Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

Background The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. Methods This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. Results A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with <70% stenosis, the predicted cumulative 5-year stroke rate was <5% in 495, 5% to 9.9% in 202, 10% to 19.9% in 142, and <20% in 84 patients. Conclusion Cerebrovascular risk stratification is possible using a combination of clinical and ultrasonic plaque features. These findings need to be validated in additional prospective studies of patients receiving optimal medical intervention alone. Copyright © 2010 by the Society for Vascular Surgery

The size of juxtaluminal hypoechoic area in ultrasound images of asymptomatic carotid plaques predicts the occurrence of stroke

Objective: To test the hypothesis that the size of a juxtaluminal black (hypoechoic) area (JBA) in ultrasound images of asymptomatic carotid artery plaques predicts future ipsilateral ischemic stroke. Methods: A JBA was defined as an area of pixels with a grayscale value &lt;25 adjacent to the lumen without a visible echogenic cap after image normalization. The size of a JBA was measured in the carotid plaque images of 1121 patients with asymptomatic carotid stenosis 50% to 99% in relation to the bulb (Asymptomatic Carotid Stenosis and Risk of Stroke study); the patients were followed for up to 8 years. Results: The JBA had a linear association with future stroke rate. The area under the receiver-operating characteristic curve was 0.816. Using Kaplan-Meier curves, the mean annual stroke rate was 0.4% in 706 patients with a JBA &lt;4 mm 2, 1.4% in 171 patients with a JBA 4 to 8 mm2, 3.2% in 46 patients with a JBA 8 to 10 mm2, and 5% in 198 patients with a JBA &gt;10 mm2 (P &lt;.001). In a Cox model with ipsilateral ischemic events (amaurosis fugax, transient ischemic attack [TIA], or stroke) as the dependent variable, the JBA (&lt;4 mm2, 4-8 mm2, &gt;8 mm2) was still significant after adjusting for other plaque features known to be associated with increased risk, including stenosis, grayscale median, presence of discrete white areas without acoustic shadowing indicating neovascularization, plaque area, and history of contralateral TIA or stroke. Plaque area and grayscale median were not significant. Using the significant variables (stenosis, discrete white areas without acoustic shadowing, JBA, and history of contralateral TIA or stroke), this model predicted the annual risk of stroke for each patient (range, 0.1%-10.0%). The average annual stroke risk was &lt;1% in 734 patients, 1% to 1.9% in 94 patients, 2% to 3.9% in 134 patients, 4% to 5.9% in 125 patients, and 6% to 10% in 34 patients. Conclusions: The size of a JBA is linearly related to the risk of stroke and can be used in risk stratification models. These findings need to be confirmed in future prospective studies or in the medical arm of randomized controlled studies in the presence of optimal medical therapy. In the meantime, the JBA may be used to select asymptomatic patients at high stroke risk for carotid endarterectomy and spare patients at low risk from an unnecessary operation

Status and Perspectives of Electric Propulsion in Italy

Electric Propulsion activities in Italy are essentially concentrated in Pisa at Centrospazio/Alta and in Florence at LABEN-Proel. Together, the two organizations’ range of activities cover all of the major EP concepts, including gridded ion thrusters (LABEN-Proel), Hall thrusters (both), FEEP (Centrospazio/Alta), magneto-plasma-dynamic (MPD) thrusters (Centrospazio/ Alta). The two companies have a relevant and recognized role in Europe in producing components (grids, cathodes, composite tanks) and in the field of specialised services, especially regarding high power thrusters testing. Qualification of complete propulsion subsystems (the FEEP microthruster and the RMT low-thrust ion engine) is underway. A joint program for the development of advanced, high power thrusters has been recently establishe

Carotid endarterectomy in diabetic patients: Does the need for insulin treatment affect early and late outcomes?

Aim. The aim of this study was to evaluate early and late results of carotid endarterectomy (CEA) in diabetic patients in a large single center experience, with particular attention to the effect of the medical management of diabetes on early and late outcomes. Methods. Over a nine-year period ending in December 2008, 2982 consecutive CEAs were performed. Patients were diabetics in 634 (21.5%) cases; diabetes was insulin-requiring in 79 cases (group 1) and oral agent-controlled in 555 cases (group 2). Early results in terms of intraoperative neurological events and 30-day stroke and death rates were analyzed and compared between the two groups. Follow-up results were analyzed with Kaplan Meyer curves and compared with log-rank test. Results. Patients of group 1 were more likely to be asymptomatic (64 cases, 81%) than patients of group 2 (380 cases, 68%; P=0.02). Interventions were performed under general anaesthesia in 39% of patients in group 1 and in 57% of patients in group 2 (P=0.003). Shunt insertion (14% and 15%, respectively) and patch closure rates (91% and 87%, respectively) were similar between the two groups. Cumulative 30 day-stroke and death rate in diabetics was 1.9%, significantly higher than in non-diabetics (0.7%). There were no differences in terms of intraoperative neurological events (1.1% and 0.5%, respectively) between group 1 and 2, and also 30-day stroke and death rates were similar between the two groups (1.2% and 1.9%, respectively). Univariate analysis for the risk of stroke and death at 30 days in diabetics demonstrated that only general anaesthesia and female sex increased perioperative risk and multivariate analysis confirmed only general anaesthesia to be independently associated with poorer early outcomes. Median duration of follow-up was 22 months (range 1-110). Estimated 36-month survival, freedom from ipsilateral neurological events and freedom from severe (&gt;70%) restenosis rates in diabetics were 95.7%, 98.5% and 93%, respectively, and were poorer than in non-diabetics. There were no differences between the two groups in terms of survival, freedom from ispilateral neurological symptoms and from severe restenosis. Conclusions. In our experience the need for insulin treatment does not seem to affect early and late results of carotid endarterectomy in diabetics, who however represent a subset of patients at higher surgical risk

Prevention of type II endoleaks: results of a study including 1000 patients

Aim: The incidence for type II endoleaks (T2E) reported in literature varies between 10% and 20% but their natural history is still unclear. The aim of this study was to retrospectively evaluate our single centre experience of approximately 1000 patients treated with endovascular aneurysm repair (EVAR) to determine the role of T2Es in mid and long term failure and to optimize their management. Methods: Baseline characteristics, operative and follow-up data of consecutive patients undergoing EVAR at our Institution were prospectively collected in a dedicated database. Patients with a demonstrated type II endoleak at the followup were divided in two groups depending on the spontaneous regression of the endoleak. We compared baseline characteristics, mortality, relation to aneurysm sac evolution, association with type I or III endoleaks and reintervention. The incidence of recurrent T2Es (defined as newly onset endoleaks after a surgical, trans-lumbar or trans-arterial treatment) was also evaluated to define a proper management of these complications. Results: From March 1999 to May 2014, 943 consecutive patients with an aortic or aorto-iliac aneurysms were treated with EVAR. During the follow-up 260 patients had a T2E. Out of these 260 patients, 99 had a spontaneous regression of the endoleak (38.1%) and were defined as Group 1 while 161 had a persistent-T2E (61.9%) and were defined as Group 2. The mean regression time of T2Es was 26.8 months (±21.8) with a median value of 18 months (12-36). During follow-up, an aneurysm sac enlargement &gt;5 mm was found in 10 patients (10.4%) in Group 1 compared with 37 (25.2%) in Group 2 (P&lt;0.001) with a consequent increase in the rate of reinterventions (18.2% vs. 30.4%) for the second group (P&lt;0.001). Adjusted analysis showed an increase risk of persistent-T2Es for age over 80 years (OR, 1.5: CI, 1.0-2.2; P=0.028), hypertension (OR, 1.5: CI, 1.0-2.3; P=0.043), ASA HI and TV (OR, 1.8: CI, 1.3-2.5; P&lt;0.001) and presence of T2E at the completion angiography (OR, 1.5: CI, 1-2.2; P=0.031). Kaplan-Meier curves showed a significant decrease in the overall survival rate for patients presenting a persistent T2E (P=0.041). Conclusion: Persistent T2Es are related with higher mortality, sac enlargement and reinterventions rates. As their treatment appears to be often unsuccessful, the identification of subclasses of patients at risk may alter the treatment option

Carotid endarterectomy in patients with acute neurological symptoms

Aim. The aim of this study was to retrospectively evaluate our experience in urgent carotid endarterectomy (CEA) in patients with acute neurological symptoms comparing the results with those obtained in stable symptomatic patients in a case-control study. Methods. From January 1996 to December 2003, 2 564 consecutive CEAs were performed at our Department. In 55 cases CEA was carried out in patients with acute neurological deficit; in all these patients, clinical presentation were recent (&lt;24 h) or crescendo (defined as 2 or more episodes in 24 h, with complete recovery after each episode) TIAs (group 1). Control group was randomly obtained from our historical database and consisted of 225 stable symptomatic patients operated on in the same period (group 2). Early (30 day) results in the 2 groups were compared by χ2 and Fisher exact tests; follow-up data were analysed by life-table analysis (Kaplan-Meier test) and results in subgroups were compared by means of log-rank test. Results. Considering mortality and any neurological morbidity, the patients of group 1 showed a cumulative rate of death and neurological complication significantly higher than those in group 2 (5.4% and 0.8%, respectively; P=0.005); however, when analyzing 30-day disabling strokes and deaths, the patients of group 1 had a cumulative complication rate of 1.8%, as in group 2 the corresponding figure was 0.4%. In patients of group 1 univariate analysis and logistic regression for multivariate analysis for 30-day risk of stroke and death did not show any influence of comorbidities, clinical status, anatomical and surgical features. Estimated cumulative 36 months-survival was significantly better in group 2 than in group 1. Considering the absence of ipsilateral stroke at 36 months, there were no differences between the 2 groups; however, analyzing the estimated absence of any neurological events, both ipsilateral and contralateral, at 36 months, patients of group 1 had a higher risk than those of group 2. Conclusion. Urgent CEA in patients with recent/crescendo TIA and appropriate carotid artery lesion carries good early and long term results, which however remain slightly poorer than those obtained in symptomatic patients with a stable neurological status

Device specific outcomes after endovascular abdominal aortic aneurysm repair

Aim. The aim of this study was to analyze early and midterm results after endovascular abdominal aortic aneurysm repair (EVAR) on the basis of the type and morphology of the device employed. Methods. From January 2000 to May 2008, 443 consecutive elective EVAR procedures using 9 different devices were performed at our institution. Data concerning the pre, intra and postoperative periods were prospectively collected in a dedicated database. Data related to the 4 most commonly used and currently available bifurcated endoprostheses were extracted and constitute the present study. Results in terms of technical success, aneurysm related morbidity and mortality (ARM) in both the perioperative period and during follow-up, need for secondary interventions, and patient survival were recorded and a device-related analysis was performed. Statistical analysis with SPSS 14.0 software was carried out and the different groups were compared by χ2 and Fisher tests. For follow-up study Kaplan-Meier curves were performed and log-rank test was used for comparing the groups. Results. A total of 391 EVAR procedures in 365 males (93%) and 26 females with a mean age of 74 years (range 52-91±7.4) were enrolled. More than 75% of the patients were ASA class III or IV. In 116 cases an Excluder (group 1), in 149 a Talent (group 2), in 77 a Zenith (group 3) and in 49 an Anaconda (group 4) endograft was deployed. Technical success was 98.7%. Thirty-day mortality and morbidity were satisfactory (0.8% and 4.8%) and no significant perioperative differences were recorded between the four groups. Mean follow-up was 26.0±21.9 (range 1-84) months. During follow-up 54 deaths, 76 endoleaks, 16 limb thromboses, 2 ruptures and 6 conversions to open repair occurred. Freedom from endoleak at 36 months was 84.4% in group 1, 90% in group 2, 84.4% in group 3 and 65.8% in group 4 (P=0.001). Overall, in 40 patients (10%) a reintervention was necessary. Freedom from reintervention at 36 months was 92% in group 1, 85% in group 2, 91% in group 3 and 77% in group 4 (P=NS). Conclusion. Outcomes with the most common commercially available devices in Italy are satisfactory. Mortality and morbidity are quite low in the perioperative period and better than results reported in the literature with standard open repair. Midterm follow-up results are good with a 98% freedom from AAA rupture at 48 months, however, close follow-up is required with approximately 10% of patients requiring secondary interventions