John F. Reavey-Cantwell

Bottleneck factor and height-width ratio: association with ruptured aneurysms in patients with multiple cerebral aneurysms.

OBJECTIVEDetermining factors predictive of the natural risk of rupture of cerebral aneurysms is difficult because of the need to control for confounding variables. We studied factors associated with rupture in a study model of patients with multiple cerebral aneurysms, one aneurysm that had ruptured and one or more that had not, in which each patient served as their own internal control. METHODSWe collected aneurysm location, one-dimensional measurements, and two-dimensional indices from the computed tomographic angiograms of patients in the proposed study model and compared ruptured versus unruptured aneurysms. Bivariate statistics were supplemented with multivariable logistic regression analysis to model ruptured status. A total of 40 candidate models were evaluated for predictive power and fit with Wald scoring, Cox and Snell R2, Hosmer and Lemeshow tests, case classification counting, and residual analysis to determine which of the computed tomographic angiographic measurements or indices were jointly associated with and predictive of aneurysm rupture. RESULTSThirty patients with 67 aneurysms (30 ruptured, 37 unruptured) were studied. Maximum diameter, height, maximum width, bulge height, parent artery diameter, aspect ratio, bottleneck factor, and aneurysm/parent artery ratio were significantly (P < 0.05) associated with ruptured aneurysms on bivariate analysis. When best subsets and stepwise multivariable logistic regression was performed, bottleneck factor (odds ratio = 1.25, confidence interval = 1.11–1.41 for every 0.1 increase) and height-width ratio (odds ratio = 1.23, confidence interval = 1.03–1.47 for every 0.1 increase) were the only measures that were significantly predictive of rupture. CONCLUSIONIn a case-control study of patients with multiple cerebral aneurysms, increased bottleneck factor and height-width ratio were consistently associated with rupture.

Comparison of N-butyl cyanoacrylate and onyx for the embolization of intracranial arteriovenous malformations: analysis of fluoroscopy and procedure times.

OBJECTIVE Intracranial arteriovenous malformations (AVM) may be managed through staged preoperative embolization and resection. Two commonly used liquid embolics are N-butyl cyanoacrylate (nBCA; Cordis Microvascular, Inc., New Brunswick, NJ) and Onyx (ev3, Inc., Irvine, CA). We sought to compare the utility of these agents in terms of fluoroscopy and procedure times. METHODS All intracranial AVMs embolized from 2002 to 2006 at the University of Florida were included in this study. Patients were stratified into three treatment groups: nBCA, Onyx, and patients who received both nBCA and Onyx during separate embolizations. Cohorts were compared by sex, age, Spetzler-Martin grade, AVM volume, fluoroscopy time, procedure time, surgical blood loss, and complications. RESULTS A total of 182 embolizations were performed on 88 patients (nBCA, 60 patients and 106 procedures; Onyx, 20 patients and 43 procedures; and nBCA/Onyx, eight patients and 16 nBCA and 17 Onyx procedures). There were no significant differences in patient demographics, AVM volumes, and Spetzler-Martin grades. Mean fluoroscopy and procedure times were increased for Onyx (57 min; 2.6 h) compared with nBCA (37 min; 2.1 h) embolizations (P < 0.0001 and P = 0.001, respectively). Cumulative mean fluoroscopy time was increased for Onyx (135 min) and nBCA/Onyx (180 min) cohorts relative to nBCA (64 min; P < 0.0001). Cumulative mean procedure time was increased in the nBCA/Onyx group (10.4 h) compared with nBCA (3.7 h) and Onyx (5.4 h; P < 0.0001). Seventy patients (80%) underwent AVM resection. No significant differences in surgical blood loss or complication rates were observed among the cohorts. CONCLUSION Onyx AVM embolization requires increased fluoroscopy and procedure times compared with nBCA. Further investigation is necessary to justify increased radiation exposure and procedure time associated with Onyx.

A Multicenter Study of Stent-Assisted Coiling of Cerebral Aneurysms With a Y Configuration

BACKGROUND Stent-assisted coiling with 2 stents in a Y configuration is a technique for coiling complex wide-neck bifurcation aneurysms. OBJECTIVE We sought to provide long-term clinical and angiographic outcomes with Y-stent coiling, which are not currently established. METHODS Seven centers provided deidentified, retrospective data on all consecutive patients who underwent stent-assisted coiling for an intracranial aneurysm with a Y-stent configuration. RESULTS Forty-five patients underwent treatment by Y-stent coiling. Their mean age was 57.9 years. Most aneurysms were basilar apex (87%), and 89% of aneurysms were unruptured. Mean size was 9.9 mm. Most aneurysms were treated with 1 open-cell and 1 closed-cell stent (51%), with 29% treated with open-open stents and 16% treated with 2 closed-cell stents. Initial aneurysm occlusion was excellent (84% in Raymond grade I or II). Procedural complications occurred in 11% of patients. Mean clinical follow-up was 7.8 months, and 93% of patients had a modified Rankin Scale score of 0 to 2 at last follow-up. Mean angiographic follow-up was 9.8 months, and 92% of patients had Raymond grade I or II occlusion on follow-up imaging. Of those patients with initial Raymond grade III occlusion and follow-up imaging, all but 1 patient progressed to a better occlusion grade (83%; P < .05). Three aneurysms required retreatment because of recanalization (10%). There was no difference in initial or follow-up angiographic occlusion, clinical outcomes, incidence of aneurysm retreatment, or in-stent stenosis among open-open, open-closed, or closed-closed stent groups. CONCLUSION In a large multicenter series of Y-stent coiling for bifurcation aneurysms, there were low complication rates and excellent clinical and angiographic outcomes.

FACTORS ASSOCIATED WITH ASPIRIN RESISTANCE IN PATIENTS PREMEDICATED WITH ASPIRIN AND CLOPIDOGREL FOR ENDOVASCULAR NEUROSURGERY

OBJECTIVEAntiplatelet therapy is critical to endovascular neurosurgical procedures. Some patients are aspirin-resistant nonresponders. We reviewed our endovascular neurosurgery patients who were premedicated with aspirin and clopidogrel and identified nonresponders to aspirin. Factors associated with aspirin resistance were determined. METHODSConsecutive endovascular neurosurgery patients were identified who were treated by the senior author (BLH) from December 2006 to October 2007 and who were premedicated with aspirin (325 mg) and clopidogrel (75 mg) for 7 days before the procedure. We retrospectively reviewed values from the platelet function analyzer-100 test (Dade-Behring, Deerfield, IL) from 1 day before the procedures. The following factors were evaluated for association with aspirin drug resistance: age, sex, body mass index, and smoking history; patients with hypertension, diabetes, coronary artery disease/ peripheral vascular disease, or hypercholesterolemia; disease pathology (aneurysm, intracranial stenosis, or extracranial stenosis); patients taking statins, β-blockers, angiotensinconverting enzyme inhibitors/angiotensin receptor blockers, or antidepressants; and white blood cell count, hemoglobin, hematocrit, and platelet levels. A stepwise logistic model selection was used to select important factors and their interactions. RESULTSEighty-one consecutive patients with the following interventions were included in the study: 35 aneurysm coilings (43%), 21 stent-assisted aneurysm coilings (26%), 13 carotid stent and angioplasties (16%), 7 intracranial stents and angioplasties (9%), and 5 extracranial vertebral artery stents and angioplasties (6%). Seventeen patients (21%) were nonresponders to aspirin. After model selection, the only factor associated with aspirin resistance was not taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (P = 0.0348; odds ratio, 0.214; 95% confidence interval, 0.051–0.896). CONCLUSIONTwenty-one percent of patients premedicated with aspirin and clopidogrel dual therapy for 7 days before endovascular neurosurgical procedures were nonresponders to aspirin. Patients not taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker may be at higher risk for aspirin drug resistance.

Mechanical thrombectomy for pediatric stroke arising from an atrial myxoma: case report.

Children experiencing severe neurological deficit due to acute ischemic stroke may benefit from endovascular intervention. The authors describe the use of mechanical thrombectomy in the treatment of embolic occlusion secondary to an atrial myxoma in a pediatric patient. This case involved an 11-year-old boy with a history notable for Raynaud syndrome and a distal extremity rash who presented to the emergency department with dense hemiparesis secondary to thromboembolic occlusion of the M1 segment of the middle cerebral artery. Following mechanical thrombectomy, the patients pediatric National Institutes of Health Stroke Scale score improved from a 16 to a 7. In the setting of acute pediatric stroke due to atrial myxoma emboli, mechanical thrombectomy may be a first-line therapy.

Pipeline Embolization Device for treatment of high cervical and skull base carotid artery dissections: clinical case series

Background Most cervical dissections are treated with anticoagulation or antiplatelet agents with very good results; however, some patients may benefit from endovascular intervention. High cervical and skull base dissections are often more challenging to treat because of the distal location and tortuous anatomy. The Pipeline Embolization Device (PED) may be a reasonable treatment option for this indication. Objectives To report a case series of patients treated with the PED for high cervical and skull base dissections, focusing on their presentation, indications for treatment, dissection revascularization success, and pseudoaneurysm obliteration evaluated by imaging, and to review available pertinent literature. Methods We retrospectively reviewed all cases of high cervical and skull base dissections treated with a PED at our institution. Patient clinical characteristics, presentation, procedural and follow-up imaging, and clinical course were analyzed to evaluate for procedure complications, dissection revascularization success, pseudoaneurysm obliteration, and clinical outcome. Results This is a retrospective case series including 11 patients with 13 carotid dissections treated in our center. There were nine traumatic and four spontaneous dissections. The most common presentation was cerebrovascular accident/transient ischemic attack (CVA/TIA; 5 patients) and headache/face pain (4 patients). Eleven dissections were associated with pseudoaneurysms. Three patients failed medical management with anticoagulation, although flow-limiting stenosis was the main indication for endovascular intervention. Up to three PEDs per vessel were deployed. Angioplasty was used in 10 cases. Complete revascularization (<10% residual stenosis) was achieved in 91% of vessels and 50% of pseudoaneurysms were completely or near completely obliterated immediately after PED(s) deployment. Proximal iatrogenic dissection was the only intraoperative complication. Follow-up imaging was available for nine treated vessels and demonstrated patent PEDs without significant in-stent stenosis up to 9 months after intervention. 75% of pseudoaneurysms were completely obliterated at follow-up. One PED partially collapsed but had no neurological consequences. There were no new CVA/TIAs. Conclusions Our initial experience with treatment of high cervical and skull base dissections with the PED appears to show that this technique may be a safe and viable treatment option. However, long-term results are needed to fully evaluate the efficacy of such treatment.

An unusual case of pediatric bow hunter's stroke

Background: Bow Hunters syndrome/stroke is defined as symptomatic, vertebrobasilar insufficiency provoked by physiologic head rotation. It is a diagnostically challenging cause of posterior circulation stroke in children. While there have been prior reports of this rare disorder, we describe an exceptional case of pediatric Bow Hunters stroke resulting from a near complete occlusion the right vertebral artery (VA) secondary to an anomalous spur emanating from the right occipital condyle. Surgical and endovascular options and approaches are also detailed herein. Case Description: A 16-year-old male presented with multiple posterior circulation ischemic strokes. A dynamic computerized tomography angiogram performed with the patients head in a rotated position revealed a near complete occlusion of the V3 segment of the right VA from a bone spur arising from his occipital condyle. The spur caused a focal dissection of the distal right VA with associated thrombus. He was initially managed with a cervical collar, antiplatelet therapy with aspirin 81 mg and anticoagulation with coumadin (INR goal 2-3) for 3 months. Despite the management plan, he had a subsequent thromboembolic event and a right VA sacrifice with coil embolization was then performed. At the 3-month follow-up, the patient was doing well with no reports of any subsequent strokes. Conclusion: We report the first reported pediatric case of Bow Hunters stroke due to dynamic right VA occlusion from an occipital condylar bone spur. The vascular compression from this spur led to a right VA dissection and thrombus formation and ultimately caused multiple posterior circulation thromboembolic strokes. Endovascular treatment options including vessel sacrifice should be considered in cases that have failed maximal medical management.

Preconditioning effect on cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND Recent experimental evidence indicates that endogenous mechanisms against cerebral vasospasm can be induced via preconditioning. OBJECTIVE To determine whether these vascular protective mechanisms are also present in vivo in humans with aneurysmal subarachnoid hemorrhage. METHODS A multicenter retrospective cohort of patients with aneurysmal subarachnoid hemorrhage was examined for ischemic preconditioning stimulus: preexisting steno-occlusive cerebrovascular disease (CVD) and/or previous cerebral infarct. Generalized estimating equation models were performed to determine the effect of the preconditioning stimulus on the primary end points of radiographic vasospasm, symptomatic vasospasm, and vasospasm-related delayed cerebral infarction and the secondary end point of discharge modified Rankin Scale score. RESULTS Of 1043 patients, 321 (31%) had preexisting CVD and 437 (42%) had radiographic vasospasm. Patients with preexisting CVD were less likely to develop radiographic vasospasm (odds ratio = 0.67; 95% confidence interval = 0.489-0.930; P = .02) but had no differences in other end points. In terms of the secondary end point, patients with preexisting CVD did not differ significantly from patients without preexisting CVD in mortality or unfavorable outcome in multivariate analyses, although patients with preexisting CVD were marginally more likely to die (P = .06). CONCLUSION This retrospective case-control study suggests that endogenous protective mechanisms against cerebral vasospasm-a preconditioning effect-may exist in humans, although these results could be the effect of atherosclerosis or some combination of preconditioning and atherosclerosis. Additional studies investigating the potential of preconditioning in aneurysmal subarachnoid hemorrhage are warranted.

Occlusion of All Aortic Arch Great Vessels: Acute Revascularization to Perform Endovascular Stroke Therapy

BACKGROUND We present a case of a patient with a left-sided stroke and occlusion of all aortic arch great vessels who was treated successfully with endovascular intervention followed by delayed cardiothoracic revascularization. CASE REPORT A 46-year-old man presented with acute onset of dense right hemiparesis, facial droop, and aphasia with an initial National Institute of Health Stroke Score of 15. The patient was taken for emergent angiography after failing intravenous tissue plasminogen activator thrombolysis. Dedicated angiography of the aortic arch revealed occlusion of all great vessels, including the right brachiocephalic, left common carotid, and left subclavian artery. Delayed arterial filling of the right brachiocephalic and left subclavian artery by aberrant collaterals was seen. More distally, flow into the bilateral subclavian arteries, right common carotid artery, and left vertebral artery was appreciated. Serial balloon angioplasty of the left common carotid artery origin reconstituted flow. Subsequent selective angiogram of the left internal carotid artery revealed a proximal middle cerebral artery occlusion. Intra-arterial injection of tissue plasminogen activator followed by mechanical thrombectomy and intracranial stenting restored flow in the middle cerebral artery. Two months later the patient underwent aortic arch reconstruction with bifurcated graft to the brachiocephalic artery and left common carotid artery. At 1-year follow-up, the patients examination revealed almost complete resolution of right hemiparesis with minimal hand weakness and mild expressive aphasia. CONCLUSIONS We report a rare case of occlusion of all aortic arch great vessels. Combined endovascular intervention and surgical revascularization resulted in an excellent durable outcome.

Paradoxical Septic Emboli Secondary to Pacemaker Endocarditis Transvenous Lead Extraction With Distal Embolization Protection

A 69-year-old woman with a history of paroxysmal atrial fibrillation and sick sinus syndrome with a dual-chamber pacemaker was admitted to our institution with Staphylococcus aureus bacteremia. She exhibited nonspecific neurological complaints, and head CT demonstrated multiple cerebral lesions consistent with septic emboli. Transesophageal echocardiography revealed a 3-cm vegetation on the right atrial pacemaker lead (Figure 1A, Video I in the Data Supplement). There was no evidence of aortic or mitral valve endocarditis; however, a patent foramen ovale with intermittent right-to-left shunting was identified (Figure 1B and 1C, Video II in the Data Supplement). Surgical removal was considered; however, the potential for hemorrhagic conversion of recent embolic strokes from high-dose heparin needed during cardiopulmonary bypass was prohibitive. Transvenous lead extraction was used and, to protect …