Outcome Analysis of Carotid Cross-Clamp Intolerance during Carotid Endarterectomy under Locoregional Anesthesia.

BACKGROUND: To analyze the predictors and describe the outcomes of cross-clamp intolerance (CCI) and the results of the use of carotid endarterectomy (CEA) with shunting or a shift strategy to immediate carotid artery stenting (CAS) in this setting. METHODS: Between January 2008 and December 2015, 385 patients were elected for single-sided, isolated CEA under locoregional anesthesia. In case of CCI, CEA with shunt was used selectively, whereas indication to immediate conversion to CAS was the immediate onset and severe persistent deterioration of the neurologic status, and/or local technical difficulties to perform endarterectomy. Primary outcome was prevention of death and all early (<30 days) perioperative cerebrovascular events. RESULTS: We treated 169 (43.9%) symptomatic lesions; urgent (≤48 hours) intervention was performed in 85 (22.1%) cases. Carotid CCI occurred in 45 (11.7%) patients. CEA with shunt was used in 16, whereas CAS in 27 (7.0%, 2 refused further treatment). Multivariable analysis identified hypertension (odds ratio [OR]: 2.93, 95% confidence interval [CI]: 1.01-8.52; P = 0.049) and symptomatic lesions (OR: 2.34, 95% CI: 1.11-4.93; P = 0.025) as significant predictors of CCI. In-hospital mortality rate was 0.5%; none occurred in CCI group. Postoperative cerebrovascular event rate was 2.3% (n = 9). At multivariable analyses, only CCI (OR: 6.60, 95% CI: 1.65-26.36; P = 0.008) was significantly associated with postoperative cerebrovascular events, with no significant different clinical outcomes between CEA and CAS. CONCLUSIONS: Hypertension and symptomatic carotid stenosis were significant predictors of CCI, which was found to be predictive for postoperative cerebrovascular events. In selected patients with CCI, CAS had satisfactory, similar results of CEA.

Numerical and analytical models to study the laser-driven plasma perturbation in a dielectric gas-filled capillary waveguide.

An alternative fast approach to study the propagation of an intense laser pulse through a dielectric capillary waveguide filled with plasma is presented. The numerical model computes the evolution of the capillary mode coupling coefficients and from these the properties of the laser and plasma response are retrieved. Moreover, an analytical description of the process is presented and compared to the numerical model.

Mapping the transverse coherence of the self amplified spontaneous emission of a free-electron laser with the heterodyne speckle method.

The two-dimensional single shot transverse coherence of the Self-Amplified Spontaneous Emission of the SPARC_LAB Free-Electron Laser was measured through the statistical analysis of a speckle field produced by heterodyning the radiation beam with a huge number of reference waves, scattered by a suspension of particles. In this paper we report the measurements and the evaluation of the transverse coherence along the SPARC_LAB undulator modules. The measure method was demonstrated to be precise and robust, it does not require any a priori assumptions and can be implemented over a wide range of wavelengths, from the optical radiation to the x-rays.

Reconstruction of lateral coherence and 2D emittance in plasma betatron X-ray sources.

X-ray sources have a strong social impact, being implemented for biomedical research, material and environmental sciences. Nowadays, compact and accessible sources are made using lasers. We report evidence of nontrivial spectral-angular correlations in a laser-driven betatron X-ray source. Furthermore, by angularly-resolved spectral measurements, we detect the signature of spatial phase modulations by the electron trajectories. This allows the lateral coherence function to be retrieved, leading to the evaluation of the coherence area of the source, determining its brightness. Finally, the proposed methodology allows the unprecedented reconstruction of the size of the X-ray source and the electron beam emittance in the two main emission planes in a single shot. This information will be of fundamental interest for user applications of new radiation sources.

The INFN-LNF present and future accelerator-based light facilities.

The INFN-Frascati National Laboratory (LNF) is nowadays running a 0.51 GeV electron-positron collider, DA Φ NE, that also represents the synchrotron radiation source of the beamlines of the DA Φ NE-Light facility. Not being DA Φ NE dedicated to synchrotron radiations activities, the DA Φ NE-Light facility can use it mainly in parasitic mode. Particle accelerators and high energy physics (HEP) have been and are the main core of the LNF research activity, but like other HEP international laboratories also LNF is now moving in the direction of developing a dedicated free electron laser (FEL) user facility, EuPRAXIA@SPARC_Lab, based on plasma acceleration. This new facility in the framework of the EuPRAXIA (European Plasma Research Accelerator with eXcellence in Applications) EU project should produce FEL radiation beams for a wide range of applications using a smaller accelerator compared to actual radio frequency-based accelerator sources dimensions.

Risk factors analysis of thromboembolectomy for acute thromboembolic lower extremity ischemia in native arteries.

BACKGROUND: Aim of this study is to report the results of thromboembolectomy (ThEmb) for acute thromboembolic lower limb ischemia (ATLI) in native arteries and to create a predictive score for amputation-free survival (AFS) at 30 days. METHODS: It is a single center, retrospective analysis of a four years period. All patients had ThEmb: adjunctive procedures included femoral and/or popliteal endarterectomy in 30 (18.3%) cases, PTA-stent in 24 (14.6%), and femoral endarterectomy plus PTA-stent in 12 (7.3%). Fasciotomies were performed in 6 (3.6%) patients. Predictors of AFS identified on univariate screen (inclusion threshold, P<.20) were included in a multivariable model. The resulting significant predictors were assigned an integer score to stratify patients into risk groups. RESULTS: Authors analyzed 164 limbs in 164 patients. Mean age was 80±10 years (range, 40-99). In-hospital mortality was 9.8% (N.=16); AFS at 30 days was 84.7% (N.=139). The anatomic level (iliac vs. femoropopliteal vs. infrapopliteal) of the occlusion did not affect AFS (P=.326). Multivariable analysis identified six significant predictors of AFS at 30 days: age >85 (P=0.050), chronic obstructive pulmonary disease (P=0.008), chronic renal insufficiency (P=0.019), late (>6 hours) onset (P=0.004), the presence of major neurologic deficit (P=0.023), and an increased (>800IU/L) level of creatine phosphokinase (P=0.001). An integer score generated two risk groups (low-risk 0-2 [70.1% of cohort], and high-risk ≥3 [29.9% of cohort]): stratification of the patients according to risk category yielded significantly different AFS at 30 days (low-risk 5.2% vs. high-risk 38.8%, P<0.0001). CONCLUSIONS: Among patients selected to undergo ThEmb for ATLI in native arteries, this risk score identified a group of patients with a 40% chance of death or major amputation at 30 days. The score can help to optimize the operative strategy, but further prospective validation is needed.

Cryopreserved Human Allografts for the Reconstruction of Aortic and Peripheral Prosthetic Graft Infection.

Background: This study aimed to present cases with cryopreserved human allografts (CHAs) for vascular reconstruction in both aortic and peripheral infected prosthetic grafts. Materials and Methods: This is a single center, observational descriptive study with retrospective analysis. In all cases, the infected prosthetic graft material was completely removed. At discharge, patients were administered anticoagulants. Follow-up examinations included clinical visits, echo-color-Doppler ultrasounds, or computed tomography angiography within 30 days and at 3, 6, and 12 months after the treatment, and then twice per year. Results: We treated 21 patients (90% men, n=19) with the mean age of 71±12 years and mean interval between the initial operation and replacement with CHA of 30 months [range, 1-216; interquartile range (IQR), 2-36]. In-hospital mortality was 14% (n=3); no CHA-related complication led to death. Limb salvage was 100%. No patient was lost at the median follow-up of 14 months (range, 2-61; IQR, 6-39). No rupture, aneurysmal degeneration, or re-infection occurred. Estimated freedom from CHA-related adverse events (95% confidence interval, 43-63) was 95% at 3 years. Conclusion: In our experience, CHAs are a viable option for prosthetic graft infections and provide satisfactory clinical results and favorable stability because of a very low rate of CHA-related adverse events during follow-up.

Strong nonlinear terahertz response induced by Dirac surface states in Bi2Se3 topological insulator.

Electrons with a linear energy/momentum dispersion are called massless Dirac electrons and represent the low-energy excitations in exotic materials such as graphene and topological insulators. Dirac electrons are characterized by notable properties such as a high mobility, a tunable density and, in topological insulators, a protection against backscattering through the spin-momentum locking mechanism. All those properties make graphene and topological insulators appealing for plasmonics applications. However, Dirac electrons are expected to present also a strong nonlinear optical behaviour. This should mirror in phenomena such as electromagnetic-induced transparency and harmonic generation. Here we demonstrate that in Bi2Se3 topological insulator, an electromagnetic-induced transparency is achieved under the application of a strong terahertz electric field. This effect, concomitantly determined by harmonic generation and charge-mobility reduction, is exclusively related to the presence of Dirac electron at the surface of Bi2Se3, and opens the road towards tunable terahertz nonlinear optical devices based on topological insulator materials.

Combined endovascular repair of a celiac trunk aneurysm using celiac-splenic stent graft and hepatic artery embolization.

Celiac trunk aneurysms are rare and usually asymptomatic lesions. However, treatment is generally warranted to avoid catastrophic rupture. We report a case of a 70-year-old man who sought care for a celiac trunk aneurysm close to the hepatosplenic bifurcation managed endovascularly by using a combined treatment of celiac-splenic stent-graft implantation and hepatic artery embolization.