The penumbra coil 400 system for treatment of wide-necked intracranial aneurysms: initial single-center experience.

Endovascular treatment of wide-necked intracranial aneurysms frequently requires stent- or balloon-assisted coiling to prevent coil herniation into the parent artery. Provided that coils can be securely deployed within the aneurysm sac, these adjunctive devices and their associated risk can be avoided. The Penumbra 400 Coil (PC-400) has a larger diameter than conventional coils and is constructed completely of metal, a feature that increases the coil stability and may improve its ability to respect the aneurysm neck. The purpose of this study was to examine the frequency of adjunctive stent usage when coiling wide-necked intracranial aneurysms with the PC-400 in comparison with conventional coils. We examined consecutive patients with unruptured wide-necked aneurysms treated at our institution with endovascular coils. Aneurysm characteristics and procedural outcomes were compared between patients treated with PC-400 compared with a control group treated with conventional coils. Thirty-eight patients met criteria for this study. Stent-assisted coiling was required in 34 % fewer cases using PC-400 compared with conventional coils (P = .049). Fewer coils and less length were required with the PC-400 to obtain the same packing densities, occlusion types, and short-term stability. This may reduce treatment cost and prove to be valuable in patients with contraindications to dual antiplatelet therapy.

Mild exercise reduces cerebral vasospasm after aneurysm subarachnoid hemorrhage: a retrospective clinical study and correlation with laboratory investigation.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) is a leading cause of death and disability and is often complicated by cerebral vasospasm (CV). Conventional management to prevent CV includes bedrest; however, inactivity places the patient at risk for nonneurological complications. We investigated the effect of mild exercise after SAH in clinical and laboratory settings. METHODS: Clinical: Data from 80 patients with SAH were analyzed retrospectively. After aneurysms were secured, physical therapy was initiated as tolerated. CV and complications were compared by the timing of active physical therapy. Laboratory: 18 Rodents were divided into three groups: (1) control, (2) SAH without exercise, and (3) SAH plus mild exercise. On day 5, brainstems were removed and analyzed for the injury marker inducible nitric oxide synthase (iNOS). RESULTS: Clinical: Mild exercise before day 4 significantly lowered the incidence of symptomatic CV compared with the nonexercised group. There was no difference in the incidence of additional complications based upon exercise. Laboratory: Staining for iNOS was significantly higher in the SAH group than the control group, but there was no difference between exercised and nonexercised SAH groups, confirming that exercise did not promote neuronal injury. CONCLUSION: Early mobilization significantly reduced clinical CV. The relationship should be studied further in a prospective trial with defined exercise regimens.

Time-dependent changes in cerebrospinal fluid metal ions following aneurysm subarachnoid hemorrhage and their association with cerebral vasospasm.

Aneurysm subarachnoid hemorrhage affects 10 in 100,000 people annually, 40 % of whom will develop neurological deficits from ischemic stroke caused by cerebral vasospasm. Currently, the underlying mechanisms are uncertain. Metal ions are important modulators of neuronal electrophysiological conduction and smooth muscle cell activity, thereby potentially contributing to vasospasm. We hypothesized that metal ion concentrations in the cerebrospinal fluid (CSF) after aneurysm rupture would change over time and be associated with vasospasm. To test this hypothesis, for 21 days, we collected CSF from patients with aneurysmal rupture and subjected it to spectrometry to detect metals. A repeated measures analysis was performed to analyze concentration changes over time. Six of the seven patients with aneurysmal rupture experienced vasospasm, all resolving by day 14. Changes in Fe²âº and Zn²âº concentrations in the CSF paralleled the incidence of vasospasm in this study population. Na²âº, Ca²âº, Mg²âº, and Cu²âº concentrations exhibited no statistically significant changes over time. In conclusion, Fe²âº concentration in the CSF was significantly elevated during days 7-10, whereas Zn²âº concentrations spiked shortly thereafter, during days 11-14. This suggests that Fe²âº may be related to the induction of vasospasm and Zn²âº may be a marker of early brain injury secondary to ischemic injury and inflammation.

Tracheostomy timing affects stroke recovery.

BACKGROUND: The timing of tracheostomy in stroke patients unable to protect their airway has become a topic of debate. Proponents for early tracheostomy (ET) cite benefits including less ventilation-associated pneumonia, less sedative drug use, shorter length of stay, and reduced mortality in comparison with late tracheostomy (LT). METHODS: We examined the timing of tracheostomy on stroke patient outcomes across the United States using the Nationwide Inpatient Sample (2008-2010). Independent samples t tests and chi-squared tests were used to make comparisons between early (≤10 days) and late (11-25 days) tracheostomy. Multivariable models, adjusted for confounding factors, investigated outcome measures. RESULTS: In total, 13,165 stroke cases were included in the study (5591 in the ET group and 7574 in the LT group). Patients receiving an ET had a significant reduction in the odds of ventilator-associated pneumonia in comparison with the LT group (OR: .688, P = .026). The length of stay for patients receiving an ET was significantly lower in comparison with the LT group (P < .001) and was associated with an 18% reduction in total hospital costs (P < .001). CONCLUSIONS: Early tracheostomy for stroke patients may reduce the incidence of ventilator-associated pneumonia, thereby shortening the hospital stay and lowering total hospital costs. These relationships warrant further investigation in a large prospective multicenter trial.

Stenting versus endarterectomy and the impact of ultra-early revascularization for emergent admissions of carotid artery stenosis.

BACKGROUND: The factors influencing outcomes after emergent admission for symptomatic carotid artery stenosis treated with revascularization by endarterectomy or stenting are yet to be fully elucidated. METHODS: We analyzed revascularization of carotid artery stenosis for patients admitted emergently using the Nationwide Inpatient Sample (2008-2011). Admission characteristics, economic measures, in-hospital mortality, and iatrogenic stroke were compared between (1) endarterectomy and stenting, (2) patients with and without cerebral infarction, and (3) ultra-early (within 48 hours of admission) and deferred (up to 2 weeks) intervention. RESULTS: 72,797 admissions meeting our inclusion criteria were identified. Factors associated with ultra-early revascularization were male patients, low comorbidity burden, stenosis without infarction, and stenting. Ultra-early intervention significantly decreased cost and length of stay, and stenting for patients without infarction decreased length of stay but increased cost. Patients without infarction treated within 48 hours had significantly lower mortality and iatrogenic stroke rate. Patients with infarction receiving ultra-early revascularization had increased odds of mortality and iatrogenic stroke in comparison with the deferred group. Patients with infarction receiving stenting experienced increased odds of mortality in comparison with those receiving endarterectomy, but there was no significant difference in iatrogenic stroke rate. Recombinant tissue plasminogen activator (rtPA) administration on the day of revascularization greatly increased the odds of iatrogenic stroke and mortality. CONCLUSIONS: Larger prospectively randomized trials evaluating the optimum timing of revascularization after emergent admission of carotid artery stenosis seem warranted.

Controversies in the role of preoperative embolization in meningioma management.

The role of preoperative embolization in meningioma management remains controversial, even though 4 decades have passed since it was first described. It has been shown to offer benefits such as decreased blood loss and "softening of the tumor" during subsequent resection. However, the actual benefits remain unclear, and the potential harm of an additional procedure along with the cost of embolization have limited its use to a small proportion of the meningiomas treated. In this article the authors retrospectively reviewed their experience with preoperative embolization of meningiomas over the previous 6 years (March 2007-March 2013). In addition, they performed a MEDLINE search using a combination of the terms "meningioma," "preoperative," and "embolization" to analyze the indications, embolizing agents, timing, and complications reported during preoperative embolization of meningiomas. In this retrospective review, 18 cases (female/male ratio 12:6) were identified in which endovascular embolization was used prior to resection of an intracranial meningioma. Craniotomy for tumor resection was performed within 4 days after endovascular embolization in all cases, with an average time to surgery of 1.9 days. The average duration of surgery was 4 hours and 18 minutes, and the average blood loss was 574 ml, with a range of 300-1000 ml. Complications following endovascular therapy were identified in 3 (16.7%) of 18 cases, including one each of transient hemiparesis, permanent hemiparesis, and tumor swelling. The literature review returned 15 articles consisting of a study population greater than 25 patients. No randomized controlled study was found. The use of small polyvinyl alcohol particles (45-150 µm) is more effective in preoperative devascularization than larger particles (150-250 µm), but is criticized due to the higher risk of complications such as cranial nerve palsies and postprocedural hemorrhage. Time to surgery after embolization is inconsistently reported across the articles, and conclusions on the appropriate timing of surgery could not be drawn. The overall complication rate reported after treatment with preoperative meningioma embolization ranges from as high as 21% in some of the older literature to approximately 6% in recent literature describing treatment with newer embolization techniques. The evidence in the literature supporting the use of preoperative meningioma embolization is mainly from case series, and represents Level III evidence. Due to the lack of randomized controlled clinical trials, it is difficult to draw any significant conclusions on the overall usefulness of preoperative embolization during the management of meningiomas to consider it a standard practice.

Aneurysm embolization grade: a predictive tool for aneurysm recurrence after coil embolization.

BACKGROUND: Coil embolization has gained importance in the management of intracranial aneurysms over the past decade. However, the recurrence risk after embolization mandates closer follow-up than surgical clip ligation. Currently, there is no reliable system for predicting aneurysm sac thrombosis. An aneurysm embolization grade (AEG) reported previously by the senior author (EMD) has been proposed as a tool for predicting the durability of aneurysm occlusion based on hemodynamic characteristics. Here, we present our internal validity results. METHODS: AEG and Raymond-Roy Occlusion Classification (RROC) scores were prospectively assigned to all aneurysms coiled from June 2008 to June 2011. The prospectively assigned AEG and RROC scores from the cerebral angiograms were collected for data analysis and validity assessment of the AEG system. 110 consecutive patients who had aneurysm coil embolization were included in this study. RESULTS: The post-coiling AEG significantly predicted follow-up angiographic filling characteristics. Pairwise comparisons revealed that the follow-up AEG for those initially scored 'A' (complete obliteration) was significantly better than the contrast-flow groups. Significant differences were also noted between contrast-stasis and contrast-flow groups. A pairwise comparison between RROC scores demonstrated that only the RROC Type 1 could be used to predict follow-up occlusion durability. Stent placement in wide-neck aneurysms had no effect on initial AEG, RROC, or long-term occlusion durability. Packing density significantly predicted initial AEG and RROC, but had no effect on long-term occlusion. CONCLUSIONS: The AEG system is uniquely based on angiographic filling characteristics of the aneurysm, and this study demonstrated its high predictive value for determining aneurysm sac thrombosis. Assigning an AEG to the aneurysm can guide the neurointerventionalist in discussions with the patient regarding the probability of aneurysm recurrence and potential need for retreatment.

Transcranial motor evoked potential changes induced by provocative testing during embolization of cerebral arteriovenous malformations in patients under total intravenous anesthesia.

Cerebral motor evoked potential (MEP) monitoring during arteriovenous malformation (AVM) embolization is not well studied (Söderman et al. 2003). Alterations of cerebral blood flow (CBF) during cerebral embolization could cause ischemia/infarction to the cerebral cortex. Permanent loss of MEPs is correlated with a permanent motor deficit. We report a case of a patient undergoing AVM embolization during which transcranial electrical motor evoked potentials (TCeMEP) reliably predicted changes to CBF induced by selective methohexital testing. Our finding demonstrated that MEPs are a useful means of intraoperative monitoring of motor pathway integrity and predicting changes. The loss of MEP predicted and prevented severe postoperative motor deficits. Intraoperative neuromonitoring with SSEP, TCeMEP and continuous EEG revealed no changes until the posterior cerebral artery (PCA), but not the anterior cerebral artery (ACA), was injected. TCeMEP may be superior to somatosensory evoked potential (SSEP) and EEG monitoring in predicting motor impairment during AVM surgery.

Direct cortical stimulation but not transcranial electrical stimulation motor evoked potentials detect brain ischemia during brain tumor resection.

Motor evoked potentials (MEPs) elicited by both direct cortical stimulation (DCS) and transcranial electrical stimulation are used during brain tumor resection. Parallel use of direct cortical stimulation motor evoked potentials (DCS-MEPs) and transcranial electrical stimulation motor evoked potentials (TCeMEPs) has been practiced during brain tumor resection. We report that DCS-MEPs elicited by direct subdural grid stimulation, but not TCeMEPs, detected brain ischemia during brain tumor resection. Following resection of a brainstem high-grade glioma in a 21-year-old, the threshold of cortical motor-evoked-potentials (cMEPs) increased from 13 mA to 20 mA while amplitudes decreased. No changes were noted in transcranial motor evoked potentials (TCMEPs), somatosensory evoked potentials (SSEPs), auditory evoked potentials (AEPs), anesthetics, or hemodynamic parameters. Our case showed the loss of cMEPs and SSEPs, but not TCeMEPs. Permanent loss of DCS-MEPs and SSEPs was correlated with permanent left hemiplegia in our patient even when appropriate action was taken. Parallel use of DCS- and TCeMEPs with SSEPs improves sensitivity of intraoperative detection of motor impairment. DCS may be superior to TCeMEPs during brain tumor resection.

Peri-operative medical management of cerebral vasospasm.

INTRODUCTION: The physiological mechanism of cerebral vasospasm after aneurysmal subarachnoid hemorrhage remains elusive and its treatment can be challenging. Traditionally, 'triple-H' therapy and the calcium channel blocker, nimodipine, are used to treat cerebral vasospasm. However, as the etiology of vasospasm is unraveled, investigative pharmaceutical agents that stop the development and attenuate the severity of cerebral vasospasm, are being investigated in clinical trials. METHODS: In this manuscript, we review the clinical presentation and characteristics of cerebral vasospasm after aneurysmal subarachnoid hemorrhage and the utility of hyperdynamic therapy and pharmacotherapies. RESULTS: Triple-H therapy improves cerebral perfusion and improves neurological outcome during clinically evident cerebral vasospasm. Nimodipine is the accepted standard medication used to reduce the incidence of cerebral vasospasm, but more importantly, has a neuroprotective effect during hypoxia. Other medications such as magnesium sulfate, HMG-CoA reductase inhibitors and enoxaparin, are also being trialed with some promising results. CONCLUSION: Endovascular administration of intra-arterial anti-spasmodic agents and balloon angioplasty are becoming more commonly utilized at institutions where endovascular therapy is available. However, triple-H therapy and nimodipine remain the accepted first-line of treatment for cerebral vasospasm after aneurysmal subarachnoid hemorrhage.