US nationwide trends in carotid revascularization: hospital outcome and predictors of outcome from 1998 to 2007.

OBJECTIVES: The goals of the study were to assess US nationwide trends in hospital outcome following carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) and to determine potential predictors of outcome. METHODS: The Nationwide Inpatient Sample, constituting a 20% representative and stratified sample of non-federal US hospitals, was analyzed retrospectively from years 1998 to 2007. RESULTS: The annual number of CEA decreased (137,877-111,658) and increased for CAS (2318-14,415). Inhospital mortality following CEA decreased from 0.4% to 0.3% (P < 0.001), whereas long-term facility (LTF) discharge increased from 8.2% to 10.5% (P < 0.001). Discharge outcome improved for CAS in both categories (mortality 2-0.5%; LTF discharge 10.7-8.3%; both P < 0.001). The trend analysis revealed an increase in patient age and a worsening comorbid profile over time. Age, women, length of stay, atrial fibrillation, and carotid stenosis with infarction were important determinants of unfavorable hospital outcome. CONCLUSION: From a nationwide practice perspective, the number of carotid revascularizations fell by 10%. CEA has resulted in stable hospital mortality rates. Meanwhile, CAS has been increasingly utilized with overall improvement in short-term outcome. Our results further suggest a decrease in the number of patients with treatment-eligible carotid disease over time. However, the increasing prevalence of high-risk comorbidity in the aging population may pose a challenge to revascularization strategies.

US nationwide trends in carotid revascularization: is there a clinical opportunity cost associated with the introduction of novel medical devices?

OBJECTIVES: Nationwide practice patterns during the implementation of novel technology, such as carotid angioplasty and stenting (CAS) and embolic protection devices (EPD), and the clinical impact thereof have received less attention. METHODS: The Nationwide Inpatient Sample, constituting a 20% representative sample of non-federal US hospitals, was analyzed from years 1998 to 2007. Hospital outcome was stratified into in-hospital mortality (IHM), long-term facility discharge, and home/ short-term facility discharge (HSF). RESULTS: Discharge outcome improved for CAS over the decade. However, this improvement occurred in two phases with a period of worsening (2003-2005) in between. During this transition period, the risk of IHM following CAS was increased (RR 1.29-2.43) and was lower for good outcome (HSF: RR 0.97-0.99) when compared with 2002/2003. During the same transition period, carotid endarterectomy (CEA) was associated with a lower risk of IHM (RR 0.75-1.00), but also a lower risk of HSF (RR 0.98-0.99). CONCLUSIONS: The results lead to the hypothesis that the nationwide introduction of CAS-EPD may have been associated with temporary increases in in-hospital mortality and discharge morbidity. If such 'clinical opportunity costs' exist with the widespread introduction and adoption of new medical technology with proven efficacy in randomized trials, effective mechanisms are needed for mitigation or prevention during the transition period.

Diagnosis and treatment of arteriovenous malformations.

Brain arteriovenous malformations (bAVMs) are among the least common of causes of brain hemorrhage, seizures, or headaches. Embedded in the brain, their widely varying size, arterial feeders draining venous pattern and nidus complexity make them among the most challenging of disorders for attempted eradication. The low prevalence has created a literature long dominated by anecdote, only recently and slowly being clarified by epidemiological, pathophysiological, and imaging data. A first-ever randomized clinical trial seeks to determine if invasive intervention to eradicate the lesion--and its attendant risks of complications--offers a better prognosis than awaiting a hemorrhage before undertaking such efforts.

Selective brain cooling with endovascular intracarotid infusion of cold saline: a pilot feasibility study.

BACKGROUND AND PURPOSE: Endovascular brain cooling as a method for rapid and selective induction of hypothermic neuroprotection has not been systematically studied in humans. In this clinical pilot study we investigated the feasibility, safety, and physiologic responses of short-term brain cooling with IC-CSI. MATERIALS AND METHODS: We studied 18 patients (50 +/- 10 years old, 9 women) undergoing follow-up cerebral angiography after previous treatment of vascular malformations. Isotonic saline (4-17 degrees C) was infused into 1 internal carotid artery at 33 mL/min for 10 minutes. Brain (JVB) and bladder/esophageal temperature measurements (n = 9) were performed. Both MCAs were monitored with transcranial Doppler sonography (n = 13). Arterial and JV blood were sampled to estimate hemodilution and brain oxygen extraction. RESULTS: JVB temperature dropped approximately 0.84 +/- 0.13 degrees C and systemic temperature by 0.15 +/- 0.08 degrees C from baseline (JVB versus systemic temperature: P = .0006). Systolic MCA-flow velocities decreased from 101 +/- 27 to 73 +/- 18 cm/s on the infused side and from 83 +/- 24 to 78 +/- 21 cm/s on the contralateral side (relative changes, -26 +/- 8% versus -4 +/- 27%; P = .009). Changes in hematocrit (-1.2 +/- 1.1%) and cerebral arteriovenous oxygen difference (0.2 +/- 1.0 mL O(2)/100 mL) were not significant. Doppler data showed no signs of vascular spasm or microemboli. No focal neurologic deficits occurred. Pain was not reported. CONCLUSIONS: The results of this pilot study suggest that brain cooling can be achieved safely, rapidly, and selectively by means of IC-CSI, opening a new potential avenue for acute neuroprotection. Clinical investigations with control of infusion parameters and measurements of CBF, oxygen consumption, and brain temperature are warranted.

Clinical and morphological determinants of focal neurological deficits in patients with unruptured brain arteriovenous malformation.

OBJECTIVE: Some patients with brain arteriovenous malformation (BAVM) present with focal neurological deficits (FNDs) unrelated to clinically discernable seizure activity or hemorrhage. The aim of this study is to determine demographic and morphological AVM characteristics associated with FNDs. METHODS: The 735 patients of the prospective Columbia AVM Databank were analyzed. Univariate and multivariate statistical models were used to test the association of demographic (age, gender), and morphological characteristics (BAVM size, anatomic location, arterial supply, venous drainage pattern, venous ectasia) with the occurrence of FNDs at the time of initial BAVM diagnosis. RESULTS: Fifty-three patients (7%, mean age 40+/-16years, 70% women) presented with FNDs. The multivariate logistic regression model revealed an independent association of FNDs with increasing age (OR 1.03; 95%-CI 1.00-1.05), female gender (OR 2.14; 95%-CI 1.15-3.97), deep brain location (OR 2.46; 95%-CI 1.24-4.88), brainstem location (OR 5.62; 95%-CI 1.65-19.23), and venous ectasia (OR 1.91; 95%-CI 1.01-3.64). No association was found for BAVM size, lobar location, arterial supply and venous drainage pattern. INTERPRETATION: Focal neurologic deficits unrelated to seizures or hemorrhage are a rare initial presentation of BAVMs. The predominance of FNDs among brainstem and deeply located BAVMs and the lack of a significant association of BAVM size with FNDs indicate selective white matter pathway-specific vulnerability, the association with patient age a time dependent effect. The higher frequency of FNDs among women suggests gender-specificity of brain tissue vulnerability.

Late endovascular revascularization in acute ischemic stroke based on clinical-diffusion mismatch.

BACKGROUND AND PURPOSE: A clinical-diffusion mismatch (CDM) among stroke patients presenting within 12-24 hours has been correlated with neurologic deterioration and infarct expansion. We sought to study the feasibility and safety of reperfusion therapy in a series of 11 consecutive patients fulfilling this criterion. MATERIALS AND METHODS: Patients presenting with large vessel syndromes were considered for revascularization therapy. Of these patients, we identified those presenting beyond 8 hours who scored > or =8 on the National Institutes of Health Stroke Scale (NIHSS) and had limited abnormalities on diffusion-weighted MR imaging. One- and 7-day NIHSS scores were obtained. Rates of early neurologic deterioration (END, increase in NIHSS score by > or =4 points) and early neurologic improvement (ENI, decrease in NIHSS score by > or =4 points) at 1 week were determined. Follow-up imaging was obtained to evaluate intracranial hemorrhage (ICH). RESULTS: Eleven patients were identified, 8 of whom were successfully revascularized. The mean age of all patients was 55 years with mean initial, 24-hour, and 1-week NIHSS scores of 14 +/- 4, 11 +/- 7, and 6 +/- 5, respectively, with lower scores at 24 hours and 1 week (8 +/- 5 and 4 +/- 3, respectively) among patients successfully revascularized. Eight of the treated patients (72% of the total, 100% of those successfully revascularized) experienced ENI. No patient had END or ICH. CONCLUSIONS: Endovascular treatment for acute ischemic stroke beyond 8 hours is feasible and may prevent END and promote ENI in patients fulfilling the criteria of a CDM. A prospective study is planned.

Aortic dissection associated with a neurointerventional guidewire retained in a perforating branch of the right posterior cerebral artery.

We report a case of a 55-year-old man with a 6.5 mm right posterior cerebral artery (PCA) aneurysm. Upon attempted Guglielmi detachable coil embolisation, the guidewire was lodged in a perforating branch of the right PCA and attempted retractions were unsuccessful. The retained guidewire was left in the patient. The patient died 10 weeks later due to a perforation that dissected through the wall of the ascending aorta resulting in haemopericardium.

Intracerebral hemorrhage in pregnancy: frequency, risk factors, and outcome.

OBJECTIVE: To describe the frequency, risk factors, and outcome of intracerebral hemorrhage (ICH) in pregnancy and the postpartum period using a large database of US inpatient hospitalizations. METHODS: The authors obtained data from an administrative dataset, the Nationwide Inpatient Sample, which includes approximately 20% of all discharges from non-Federal hospitals, for the years 1993 through 2002. Women aged 15 to 44 years with a diagnosis of ICH were selected from the database for analysis, and within this group patients coded as pregnant or postpartum were identified. Using US Census data, estimates were made of the rates of ICH in pregnant/postpartum and non-pregnant women. Rates of various comorbidities in patients with pregnancy-related ICH were compared to the rates found in the general population of delivering patients using multivariate logistic regression to identify independent risk factors for pregnancy-related ICH. RESULTS: The authors identified 423 patients with pregnancy-related ICH, which corresponded to 6.1 pregnancy-related ICH per 100,000 deliveries and 7.1 pregnancy-related ICH per 100,000 at-risk person-years (compared to 5.0 per 100,000 person-years for non-pregnant women in the age range considered). The increased risk of ICH associated with pregnancy was largely attributable to ICH occurring in the postpartum period. The in-hospital mortality rate for pregnancy-related ICH was 20.3%. ICH accounted for 7.1% of all pregnancy-related mortality recorded in this database. Significant independent risk factors for pregnancy-related ICH included advanced maternal age (OR 2.11, 95% CI 1.69 to 2.64), African American race (OR 1.83, 95% CI 1.39 to 2.41), preexisting hypertension (OR 2.61, 95% CI 1.34 to 5.07), gestational hypertension (OR 2.41, 95% CI 1.62 to 3.59), preeclampsia/eclampsia (OR 10.39, 95% CI 8.32 to 12.98), preexisting hypertension with superimposed preeclampsia/eclampsia (OR 9.23, 95% CI 5.26 to 16.19), coagulopathy (OR 20.66, 95% CI 13.67 to 31.23), and tobacco abuse (OR 1.95, 95% CI 1.11 to 3.42). CONCLUSION: Intracerebral hemorrhage (ICH) accounts for a substantial portion of pregnancy-related mortality. The risk of ICH associated with pregnancy is greatest in the postpartum period. Advanced maternal age, African American race, hypertensive diseases, coagulopathy, and tobacco abuse were all independent risk factors for pregnancy-related ICH.

Predictors of hemorrhage in patients with untreated brain arteriovenous malformation.

BACKGROUND: Intracranial hemorrhage is a serious possible complication in patients with brain arteriovenous malformation (AVM). Several morphologic factors associated with hemorrhagic AVM presentation have been established, but their relevance for the risk of subsequent AVM hemorrhage remains unclear. METHODS: The authors analyzed follow-up data on 622 consecutive patients from the prospective Columbia AVM database, limited to the period between initial AVM diagnosis and the start of treatment (i.e., any endovascular, surgical, or radiation therapy). Univariate and multivariate logistic regression and Cox proportional hazard models were applied to analyze the effect of patient age, gender, AVM size, anatomic location, venous drainage pattern, and associated arterial aneurysms on the risk of intracranial hemorrhage at initial presentation and during follow-up. RESULTS: The mean pretreatment follow-up was 829 days (median: 102 days), during which 39 (6%) patients experienced AVM hemorrhage. Increasing age (hazard ratio [HR] 1.05, 95% CI 1.03 to 1.08), initial hemorrhagic AVM presentation (HR 5.38, 95% CI 2.64 to 10.96), deep brain location (HR 3.25, 95% CI 1.30 to 8.16), and exclusive deep venous drainage (HR 3.25, 95% CI 1.01 to 5.67) were independent predictors of subsequent hemorrhage. Annual hemorrhage rates on follow-up ranged from 0.9% for patients without hemorrhagic AVM presentation, deep AVM location, or deep venous drainage to as high as 34.4% for those harboring all three risk factors. CONCLUSIONS: Hemorrhagic arteriovenous malformation (AVM) presentation, increasing age, deep brain location, and exclusive deep venous drainage appear to be independent predictors for AVM hemorrhage during natural history follow-up. The risk of spontaneous hemorrhage may be low in AVMs without these risk factors.

Definitive embolization of meningiomas. A review.

SUMMARY: This review examines the possible role for definitive embolization as a primary therapy for intracranial meningiomas. Surgery or radiosurgery are currently considered the standard of care for most benign meningiomas. However, each of these carries substantial risks. The perioperative mortality for surgical resection, as reported in large series, is between 3.7-9.4%; these studies report a similarly high rate of new neurological deficits following surgery. The rate of complications from radiosurgery is reported between 2-16% and it may take months to years before improvement in symptoms occurs following this therapy. There are a few reports of treating meningiomas by embolization without subsequent surgery. While these studies include small numbers of patients and have limited follow-up, the initial results are very promising. Given the risks and limitations of surgery and radiosurgery, prospective trials are now needed to determine the safety and efficacy of definitive embolization.

Association of infratentorial brain arteriovenous malformations with hemorrhage at initial presentation.

BACKGROUND AND PURPOSE: The goal of this study was to analyze the association of hemorrhagic presentation with infratentorial brain arteriovenous malformations (AVMs). METHODS: The 623 consecutive, prospectively enrolled patients from the Columbia AVM Databank were analyzed in a cross-sectional study. Clinical presentation (diagnostic event) was categorized as intracranial hemorrhage or nonhemorrhagic presentation. From brain imaging and cerebral angiography, AVM location was classified as either infratentorial or supratentorial. Univariate and multivariate statistical models were applied to test the effect of age, sex, AVM size and location, venous drainage pattern, and associated (ie, feeding artery or intranidal) arterial aneurysms on the likelihood of hemorrhage at initial AVM presentation. RESULTS: Of the 623 patients, 72 (12%) had an infratentorial and 551 (88%) had a supratentorial AVM. Intracranial hemorrhage was the presenting symptom in 283 patients (45%), and infratentorial AVM location was significantly more frequent (18%) among patients who bled initially (6%; odds ratio [OR], 3.60; 95% confidence interval [CI], 2.09 to 6.20). This difference remained significant (OR, 1.99; 95% CI, 1.07 to 3.69) in the multivariate logistic regression model controlling for age, sex, AVM size, deep venous drainage, and associated arterial aneurysms. In the same model, the effect of other established determinants for AVM hemorrhage--ie, AVM size (in 1-mm increments; OR, 0.95; 95% CI, 0.94 to 0.96), deep venous drainage (OR, 3.09; 95% CI, 1.87 to 5.12), and associated aneurysms (OR, 2.78; 95% CI, 1.76 to 4.40)--remained significant. CONCLUSIONS: Our findings suggest that infratentorial AVM location is independently associated with hemorrhagic AVM presentation.

Urgent endovascular revascularization for symptomatic intracranial atherosclerotic stenosis.

BACKGROUND: Endovascular revascularization for intracranial atherosclerotic stenoses is being increasingly performed at major medical centers and has been reported to be technically feasible and safe. The authors report their experience with patients who underwent such a procedure for impending stroke and neurologic instability. METHOD: All 18 patients (21 intracranial lesions) treated between 1997 and 2002 at the authors' institution with endovascular revascularization were retrospectively reviewed. Each patient had failed maximal medical therapy and was thought to be at high risk for an imminent stroke. RESULTS: Endovascular revascularization was performed on eight distal internal carotid artery lesions, six middle cerebral artery lesions, four intracranial vertebral artery lesions, and three basilar artery lesions. Recanalization was complete in 5 arteries (Thrombolysis in Myocardial Infarction [TIMI] Grade III), partial in 14 arteries (TIMI Grade II), and complete occlusion (TIMI 0) developed in 1 artery. In a patient with a tight basilar stenosis, no angioplasty could be performed because of the inability to cross the stenosis with the guidewire. Major periprocedural complications occurred in 9 (50%) patients: intracranial hemorrhage in 3 (17%), disabling ischemic stroke in 2 (11%), and major extracranial hemorrhage in 4 (22%). Three patients died: one from intracerebral hemorrhage and two from cardiorespiratory failure. CONCLUSIONS: Endovascular revascularization of intracranial vessels is technically feasible and may be performed successfully. However, periprocedural complication and fatality rates in neurologically unstable patients are high. The results suggest that patient selection, procedure timing, and periprocedural medical management are critical factors to reduce periprocedural morbidity and mortality.

Endovascular mechanical thrombectomy of an occluded superior division branch of the left MCA for acute cardioembolic stroke.

Cardiac embolism accounts for a large proportion of ischemic stroke. Revascularization using systemic or intra-arterial thrombolysis is associated with increasing risks of cerebral hemorrhage as time passes from stroke onset. We report successful mechanical thrombectomy from a distal branch of the middle cerebral artery (MCA) using a novel technique. A 72-year old man suffered an acute ischemic stroke from an echocardiographically proven ventricular thrombus due to a recent myocardial infarction. Intraarterial administration of 4 mg rt-PA initiated at 5.7 hours post-ictus failed to recanalize an occluded superior division branch of the left MCA. At 6 hours, symptomatic embolic occlusion persisted. Mechanical extraction of the clot using an Attracter-18 device (Target Therapeutics, Freemont, CA) resulted in immediate recanalization of the MCA branch. Attracter-18 for acute occlusion of MCA branches may be considered in selected patients who fail conventional thrombolysis or are nearing closure of the therapeutic window for use of thrombolytic agents.

Effect of age on clinical and morphological characteristics in patients with brain arteriovenous malformation.

BACKGROUND AND PURPOSE: The goal of this work was to determine the effect of age at initial presentation on clinical and morphological characteristics in patients with brain arteriovenous malformation (AVM). METHODS: The 542 consecutive patients from the prospective Columbia AVM database (mean+/-SD age, 34+/-15 years) were analyzed. Univariate statistical models were used to test the effect of age at initial presentation on clinical (AVM hemorrhage, seizures, headaches, neurological deficit, other/asymptomatic) and morphological (AVM size, venous drainage pattern, AVM brain location, concurrent arterial aneurysms) characteristics. RESULTS: Hemorrhage was the presenting symptom in 46% (n=247); 29% (n=155) presented with seizures, 13% (n=71) with headaches, 7% (n=36) with a neurological deficit, and 6% (n=33) without AVM-related symptoms. Increasing age correlated positively with intracranial hemorrhage (P=0.001), focal neurological deficits (P=0.007), infratentorial AVMs (P<0.001), and concurrent arterial aneurysms (P<0.001); an inverse correlation was found with seizures (P<0.001), AVM size (P=0.001), and lobar (P<0.001), deep (P=0.008), and borderzone (P=0.014) location. No age differences were found for sex, headache, asymptomatic presentation, and venous drainage pattern. CONCLUSIONS: Our data suggest a significant interaction of patient age and clinical and morphological AVM features and argue against uniform AVM characteristics across different age classes at initial presentation. In particular, AVM patients diagnosed at a higher age show a higher fraction of AVM hemorrhage and are more likely to harbor additional risk factors such as concurrent arterial aneurysms and small AVM diameter. Longitudinal population-based AVM data are necessary to confirm these findings.

The New York Islands AVM Study: design, study progress, and initial results.

BACKGROUND AND PURPOSE: Prospective population-based data on the incidence of brain arteriovenous malformation (AVM) hemorrhage are scarce. We studied lifetime detection rates of brain AVM and incident AVM hemorrhage in a defined population. METHODS: The New York islands (ie, Manhattan Island, Staten Island, and Long Island) comprise a 9,429,541 population according to the 2000 census. Since March 15, 2000, all major New York islands hospitals have prospectively reported data on consecutive patients living in the study area with a diagnosis of brain AVM and whether the patient had suffered AVM hemorrhage. Patients living outside the ZIP code-defined study area were excluded from the study population. RESULTS: As of June 14, 2002, 284 prospective AVM patients (mean+/-SD age, 35+/-18 years; 49% women) were encountered during 21,216,467 person-years of observation, leading to an average annual AVM detection rate of 1.34 per 100,000 person-years (95% CI, 1.18 to 1.49). The incidence of first-ever AVM hemorrhage (n=108; mean age, 31+/-19 years; 45% women) was 0.51 per 100,000 person-years (95% CI, 0.41 to 0.61). The estimated prevalence of AVM hemorrhage among detected cases (n=144; mean age, 33+/-19 years; 50% women) was 0.68 per 100,000 (95% CI, 0.57 to 0.79). CONCLUSIONS: Our prospective data, spanning 27 months, suggest stable rates for AVM detection and incident AVM hemorrhage. Approximately half of AVM patients may suffer intracranial hemorrhage.

Concurrent arterial aneurysms in brain arteriovenous malformations with haemorrhagic presentation.

OBJECTIVE: To assess the effect of concurrent arterial aneurysms on the risk of incident haemorrhage from brain arteriovenous malformations (AVMs). METHODS: In a cross sectional study, 463 consecutive, prospectively enrolled patients from the Columbia AVM Databank were analysed. Concurrent arterial aneurysms on brain angiography were classified as feeding artery aneurysms, intranidal aneurysms, and aneurysms unrelated to blood flow to the AVM. Clinical presentation (diagnostic event) was categorised as intracranial haemorrhage proved by imaging or non-haemorrhagic presentation. Univariate and multivariate statistical models were applied to test the effect of age, sex, AVM size, venous drainage pattern, and the three types of aneurysms on the risk of AVM haemorrhage at initial presentation. RESULTS: Arterial aneurysms were found in 117 (25%) patients with AVM (54 had feeding artery aneurysms, 21 had intranidal aneurysms, 18 had unrelated aneurysms, and 24 had more than one aneurysm type). Intracranial haemorrhage was the presenting symptom in 204 (44%) patients with AVM. In the univariate model, the relative risk for haemorrhagic AVM presentation was 2.28 (95% confidence interval (CI) 1.12 to 4.64) for patients with intranidal aneurysms and 1.88 (95% CI 1.14 to 3.08) for those with feeding artery aneurysms. In the multivariate model an independent effect of feeding artery aneurysms (odds ratio 2.11, 95% CI 1.18 to 3.78) on haemorrhagic AVM presentation was found. No significant effect was seen for intranidal and unrelated aneurysms. The attributable risk of feeding artery aneurysms for incident haemorrhage in patients with AVM was 6% (95% CI 1% to 11%). CONCLUSIONS: The findings suggest that feeding artery aneurysms are an independent determinant for increased risk of incident AVM haemorrhage.

Risk of endovascular treatment of brain arteriovenous malformations.

BACKGROUND AND PURPOSE: Independently assessed data on frequency, severity, and determinants of neurological deficits after endovascular treatment of brain arteriovenous malformations (AVMs) are scarce. METHODS: From the prospective Columbia AVM Study Project, 233 consecutive patients with brain AVM receiving > or =1 endovascular treatments were analyzed. Neurological impairment was assessed by a neurologist using the Rankin Scale before and after completed endovascular therapy. Multivariate logistic regression models were used to identify demographic, clinical, and morphological predictors of treatment-related neurological deficits. The analysis included the components used in the Spetzler-Martin risk score for AVM surgery (AVM size, venous drainage pattern, and eloquence of AVM location). RESULTS: The 233 patients were treated with 545 endovascular procedures. Mean follow-up time was 9.6 months (SD, 18.1 months). Two hundred patients (86%) experienced no change in neurological status after treatment, and 33 patients (14%) showed treatment-related neurological deficits. Of the latter, 5 (2%) had persistent disabling deficits (Rankin score >2), and 2 (1%) died. Increasing patient age [odds ratio (OR), 1.04; 95% confidence interval (CI), 1.01 to 1.08], number of embolizations (OR, 1.41; 95% CI, 1.16 to 1.70), and absence of a pretreatment neurological deficit (OR, 4.55; 95% CI, 1.03 to 20.0) were associated with new neurological deficits. None of the morphological AVM characteristics tested predicted treatment complications. CONCLUSIONS: From independent neurological assessment and prospective data collection, our findings suggest a low rate of disabling treatment complications in this center for endovascular brain AVM treatment. Risk predictors for endovascular treatment differ from those for AVM surgery.