geometric considerations. SAR and time limitations on MR scanning are proposed for patients with this microcatheter entrapped in their vasculature. In contrast, tungsten and PEEK braided microcatheters showed potential safe use in MRI.
    Journal of Neurointerventional Surgery 05/2013; · 2.50 Impact Factor
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    ABSTRACT: 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.
    Pediatric Dermatology 05/2013; · 1.04 Impact Factor
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    ABSTRACT: 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.
    Journal of Neurointerventional Surgery 01/2013; · 2.50 Impact Factor
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    ABSTRACT: 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.
    Case Reports 01/2013; 2013.
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    ABSTRACT: 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.
    Stroke 10/2012; · 6.16 Impact Factor
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    ABSTRACT: NGAVFs are rare vascular malformations usually presenting in infancy or childhood. We sought to identify clinical and angiographic predictors of clinical outcome for these lesions. Retrospective review of a neurointerventional data base identified 386 pediatric patients with intracranial AVFs and AVMs, from which a cohort of 25 patients with NGAVF were selected for medical record and imaging analysis. NGAVFs constituted 7.3% of pediatric intracranial vascular lesions with a nondural arteriovenous shunt. Seven of 8 patients who presented in the first month of life had CHF and harbored large, complex fistulas with multiple sites of arteriovenous shunting. Single-hole fistulas predominated later in childhood and more frequently presented with seizures, hemorrhage, or focal neurologic deficits. More treatment procedures were performed in subjects presenting at ≤2 years of age compared with older children (median = 3 versus 2, P = .041), and in those harboring a multi-hole fistula versus those with a single-hole fistula (median = 3 versus 2, P = .003). Eighteen patients (72%) had complete posttreatment elimination of NGAVF shunting. Compared with patients presenting at >2 years of age, patients presenting in the first 2 years of life were more likely to have a multi-hole fistula (100% versus 25%, P = .0001) and to have a poor clinical outcome (54% versus 0%, P = .0052), defined as a pediatric mRS of ≥3. The morbidity of NGAVF appears higher than previously reported despite a somewhat higher rate of angiographic cure. Poor clinical outcome occurred primarily in patients with multi-hole NGAVFs presenting at ≤2 years of age.
    American Journal of Neuroradiology 07/2012; 33(9):1710-9. · 3.17 Impact Factor

Publication Stats

5k Citations
610.56 Total Impact Points

Institutions

  • 1989–2014
    • University of California, San Francisco
      • • Department of Radiology and Biomedical Imaging
      • • Division of Hospital Medicine
      • • Department of Neurological Surgery
      San Francisco, California, United States
  • 2012
    • Brigham and Women's Hospital
      • Department of Neurosurgery
      Boston, MA, United States
  • 1991–2012
    • San Francisco VA Medical Center
      San Francisco, California, United States
  • 2000
    • Royal Perth Hospital
      Perth City, Western Australia, Australia
  • 1996
    • Wakayama Medical University
      Wakayama, Wakayama, Japan