Christian Hametner

Emergency Cervical Internal Carotid Artery Stenting in Combination with Intracranial Thrombectomy in Acute Stroke

BACKGROUND AND PURPOSE: In past years, thrombectomy has become a widely used procedure in interventional neuroradiology for the treatment of acute intracranial occlusions. However, in 10–20% of patients, there are additional occlusions or stenotic lesions of the ipsilateral cervical internal carotid artery. The purpose of this study was to evaluate the feasibility of emergency carotid artery stent placement in combination with intracranial thrombectomy and the clinical outcome of the treated patients. MATERIALS AND METHODS: We analyzed clinical and angiographic data of patients who underwent emergency cervical ICA stent placement and intracranial thrombectomy with stent-retriever devices in our institution between November 2009 and July 2012. Recanalization was assessed according to the Thrombolysis in Cerebral-Infarction score. Clinical outcome was evaluated at discharge (NIHSS) and after 3 months (mRS). RESULTS: Overall, 24 patients were treated. The mean age was 67.2 years; mean occlusion time, 230.2 minutes. On admission, the median NIHSS score was 18. In all patients, the Thrombolysis in Cerebral Infarction score was zero before the procedure. Stent implantation was feasible in all cases. In 15 patients (62.5%), a Thrombolysis in Cerebral Infarction score ≥ 2b could be achieved. Six patients (25%) improved ≥10 NIHSS points between admission and discharge. After 90 days, the median mRS score was 3.0. Seven patients (29.2%) had a good clinical outcome (mRS 0–2), and 4 patients (16.6%) died, 1 due to fatal intracranial hemorrhage. Overall, symptomatic intracranial hemorrhage occurred in 4 patients (16.6%). CONCLUSIONS: Emergency ICA stent implantation was technically feasible in all patients, and the intracranial recanalization Thrombolysis in Cerebral Infarction score of ≥2b was reached in a high number of patients. Clinical outcome and mortality seem to be acceptable for a cohort with severe stroke. However, a high rate of symptomatic intracranial hemorrhage occurred in our study.

Mechanical thrombectomy with stent retrievers in acute basilar artery occlusion.

BACKGROUND AND PURPOSE: Basilar artery occlusion remains one of the most devastating subtypes of ischemic stroke. The prognosis is poor if early recanalization is not achieved. The purpose of this study was to evaluate the safety and technical feasibility of self-expanding retrievable stents in the endovascular treatment of acute basilar artery occlusion. MATERIALS AND METHODS: Twenty-four patients with acute basilar artery occlusion were treated with Solitaire FR or Revive SE devices between December 2009 and May 2012. Additional treatment included intravenous and/or intra-arterial thrombolysis (21/24) and percutaneous transluminal angioplasty/permanent stent placement (7/24). Recanalization was assessed by means of the TICI score. Clinical outcome was determined at discharge (NIHSS), and at 3 months (mRS). RESULTS: Median NIHSS score on admission was 24; median duration of symptoms was 254 minutes. Successful recanalization (TICI 2b +3) by thrombectomy only was achieved in 18 patients (75%). Intracranial stent deployment after thrombectomy caused by underlying atherosclerotic stenosis was performed in 7 patients. If these patients with intracranial stent placement are included, successful recanalization was achieved in 21 of 24 patients (87.5%). NIHSS improvement ≥10 points was reached in 54% of patients (n = 13/24). Mortality during the first 3 months was 29% (7/24). After 3 months, 8 patients (33%) had a favorable clinical outcome (mRS 0–2). CONCLUSIONS: In our series, application of self-expanding retrievable stents in acute basilar artery occlusion resulted in a high recanalization rate without procedural complications and good clinical outcome in one-third of patients.

Endovascular Stroke Therapy Tirofiban Is Associated With Risk of Fatal Intracerebral Hemorrhage and Poor Outcome

Background and Purpose— To investigate the relationship between severe bleeding complications and outcome after mechanical thrombectomy with or without glycoprotein-IIb/IIIa inhibitor tirofiban treatment. Methods— The study included prospectively collected data of consecutive patients with acute ischemic stroke in whom mechanical thrombectomy was perfomed in the years 2006 to 2011. Results— Of 162 patients, 128 patients had anterior circulation stroke, and 34 patients had posterior circulation stroke. Additional treatment with tirofiban was given to 30 of 128 patients with anterior circulation stroke and to 20 of 34 patients with posterior circulation stroke. Treatment with tirofiban did not influence recanalization rates. Fatal intracerebral hemorrhage occurred more frequently in tirofiban-treated patients in the entire cohort (12.0% vs 2.7%; P=0.03) and in tirofiban-treated patients with anterior circulation stroke (13.3% vs 3.1%; P=0.05). Logistic regression found age (odds ratio, 1.17; 95% confidence interval, 1.00–1.37; P=0.05) and tirofiban treatment (odds ratio, 3.03; 95% confidence interval, 1.50–4.05; P=0.04) to be independent predictors for fatal intracerebral hemorrhage. Tirofiban treatment was also an independent predictor for poor outcome (odds ratio, 6.60; 95% confidence interval, 1.06–41.52; P=0.04) in addition to National Institute of Health Stroke Scale (odds ratio, 1.08; 95% confidence interval, 1.00–1.17; P=0.05). Conclusions— In endovascular stroke therapy, additional treatment with the glycoprotein-IIb/IIIa inhibitor tirofiban is associated with increased risk of fatal intracerebral hemorrhage and poor outcome.

Comparison of stroke recognition and stroke severity scores for stroke detection in a single cohort

Objective First, to determine the sensitivity and specificity of six stroke recognition scores in a single cohort to improve interscore comparability. Second, to test four stroke severity scores repurposed to recognise stroke in parallel. Methods Of 9154 emergency runs, 689 consecutive cases of preclinically ‘suspected central nervous system disorder’ admitted to the emergency room (ER) of the Heidelberg University Hospital were included in the validation cohort. Using data abstracted from the neurological ER medical reports, retrospective assessment of stroke recognition scores became possible for the Cincinnati Prehospital Stroke Scale (CPSS), Face Arm Speech Test (FAST), Los Angeles Prehospital Stroke Screen (LAPSS), Melbourne Ambulance Stroke Screen (MASS), Medic Prehospital Assessment for Code Stroke (Med PACS) and Recognition of Stroke in the Emergency Room score (ROSIER), and that of stroke severity scores became possible for the Kurashiki Prehospital Stroke Scale (KPSS), Los Angeles Motor Scale (LAMS) and shortened National Institutes of Health Stroke Scale (sNIHSS)-8/sNIHSS-5. Test characteristics were calculated using the hospital discharge diagnosis as the reference standard. Results The CPSS and FAST had a sensitivity of 83% (95% CI 76 to 88) and 85% (78% to 90%) and a specificity of 69% (64% to 73%) and 68% (63% to 72%), respectively. The more complex LAPSS, MASS and Med PACS had a high specificity (92% to 98%) but low sensitivity (44% to 71%). In the ROSIER, sensitivity (80%, 73 to 85) and specificity (79%, 75 to 83) were similar. Test characteristics for KPSS, sNIHSS-8 and sNIHSS-5 were similar to the simple recognition scores (sensitivity 83% to 86%, specificity 60% to 69%). The LAMS offered only low sensitivity. Conclusions The simple CPSS and FAST scores provide good sensitivity for stroke recognition. More complex scores do not result in better diagnostic performance. Stroke severity scores can be repurposed to recognise stroke at the same time because test characteristics are comparable with pure stroke recognition scores. Particular shortcomings of the individual scores are discussed.

Induction of Cooling With a Passive Head and Neck Cooling Device: Effects on Brain Temperature After Stroke

Background and Purpose— Therapeutic hypothermia improves clinical outcome after cardiac arrest and appears beneficial in other cerebrovascular diseases. We conducted this study to investigate the relationship between surface head/neck cooling and brain temperature. Methods— Prospective observational study enrolling consecutive patients with severe ischemic or hemorrhagic stroke undergoing intracranial pressure (ICP) and brain temperature monitoring. Arterial pressure, ICP, cerebral perfusion pressure, heart rate, brain, tympanic, and bladder temperature were continuously registered. Fifty-one applications of the Sovika cooling device were analyzed in 11 individual patients. Results— Sovika application led to a significant decrease of brain temperature compared with baseline with a maximum of −0.36°C (SD, 0.22) after 49 minutes (SD, 17). During cooling, dynamics of brain temperature differed significantly from bladder (−0.25°C [SD, 0.15] after 48 minutes [SD, 19]) and tympanic temperature (−1.79°C [SD, 1.19] after 37 minutes [SD, 16]). Treatment led to an increase in systolic arterial pressure by >20 mm Hg in 14 applications (n=7 patients) resulting in severe hypertension (>180 mm Hg) in 4 applications (n=3). ICP increased by >10 mm Hg in 7 applications (n=3), led to ICP crisis >20 mm Hg in 6 applications (n=3), and a drop of cerebral perfusion pressure <50 mm Hg in 1 application. Conclusions— Although the decrease of brain temperature after Sovika cooling device application was statistically significant, we doubt clinical relevance of this rather limited effect (−0.36°C). Moreover, the transient increases of blood pressure and ICP warrant caution.

Effect of thrombus size on recanalization by bridging intravenous thrombolysis

Thrombus length has been reported as an important predictor of successful recanalization by intravenous thrombolysis but its influence on bridging thrombolysis has not been investigated yet. The effect of thrombus length on recanalization rates evaluated by catheter angiography early after intravenous bridging thrombolysis was analyzed.

Sex Differences and Functional Outcome After Intravenous Thrombolysis

Background and Purpose— Women have a worse outcome after stroke compared with men, although in intravenous thrombolysis (IVT)–treated patients, women seem to benefit more. Besides sex differences, age has also a possible effect on functional outcome. The interaction of sex on the functional outcome in IVT-treated patients in relation to age remains complex. The purpose of this study was to compare outcome after IVT between women and men with regard to age in a large multicenter European cohort reflecting daily clinical practice of acute stroke care. Methods— Data were obtained from IVT registries of 12 European tertiary hospitals. The primary outcome was poor functional outcome, defined as a modified Rankin scale score of 3 to 6 at 3 months. We stratified outcome by age in decades. Safety measures were symptomatic intracranial hemorrhage and mortality at 3 months. Results— In this cohort, 9495 patients were treated with IVT, and 4170 (43.9%) were women with a mean age of 71.9 years. After adjustments for baseline differences, female sex remained associated with poor functional outcome (odds ratio, 1.15; 95% confidence interval, 1.02–1.31). There was no association between sex and functional outcome when data were stratified by age. Symptomatic intracranial hemorrhage rate was similar in both sexes (adjusted odds ratio, 0.93; 95% confidence interval, 0.73–1.19), whereas mortality was lower among women (adjusted odds ratio, 0.83; 95% confidence interval, 0.70–0.99). Conclusions— In this large cohort of IVT-treated patients, women more often had poor functional outcome compared with men. This difference was not dependent on age.

Noninvasive cerebral oximetry during endovascular therapy for acute ischemic stroke: an observational study.

Implementing endovascular stroke care often impedes neurologic assessment in patients who need sedation or general anesthesia. Cerebral near-infrared spectroscopy (NIRS) may help physicians monitor cerebral tissue viability, but data in hyperacute stroke patients receiving endovascular treatment are sparse. In this observational study, the NIRS index regional oxygen saturation (rSO2) was measured noninvasively before, during, and after endovascular therapy via bilateral forehead NIRS optodes. During the study period, 63 patients were monitored with NIRS; 43 qualified for analysis. Before recanalization, 10 distinct rSO2 decreases occurred in 11 patients with respect to time to intubation. During recanalization, two kinds of unilateral rSO2 changes occurred in the affected hemisphere: small peaks throughout the treatment (n = 14, 32.6%) and sustained increases immediately after recanalization (n = 2, 4.7%). Lower area under the curve 10% below baseline was associated with better reperfusion status (thrombolysis in cerebral infarction ≥ 2b, P = 0.009). At the end of the intervention, lower interhemispheric rSO2 difference predicted death within 90 days (P = 0.037). After the intervention, higher rSO2 variability predicted poor outcome (modified Rankin scale > 3, P = 0.032). Our findings suggest that bi-channel rSO2-NIRS has potential for guiding neuroanesthesia and predicting outcome. To better monitor local revascularization, an improved stroke-specific set-up in future studies is necessary.

Impact of sex in stroke thrombolysis: a coarsened exact matching study

BackgroundIt is not established whether sex influences outcome and safety following intravenous thrombolysis (IVT) in acute stroke. As a significant imbalance exists between the baseline conditions of women and men, regression analysis alone may be subject to bias. Here we aimed to overcome this methodical shortcoming by balancing both groups using coarsened exact matching (CEM) before evaluating outcome.MethodsFrom our local prospective stroke database we analyzed consecutive patients who suffered anterior circulation stroke and received IVT from 1998 to 04/2013 (n = 1391, 668 female, 723 male). Data were preprocessed by CEM, balancing for age, NIHSS, lesion side, hypertension, diabetes, atrial fibrillation, smoking, coronary heart disease, and previous stroke, which yielded a matched cohort of 502 women and 436 men (n = 938). Outcome was estimated by adjusted binomial logistic regression analysis incorporating matched weights.ResultsNo effect of sex was seen to predict good outcome (OR 1.04, CI 0.76–1.43) or mortality (OR 1.13, CI 0.73–1.73). However, female sex was a strong independent predictor of symptomatic intracerebral hemorrhage (sICH – ECASS-II definition, OR 3.62, CI 1.77-7.41) and fatal ICH (OR 4.53, CI 1.61-12.7).ConclusionIn balanced groups, the two sexes showed comparable outcomes following IVT. A novel finding was the higher rate of sICH and fatal ICH in women. In this analysis we also demonstrate how CEM can reduce multivariate imbalance and thereby improve estimates, already in crude, but more importantly, in adjusted regression analysis. Further investigations of multicentre data with improved analytical approaches that yield balanced sex-groups are therefore warranted.

Reciprocal Interaction of 24-Hour Blood Pressure Variability and Systolic Blood Pressure on Outcome in Stroke Thrombolysis

Background and Purpose— Significance and management of blood pressure (BP) changes in acute stroke care are unclear. Here, we aimed to investigate the impact of 24-hour BP variability (BPV) on outcome in patients with acute ischemic stroke treated with intravenous thrombolysis. Methods— From the Safe Implementation of Treatment in Stroke International Stroke Thrombolysis registry, 28 976 patients with documented pre-treatment systolic BP at 2 and 24 hours were analyzed. The primary measure of BP variability was successive variability. Data were preprocessed using coarsened exact matching. We assessed early neurological improvement, symptomatic intracerebral hemorrhage (SICH), and long-term functional outcome (modified Rankin Scale [mRS] at 90 days) by binary and ordinal regression analyses. Results— Attempts to explain successive variation for analysis of BPV with patients characteristics at admission found systolic BP (5.5% variance) to be most influential, yet 92% of BPV variance remained unexplained. Independently from systolic BP, successive variation for analysis of BPV was associated with poor functional outcome mRS score of 0 to 2 (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.90–0.98), disadvantage across the shift of mRS (OR, 1.04; 95% CI, 1.01–1.08), mortality (OR, 1.10; 95% CI, 1.01–1.08), SICHSITS (OR, 1.14; 95% CI, 1.06–1.23), and SICHECASS (OR, 1.24; 95% CI, 1.10–1.40; ECASS [European Cooperative Acute Stroke Study 2]). Analyzing successive variation for analysis of BPV as a function of pre-treatment, systolic BP significantly improved the prediction of functional outcome (mRS score of 0–1, mRS score of 0–2, neurological improvement, mRS-shift: all Pinteraction<0.01). Excluding patients with atrial fibrillation in a sensitivity analysis gave consistent results overall. Conclusions— This study suggests the need for a more individual BP management accounting for pre-treatment BP and the acute BP course (ie, BPV) to achieve best possible outcome for the patient.