Revascularization grading in endovascular acute ischemic stroke therapy.

BACKGROUND: Recanalization and angiographic reperfusion are key elements to successful endovascular and interventional acute ischemic stroke (AIS) therapy. Intravenous recombinant tissue plasminogen activator (rt-PA), the only established revascularization therapy approved by the US Food & Drug Administration for AIS, may be less effective for large artery occlusion. Thus, there is enthusiasm for endovascular revascularization therapies, which likely provide higher recanalization rates, and trials are ongoing to determine clinical efficacy and compare various methods. It is anticipated that clinical efficacy will be well correlated with revascularization of viable tissue in a timely manner. METHOD: Reporting, interpretation, and comparison of the various revascularization grading methods require agreement on measurement criteria, reproducibility, ease of use, and correlation with clinical outcome. These parameters were reviewed by performing a Medline literature search from 1965 to 2011. This review critically evaluates current revascularization grading systems. RESULTS AND CONCLUSION: The most commonly used revascularization grading methods in AIS interventional therapy trials are the thrombolysis in cerebral ischemia (TICI, pronounced "tissy") and thrombolysis in myocardial ischemia (TIMI) scores. Until further technical and imaging advances can incorporate real-time reliable perfusion studies in the angio-suite to delineate regional perfusion more accurately, the TICI grading system is the best defined and most widely used scheme. Other grading systems may be used for research and correlation purposes. A new scale that combines primary site occlusion, lesion location, and perfusion should be explored in the future.

Vertebral artery origin stent placement with distal protection: technical and clinical results.

OBJECTIVE: To report the feasibility, safety, and 1-month results of performing stent placement for vertebral origin stenosis with the use of a distal protection device. Distal protection devices have been shown to reduce the number of cerebral emboli and subsequent ischemic events when used as adjuncts to percutaneous carotid intervention; however, one case of the use of a distal protection device for vertebral artery has been reported in the literature. METHODS: We retrospectively determined rates of technical success and 1-month stroke or death associated with stent placement by using distal protection (Filter EX; Boston Scientific, Natick, Mass) in patients with symptomatic vertebral artery origin stenosis. Technical success was defined as successful deployment of distal protection device and stent at target lesion followed by successful retrieval of the device and a final residual stenosis of less than 30%. Other outcomes ascertained included any stroke, death, and semiquantitative assessment of particulate material retained by the filter device. RESULTS: The mean age of the 12 treated patients was 68 years (range, 52-88 years) and the group included 9 men and 3 women. The mean percentage of vertebral artery origin stenosis was 71 +/- 6%. Femoral and radial approaches were used in 9 and 3 cases, respectively. Technical success was achieved in 11 of the 12 patients in whom distal protection device placement was attempted. Postprocedure residual stenosis was 5 +/- 4%. Eight devices held macroscopically visible embolic debris (large and small amounts in 3 and 5 devices, respectively). No stroke or death was observed in the 1-month follow-up. CONCLUSION: The present study demonstrates the feasibility of performing stent placement for vertebral artery origin stenosis by using a distal protection device. Further studies are required to determine the effectiveness of this approach for vertebral artery origin atherosclerosis.

Is IV tissue plasminogen activator beneficial in patients with hyperdense artery sign?

OBJECTIVE: To evaluate the effect of IV recombinant tissue plasminogen activator (rt-PA) in patients with hyperdense artery sign (HAS) on initial CT scan. METHODS: The authors determined the differential effect of IV rt-PA (0.9 mg/kg) in patients with HAS by testing the interaction of rt-PA and HAS in a logistic regression model after adjusting for age, sex, initial NIH Stroke Scale score (NIHSSS), time to randomization, systolic blood pressure, serum glucose, body temperature, and rt-PA in 616 patients treated within 3 hours of symptom onset. Outcomes evaluated included intracranial hemorrhage, modified Rankin scale (mRS) 0-1, Barthel Index (BI) of > or = 95, Glasgow Outcome Scale (GOS) of 0-1, NIHSSS 0-1, and death at 90 days. RESULTS: HAS was detected on the initial CT scan in 91 (15%) of the 616 patients by an independent neuroradiologist. Significantly lower rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days were observed among patients with HAS. IV rt-PA significantly increased the rates of mRS 0-1, BI > or = 95, GOS of 0-1, or NIHSSS 0-1 at 90 days after adjusting for potential confounders without any significant modifying effect (interaction) of HAS. Among the 91 patients with HAS, rt-PA use demonstrated a trend or significance for increased adjusted rates of favorable outcomes by mRS (p = 0.04), BI (p = 0.1), GOS (p = 0.03), and NIHSSS (p = 0.01). CONCLUSION: Although hyperdense artery sign is associated with poor outcome, IV recombinant tissue plasminogen activator may be beneficial in this subgroup of patients with ischemic stroke.

Comparison of 1- and 2-marker techniques for calculating system magnification factor for angiographic measurement of intracranial vessels.

BACKGROUND AND PURPOSE: Accurate estimation of an intracranial vessel size is crucial during a diagnostic or therapeutic angiography procedure. The use of 1 or 2 external markers of known size is previously proposed to manually estimate the magnification factor (MF) of an intracranial vessel. The authors evaluated the use of different external marker techniques commonly used during angiographic measurements. METHODS: Forty-three intracranial vessels in 17 patients were measured using 1-and 2-marker techniques. To obtain the MF, 2 metallic markers were attached to the frontal-temporal regions. The MFs for the targeted vessels were obtained from the x-ray films by measuring the image sizes of the markers and their positions with respect to the target vessel. RESULTS: Using a phantom, the errors resulted from (a) linear interpolation of MFs, (b) linear interpolation of inverse MFs, and (c) using the MFs of 1 marker, which were 1.23% to 2.23%, 0.8% to 1.55%, and 3.85% to 14.62%, respectively. A similar trend was observed for the measurement of cerebral arteries. CONCLUSION: The use of 2 markers can result in a more accurate estimation of the vessel size. The use of only 1 external marker can lead to substantial error based on the location of the target vessel. Optimizing image acquisition is also crucial for accurate determination of vessel size.

Time to hospital arrival, use of thrombolytics, and in-hospital outcomes in ischemic stroke.

OBJECTIVE: To determine the interval between symptom onset and hospital arrival and its relationship to baseline clinical characteristics, use of thrombolysis, and in-hospital outcomes in patients with acute ischemic stroke admitted to the 11 hospitals in the Buffalo metropolitan area and Erie County. METHODS: The medical records of 1,590 patients were reviewed to determine the severity of the neurologic deficits (NIH Stroke Scale [NIHSS]), in-hospital mortality, favorable outcome (modified Rankin Scale score of < or = 2 at discharge), and strata of time interval between symptom onset and hospital arrival. RESULTS: The time interval between symptom onset and hospital arrival was 0 to 3 hours in 337 (21%) patients, 3 to 6 hours in 177 (11%) patients, 6 to 24 hours in 301 (19%) patients, > 24 hours in 420 (26%) patients, and undetermined in 355 (22%) patients. IV (n = 23) and intra-arterial (n = 4) thrombolysis was used in 27 (8%) of the 337 patients that presented within 3 hours of symptom onset. In 1,235 patients with known time interval between symptom onset and hospital arrival, an association (p = 0.008) was observed between strata of increasing time interval and higher proportion of favorable outcomes at discharge. The initial NIHSS score was higher with decreasing interval between symptom onset and hospital arrival (p < 0.0001). CONCLUSIONS: A small proportion of patients who present within 3 hours of symptom onset receive thrombolytic therapy. The observation that patients with more severe neurologic deficits and subsequently worse in-hospital outcomes appear to present early after symptom onset to the hospital may have implications for clinical studies.