Accuracy in Identifying the Source of Subarachnoid Hemorrhage in the Setting of Multiple Intracranial Aneurysms.

Background: Subarachnoid hemorrhage cases with multiple cerebral aneurysms frequently demonstrate a hemorrhage pattern that does not definitively delineate the source aneurysm. In these cases, rupture site is ascertained from angiographic features of the aneurysm such as size, morphology, and location.

Objective: To examine the frequency with which such features lead to misidentification of the ruptured aneurysm.

Reducing length of stay in aneurysmal subarachnoid hemorrhage: A three year institutional experience.

Hospital length of stay is a common metric of excellence in health care. With limited data evaluating hospital length of stay (LOS) and cost in subarachnoid hemorrhage (SAH), in this study we explore multiple prognostic factors and present our institutional experience in shortening LOS. 345 SAH patients were reviewed over a three year period.

Safety and efficacy of balloon angioplasty of the anterior cerebral artery for vasospasm treatment after subarachnoid hemorrhage.

Balloon angioplasty is often performed for symptomatic vasospasm following aneurysmal subarachnoid hemorrhage. Angioplasty of the anterior cerebral artery (ACA), however, is perceived to be a challenging endeavor and not routinely performed due to technical and safety concerns. Here, we evaluate the safety and efficacy of balloon angioplasty of the anterior cerebral artery for vasospasm treatment.

Changes in pulsatility and resistance indices of cerebral arteriovenous malformation feeder arteries after embolization and surgery.

Objectives: Embolization reduces flow in cerebral arteriovenous malformations (AVMs) before surgical resection, but changes in pulsatility and resistance indices (PI, RI) are unknown. Here, we measure PI, RI in AVM arterial feeders before and after embolization/surgery.

Methods: Records of patients who underwent AVM embolization and surgical resection at our institution between 2007 and 2014 and had PI, RI, and flows obtained using quantitative magnetic resonance angiography were retrospectively reviewed.

Quantitative assessment of parent vessel and distal intracranial hemodynamics following pipeline flow diversion.

Background Pipeline embolization devices (PEDs) are commonly used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intraparenchymal hemorrhage. Although intra-aneurysmal hemodynamic changes have been studied, parent vessel and intracranial hemodynamics after PED use are unknown. We examine the impact of flow diversion on parent artery and distal intracranial hemodynamics.

Relationship of pulsatility and resistance indices to cerebral arteriovenous malformation angioarchitectural features and hemorrhage.

The role that hemodynamics plays in the pathophysiology of cerebral arteriovenous malformation (AVM) hemorrhage remains unclear. Here, we examine the relationship of pulsatility and resistance indices to AVM angioarchitectural features and hemorrhage. Records of patients with cerebral AVMs evaluated at our institution between 2007-2014 and with flows obtained before treatment using quantitative magnetic resonance angiography (QMRA) were retrospectively reviewed.

Effect of Hemodynamics on Stroke Risk in Symptomatic Atherosclerotic Vertebrobasilar Occlusive Disease.

Importance: Atherosclerotic vertebrobasilar (VB) occlusive disease is a significant etiology of posterior circulation stroke, with regional hypoperfusion as an important potential contributor to stroke risk.

Objective: To test the hypothesis that, among patients with symptomatic VB stenosis or occlusion, those with distal blood flow compromise as measured by large-vessel quantitative magnetic resonance angiography (QMRA) are at higher risk of subsequent posterior circulation stroke.

Design, Setting, And Participants: A prospective, blinded, longitudinal cohort study was conducted at 5 academic hospital-based centers in the United States and Canada; 82 patients from inpatient and outpatient settings were enrolled.

Effects of nidus microarchitecture on cerebral arteriovenous malformation hemodynamics.

Intranidal vessel geometry and organization underlying flow within cerebral arteriovenous malformations (AVM) is poorly understood. We examine the relationship between intranidal vessel characteristics and AVM flow. Records of patients with AVM evaluated at our institution between 2007 and 2013 were retrospectively reviewed.

Detection of unruptured intracranial aneurysms on noninvasive imaging. Is there still a role for digital subtraction angiography?

Background: To determine the utility of digital subtraction angiography (DSA) in patients with unruptured intracranial aneurysms (UIA) detected on noninvasive imaging, such as magnetic resonance angiography (MRA) and computed tomography angiography (CTA). The follow-up of patients with untreated UIAs involves serial imaging; however, this diagnosis may be based on false positive (FP) results. We examined the incidence of FPs in our institutional series.

Correlation between angiographic transit times and neurological status on admission in patients with aneurysmal subarachnoid hemorrhage.

Objective: The use of digital subtraction angiography (DSA) for semiquantitative cerebral blood flow(CBF) assessment is a new technique. The aim of this study was to determine whether patients with aneurysmal subarachnoid hemorrhage (aSAH) with higher Hunt and Hess grades also had higher angiographic contrast transit times (TTs) than patients with lower grades.

Methods: A cohort of 30 patients with aSAH and 10 patients without aSAH was included.

Hemodynamic Features of Symptomatic Vertebrobasilar Disease.

Background And Purpose: Atherosclerotic vertebrobasilar disease is an important cause of posterior circulation stroke. To examine the role of hemodynamic compromise, a prospective multicenter study, Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke (VERiTAS), was conducted. Here, we report clinical features and vessel flow measurements from the study cohort.

Changes in wall shear stress of cerebral arteriovenous malformation feeder arteries after embolization and surgery.

Background And Purpose: Wall shear stress (WSS) has been implicated as an important stimulus for vascular remodeling. The purpose of this study is to measure WSS in AVM arterial feeders using quantitative magnetic resonance angiography pre- and post-embolization/surgery.

Methods: Records of patients who underwent AVM embolization and surgical resection at our institution between 2007 and 2013 and had WSS, flow rate, and vessel diameter obtained pre- and post-treatment using quantitative magnetic resonance angiography were retrospectively reviewed.

Quantitative assessment of changes in cerebral arteriovenous malformation hemodynamics after embolization.

Background And Purpose: Embolization reduces flow in arteriovenous malformations (AVMs) before surgical resection, but achievement of this goal is determined subjectively from angiograms. Here, we quantify effects of embolization on AVM flow.

Methods: Records of patients who underwent AVM embolization at our institution between 2007 and 2013 and had flow rates obtained pre- and postembolization using quantitative magnetic resonance angiography were retrospectively reviewed.

Intracranial blood flow changes after extracranial carotid artery stenting.

Background: Carotid artery stenting is an endovascular treatment option for patients with extracranial carotid stenosis. However, intracranial blood flow changes following stenting have not been established.

Objective: To determine the effects of stenting on intracranial blood flow.

Neurological outcomes and cure rates of embolization of brain arteriovenous malformations with n-butyl cyanoacrylate or Onyx: a meta-analysis.

Background: In the past decade, preoperative endovascular embolization of cerebral arteriovenous malformations (AVMs) became an essential tool in the treatment of these entities. With the current expansion of technology and wide incorporation of new devices, the indications for the use of endovascular embolization have expanded to include embolization for cure. This has been facilitated by the wide use of the new liquid embolic agents (ethylene-vinyl alcohol co-polymer (EVOH)) in addition to n-butyl cyanoacrylate (NBCA).

Effects of extracranial carotid stenosis on intracranial blood flow.

Background And Purpose: The hemodynamic effects of extracranial carotid stenosis on intracranial blood flow are not well characterized. We sought to determine the impact of degree of stenosis, stenosis length, and residual lumen on intracranial blood flow in patients with extracranial carotid stenosis.

Methods: Carotid stenosis patients who had undergone both vessel flow rate measurements using quantitative magnetic resonance angiography and digital subtraction angiography were examined.

Augmentation of N-butyl cyanoacrylate embolization of cranial, head, and neck tumors by simultaneous infusion of 5% dextrose solution.

Background: N-Butyl cyanoacrylate (NBCA) is an adhesive liquid embolic agent widely used for embolization of cranial, head and neck tumors. Adequate distal penetration of NBCA into vessels with the smallest possible diameter, while preventing its reflux, is still a challenge, even in experienced hands. Simultaneous infusion of 5% dextrose in water solution (D5W) through the guiding catheter has been described before as a technique for improving embolization of dural arteriovenous malformations.

Rare presentation of intracranial vascular blowout after tumor resection and radiation therapy.

A middle-aged patient presented with a rapidly growing right dural-based extra-axial posterior clinoid mass extending to the right cavernous sinus that was surgically resected. Histological examination showed solid growth of primitive neuroectodermal tumor arising from the third nerve. Following surgical resection, the patient was further managed by radiation and chemotherapy.

Rare presentation of intracranial vascular blowout after tumor resection and radiation therapy.

A middle-aged patient presented with a rapidly growing right dural-based extra-axial posterior clinoid mass extending to the right cavernous sinus that was surgically resected. Histological examination showed solid growth of primitive neuroectodermal tumor arising from the third nerve. Following surgical resection, the patient was further managed by radiation and chemotherapy.

Continued concern about parent vessel steno-occlusive progression with Onyx HD-500 and the utility of quantitative magnetic resonance imaging in serial assessment.

Background: Onyx HD-500 is a liquid embolic used to treat intracranial aneurysms.

Objective: To determine the incidence of parent vessel stenosis and the management strategy for these patients.

Methods: Medical records of patients treated with Onyx HD-500 between 2008 and 2011 were retrospectively reviewed.

The bihemispheric posterior interior cerebellar artery: anatomic variations and clinical relevance in 11 cases.

Purpose: Although the anatomic course of the posterior interior cerebellar artery (PICA) is variable, it is thought to be very rare for the artery to cross midline, with an estimated incidence of 0.1%. Bihemispheric PICA crosses midline and typically serves both PICA territories.

Extracranial carotid-vertebral bypass for endovascular access to complex posterior circulation aneurysms: a novel management approach.

Background: Endovascular embolization is a desirable treatment option for complex posterior circulation aneurysms, particularly recurrent aneurysms or those in difficult-to-access surgical locations. However, endovascular access is occasionally prohibited by proximal vertebral artery (VA) occlusion or vessel tortuosity. One strategy in such instances involves creation of an extracranial bypass conduit to the distal VA.

Detection of intracranial in-stent restenosis using quantitative magnetic resonance angiography.

Background And Purpose: In-stent restenosis (ISR) after angioplasty/stenting for intracranial stenosis has been reported in up to 25% to 30% of patients. Detection and monitoring of ISR relies primarily on serial catheter angiography, because noninvasive imaging methods are typically hampered by stent-related artifact. We examined the value of serial vessel flow measurements using quantitative magnetic resonance angiography (QMRA) in detection of ISR.

Follow-up angiography of intracranial aneurysms treated with endovascular placement of Guglielmi detachable coils.

Objective: The success of endovascular treatment of intracranial aneurysms with Guglielmi detachable coils (GDCs) is dependent on the long-term exclusion of the aneurysm from the circulation. We reviewed our experience with the long-term angiographic follow-up monitoring of aneurysms that had been treated with GDCs.

Methods: All patients whose aneurysms had been treated with GDCs between January 1995 and August 1999 and who subsequently underwent follow-up angiography at 6 months or more were included in this study.