Device migration after endoluminal abdominal aortic aneurysm repair: Analysis of 113 cases with a minimum follow-up period of 2 years

AbstractPurpose: Device migration (DM) has been shown to cause late failure after endoluminal abdominal aortic aneurysm (AAA) repair. To establish the incidence rate and the predictive factors of distal migration of the proximal portion of the endograft, computed tomographic (CT) scans performed at different time intervals during follow-up examination of 113 patients were reviewed. Patients and Methods: Between April 1997 and March 1999, 148 patients underwent endoluminal AAA repair with a modular endograft with infrarenal fixation (Medtronic-AVE AneuRx, Santa Rosa, Calif) at our unit. CT scans performed at 1, 6, and 12 months after surgery and yearly thereafter were prospectively stored in a computer imaging database. Patient demographics, risk factors, operative details, and follow-up events were prospectively collected. No patients were lost to follow-up examination. Twelve patients died within 2 years of surgery, four patients underwent immediate conversion to open repair, and adequate CT measurements were not feasible in 19 cases, which left 113 patients available for a minimum 2-year assessment and 418 CT scan results reviewed. Two vascular surgeons, blinded to patient identity and history with tested interobserver agreement (κ = 0.64), separately reviewed axial reconstructions of CT scans. DM was defined as changes of 10 mm or more in the distance between the lower renal artery and the first visible portion of the endograft at follow-up examination. Ten possible independent predictors of DM were analyzed with multivariate Cox proportional hazards regression model. Results: One AAA rupture, which was successfully treated, occurred at a mean follow-up period of 28 months (range, 24 to 46 months). Seventeen patients (15%) showed DM. Eight patients (47%) with DM underwent reintervention: a proximal cuff was positioned in six patients and late conversion to open repair was performed in two patients. Of the 10 variables analyzed with Cox proportional hazards regression model, AAA neck enlargement of more than 10% after endoluminal repair (hazard ratio, 7.3; confidence interval, 1.8 to 29.2; P =.004) and preoperative AAA diameter of 55 mm or more (hazard ratio, 4.5; confidence interval, 1.2 to 16.7; P =.02) were positive independent predictors of DM. The probability of DM at 36 months was 27% according to life table analysis. Conclusion: DM occurred in a significant portion of our patients, yet aggressive follow-up examination and a high reintervention rate prevented aneurysm-related death. According to our data, dilatation of the infrarenal aortic neck is an important factor that contributes to the distal migration of stent grafts, and patients with large aneurysms are at high risk for DM. (J Vasc Surg 2002;35:229-35.

Appropriateness of learning curve for carotid artery stenting: An analysis of periprocedural complications

ObjectivesCerebral embolism is the first cause of neurologic complications of carotid artery stenting (CAS). A large debate has been raised to identify the caseload necessary for an appropriate learning curve before systematic use of CAS. This study examined (1) the timing of periprocedural complications during CAS and how these complications vary over time to identify factors that contribute to neurologic morbidity and (2) a sufficient number of procedures for adequate training.MethodsDuring 2001 to 2006, 627 CAS procedures with cerebral protection devices (CPD) were performed in a single vascular surgery center by a team including a vascular surgeon and an interventional radiologist. These represented 38% of a total of 1598 carotid revascularizations performed in the same interval. CAS procedures were divided into two groups according to time interval: the first period, 2001 to 2003, included 195 CAS procedures, and the second period, 2004 to 2006, included 432 CAS procedures. During each CAS procedure, five major steps were considered: phase 1, or the catheterization phase, included the passage of the aortic arch, catheterization of the target vessel, and introduction of a guiding catheter or sheath. Phase 2, or the crossing stenosis phase, included the placement of a CPD. Phase 3, or the stent ballooning phase, included predilation (when indicated), stent implantation, postdilation, and recovery of the protection system. Phase 4, or the early postinterventional phase, included the first 24 hours after leaving the catheterization table. Phase 5, or the late postinterventional phase, included the interval from the first postoperative day to 30 days.ResultsAt 30 days, 10 major strokes (2 of which were fatal) and 1 cardiac death occurred, for an overall major stroke/death rate of 1.75%. Furthermore, 18 minor strokes (2.9%) were recorded. By analyzing the occurrence of major strokes according to the three intraprocedural phases, four occurred in phase 1 and six in phase 3. All strokes but one were ischemic; six were ipsilateral, three were contralateral, and one was posterior. Minor strokes occurred prevalently after the procedure (11 in phase 4, 5 in phase 5, and 1 for phases 1 and 3). Comparing the first with the second interval of the study period, the 30-day major stroke and death rate decreased from 3.1% to 0.9% (P = .047), and the 30-day any stroke and death rate decreased from 8.2% to 2.7% (P = .005). According to multivariate analysis, study interval (hazard ratio, 3.68; 95% confidence interval, 1.49-9.01; P = .005) and age (hazard ratio, 1.06; 95% confidence interval, 1.00-1.12; P = .05) were significant predictors of stroke.ConclusionsA large proportion of major strokes (4/10) from CAS cannot be prevented by using CPD, because these strokes occur during catheterization (phase 1). This finding, together with the significant decrease in the overall stroke/death rate between the first and the last interval of the study period, enhances the importance of an appropriate learning curve that involves a caseload larger than that generally accepted for credentialing. The noticeable number of postprocedural cerebral embolizations leading to minor strokes and occurring in the early and late postinterventional phases (16/18) is likely due to factors less strictly related to the learning-curve effect, such as stent design and medical therapy. Moreover, expertise in selecting material and design of the stents according to different vessel morphology, in association with correct medical treatment, may be useful in reducing the number of minor strokes that occur in the later postinterventional phases of CAS

MicroRNA-21/PDCD4 proapoptotic signaling from circulating CD34+ cells to vascular endothelial cells:a potential contributor to adverse cardiovascular outcomes in patients with critical limb ischemia

Dataset related to the article with title: MicroRNA-21/PDCD4 proapoptotic signaling from circulating CD34+ cells to vascular endothelial cells: a potential contributor to adverse cardiovascular outcomes in patients with critical limb ischemia By:Gaia Spinetti1, Elena Sangalli1, Elena Tagliabue1, Davide Maselli1, Ornella Colpani1, David Ferland-McCollough2, Franco Carnelli1, Patrizia Orlando1, Agostino Paccagnella3, Anna Furlan3, Piero Maria Stefani3, Luisa Sambado3, Maria Sambataro3, and Paolo Madeddu2. 1IRCCS MultiMedica, Milan, Italy; 2University of Bristol, Bristol, UK, 3Ca Foncello Hospital, Treviso, Italy. Diabetes Care. 2020 Jul;43(7):1520-1529. doi: 10.2337/dc19-2227. Epub 2020 May 1. Abstract Objective. In patients with type 2 diabetes (T2D) and critical limb ischemia (CLI), migration of circulating CD34+ cells predicted cardiovascular mortality at 18 months post-revascularization. This study aimed to provide long-term validation and mechanistic understanding of the biomarker. Research Design and Methods. The association between CD34+ cell migration and cardiovascular mortality was reassessed at 6 years post-revascularization. In a new series of T2D-CLI and control subjects, immuno-sorted bone marrow (BM)-CD34+ cells were profiled for microRNA expression and assessed for apoptosis and angiogenesis activity. The differentially regulated microRNA-21, and its pro-apoptotic target PDCD4, were titrated to verify their contribution in transferring damaging signals from CD34+ cells to endothelial cells. Results. Multivariable regression analysis confirmed CD34+ cell migration forecasts long-term cardiovascular mortality. CD34+ cells from T2D-CLI patients were more apoptotic and less proangiogenic than controls and featured microRNA-21 downregulation, modulation of several long non-coding RNAs acting as microRNA-21 sponges, and upregulation of the microRNA-21 proapoptotic target PDCD4. Silencing miR-21 in control CD34+ cells phenocopied the T2D-CLI cell behavior. In coculture, T2D-CLI CD34+ cells imprinted naïve endothelial cells, increasing apoptosis, reducing network formation, and modulating the TUG1 sponge/microRNA-21/PDCD4 axis. Silencing PDCD4 or scavenging ROS protected endothelial cells from the negative influence of T2D-CLI CD34+ cells Conclusions. Migration of CD34+ cells predicts long-term cardiovascular mortality in T2D-CLI patients. An altered paracrine signalling conveys anti-angiogenic and pro-apoptotic features from CD34+ cells to the endothelium. This damaging interaction may increase the risk for life-threatening complications

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets