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Introduction/purpose To best achieve complete occlusion of aneurysms treated with flow diverters (FDs), devices must be accurately sized to precisely match the parent vessel diameter. Appropriately sized FDs will have maximal coverage over the aneurysm neck and will be more likely to induce thrombosis. Catheterization for diagnostic angiography can cause vasospasm that may affect vessel measurements. This study evaluates the effects of intra-arterial infusion of a calcium channel blocker (CCB) on angiographic measurements in patients treated with FDs, investigating the impact on the final diameter of the expanded stent following deployment and subsequent occlusion. Materials and methods Retrospective analysis was performed of prospectively maintained procedure records to identify patients with aneurysms treated with FDs. In all patients, pre-treatment measurements were recorded for vessel diameter of the distal and proximal landing zones, as well as maximum and minimum diameters between these segments. Post-treatment measurements of the stent itself following deployment were recorded at the distal and proximal ends in addition to maximum and minimum diameters. When CCB was infused prior to treatment, post-infusion pre-treatment measurements were recorded. All measurements were performed after calibrating to a catheter included on the image. Rates of occlusion and time to confirmed occlusion were noted for all patients. Independent-sample 2 tailed T-tests were performed to assess for differences in pre- and post-treatment measurements, rates of occlusion, and time to confirmed occlusion between groups with and without CCB infusion. Results 21 FDs were deployed to treat 19 aneurysms in 18 patients. CCB infusion was performed prior to deployment of 9 devices. The change in measurements noted after CCB infusion are summarized in Table 1. No significant difference was noted between groups for pre- and post-treatment measurement changes. Subsequent aneurysm occlusion was more likely to occur in the CCB infusion group (100% vs. 44.4%, p Conclusion Optimization of device sizing is important to increase FD density over the aneurysm neck and promote thrombosis. To improve accuracy of measurements of parent vessels prior to device selection, CCB infusion can reduce the effects of mild vasospasm. In this study, subsequent aneurysm occlusion was more likely to occur following FD treatment when device size selection was based on measurements performed following CCB infusion. Disclosures M. Alexander: None. R. Darflinger: None. F. Settecase: None. A. Nicholson: None. D. Cooke: None. M. Amans: None. S. Hetts: None. C. Dowd: None. R. Higashida: None. V. Halbach: None.

OBJECTIVE The most common location for dural arteriovenous fistulae (AVFs) is the transverse/sigmoid sinus. We describe our prospective analysis of data for 10 patients with recipient fistulae parallel to the transverse/sigmoid sinus. Recognition of this entity allows embolization of the fistula with preservation of the parent sinus. This report reviews the presentation and angiographic characteristics of the “parallel venous channel” and the treatment results for this series of patients. METHODS Between 1995 and June 2002, at the medical center of the University of California, San Francisco, we identified 10 patients with a parallel venous channel as the recipient pouch for all arterial input into a transverse/sigmoid sinus AVF. The clinical presentations, angiographic features, endovascular treatments, and outcomes are described. Angiographic follow-up monitoring was performed for 1 to 6 years for all patients with cortical venous drainage (5 of 10 patients). Clinical follow-up periods ranged from 1 to 7 years. RESULTS All patients presented with pulsatile tinnitus disruptive to sleep. Other symptoms included severe headaches, papilledema and visual disturbances, hemiparesis, and mastoid pain. All 10 parallel venous channels communicated with the transverse or sigmoid sinus. Cortical venous drainage was present in 50% of cases. Endovascular ablative procedures, using either coils or ethanol, were performed for all patients. The parallel venous channel was successfully embolized, with preservation of the transverse/sigmoid sinus, for all 10 patients. There were no major complications. All patients experienced resolution of their symptoms, with no recurrence. CONCLUSION The existence of a parallel venous channel as the recipient pouch for all arterial inflow in a series of 10 transverse/sigmoid sinus AVFs is described. Endovascular obliteration of the parallel channel, with preservation of the parent sinus, was successfully performed for all 10 patients. Recognition of the parallel venous channel is clinically important for the treatment of transverse/sigmoid AVFs.

OBJECTIVE To determine the usefulness of endovascular embolization for treatment of dural arteriovenous fistulae of the superior petrosal sinus. METHODS We performed a retrospective review of 18 patients treated during a 16-year period. Transarterial and/or transvenous embolizations were performed as a preoperative adjunct or definitive therapy. Clinical follow-up status was supplemented by telephone interviews to determine Glasgow Outcome Scale scores. RESULTS Fourteen patients (78%) were treated with a combination of endovascular therapy and open surgery, and 4 were treated by embolization alone (22%). Angiographic cure was achieved in all patients (100%). Thirty-day morbidity and mortality were 11 and 0%, respectively. The mean follow-up period was 5.4 years. At the latest follow-up examination, all patients had returned to independent clinical status (Glasgow Outcome Scale scores of 1 or 2). CONCLUSION Endovascular treatment of dural arteriovenous fistulae of the superior petrosal sinus can result in cure when access to the site of the fistula can be achieved. Preoperative embolization is a safe and effective adjunct to minimize bleeding during open neurosurgery.

The field of interventional neuroradiology has experienced remarkable technological developments in microcatheters and embolic materials during the past two decades. The realm of meningioma therapy has benefited handsomely from the combination of these technical improvements and the knowledge of experienced practitioners in this field. Transarterial embolization has become a standard procedure in the preoperative management of meningiomas. The authors describe the indications, pretreatment evaluation, techniques, and outcomes when preoperative angiography and embolization are performed in the treatment of these tumors.

Background and Purpose— Excessive degradation of the vascular matrix by matrix metalloproteinases (MMPs) can lead to structural instability of vessels. In this study we examined the expression of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in brain arteriovenous malformations (BAVMs). Methods— We performed gelatin zymography for MMPs and Western blot for MMP-9, MMP-2, TIMP-1, TIMP-2, TIMP-3, and TIMP-4. MMP-9 expression was localized by immunohistochemistry. Results— We analyzed 37 BAVM specimens and 9 control brain specimens from epilepsy surgery. Thirty-two BAVM patients had embolization treatment before resection. Eighteen BAVM patients had a history of hemorrhage from BAVMs. Neither MMP-2 nor TIMP-2 was detected in BAVMs or control brain specimens. Compared with control brain samples, BAVM samples had higher levels of total MMP-9, active MMP-9, pro-MMP-9, TIMP-1, and TIMP-3. TIMP-4 levels were higher in the control brain than in BAVM specimens. MMP-9 was localized to the endothelial cell/peri–endothelial cell layer and infiltrating neutrophils of BAVMs. BAVMs with venous stenosis ≥50% had higher expression of MMP-9 than BAVMs with venous stenosis Conclusions— We found increased levels of MMP-9 and TIMPs in BAVMs. Abnormal balance of MMP-9 and TIMPs may contribute to vascular instability of BAVMs.

Endovascular techniques and associated technology are rapidly changing the management of vascular pathology of the spinal cord. Such an approach can serve as an adjunct to traditional neurosurgical techniques or as definitive therapy. This review summarizes the role of endovascular treatment of spinal cord vascular malformations.

OBJECTIVE Although anterior circulation disease has both medical and surgical treatment options, management of vertebrobasilar disease has predominantly had only medical options. Some patients remain symptomatic despite medical treatment, and angioplasty has been demonstrated to relieve critical stenoses. However, the relative safety and effectiveness of medical and surgical treatments is not clearly known. This report reviews the clinical characteristics, indications, and procedural risks of intracranial angioplasty in a series of patients with symptomatic posterior circulation ischemia. METHODS All patients undergoing angioplasty for critical intracranial vertebral or basilar artery stenosis at the University of California at San Francisco Medical Center between June 1986 and July 1999 were included in a retrospective record review. Clinical features and procedural complications were recorded. RESULTS Angioplasty was performed on 25 vessel lesions in 25 patients in whom medical therapy had failed. The patients ranged in age from 50 to 87 years. Of the 25 stenoses, 10 were intracranial vertebral, 9 vertebrobasilar junction, and 6 basilar in location. Angioplasty was effective in reducing the degree of stenosis by more than 40% in all 25 vessels. The overall risk of stroke or death was 28%, and the risk of disabling stroke or death was 16%. CONCLUSION Intracranial posterior circulation angioplasty is effective in the reduction of stenosis and can be performed with relative safety. Angioplasty can be considered as a treatment option in patients with recurrent ischemic symptoms despite medical therapy.

Background — Patients harboring a brain arteriovenous malformation (BAVM) often have coexisting arterial aneurysms. Experts have argued about the clinical significance of these aneurysms, which may be important for risk stratification in patient management and clinical trials. We studied the association between coexisting aneurysms and initial presentation with intracranial hemorrhage (ICH) in patients with BAVM evaluated at two tertiary-care centers. Methods — Demographic and clinical data were collected from a prospective series of patients evaluated for BAVM at the University of California, San Francisco (UCSF; n=82), and Columbia-Presbyterian Medical Center, New York (CPMC; n=254). Using multivariate logistic regression, we examined the independent association between ICH presentation and the presence of a coexisting aneurysm, and compared the association at the two hospitals. Results — Aneurysms were associated with 28 BAVMs at UCSF (34%) and 74 at CPMC (29%; P =0.39). Initial presentation with ICH was associated with the presence of a coexisting aneurysm at CPMC (odds ratio 1.8, 95% confidence interval 1.0 to 3.0, P =0.044). The opposite trend was observed at UCSF (odds ratio 0.4, 95% confidence interval 0.2 to 1.1, P =0.085). We observed an interaction by site involving the association between ICH presentation and aneurysm ( P =0.016). Conclusion — Although many BAVM characteristics were similar at the referral centers studied, the association between initial presentation with ICH and coexisting aneurysms was not. This heterogeneity between populations undermines the validity of inferences on the role of aneurysms from any single referral series, and emphasizes the complexity in creating BAVM risk-stratification models that incorporate aneurysms.

Osteoporosis is a debilitating disease that occurs in epidemic proportions in Western societies and has a large economic impact. Percutaneous vertebroplasty is successful in alleviating subacute and chronic pain caused by osteoporotic compression fractures and pathological vertebral fractures from tumor infiltration. The technique is safe and can be performed on an outpatient basis utilizing high-resolution fluoroscopy.

SUMMARY: A 7-year-old girl with a history of headaches and Gorham disease was surgically treated in infancy for Chiari I malformation. Subsequent investigation revealed that her cerebellar tonsillar ectopia was due to a long-standing spinal CSF-lymphatic fistula causing intracranial hypotension. Percutaneous fistula closure was performed several times, resulting in transient symptomatic improvement.

BackgroundIntracranial atherosclerotic disease (ICAD) causes substantial morbidity and mortality. Treatment decisions have most commonly been driven by the degree of luminal stenosis. This study compares ICAD lesion stability features with percentage stenosis for associations with adverse outcomes following treatment with stents.Materials and methodsRetrospective analysis was performed of prospectively maintained procedure logs. Lesions were classified by symptom type as hypoperfusion, non-hypoperfusion, or indeterminate, and pretreatment asymptomatic intervals were noted. Hypoperfusion lesions and indeterminate or non-hypoperfusion lesions with ≥14 days of asymptomatic interval were classified as stable. Percentage stenosis was calculated and compared against these other symptom features for value in predicting technical complication, ischemic stroke, disability, or death at 90 days and 2 years using univariate and multivariate analysis.Results130 lesions were treated in 124 patients. The only statistically significant percent stenosis finding was lesions with 60–99% stenosis were less likely to have technical complications. In univariate analysis, stroke at 2 years was less common with hypoperfusion and stable lesions. In multivariate analysis, only hypoperfusion status was associated with lower stroke rates at 2 years.ConclusionsLesion stability features, particularly non-hypoperfusion symptomatology, outperform percentage stenosis in predicting outcomes following treatment of ICAD with stents. Further examination is needed to better classify the natural history of ICAD and more precisely classify lesion stability.

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.

BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

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.

Background and purposeThe 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 methodsA 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.ResultsResults 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

BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Background and Purpose: To determine if clinical and angioarchitectural features of brain AVMs differ between children and adults. Materials and Methods: A prospectively collected institutional database 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) versus adults (>18 years). Children were more likely to present with AVM hemorrhage than adults (59% vs. 41%, p=0.001). Although AVMs with a larger nidus presented at younger ages (mean of 26.8 years for greater than 6 cm compared to 37.1 years for less than 3 cm), this was not significantly different between children and adults (p=0.069). Exclusively deep venous drainage was more common in younger subjects both when age was treated continuously (p=0.04), or dichotomized (p Conclusion: 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 underrepresented in children, suggesting that these particular high risk features take time to develop.

Neurologic complications of imaging procedures are varied and largely related to either local complications of an invasive procedure or complications arising from the systemic use of intravenous contrast agents. This chapter provides a summary of neurologic complications related to those imaging procedures that are commonly performed in modern radiologic practices. Some historical perspective is presented as well, and the reader must be aware that changes in the practice of radiologic procedures affect the kinds of complications and their incidence over time.

Objectives: PHACE is an acronym coined to describe a neurocutaneous syndrome encompassing the following features: posterior fossa brain malformations, large facial hemangiomas, arterial anomalies, cardiac anomalies and aortic coarctation, and eye abnormalities. We evaluated the spectrum of disease and significance of potential underlying brain anomalies among affected children. Study design: The records of 14 patients with PHACE syndrome, evaluated between 1995 and 2000, were retrospectively reviewed. A literature review revealed 116 additional cases. Results: PHACE syndrome represents a spectrum of anomalies, because most affected children have only one extracutaneous manifestation. The syndrome is associated with a high incidence of arterial and structural central nervous system anomalies with secondary neurologic sequelae. The potential for progressive neurovascular disease also exists among those patients with anomalous vasculature. Conclusion: PHACE syndrome should be considered in any infant presenting with a large, segmental, plaque-type facial hemangioma. Children at risk should receive careful ophthalmologic, cardiac, and neurologic assessment. (J Pediatr 2001;139:117-23)

“If you wish to converse with me,” said Voltaire, “define your terms.” How many a debate would have been deflated into a paragraph if the disputants had dared to define their terms! Will Durant: The Story of Philosophy

The authors describe the diagnosis and endovascular management of a multiaperture, ruptured cavernous internal carotid artery aneurysm causing a carotid cavernous fistula (CCF) using both transarterial and transvenous techniques. Although uncommon, recognition of the imaging characteristics of such a lesion will aide in successful management and improve treatment outcome. To the authors' knowledge, CCF due to a ruptured cavernous aneurysm with multiple shunts has not been previously reported.

Carotid arterial endarterectomy is considered to be the standard for the treatment of atherosclerotic carotid arterial occlusive disease. This has been validated with results of several randomized controlled trials in which its effectiveness has been demonstrated over that of the best nonsurgical therapy. In the past several years, however, carotid angioplasty with stent placement has emerged as a potential alternative to carotid endarterectomy. This article represents a critical examination of the rationale for carotid revascularization; the history of endovascular techniques for the treatment of carotid atherosclerosis, beginning with balloon angioplasty and evolving to the use of stents; and the evidence supporting the effectiveness of the endovascular approach. A brief description of the current technical aspects of carotid artery stent placement is presented. The future status of the endovascular approach will be determined with randomized trials in which carotid artery stent placement is directly compared with endarterectomy, as well as by the potential for further innovation and improvement in endovascular devices, technique, and safety.

Objective Cerebral hyperperfusion syndrome is a recognized complication of carotid endarterectomy, with a reported incidence of 0.3 to 1.2%. The incidence of cerebral hyperperfusion after endovascular revascularization procedures of the craniocervical arteries remains unknown. We evaluated the incidence of cerebral hyperperfusion syndrome in our endovascular revascularization series. To our knowledge, there are no previous studies evaluating the incidence of hyperperfusion syndrome after percutaneous transluminal angioplasty/stenting. Methods Between March 1996 and February 2000, 140 patients underwent percutaneous transluminal angioplasty/stenting of the craniocervical arteries at our institution. In all patients, selective bilateral arteriography of the carotid and vertebral arteries was performed to document the sites of craniocervical stenosis and collateral blood flow and the results of the endovascular revascularization procedure. We then reviewed all pertinent medical records, arteriographic films, and sectional imaging studies to determine the incidence of cerebral hyperperfusion in this series. Results Seven patients (5.0%) developed clinical or radiological manifestations of cerebral hyperperfusion. In the target group, percutaneous transluminal stenting achieved a 90 to 100% reduction in stenotic lesions (mean stenosis, 91%) of the carotid (n = 5) and vertebral (n = 2) arteries. All seven patients remained neurologically stable immediately after treatment. There was delayed development of clinical and radiographic findings, suggestive of cerebral hyperperfusion. Six patients showed evidence of ipsilateral hemispheric edema, including two patients who developed intracranial hemorrhage (one parenchymal, one parenchymal and subarachnoid) documented by computed tomographic brain scans. Symptoms resolved within 72 hours in the four patients without hemorrhage. The two patients with hemorrhage recovered during a more protracted period (range, 3 wk to 6 mo). There were no long-term sequelae or deaths during a cumulative follow-up of 84 months (mean follow-up, 12 mo). Conclusion Hyperperfusion syndrome is an uncommon but potentially serious complication of extracranial and intracranial angioplasty and stenting procedures. The clinical manifestations are similar to hyperperfusion syndrome after carotid endarterectomy; however, the prevalence may be greater in the high-risk cohort commonly referred for endovascular treatment. Our findings suggest that patients undergoing endovascular stenting procedures should be closely monitored for evidence of hyperperfusion, with careful monitoring of blood pressure, heart rate, and anticoagulation. Further research is needed to confirm that cerebral hyperperfusion is the pathogenesis of this condition.

Unruptured cerebral aneurysms are commonly treated by surgical clipping, but endovascular coil embolization is increasingly employed as an alternative. In a blinded review of unruptured aneurysms treated at our institution since 1990, we identified patients whose aneurysms were judged to be treatable by both neurosurgeons and neurointerventional radiologists. A change in Rankin Scale score of 2 or more from hospital admission to discharge, indicating a new moderate disability or worse, was predefined as the primary outcome measure. Long-term follow-up was obtained by mailed questionnaire and telephone interview. Length of stay and hospital charges were totaled for all hospitalizations, including follow-up. Sixty-eight patients treated surgically and 62 patients treated with endovascular coil embolization were considered candidates for either procedure on blinded review, and overall anticipated procedure risk was rated as identical. A larger proportion of patients in the surgical group developed a change in Rankin Scale score of 2 or more (25% of surgical patients vs 8% of endovascular patients). Total length of stay was longer (mean days: 7.7 for surgical patients vs 5.0 for endovascular patients) and hospital charges were greater (mean, $38,000 for surgical patients vs $33,400 for endovascular patients) for the surgical patients. At follow-up, an average of 3.9 years after the procedure, surgical patients were more likely to report persistent new symptoms or disability since treatment (34% of surgical patients vs 8% of endovascular patients) and a longer period for recovery to normal (50% returning to normal in 1 year for surgery and in 27 days for coil embolization). Coil embolization of unruptured cerebral aneurysms seems to be associated with significantly fewer complications than surgical clipping. More long-term data on aneurysm rupture rates are required to confirm efficacy.

The authors report on a series of spontaneous intracranial hemorrhages associated with vein of Galen aneurysmal malformations (VGAMs). Thirty-four children with VGAMs have been treated at this institution since 1986. Eight children (24%) harbored the mural-type malformation, and 26 (76%) had the choroidal-type lesion. Two children (25%) with mural lesions and 1 (4%) with a choroidal lesion suffered hemorrhagic complications. Two presented with acute intracranial hemorrhage. A third child developed acute intracranial hemorrhage due to delayed dural sinus thrombosis after endovascular treatment of his choroidal-type VGAM. The subjects ranged in age from 13 days to 17 months at the time of presentation. Each patient underwent rapid radiological evaluation and treatment with endovascular surgery. Post-procedural arteriography demonstrated complete occlusion of the malformation in each patient. For the 3 patients with hemorrhage, follow-up has taken place over 49-, 107-, and 43-month intervals, respectively. Vein of Galen aneurysmal malformations can present with acute intracranial hemorrhage or develop delayed intracranial hemorrhage but respond to treatment using standard endovascular techniques. The presence of hemorrhage does not de facto portend a poor prognosis.

The last two decades have witnessed a growing application of endovascular techniques for the treatment of atherosclerotic disease of the extracranial vertebral arteries, subclavian arteries, and brachiocephalic artery. Beginning with simple balloon angioplasty, these minimally invasive techniques have now progressed to the use of stent-supported angioplasty. Stent-supported angioplasty is currently providing a therapeutic alternative to traditional methods of open surgery for revascularization of these vessels and increasing the therapeutic options available for patients who have failed maximal medical therapy. Additionally, endovascular techniques are also being used successfully to treat a variety of nonatherosclerotic diseases affecting the noncarotid extacranial arteries, such as inflammatory, radiation, and anastomotic-graft strictures; acute intimai dissection; traumatic and spontaneous arteriovenous fistulas; and aneurysms or pseudoaneurysms. Continued innovation and refinement of endovascular devices and techniques will inevitably improve technical success rates, reduce procedure-related complications, and broaden the endovascular therapeutic spectrum for extracranial cerebrovascular disease.

✓ Domestic violence leading to strangulation by an abusive spouse can cause carotid artery dissection. This phenomenon is rare and has been described in only three previous instances. The authors present their management strategies in three additional cases.Three young women aged 24 to 43 years were victims of manual strangulation committed by their spouses 3 months to 1 year before presentation. Two of the patients suffered delayed cerebral infarctions before presentation and angiography demonstrated focal, mirror-image severe residual stenoses in the high-cervical internal carotid artery (ICA), which were characteristic of a healed chronic dissection; there was no evidence of fibromuscular dysplasia. One of these patients underwent unilateral percutaneous angioplasty with stent placement, and the other underwent bilateral percutaneous angioplasty. Both patients have recovered from their strokes and remain clinically stable at 8 and 20 months posttreatment, respectively. The third patient presented with bilateral ischemic frontal watershed infarctions resulting from an occluded left ICA and a severely narrowed right ICA. Given the extent of the established infarctions, this case was managed with a long-term regimen of anticoagulation medications, and the patient remains neurologically impaired.These cases illustrate the susceptibility of the manually compressed ICA to traumatic injury as a result of domestic violence. They identify bilateral symmetrical ICA dissection as a consistent finding and the real danger of delayed stroke as a consequence of strangulation. Endovascular therapy in which percutaneous angioplasty and/or stent placement are used can be useful in treating residual focal stenoses to improve cerebral perfusion and to lower the risk of embolic or ischemic stroke.

Over the past 2 decades, the application of endovascular techniques has revolutionized the care of patients with midline facial and skull base diseases. These techniques have been applied as adjuncts to surgery or as definitive, stand-alone therapies. This article details the endovascular techniques used in the skull base and midline facial region to treat vascular lesions such as aneurysms and congenital vascular malformations, traumatic conditions, and tumors.

The treatment of carotid cavernous fistulas has undergone a fundamental transformation during the preceding 30 years. Endovascular techniques have not only largely replaced surgical management of this disease, but have also resulted in substantially lower rates of procedure-associated morbidity and mortality. Percutaneous transarterial occlusion of direct cavernous carotid fistulas with preservation of the carotid artery using detachable balloons is now considered the current preferred therapeutic objective. Concurrent progress in percutaneous transvenous embolization techniques and materials has led to more effective and better-tailored therapies for indirect (dural) carotid cavernous fistulas. The current understanding of the clinico-pathologic mechanisms associated with carotid cavernous fistulas and the endovascular therapies used in the contemporary management of this condition are reviewed.

Dural arteriovenous fistulas (DAVFs) or malformations consist of pathological vascular channels located within the substance of the dura mater and usually involve the walls of a dural sinus or adjacent cortical vein. DAVFs can affect a variety of cerebral venous structures and can present at various clinical stages. Although some fistulas can spontaneously thrombose, the clinical course usually involves progression from venous sinus pressurization to occlusion and retrograde cortical venous drainage. The spectrum of clinical presentation ranges from an irritating pulse-synchronous bruit to a disabling neurologic ischemic deficit or life-threatening intracranial hemorrhage from venous hypertension. The authors present their clinical experience in the radiographic diagnosis and endovascular treatment of these potentially dangerous lesions.

A neonate with congestive heart failure at birth due to a nearly holohemispheric pial arteriovenous malformation is described. This occurred despite a normal second trimester prenatal sonogram. Successful treatment of heart failure was achieved by embolization alone. This case demonstrates that hemodynamically significant lesions may arise later or enlarge more rapidly in utero than previously thought.

Options for treatment of intracranial aneurysms have expanded with the advent of the Guglielmi Detachable Cod (GDC) eight years ago. We have reviewed 435 cases of intracranial aneurysms treated at UCSF by endovascular means using the GDC system. Of these, 55% represent anterior circulation aneurysms, and 45% are located in the posterior circulation. Additionally, 55% of the aneurysms presented with subarachnoid hemorrhage (SAH) and 45% were unruptured. Factors which hindered optimal coiling include the following: wide aneurysm neck in relation to the overall aneurysm size, mural thrombus, giant aneurysm, arteries originating from the aneurysm sac, and middle cerebral location. After initial experience was gained, we tended to avoid these aneurysms especially in the non-ruptured group. This may be especially important in light of new epidemiological data suggesting that the natural history of unruptured aneurysms is significantly lower than previously thought. New technical developments which may reduce the risk of treating unruptured aneurysms include the two-dimensional coil, the three-dimensional coil, the balloon-assist technique for wide-necked aneurysms, and combined stent-coil procedures.

Background and Purpose —Vertebrobasilar territory ischemia (VBI) leads to disabling neurological symptoms and poses a risk for stroke by an embolic or flow-related mechanism. We present our clinical experience in the endovascular treatment of patients with symptomatic VBI from severe atherosclerosis or dissection of the vertebral and subclavian arteries that was unresponsive to medical therapy. Methods —Twenty-one patients (9 female, 12 male) with a mean age of 65.7 years (range 47 to 81 years) underwent treatment with percutaneous endovascular balloon angioplasty and stent placement. Sixteen patients (76.2%) had evidence of contralateral involvement, and 9 (42.8%) demonstrated severe anterior-circulation atherosclerosis. Nine patients had a previous infarct in the occipital lobe, cerebellum, or pons before treatment. Follow-up was available for all patients. Results —Balloon angioplasty with intravascular stent placement was performed in 13 vertebral artery lesions (10 at the origin, 3 in the cervical segment) and in 8 subclavian lesions. The prestenting stenosis was 75% (50% to 100%) and was reduced to 4.5% (0% to 20%) after stenting. Six of the patients with proximal subclavian stenosis demonstrated angiographic evidence of subclavian steal, which resolved in all cases after treatment. All patients showed improvement in symptoms after the procedure except for 1 who developed a hemispheric stroke after thrombotic occlusion of an untreated cavernous carotid artery stenosis (rate of major stroke and mortality=4.8%). One patient (4.8%) had a periprocedural transient ischemic attack (TIA), and none had minor stroke. At long-term follow-up (mean=20.7±3.6 months) of the surviving 20 patients, 12 (57.1%) remained symptom-free, 4 (19%) had at most 1 TIA over a 3-month period, 2 (9.5%) had at most 1 TIA per month, and 2 (9.5%) had persistent symptoms. There were no clinically evident infarcts during the follow-up period. Conclusions —Endovascular treatment using balloon angioplasty with intravascular stent placement for symptomatic stenotic lesions resulting in VBI that is unresponsive to medical therapy appears to be of benefit in this high-risk subset of patients with poor collateral flow.

Objective and importance Intimal dissection constitutes one of the complications associated with angioplasty of intracranial vessels. We present a case of iatrogenic dissection of the entire basilar artery, which was induced by angioplasty and stenting of symptomatic, focal, intracranial vertebral artery stenosis, and its successful treatment with tandem deployment of a downstream stent. Clinical presentation A 61-year-old, hypertensive, renal transplant recipient presented with orthostatic vertebrobasilar insufficiency that was refractory to medical management, including anticoagulation therapy. Angiography revealed an occluded right vertebral artery and focal, high-grade, left intracranial vertebral artery stenosis. Magnetic resonance imaging showed multiple posterior fossa infarctions. The left intracranial vertebral artery stenosis was successfully treated with primary stent deployment and balloon angioplasty, with symptom resolution. On postprocedure Day 2, the patient noted worsening right hemiparesis. Intervention Subsequent angiography revealed a flow-limiting, windsock-type, basilar artery dissection beginning at the distal end of the left vertebral artery stent and extending to the origin of the left posterior cerebral artery. A tandem stent was navigated intracranially and deployed past the first one, successfully sealing the dissection inflow zone and reconstituting normal flow to the top of the basilar artery. A clinical follow-up examination at 3 months revealed no further orthostatic symptoms and only mild residual right-sided weakness. Conclusion This is the first description of iatrogenic stent-induced dissection of the entire basilar artery that was successfully treated by inflow zone control via tandem intracranial stent deployment.

For radiosurgery of large arteriovenous malformations (AVMs), the optimal relationship of dose and volume to obliteration, complications, and hemorrhage is not well defined. Multivariate analysis was performed to assess the relationship of multiple AVM and treatment factors to the outcome of AVMs significantly larger than previously reported in the literature.73 patients with intracranial AVMs underwent LINAC radiosurgery. Over 50% of the AVMs were larger than 3 cm in diameter and the median and mean treatment volumes were 8.4 cc and 15.3 cc, respectively (range 0.4-143.4 cc). Minimum AVM treatment doses varied between 1000-2200 cGy (median: 1600 cGy).The obliteration rates for treatment volumes4 cc, 4-13.9 cc, andor = 14 cc were 67%, 58%, and 23%, respectively. AVM obliteration was significantly associated with higher minimum treatment dose and negatively associated with a history of prior embolization with particulate materials. No AVM receiving1400 cGy was obliterated. The incidence of post-radiosurgical imaging abnormalities and clinical complications rose with increasing treatment volume. For treatment volumes14 cc receivingor = 1600 cGy, the incidence of post-radiosurgical MRI T2 abnormalities was 72% and the incidence of radiation necrosis requiring resection was 22%. The rate of post-radiosurgical hemorrhage was 2.7% per person-year for AVMs with treatment volumes14 cc and 7.5% per person-year for AVMsor = 14 cc.As AVM size increases, the dose-volume range for the optimal balance between successful obliteration and the risk of complications and post-radiosurgical hemorrhage narrows.

OBJECTIVE AND IMPORTANCE: The goal of this report was to describe the successful percutaneous endovascular use of a Gianturco-Roubin-2 coronary stent in the treatment of an acute atherothrombotic occlusion of the basilar artery. To our knowledge, the percutaneous endovascular deployment of an intra-arterial stent for the treatment of an acute atherothrombotic occlusion of the basilar artery and the percutaneous endovascular placement of a Gianturco-Roubin-2 stent in the basilar artery have not been previously reported. CLINICAL PRESENTATION: An 83-year-old man presented with a recurrent, transient, locked-in syndrome resulting from a lower basilar artery occlusion caused by vertebrobasilar thrombosis superimposed on severe proximal basilar artery atheromatous stenosis. INTERVENTION: After successful superselective intra-arterial thrombolysis of the vertebrobasilar clot, balloon angioplasty of the underlying basilar artery stenosis was performed, without significant angiographic improvement. Percutaneous endovascular deployment of a Gianturco-Roubin-2 coronary stent of 4-mm diameter was subsequently performed, with excellent angiographic results. CONCLUSION: The patient made a very good neurological recovery but unfortunately died as a result of cardiogenic shock and sepsis. Detailed neuropathological follow-up results are presented; stent patency was revealed in the postmortem examination. The anatomic and pathophysiological considerations of basilar artery stent placement for the treatment of acute basilar artery occlusion related to atherosclerotic stenosis are discussed.

Over the last 5 years, the clinical use of intravascular stents for treatment of carotid artery pathology has become more prevalent and the spectrum of potential indications has widened. Endovascular stenting is providing an alternative to surgical endarterectomy for treatment of cervical carotid artery atherosclerotic disease. This has prompted a North American, randomized, controlled clinical trial directly comparing these two therapies. In this article we review the major surgical endarterectomy trials that currently provide the scientific rationale for revascularization of carotid artery occlusive disease, critically evaluate the evidence supporting the application of endovascular stenting procedures for the treatment of occlusive and nonocclusive disease of the extracranial and intracranial carotid artery, consider the current clinical indications for use of stents in the carotid artery, and discuss current equipment, technique, and potential procedure-related complications.

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.

Background and purposeThe three largest adult stroke trials investigating mechanical embolectomy retrieval devices in acute stroke (the Merci, Multi Merci and Penumbra Pivotal Stroke Trials) excluded children. There is a need to expand the literature on mechanical embolectomy in large vessel pediatric arterial ischemic stroke. This paper reports the use of two mechanical embolectomy devices cleared by the Federal Drug Administration (FDA) in four consecutive cases.MethodsOur pediatric stroke database from 2002 to the present was reviewed retrospectively. Patients were included if they were diagnosed with an acute large vessel occlusion, were

Background: Vertebral artery dissection due to dynamic compression by abnormal C1-C2 anatomy is under-recognized in childhood stroke. Our aim was to describe underlying pathologic variants of C1-C2 soft tissue or bone in children with vertebral artery dissection and posterior circulation strokes. Methods: A series of five children diagnosed with vertebral artery dissection from compression by C1-C2 soft tissue or bone were identified at a single pediatric stroke center. Diagnostic evaluation, anatomic cause of dissection, and treatment were abstracted from medical records. Results: Five children (all boys, ages 6 - 14) were identified with a diagnosis of posterior circulation embolic strokes due to focal vertebral artery dissection and presumed compression against adjacent C1-C2 abnormalities. Four had recurrent events, including basilar artery thrombosis, before the cervical abnormality was identified. Vertebral artery dissections were caused by bony (congenital arcuate foramen, post-traumatic os odontoideum) and soft tissue pathology (ruptured atlantoaxial bursa, anomalous C1-C2 connective tissue bands) (Table). Vertebral artery compression at dissection sites during head rotation was confirmed by angiography with head in neutral and rotated in children with soft tissue anomalies. No other etiology for stroke or dissection was found in any of the cases. For secondary stroke prevention, four children underwent direct surgical decompression of the vertebral artery or spinal fusion; one opted for activity restriction and aspirin. None had further recurrences after treatment with a median follow-up of 9 months (range 1 to 61). Conclusions: In children with recurrent vertebral artery dissection and strokes, C1-C2 bone imaging and dynamic angiogram with neck rotation can identify cervical pathology that may otherwise be missed. Cervical stabilization or resection of the compressive pathology should be considered to prevent stroke recurrence.

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.

Dural arteriovenous fistulas (dAVFs) are known to be acquired disorders. Angiogenic stimulants, such as basic fibroblast growth factor (bFGF), may be involved in the evolution of this disorder. We examined the appearance and localization of bFGF, in human dAVF sinuses, versus a control using immunohistochemical techniques, to evaluate these qualitative differences. Four human dural sinuses from dAVF patients, and one control dural sinus were removed at surgery or autopsy and used for this study. Immunohistochemistry for bFGF was performed in all five specimens to identify its appearance and localization. Immunohistochemistry for alpha smooth muscle actin, factor VIII related antigen, and macrophage (CD-68) were done in all tissues to identify the bFGF positive cell types. In the control dural sinus, there was negative staining by bFGF immunohistochemistry. However, in all four sinuses of the dAVF patients, smooth muscle cells, endothelial cells, and meningeal cells were stained positively in various degrees by bFGF immunohistochemistry. bFGF may be significant in the development of dAVFs, judging from its strong immunoreactivity in the sinuses of dAVF patients.

The authors report their experience with transluminal angioplasty of the extracranial carotid artery over the past 14 years. The angioplasty sites included the common carotid artery in 59 patients, the internal carotid artery in 55 patients, and the external carotid artery in 11 patients. The indications for treatment included patients who harbored symptomatic stenosis of 70% or greater, with the majority failing medical therapy and considered poor surgical candidates.

Percutaneous transluminal angioplasty, alone or in conjunction with thrombolysis and/or stenting, is now being performed in selected cases for hemodynamically significant stenosis (> 70%), involving both extracranial and intracranial cerebral vascular lesions. In the majority of cases, atherosclerosis was the major cause for symptomatic narrowing, although other causes included fibromuscular dysplasia, cerebral arteritis, postsurgical intimal hyperplasia, and acute arterial dissection. In some cases, direct intraarterial thrombolysis and angioplasty successfully restored perfusion to completely occluded blood vessels to the brain, and in other cases acute vessel closure or dissection of extracranial vessels was successfully managed with stent deployment. Since 1981, 325 patients, ranging in age from 9–78 years old, have been successfully treated by these techniques: 143 (44%) cases involved the anterior cerebral circulation; and 182 (56%) cases, the posterior cerebral circulation. Complications included 17 (5.2%) strokes (of which 4 [1.2%] died), and 23 (7.1%) cases of transient cerebral ischemia. Radiological follow-up demonstrated 24 (7.4%) cases of restenosis. This study indicates the feasibility of angioplasty as a treatment alternative, in conjunction with thrombolysis and intravascular stenting, for extracranial and intracranial obstructive cerebral vascular disorders and may also provide an interventional pathway in the treatment of acute stroke patients.

Purpose: The endovascular surgical approach to complex disorders of the central nervous system has made rapid and significant advancements over the past decade. Patients with intracranial arterial aneurysms, traumatic carotid and vertebral artery lesions, including fistulas and pseudoaneurysms, hemodynamically significant atherosclerotic lesions, vasospasm, and acute stroke are now being approached and treated by newer and less invasive techniques, including cerebral angioplasty and thrombolytic therapy. Methods: All procedures are usually performed from a transfemoral approach utilizing a variety of occlusion devices, including detachable silicone balloons, microcoils, electrolytic detachable coils, liquid tissue adhesives, and particulate emboli for vessel occlusion. For dilatation and reperfusion of vessels, balloon angioplasty catheters, stents, and thrombolytic drugs are being used. Results: For the treatment of traumatic vascular injuries, such as carotid cavernous sinus fistulas and vertebral arteriovenous fistulas and pseudoaneurysms, endovascular therapy has become the treatment of choice. The endovascular approach for intracranial aneurysms is emerging as a therapeutic option in selected cases. For occlusive disorders in patients presenting with acute cerebral ischemia, extracranial angioplasty and cerebral thrombolysis techniques are currently under investigation. Conclusions: As these techniques continue to evolve, the field of interventional neuroradiology will expand the therapeutic options for managing complex cerebrovascular disorders and improve patient outcome in acute stroke therapy.

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 r =0.73, P P =0.01, 0.006, 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.

BACKGROUND AND PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Introduction/purpose Numerous processes can cause pulsatile tinnitus (PT), some of which are potentially life threatening. This case series describes a cause of PT – prominent condylar veins – that has undergone little investigation to date. This report characterizes angiographic findings in patients with prominent condylar veins and means to localize symptoms to these structures using dynamic angiography with head positioning and venous balloon test occlusion. Materials and methods Retrospective analysis was performed under IRB approved protocol for 43 consecutive PT patients referred for diagnostic angiography at a major academic medical center between January 2013 and December 2015. Rates of different etiologies of PT among patients in this group were noted. In addition to standard diagnostic cervicocerebral angiography, dynamic angiography with head turning was conducted. The effects of provocative maneuvers were measured using time-resolved flow analysis known (iFlow, Siemens Healthcare, Erlangen Germany). Results 5 (11.6%) patients were found to have prominent condylar veins. 16 (37.2%) had a dAVF, 4 (9.3%) had a venous diverticulum, and 9 (20.9%) had no angiographic abnormality detected. The findings of the five patients with prominent condylar veins are summarized in the table. Representative images are provided in the figure. Conclusion Prominent flow in condylar veins should be considered among the numerous causes of PT. This may be a frequent cause of these symptoms in patients who previously would have had no identifiable cause Further investigation is warranted with respect to this cause of PT and PT in general. Disclosures M. Alexander: None. K. Meisel: None. V. Halbach: None. R. Darflinger: None. A. Nicholson: None. F. Settecase: None. D. Cooke: None. R. Higashida: None. C. Dowd: None. S. Hetts: None. M. Amans: None.

Interventional neurovascular techniques for the treatment of patients presenting with symptoms of acute or impending stroke, are now being utilized with increasing frequency in three major areas. (i) For patients presenting with cerebrovascular ischaemic symptoms due to haemodynamically significant stenosis from atherosclerosis, vasculitis, intimal hyperplasia, and dissection, cerebral percutaneous transluminal angioplasty has been shown to be beneficial for both extracranial and intracranial disease. (ii) Patients with acute, embolic occlusion of the internal carotid, middle cerebral, distal vertebral, and basilar arteries have been successfully treated by placement of microcatheters directly into the thrombus with successful thrombolysis, recanalization, and reperfusion to the distal ischemic brain. (iii) Acute arterial vasospasm secondary to subarachnoid haemorrhage is now being managed by balloon angioplasty in those instances where conventional medical therapy has failed. These techniques are altering our current management and broadening the therapeutic alternatives for patients who present with acute cerebrovascular insufficiency and stroke in evolution. As wider experience is gained in these techniques, the clinical indications for their use will also broaden.