MR Imaging of Individual Perfusion Reorganization Using Superselective Pseudocontinuous Arterial Spin-Labeling in Patients with Complex Extracranial Steno-Occlusive Disease.

BACKGROUND AND PURPOSE: Patients with multiple stenoses or occlusions of the extracranial arteries require an individualized diagnostic approach. We evaluated the feasibility and clinical utility of a novel MR imaging technique for regional perfusion imaging in this patient group. MATERIALS AND METHODS: Superselective pseudocontinuous arterial spin-labeling with a circular labeling spot enabling selective vessel labeling was added to routine imaging in a prospective pilot study in 50 patients (10 women, 70.05 ± 10.55 years of age) with extracranial steno-occlusive disease. Thirty-three had infarct lesions. DSC-MR imaging was performed in 16/50 (32%), and cerebral DSA, in 12/50 patients (24%). Vascular anatomy and the distribution of vessel stenoses and occlusions were defined on sonography and TOF-MRA. Stenoses were classified according to the NASCET criteria. Infarct lesions and perfusion deficits were defined on FLAIR and DSC-MR imaging, respectively. Individual perfusion patterns were defined on the superselective pseudocontinuous arterial spin-labeling maps and were correlated with vascular anatomy and infarct lesion localization. RESULTS: The superselective pseudocontinuous arterial spin-labeling imaging sequence could be readily applied by trained technicians, and the additional scan time of 12.7 minutes was well-tolerated by patients. The detected vessel occlusions/stenoses and perfusion patterns corresponded between cerebral DSA and superselective pseudocontinuous arterial spin-labeling maps in all cases. Perfusion deficits on DSC-CBF maps significantly correlated with those on superselective pseudocontinuous arterial spin-labeling maps (Pearson r = 0.9593, P < .01). Individual collateral recruitment patterns were not predictable from the vascular anatomy in 71% of our patients. CONCLUSIONS: Superselective pseudocontinuous arterial spin-labeling is a robust technique for regional brain perfusion imaging, suitable for the noninvasive diagnostics of individual perfusion patterns in patients with complex cerebrovascular disease.

Stroke risk in the early period after carotid related symptoms: a systematic review.

Current guidelines recommend performing carotid endarterectomy in patients with symptomatic carotid disease as soon as possible after the neurological index event. However, early stroke risk has not been well documented for this patient group. We therefore conducted a systematic analysis of the current literature on the recurrent risk of ischemic events in patients with symptomatic carotid stenosis. Systematic review was performed by searching the MEDLINE® database from 1950 until June 8, 2015 (key words: cerebral ischemia, transient ischemic attack, amaurosis fugax, stroke, symptomatic carotid stenosis, recurrent risk, outcome, prognosis, follow-up, cohort and natural history). All studies reporting stroke risks in patients with symptomatic carotid stenosis after neurologic index events within a period of 7 days were included. Cumulative stroke risks with 95% confidence intervals after a neurologic index event were recalculated at 2-3, 7, 14 and 30 days and a meta-analysis including an analysis of heterogeneity were performed using the statistical package R and Excel for Mac 2003. Ten studies with a total number of 2634 patients were included. Results of an overall stroke risk were as follows: 2.0-17.2% at 2-3 days, 0-22.1% at 7 days, 0-29.6% at 14 days and 0-11.1% at 30 days in patients with a symptomatic extracranial carotid stenosis. The pooled stroke risk in the six studies with active follow-up was 6.0% (95% CI 2.4-14.4) at 2-3 days, 10.9% (6.1-18.7) at 7 days and 17.6% (9.7-29.9) at 14 days. Pooled stroke risk in the three studies with uncensored populations was even higher with 6.4% (1.5-23.8%) at 2-3 days, 19.5% (12.7-28.7) at 7 days and 26.1% (20.6-32.5%) at 14 days. Significant heterogeneity (P<0.001) could be explained by the different inclusion criteria and the study's design. Retrospective studies with passive follow-up had the lowest stroke risk whereas prospective studies with active follow-up and without bias through early intervention by carotid endarterectomy or carotid stenting had the highest stroke risk. The risk of recurrence of cerebrovascular events in patients with symptomatic carotid stenosis within the first days after a neurologic index event is as high as 6.4% (1.5-23.8), 19.5% (12.7-28.7) and 26.1% (20.6-32.5) after 2-3, 7 and 14 days respectively. Patients with a symptomatic carotid stenosis are therefore at a very high risk of a definitive stroke. Recommendations by current guidelines to perform carotid endarterectomy as soon as possible after the neurologic index event are therefore justified.

Patient characteristics and outcomes of carotid endarterectomy and carotid artery stenting: analysis of the German mandatory national quality assurance registry - 2003 to 2014.

AIM: In Germany, every surgical or endovascular procedure on the extracranial carotid artery is documented in a mandatory quality assurance registry. The purpose of this study is to describe the patient characteristics, the indications for treatment, and the short-term outcomes as well as to analyse the corresponding trends from 2003 to 2014. METHODS: Data on demographics, peri-procedural measures, and outcomes were extracted from the annual quality reports published by the Federal Agency for Quality Assurance and the Institute for Applied Quality Improvement and Research in Health Care. Data were available from 2003 to 2014 for carotid endarterectomy (CEA) and from 2012 to 2014 for carotid artery stenting (CAS). The primary outcome event of this study is any stroke or death until discharge from hospital. Temporal trends of categorical variables were statistically analysed using the Cochran-Armitage test for trend. RESULTS: Between 2003 and 2014, 309,405 CEAs and 18,047 CAS procedures were documented in the database; 68.1% of all patients were male. The mean age of patients treated with CEA increased from 68.9 years in 2003 to 70.9 years in 2014. The proportion of patients with ASA stages III to V increased from 65% to 71% in CEA, whereas it decreased from 44% to 41% in CAS patients. 53.1% of all CEAs were performed for asymptomatic patients (group A), 34.4% for symptomatic patients treated electively (group B), and 11.2% a in a collective group including other indications for CEA or CAS (such as recurrent stenosis, carotid aneurysms, emergency treatment due to stroke-in-evolution). The corresponding data for CAS are 49.3%, 26.1% and 26.3% respectively. In group B, the interval between the neurological index event and CEA decreased from 28 to 8 days (P<0.001). In patients treated with CAS, this interval was 9 days in 2012 (no further data available). On average, 67.1% and 48.2% of surgically treated patients as well as 77.8% and 69.8% of CAS patients were neurologically assessed before and after the procedure, respectively. From 2003 to 2014, CEA procedures were performed more frequently in locoregional anesthesia (10.1% to 29.1%, P<0.001). The same trend was observed for the application of the eversion technique (37.0% to 41.6%, P<0.001), the neurophysiological monitoring (49.8% to 61.8%, P<0.001), and the intra-procedural assessment of the treated artery (44.5% to 69.7%, P<0.001). In contrast, shunting was used less frequently (48.1% to 43.0%, P<0.001). Averagely 95.7% of all endovascular procedures were performed using stent-angioplasty. In 54.2% a protection device was used. Nitinol and bare metal stents were used in 74.1% and 21.4% of cases, respectively. The in-hospital rate of any stroke or death decreased from 2.0% to 1.1% in asymptomatic patients treated with CEA without a contralateral stenosis ≥75% or occlusion, P<0.001). In patients treated with CAS this rate did not increase (1.7% to 1.8%, p=0.909). The corresponding rates in CEA and CAS patients with severe contralateral stenosis or occlusion varied between 1.9%-3.1% and 2.2%-2.6%, respectively. In symptomatic patients (group B) with a stenosis of 50 percent or more, the rate of any stroke or death decreased significantly after CEA from 4.2% to 2.4% (P<0.001) and remained stable after CAS (3.9% to 3.5%, P=0.577). CONCLUSION: This report on 327,452 carotid procedures analysed one of the largest quality registries on CEA and CAS worldwide. Data indicate that treated patients became older and sicker, whereas in contrast, the in-hospital rates of stroke or death are decreasing over time.

Ultrasound surveillance after CAS and CEA: what's the evidence?

AIM: The rationale of clinical and Duplex ultrasound (DUS) surveillance after carotid endarterectomy (CEA) and carotid artery stenting (CAS) is the detection of recurrent stenoses and the prevention of future carotid-related cerebral ischemic events. This paper addresses the evidence for this approach. METHODS: The multicenter randomized controlled trials (RCTs) published between 1990 and 2013 were reviewed with respect to DUS surveillance intervals, recurrent stenoses rates and recurrent ipsilateral stroke rates. In addition a Medline literature search from January 1990 until February 2014 was performed by use of the following keywords: "surveillance"; "carotid endarterectomy"; "carotid stenting"; "carotid artery surveillance"; "carotid artery stenosis". Finally we analyzed all carotid-related guidelines published between 2006 and 2013 for recommendations on DUS surveillance after CEA or CAS. RESULTS: Nine RCT protocols (NASCET, ECST, ACST, ACAS, CAVATAS, SAPPHIRE, EVA-3S, CREST, and SPACE) showed similar follow-up intervals (at 1 month, 3 or 4 and at 6, and 12 months after CAS and CEA, then at least once a year). The incidence of a recurrent carotid stenosis (≥50%) or occlusion ranged around 6% four years after CEA or CAS. The annual incidence of any ipsilateral cerebral ischemic event was about 1% and 0.5% after CEA for a symptomatic or an asymptomatic stenosis respectively. Since the overall incidence of carotid recurrent stenosis and postprocedural strokes is low, DUS is questioned as necessary for all patients after CEA and CAS in prospective single center series. However, certain subgroups of patients (women, diabetics, patients with dyslipidemia, smokers) might have increased rates of restenosis after CEA or CAS. Data on DUS surveillance intervals following CAS is rare. Three out of 21 identified guidelines recommend long-term DUS surveillance, as the benefits are considered to exceed the risks. However, the level of evidence for any recommendation on DUS surveillance is consistently low. CONCLUSION: Our literature review reveals only little evidence to support routine DUS after CEA within short intervals. Currently a practice with one periprocedural DUS and one DUS after 12 months after CEA seems to be reasonable. In patients with an ipsilateral restenosis≥50%, contralateral disease progression≥50% and in patients who are considered to be at higher risk of restenosis further DUS surveillance seems appropriate. Due to inconsistent long-term data on surveillance after CAS imaging at 6 months and then annually seems reasonable. Further studies on DUS surveillance are necessary.