Risk factors associated with major cerebrovascular complications after intracranial stenting

BACKGROUND

There are limited data on the relationship between patient and site characteristics and clinical outcomes after intracranial stenting.

METHODS

We performed a multivariable analysis that correlated patient and site characteristics with the occurrence of the primary endpoint (any stroke or death within 30 days of stenting or stroke in the territory of the stented artery beyond 30 days) in 160 patients enrolled in this stenting registry. All patients presented with an ischemic stroke, TIA, or other cerebral ischemic event (e.g., vertebrobasilar insufficiency) in the territory of a suspected 50-99% stenosis of a major intracranial artery while on antithrombotic therapy.

RESULTS

Cerebral angiography confirmed that 99% (158/160) of patients had a 50-99% stenosis. In multivariable analysis, the primary endpoint was associated with posterior circulation stenosis (vs anterior circulation) (hazard ratio [HR] 3.4, 95% confidence interval [CI] 1.2-9.3, p = 0.018), stenting at low enrollment sites (< 10 patients each) (vs high enrollment site) (HR 2.8, 95% CI 1.1-7.6, p = 0.038), < or = 10 days from qualifying event to stenting (vs > or = 10 days) (HR 2.7, 95% CI 1.0-7.8, p = 0.058), and stroke as a qualifying event (vs TIA/other) (HR 3.2, 95% CI 0.9-11.2, p = 0.064). There was no significant difference in the primary endpoint based on age, gender, race, or percent stenosis (50-69% vs 70-99%).

CONCLUSIONS

Major cerebrovascular complications after intracranial stenting may be associated with posterior circulation stenosis, low volume sites, stenting soon after a qualifying event, and stroke as the qualifying event. These factors will need to be monitored in future trials of intracranial stenting.

The NIH registry on use of the Wingspan stent for symptomatic 70-99% intracranial arterial stenosis

BACKGROUND

The Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial showed that patients with symptomatic 70% to 99% intracranial arterial stenosis are at particularly high risk of ipsilateral stroke on medical therapy: 18% at 1 year (95% CI = 3% to 24%). The Wingspan intracranial stent is another therapeutic option but there are limited data on the technical success of stenting and outcome of patients with 70% to 99% stenosis treated with a Wingspan stent.

METHODS

Sixteen medical centers enrolled consecutive patients treated with a Wingspan stent in this registry between November 2005 and October 2006. Data on stenting indication, severity of stenosis, technical success (stent placement across the target lesion with <50% residual stenosis), follow-up angiography, and outcome were collected.

RESULTS

A total of 129 patients with symptomatic 70% to 99% intracranial stenosis were enrolled. The technical success rate was 96.7%. The mean pre and post-stent stenoses were 82% and 20%. The frequency of any stroke, intracerebral hemorrhage, or death within 30 days or ipsilateral stroke beyond 30 days was 14.0% at 6 months (95% CI = 8.7% to 22.1%). The frequency of >or=50% restenosis on follow-up angiography was 13/52 (25%).

CONCLUSION

The use of a Wingspan stent in patients with severe intracranial stenosis is relatively safe with high rate of technical success with moderately high rate of restenosis. Comparison of the event rates in high-risk patients in Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) vs this registry do not rule out either that stenting could be associated with a substantial relative risk reduction (e.g., 50%) or has no advantage compared with medical therapy. A randomized trial comparing stenting with medical therapy is needed.

An update of neuroprotectants in clinical development for acute stroke

Neuroprotectants are drugs designed to treat stroke by preserving ischemic neurons in the penumbra. Despite numerous studies over the past ten years, no such drug has yet shown clinical efficacy. This article reviews those trials completed since 1999, including assessments of drugs that modify receptors or ion flow, block leukocyte adhesion receptors or stabilize membranes. In addition, ongoing trials and early trials using novel mechanisms of action, such as hypothermia and antioxidants, are discussed.

Localizing acute stroke-related EEG changes: assessing the effects of spatial undersampling

Because of its sensitivity to metabolic and ionic disturbances related to ischemia, the EEG can be a potentially useful tool for acute stroke detection and for monitoring affected tissue. However, the clinical use of the EEG in detecting stroke is determined in part by how accurately the spatial information is characterized. The purpose of the current study was to determine the effects of spatial undersampling on the distribution and interpretation of the stroke-related topographic EEG. Using a 128-channel sensor montage, EEG was recorded from six stroke patients acutely (between 8 and 36 hours) after symptom onset. The EEG was submitted to a spectral analysis and was compared with patient symptoms and MRI and computed tomographic findings. To determine loss of spatial and clinical information resulting from spatial undersampling, the average-referenced data from the original 128-channel recording montage were subsampled into 64-, 32-, and 19-channel arrays. Furthermore, the analytical findings were compared with a board-certified electroencephalographer's review of the raw EEG using a conventional clinical montage. As predicted, the results showed that accurate description of stroke-related topographic EEG changes is dependent on adequate spatial sampling density. Accurate description of the spatial distribution of the stroke-related EEG was achieved only with the 64- and 128-channel EEG. As the recording density decreases to 32 channels, the distribution of the scalp EEG spectra is distorted, potentially resulting in mislocalization of the affected region. Results of the clinical review by an expert electroencephalographer corroborated the quantitative analyses, and the results also demonstrated the shortcomings of the conventional 10-20 recording density for capturing focal EEG abnormalities in several cases. The EEG provides useful information about the localization of acute cerebral ischemia, but recording densities of 64 channels or higher are required for accurate spatial characterization of focal stroke-related EEG changes.

Emergi-paths and stroke teams: an emergency department approach to acute ischemic stroke

In patients with early acute ischemic stroke (AIS), studies have shown improved recovery rates when thrombolytic therapy is appropriately initiated. However, in clinical practice, there are several barriers to rapid patient evaluation and drug administration. To facilitate the management of this population, an AIS clinical pathway, Emergi-path, was developed. Initiated at the time of the patients' arrival to the emergency department, Emergi-path provides a step-by-step guide for early care of AIS patients. A citywide stroke team plays an integral role in this process by responding to stroke codes. Implementation of an AIS pathway and activation of an organized team of stroke specialists can facilitate rapid evaluation and treatment of this high-risk population.

Efficacy of intraarterial thrombolysis of basilar artery stroke

BACKGROUND

Stroke from basilar artery (BA) occlusion is a devastating neurological event with reported mortality rates of up to 90%. This series reports our experience in 15 cases using intraarterial (IA) thrombolysis to treat basilar artery stroke at the Oregon Stroke Center.

METHODS

Over a 4-year period, consecutive cases of basilar artery stroke were treated with IA urokinase (UK) if they met the following criteria: had a baseline National Institutes of Health Stroke Scale (NIHSS) score greater than 6; symptoms began within 48 hours; had no or minimal early infarct signs on computed tomography (CT) scan; and angiogram confirmed basilar occlusion. Patients were treated with UK infused via a microcatheter directly into the clot. Angiographic efficacy was assessed by a repeat angiogram at the end of infusion and clinical efficacy was determined by NIHSS evaluation at 48 hours and 3 months.

RESULTS

Fifteen patients, mean age 59 (16 to 78) and baseline NIHSS of 30 (7 to 40), were treated at a mean of 12 hours (4 to 48). An average dose of 500,000 (150,000 to 1,250,000) units of UK was given over 1 to 2 hours. Excellent vessel recanalization occurred in 12 of 15 (80%) patients. All three cases without recanalization died within 48 hours (100%). Of the 12 patients with recanalization, 2 died (16.7%), whereas the 9 of 10 remaining had mild or moderate neurological deficits (mean NIHSS of 5) at 3 months.

CONCLUSION

IA thrombolysis has the potential to decrease mortality and improve outcome in cases with severe basilar artery stroke even when administered after 6 hours.