Mobile stroke unit use for prehospital stroke treatment-an update.

BACKGROUND: Acute ischemic stroke is a treatable disease. Moreover, there is increasing evidence supporting mechanical recanalization for large-vessel occlusion, even beyond a strict time window. However, only small numbers of patients receive causal treatment. METHODS: One of the main reasons that patients do not receive causal therapy is their late arrival at the correct target hospital, which, depending on the type of stroke, is either a regional stroke unit or a comprehensive stroke center for interventional treatment. In order to triage patients correctly, a fast and complex diagnostic work-up is necessary, allowing a stroke specialist to decide on the best therapy option. As treatment possibilities become more comprehensive with the need for individualized decisions, the gap between treatment options and practical implementation is increasing. RESULTS: The "mobile stroke unit" concept encompasses the administration of prehospital acute stroke diagnostic work-up, therapy initiation, and triage to the correct hospital using a specially equipped ambulance, staffed with a team specialized in stroke. The concept, which was conceived and first put into practice in Homburg/Saar, Germany, in 2008, is currently spreading with more than 20 active mobile stroke unit centers worldwide. The use of mobile stroke units can reduce the time until stroke treatment by 50% with a tenfold increase of patients treated within the first 60 min of symptom onset. CONCLUSION: The mobile stroke unit concept for acute stroke prehospital management is spreading worldwide. Intensive research is still needed to analyze the best setting for prehospital stroke management.

[Mobile stroke unit for prehospital stroke treatment]. / Mobile Stroke Unit zur prähospitalen Schlaganfalltherapie.

CLINICAL ISSUE AND DIAGNOSTIC STANDARDS: The management of acute stroke patients suffers from several major problems in the daily clinical routine. In order to achieve optimal treatment a complex diagnostic work-up and rapid initiation of therapy are necessary; however, most patients arrive at hospital too late for any type of acute stroke treatment, although all forms of treatment are highly time-dependent according to the generally accepted "time is brain" concept. DIAGNOSTIC INNOVATIONS: Recently, two randomized clinical trials demonstrated the feasibility of prehospital stroke diagnostic work-up and treatment. This was accomplished by use of a specialized ambulance, equipped with computed tomography for multimodal imaging and a point-of-care laboratory system. PERFORMANCE: In both trials the results demonstrated a clear superiority of the prehospital treatment group with a significant reduction of treatment times, significantly increased number of patients treated within the first 60 min after symptom onset and an optimized triage to the correct target hospital. ACHIEVEMENTS AND PRACTICAL RECOMMENDATIONS: Currently, mobile stroke units are in operation in various countries and should lead to an improvement in stroke treatment; nevertheless, intensive research is still needed to analyze the best framework settings for prehospital stroke management.

["Time is brain". Optimizing prehospital stroke management]. / "Zeit ist Hirn". Optimierung des prähospitalen Schlaganfallmanagements.

Acute stroke is one of the main causes of death and chronic disability. Thrombolysis, achieved by administering recombinant tissue plasminogen activator within 4.5 h, is an effective therapeutic option for ischemic stroke. However, less than 2-12 % of patients receive this treatment and a major reason is that most patients reach the hospital too late. Several time-saving measures should be implemented. Firstly, optimized and continual public awareness campaigns for patients should be initiated to reduce delays in notifying the emergency medical service. Secondly, emergency medical service personnel should develop protocols for prenotification of the receiving hospital. Other suggested measures involve educating emergency medical service personnel to systematically use scales for recognizing the symptoms of stroke and to triage patients to experienced stroke centers. In the future, administering treatment at the emergency site (mobile stroke unit concept) may allow more than a small minority of patients to benefit from available recanalization treatment options.

Comparison of stent free cell area and cerebral lesions after unprotected carotid artery stent placement.

OBJECTIVE: This study evaluates the correlation between closed, semi-closed and open-cell stent design and the association between stent type and clinical outcome as well as magnetic resonance imaging (MRI) findings. DESIGN: A total of 194 patients who underwent unprotected carotid artery stenting (CAS) as well as diffusion-weighted magnetic resonance imaging (DW-MRI) before and after intervention were retrospectively reviewed. MATERIALS AND METHODS: Three stent designs were studied: closed cell, semi-closed cell and open cell. Spearman's Rho test was performed between the stent free cell area and the number and area of ischaemic lesions found after intervention. Adverse events were evaluated. RESULTS: There was no significant difference in clinical outcome between the three stent groups (Zilver, Cook Europe, Denmark; Smart, Codman, MA; and Wallstent, Stryker, MN, USA). A significant correlation was found between the stent free cell area and the number and area of new ischaemic lesions on DW-MRI (P = 0.023). There were significantly fewer new lesions with an open-cell design (Zilver; 12.76 mm(2) free cell area) than with a closed-cell design (Wallstent; 1.08 mm(2) free cell area). CONCLUSIONS: Open-cell stent was related to a lower number and area of silent cerebral ischaemic lesions after unprotected CAS. However, clinical outcome, measured by incidence of adverse events and clinical neurologic assessment, was not significantly different between patients with different stent designs.

[Recent studies on intracranial stenosis]. / Neueste Studien zu intrakraniellen Stenosen.

CLINICAL ISSUE: Symptomatic intracranial stenoses are associated with a high risk of stroke. Medical management with platelet inhibitors or anticoagulation has not been shown to substantially lower this risk. Hence, alternative treatment options are desperately needed. TREATMENT INNOVATIONS: The concept of percutaneous intervention using balloon angioplasty with or without stenting is appealing at first sight which is why intracranial balloons and stents were developed. PERFORMANCE: Initial studies using dedicated intracranial stents were more promising; however, the only randomized trial recently published using a dedicated intracranial self-expanding stent demonstrated a high periprocedural complication rate. EVALUATION AND PRACTICAL RECOMMENDATIONS: Due to study design limitations it would be premature to categorically denounce an interventional option for the treatment of symptomatic intracranial stenoses. More importantly, the results of the randomized SAMMPRIS trial should stimulate the development of safer technology and patient selection to minimize procedural risks. This will perhaps allow significant risk reduction of this potentially devastating intracranial condition when it cannot otherwise be addressed.

Controversies around carotid stenting.

In the last 10 years, CAS became an important alternative to surgery. However, many of the trials regarding stroke prevention had controversial requirements regarding the endovascular approach, leading to questionable conclusions. This review critically addresses results from previous randomized studies on efficacy and safety of the first established therapy for carotid artery stenosis, carotid endarterectomy (CEA) compared to the challenger, carotid artery stenting (CAS), as a newer and less invasive endovascular technique.

Revascularization in acute ischaemic stroke using the penumbra system: the first single center experience.

BACKGROUND AND PURPOSE: This is the first single center experience illustrating the effectiveness of the penumbra system (PS) in the treatment of large vessel occlusive disease in the arena of acute ischaemic stroke. The PS is an innovative mechanical thrombectomy device, employed in the revascularization of large cerebral vessel occlusions in patients via the utilization of an aspiration platform. METHODS: This is a prospective, non-randomized controlled trial evaluating the clinical and functional outcome in 29 patients with acute intra-cranial occlusions consequent to mechanical thrombectomy by the PS either as mono-therapy or as an adjunct to current standard of care. Patients were evaluated by a neurologist and treated by our in house interventional neuro-radiologists. Primary end-points were revascularization of the occluded target vessel to TIMI grade 2 or 3 and neurological outcome as measured by an improvement in the NIH Stroke Scale (NIHSS) score after the procedure. RESULTS: Complete revascularization (TIMI 3) was achieved in 21/29 (72.4%) of patients. Partial revascularization (TIMI 2) was established in 4/29 (13.8%) of patients. Revascularization failed in four (13.8%) patients. Nineteen (19) patients (65.5%) had at least a four-point improvement in NIHSS scores. Modified Rankin scale scores of < or =2 were seen in 37.9% of patients. There were no device-related adverse events. Symptomatic intra-cranial hemorrhage occurred in 7% of patients. CONCLUSIONS: The PS has the potential of exercising a significant impact in the interventional treatment of ischaemic stroke in the future.

Hyperperfusion syndrome after carotid stent angioplasty.

INTRODUCTION: This study assesses the incidence and causes of hyperperfusion syndrome occurring after carotid artery stenting (CAS). MATERIALS AND METHODS: We retrospectively reviewed the clinical database of 417 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or intracranial hemorrhage. Magnetic resonance imaging (MRI) including fluid-attenuated inversion recovery and diffusion-weighted imaging was performed before and after CAS in 269 cases. A Spearman's rho nonparametric correlation was performed to determine whether there was a correlation between the occurrence/development of hyperperfusion syndrome and the patient's age, degree of stenosis on the stented and contralateral side, risk factors such as diabetes, smoking, hypertension, adiposity, gender and fluoroscopy time, and mean area of postprocedural lesions as well as preexisting lesions. Significance was established at p < 0.05. RESULTS: Of the 417 carotid arteries stented and where MRI was also completed, we found hyperperfusion syndrome in 2.4% (ten cases). Patients who had preexisting brain lesions (previous or acute stroke) were at a higher risk of developing hyperperfusion syndrome (p = 0.022; Spearman's rho test). We could not validate any correlation with the other patient characteristics. CONCLUSION: Extensive microvascular disease may be a predictor of hyperperfusion syndrome after carotid stent placement. We believe that further studies are warranted to predict more accurately which patients are at greater risk of developing this often fatal complication.

Lesion load in unprotected carotid artery stenting.

INTRODUCTION: The purpose of the study was to determine the incidence of new ischemic lesions found on diffusion-weighted MR imaging (DWI) in nonselected patients after unprotected carotid artery stent placement. MATERIALS AND METHODS: We retrospectively reviewed a nonrandomized cohort of 197 patients presenting with carotid occlusive disease who underwent unprotected carotid artery stent placement between 2003 and 2006. Mean degree of stenosis was 86.94% +/- 9.72. In all patients, DWI was obtained before and 24 h after stent placement. New lesions were evaluated according to size and location. RESULTS: In 59 of 197 patients (29.9%), new ischemic lesions were found on DWI in the vessel dependent area. In 23 of 197 patients (11.7%), new ischemic lesions were found in the vessel independent area. Combined stroke/death rate was 3.63%. CONCLUSION: In our series of unprotected carotid angioplasty with stent, we found new DWI lesions in 34% of the patients. Further studies should now show in how far protection devices can reduce these lesions.

[Carotid artery stenting for acute stroke]. / Karotisstent beim akuten Schlaganfall.

For patients with acute ischemic stroke due to total occlusion of the internal carotid artery (ICA), an effective intervention to improve neurologic symptoms and clinical outcome has not yet been established. Some authors have reported successful revascularization for patients with acute stroke symptoms secondary to ICA occlusion only in isolated series and case reports. Emergency recanalization and carotid artery stent placement can improve neurologic outcome in selected patients with acute ischemic stroke and total occlusion of the ICA.

[Complex carotid cavernous sinus fistulas Barrow type D: endovascular treatment via the ophthalmic vein, imaging control with standardized MRI, long-term results]. / Interdisziplinäre Embolisation spontaner Karotis-Cavernosus-Fisteln Typ D nach Barrow über die Vena ophthalmica: klinische Langzeitergebnisse und kernspintomografische Befunde.

PURPOSE: Since feeding arteries from both the internal and external carotid artery are common, cavernous fistulas of Barrow type D are difficult to treat. Embolization using the transarterial approach is considered to be the standard therapy. However, it is often impossible to embolize feeders from the internal carotid artery. The transorbital approach after anterior orbitotomy through the ophthalmic vein is an alternative in this complex situation. The following reports our experience with three female patients who underwent transvenous embolization. Procedural success was documented using standardized MRI and clinical reevaluation. MATERIALS AND METHODS: Three female patients between 57 and 78 years of age were diagnosed with carotid cavernous fistulas by conventional angiogram. All patients were suffering from exophthalmus and visual impairment. Two patients showed secondary glaucoma and diplopia. In one patient we performed a technically successful transarterial embolization using particles, but no relevant improvement of the patient's condition was seen. Transfemoral transvenous access via the sinus petrosus was not possible in any patient. All patients were then embolized via the ophthalmic vein using GDC detachable coils. All patients were clinically reevaluated by an ophthalmologist. Also a standardized MRI was performed for documentation. Follow-up was performed for the first patient for 32 months, for the second patient for 34 months and for the third patient for 50 months. RESULTS: Transvenous embolization was technically successful in all three cases. Clinical symptoms disappeared rapidly. Postprocedural MRI showed a symmetric diameter of the ophthalmic vein. Venous congestion of the orbit caused by fatty tissue edema regressed completely. Contrast-enhanced magnetic resonance angiography showed normal arterial vessels without evidence of fistula. CONCLUSION: Complex carotid cavernous fistulas of Barrow type D seem to be successfully treatable by embolization using the transvenous approach. Clinical symptoms seem to regress rapidly after the procedure, with diplopia being the last to regress. MRI imaging criteria for procedural success include a diameter reduction of the ophthalmic vein, a reduction of the orbital fatty tissue edema and an inconspicuous CE-MRA.