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Coronary catheterization after transcatheter aortic valve implantation (TAVR) may be challenging. The main objective of the study is to assess the feasibility of coronary catheterization and angioplasty according to each type of valve. We retrospectively studied coronary angiography or percutaneous angioplasty procedures after TAVR in two different centers. The catheterization success of coronary artery was evaluated according to the quality of engagement in ostium and opacification of the artery. Other indicators were collected including catheters used, fluoroscopy and angiography times, DAP and the volume of the contrast agent. Among 1512 TAVR procedures, 33 patients were included. The Sapien 3® valve was implanted in 22 patients and the Evolut® in 11 patients (7 Evolut-R® and 4 Evolut Pro®). Coronary angiography with selective or partially selective catheterization has been successfully performed in all patients with a Sapien 3® valve. In the Evolut® group we identified 3 cases of non-selective catheterization for the right coronary and 1 case for the left coronary. Standard Judkins catheters seem to be the most suitable for both types of valve with very good efficiency. The results of our study is promising for the future of TAVR with a coronary catheterization success rate close to 100% with some difficulties for the Evolut® supra-annular valves. Special attention should be paid to the technique of implantation and orientation of cups in the aortic sinus. [ABSTRACT FROM AUTHOR]

Les complications vasculaires au cours d'un remplacement valvulaire aortique percutané nécessitent parfois la mise en place d'un stent couvert dans l'artère fémorale commune. Or, il s'agit d'une zone anatomique soumise à de fortes contraintes de mobilisation, exposant au risque de fracture voire d'occlusion de stent. Nous avons analysé rétrospectivement les dossiers des patients ayant présenté une complication vasculaire per-procédure entre 2015 et 2018, traités par angioplastie de l'artère fémorale commune ou chirurgie conventionnelle. Des symptômes vasculaires suspects ont été recherchés à distance par suivi téléphonique. Parmi 552 patients, 43 patients ont présenté une complication vasculaire, 12 (27,9 %) ont été traités par angioplastie au ballon seul, 5 (11,6 %) ont été traités par chirurgie d'emblée et 26 (60,4 %) ont été traités par implantation d'un stent couvert. Chez ces derniers, le succès d'implantation du stent était de 100 % et l'efficacité sur la complication était de 92,3 %. Le suivi médian était de 430 jours [3–1499]. Le groupe chirurgie présentait un sur-risque de transfusion et de décès toute cause. Aucun patient des trois groupes ne présentait de complication ou de symptôme vasculaire suspect au suivi. Quatre patients (9,3 %) du groupe stent couvert ont bénéficié d'une imagerie de réévaluation, sans fracture ni occlusion de stent retrouvée. Dans notre population, l'implantation d'un stent couvert dans l'artère fémorale commune au décours d'une complication de remplacement valvulaire aortique percutané était une stratégie efficace et n'était associée à aucune complication à distance. Vascular complications are frequent in the context of transcatheter aortic valve replacement and may require the implantation of a covered stent graft in the common femforal artery. However, common femoral artery is considered to be at high risk of stent fracture or occlusion due to high mobility of the hip joint. We analyzed medical records of patients with transcatheter aortic valve replacement related vascular complications between 2015 and 2018, treated with commom femoral artery transluminal angioplasty or surgery. Vascular complications or suspect symptoms were followed up by phone calls. Among 552 patients, 43 patients were included. Twelve (11.6 %) were managed by prolonged balloon inflation, 5 (11.6 %) by first line surgery and 26 (60.4 %) by the implantation of a covered stent graft. Among the latter group, the covered stent graft was efficient in 24 patients (92.3 %). The median follow-up was 430 days [3–1499]. The first-line surgery group had a higher risk of red blood cell transfusion and all causes mortality. At follow-up, no patient had suspicious symptoms of vascular covered stent complication. Four patients (9.3 %) had US-doppler or CT vascular imaging at follow-up, showing no evidence of stent fracture or occlusion. In our study, the implantation of a covered stent graft in the common femoral artery was an efficient and safe strategy for the management of transcatheter aortic valve replacement related vascular complications. [ABSTRACT FROM AUTHOR]

We have performed an extended palaeomagnetic study of the Oslo Graben volcanics, compared to the study of half a century ago by van Everdingen, using modern techniques and a four times larger amount of sites, plus additional rock magnetic experiments. We conclude that the average direction (D = 204.0, I = -37.9, k = 46.9, α95 = 2.0) and associated palaeomagnetic pole (λ = 48.3, φ = 155.5, K = 52.2, A95 = 1.9) of the Krokskogen and Vestfold volcanics together are statistically identical to those of the earlier study. This gives confidence in the fact that older palaeomagnetic studies can be reliable and robust, even though methods have improved. Our larger number of samples, and better age constraints, enable us to separate the data into two major intervals: the younger, on average, Krokskogen area and the older Vestfold area. The results show firstly that palaeolatitudes are slightly higher than predicted by the latest apparent polar wander path (APWP) for Eurasia by Torsvik et al. These data support an early Permian Pangaea A configuration and do not necessitate a Pangaea B configuration. The larger data set also allows us to assess the distribution of the characteristic remanent magnetization directions of the Oslo Graben in terms of geomagnetic field behaviour, which were acquired during a long period of dominantly single polarity the Permo-Carboniferous Reversed Superchron (PCRS). The distributions show a significantly lower virtual geomagnetic pole (VGP) scatter at the observed (low) latitudes than expected from a compilation from lavas of the last 5 Myr. The data do however show excellent agreement with the scatter observed both during the Cretaceous Normal Superchron and the PCRS. A comparison of the directional distributions in terms of elongation is less discriminating, since the large errors in all cases allow a fit to the predicted elongation/inclination behaviour of the TK03.GAD model. [ABSTRACT FROM AUTHOR]

Background: Quantitative flow ratio (QFR) and target-vessel SYNTAX score (tvSS) are novel indices used to assess lesion physiology and morphology in percutaneous coronary intervention (PCI). Their prognostic implication after successful recanalization of coronary chronic total occlusion (CTO) is unknown., Objectives: To investigate the prognostic value of QFR measured immediately after successful CTO-recanalization in predicting vessel-oriented adverse events, and to compare it with the pre-procedural morphological tvSS., Methods: QFR was measured offline after successful CTO-PCIs in a single center. We grouped the patients according to a cut-off value of post-PCI QFR (0.91). The primary outcome was target-vessel failure (TVF) at 2 years., Results: Among 470 CTO lesions performed during the study period, 324 were eligible for QFR analysis (258 with QFR ≥ 0.91 and 66 with QFR < 0.91). The mean age of the study population was 68.3 ± 10.7 years. The low QFR group had a lower left ventricular ejection fraction (45.8 ± 13.9% vs. 49.8 ± 12.4%, p = 0.025) and a higher rate of atrial fibrillation (19.7% vs. 11.2%, p = 0.020). The mean tvSS was 12.8 ± 4.8, and it showed no significant difference in both groups (13.6 ± 5.1 vs. 12.6 ± 4.6, p = 0.122). Patients with low post-CTO QFR had a trend to develop more TVF at 2 years (21.2% vs. 12.4%, HR 1.74; 95% CI 0.93-3.25, p = 0.086). Low post-CTO QFR failed to predict 2-year TVF (aHR 1.67; 95% CI 0.85-3.29, p = 0.136), while pre-procedural tvSS was an independent predictor for 2-year TVF (aHR 1.06; 95% CI 1.01-1.13, p = 0.030)., Conclusion: We found a limited prognostic value of immediate physiological assessment using QFR after successful CTO intervention. Pre-procedure morphological characteristics of CTO lesions using tvSS can play a role in predicting long-term adverse events., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Although the use of rotational atherectomy (RA) is off-label in the setting of ST-elevation myocardial infarction (STEMI), it can be the only option in severely calcified culprit lesions to achieve procedural success. We sought to investigate the safety and feasibility of RA during primary percutaneous coronary intervention (PPCI)., Methods: This was a retrospective observational study of patients who underwent RA during PPCI from 12 European centres. The main outcomes were procedural success (defined as successful stent implantation with final thrombolysis in myocardial infarction [TIMI] flow 3 and residual stenosis < 30%) and in-hospital mortality. A comparison of patients presenting with and without shock was performed., Results: In 104 patients with RA during STEMI, the mean age was 72.8 ± 9.1 years, and 35% presented with cardiogenic shock. Bailout RA was performed in 76.9% of cases. Mean burr size was 1.42 ± 0.21 mm. Procedural success was achieved in 86.5% of cases, with no difference between shocked and nonshocked patients (94.4% vs 82.4%; P = 0.13). In-hospital stent thrombosis occurred in 0.96%, perforation in 1.9% and burr entrapment in 2.9% of cases. In spite of equally high procedural success, in-hospital mortality was higher in shocked (50%) compared with nonshocked patients (1.5%; P < 0.0001)., Conclusions: Patients presenting with STEMI requiring RA, represent a high-risk population, frequently presenting with cardiogenic shock. In this analysis of selected patients, RA was performed as a bailout strategy in the majority, and, as such, RA seems to be feasible with a high procedural success rate. In the absence of cardiogenic shock, RA-facilitated PCI seems to be associated with low in-hospital mortality., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: With the established use of crossover stenting technique in bifurcation coronary artery lesions, added clinical benefit of final kissing of the side branch remains debatable. We report a case of a stenosis and thrombus formation of an ostial side branch after crossover stenting. A 38-year-old man was admitted with acute coronary syndrome complicated by acute pulmonary oedema. He was treated with stenting of the left descending artery (LAD) into the left main coronary artery (LMCA) 12 months earlier. Coronary angiography showed a filling defect in the ostial left circumflex coronary artery (LCX). Optical coherence tomography revealed neointimal growth of the LAD stent resulting in narrowing the LCX orifice and a large thrombus behind stent struts. After treatment of the lesion and optimised implantations of drug-eluting stents, the patient was transferred to the intensive care unit and monitored closely. Given his advanced ischaemic cardiomyopathy, the patient is being evaluated for heart transplantation eligibility., Discussion: Stent struts across a bifurcated major side branch after crossover stenting could risk late stenosis and thrombus formation of the side branch. The clinical usefulness of routine imaging-guided kissing techniques even with good angiographic results in these cases should be evaluated., (© 2022. The Author(s).)

The aim of the present work was to investigate the 'fine granular area' (FGA) formation based on artificially generated internal defects in additively manufactured Ti6Al4V specimens in the early stage of fatigue crack growth in the 'very high cycle fatigue' (VHCF) regime. Fatigue tests were performed with constant amplitude at pure tension-compression loading ( R = -1) using an ultrasonic fatigue testing setup. Failed specimens were investigated using optical microscopy, high-resolution 'scanning electron microscopy' (SEM), and 'focused ion beam' (FIB) techniques. Further, the paper introduces alternative proposals to identify the FGA layer beneath the fracture surfaces in terms of the 'cross section polishing' (CSP) technique and metallic grindings with special attention paid to the crack origin, the surrounding microstructure, and the expansion of the nanograin layer beneath the fracture surface. Different existing fracture mechanical approaches were applied to evaluate if an FGA formation is possible. Moreover, the results were discussed in comparison to the experimental findings.

Femoral bone loss due to stress and strain shielding is a common problem in hip resurfacing arthroplasty (HRA), which arises from the different stiffness of implant materials and the adjacent bone. Usually, the implants used in HRA are made of cobalt-chromium alloy (CoCr). As a novel concept, implants may also be made of ceramics, whose stiffness exceeds that of the adjacent bone by a multiple. Therefore, this computational study aimed to evaluate whether poly (ether-ether-ketone) (PEEK) or a hybrid material with a PEEK body and ceramic surface made of alumina toughened zirconia (ATZ) might be more suitable implant alternatives for HRA, as they can avoid stress and strain shielding. A reconstructed model of a human femur with an HRA implant was simulated, whereby the material of the HRA was varied between CoCr, ATZ, zirconia toughened alumina (ZTA), PEEK, and a hybrid PEEK-ATZ material. The implant fixation method also varied (cemented or cementless). The simulated models were compared with an intact model to analyze stress and strain distribution in the femoral head and neck. The strain distribution was evaluated at a total of 30,344 (cemented HRA) and 63,531 (uncemented HRA) nodes in the femoral head and neck region and divided into different strain regions (<400 µm/m: atrophy; 400-3000 μm/m: bone preserving and building; 3000-20,000 μm/m: yielding and >20,000 μm/m fracture). In addition, the mechanical stability of the implants was evaluated. When the material of the HRA implant was simulated as metal or ceramic while evaluating the strains, it was seen that around 22-26% of the analyzed nodes in the femoral head and neck were in an atrophic region, 47-51% were in a preserving or building region, and 27-28% were in a yielding region. In the case of PEEK implant, less than 0.5% of the analyzed nodes were in an atrophic region, 66-69% in a preserving or building region, and 31-34% in a yielding region. The fixation technique also had a small influence. When a hybrid HRA was simulated, the strains at the analyzed nodes depended on the thickness of the ceramic material. In conclusion, the material of the HRA implant was crucial in terms of stress and strain distribution in the adjacent bone. HRA made of PEEK or a hybrid material leads to decisively reduced stress and strain alteration compared to stiffer materials such as CoCr, ATZ, and ZTA. This confirms the potential for reduction in stress and strain shielding in the femoral head with the use of a hybrid material with a PEEK body for HRA., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The present study aims to carry out an experimental, analytical and numerical investigation of the monotonic and fatigue performance of electron beam melted Ti-6Al-4V structures. Therefore, tensile tests, multiple step tests and strain-life tests were performed on machined EBM Ti-6Al-4V solid samples. An elastic-plastic material model in combination with a numerical damage model was examined according to the experimental tensile tests. Analytical models proposed by Ramberg and Osgood, as well as Coffin and Manson were obtained to describe the cyclic stress-strain curves and strain-life curves, respectively. The fracture surfaces of the tested samples and the influence of different build directions were analyzed. A prediction of the static and fatigue material properties is of particular importance, e.g., for the safe application of additively manufactured load-bearing implant structures. Based on the determined analytical and numerical models, the material and product behavior of complex electron beam melted structures under cyclic loading and fatigue life determination can be investigated in the early stages of the product development process.