Background: Transcatheter aortic valve replacement (TAVR)-in-TAVR within index supra-annular transcatheter heart valves (THVs) and high-risk anatomy can compromise coronary perfusion and re-access.
Case Summary: An 80-year-old male presented with acute heart failure caused by degeneration of an Evolut R THV, leading to severe aortic regurgitation. Aortic computed tomography imaging revealed a high-risk anatomy characterized by the index THV's commissural plane being placed above the coronary ostia and a valve-to-aorta distance of less than 2 mm, resulting not eligible for redo-TAVR according to recent literature.
Background: Transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve (BAV) disease is still burdened by a non-negligible rate of stroke and permanent pacemaker implantation (PPI). These suboptimal results, possibly related to the unique BAV anatomy, might suggest the use of a different sizing method in this setting. The aim of our study is to evaluate whether the application of the supra-annular LIRA method might improve clinical outcomes in this population.
View Article and Find Full Text PDFThe two surgical options for mitral valve regurgitation are replacement and repair, with annuloplasty being the cornerstone of correction. In cases of repair failure, especially in high surgical risk patients, transcatheter mitral valve-in-ring (MViR) procedures represent emerging and challenging options. Among the several complications linked to this treatment, this paper delves into the role that native mitral leaflets may play in precipitating acute bioprosthesis dysfunction in the MViR procedure.
View Article and Find Full Text PDFDue to their remarkable intrinsic physical properties, carbon nanotubes (CNTs) can enhance mechanical properties and confer electrical and thermal conductivity to polymers currently being investigated for use in advanced applications based on thermal management. An epoxy resin filled with varying concentrations of CNTs (up to 3 wt%) was produced and experimentally characterized. The electrical percolation curve identified the following two critical filler concentrations: 0.
View Article and Find Full Text PDFValve-in-valve transcatheter aortic valve implantation (ViV TAVI) is rapidly arising as a safe and effective alternative to redo-surgery in the treatment of bioprostheses deterioration. While scientific community is currently focusing its attention on the most common limitations related to this procedure, such as the risk of coronary obstruction and patient-prosthesis mismatch, data regarding the first step of a ViV TAVI, the crossing of a degenerated bioprosthesis, are still lacking. The aim of this review is to analyze the available information about bioprosthesis crossing, to show the inherent challenges encountered by interventional cardiologists during valve crossing and to describe the current strategies to perform a correct crossing.
View Article and Find Full Text PDFObjectives: To present the results of a survey on the assessment of treatment response with imaging in oncologic patient, in routine clinical practice. The survey was promoted by the European Society of Oncologic Imaging to gather information for the development of reporting models and recommendations.
Methods: The survey was launched on the European Society of Oncologic Imaging website and was available for 3 weeks.
Materials (Basel)
September 2023
Although on the one hand polymers are arousing increasing interest due to their remarkable properties in terms of lightness, cost-effectiveness, easy processing, and mechanical resistance, on the other hand, they still present several restrictions in practical applications [...
View Article and Find Full Text PDFCatheter Cardiovasc Interv
September 2023
The current state of the art on material science emphasizes recent research efforts aimed at designing novel materials characterized by low-density and advanced properties. The present article reports the experimental, theoretical and simulation results on the thermal behavior of 3D printed discs. Filaments of pure poly (lactic acid) PLA and filled with 6 wt% of graphene nanoplatelets (GNPs) are used as feedstocks.
View Article and Find Full Text PDFBackground: New permanent pacemaker implantation (new-PPI) remains a compelling issue after Transcatheter Aortic Valve Replacement (TAVR). Previous studies reported the relationship between a short MS length and the new-PPI post-TAVR with a self-expanding THV. However, this relationship has not been investigated in different currently available THV.
View Article and Find Full Text PDFRecent evidence has shown that transcatheter heart valve (THV) anchoring in bicuspid aortic valve (BAV) patients occurs at the level of the raphe, known as the LIRA (Level of Implantation at the RAphe) plane. Our previous work in a cohort of 20 patients has shown that the delineation of the perimeter and device sizing at this level is associated with optimal procedural outcome. The goals of this study were to confirm the feasibility of this method, evaluate 30-day outcomes of LIRA sizing in a larger cohort of patients, assess interobserver variation and reproducibility of this sizing methodology, and analyse the interaction of LIRA-sized prostheses with the surrounding anatomy.
View Article and Find Full Text PDFOverheating effect is a crucial issue in different fields. Thermally conductive polymer-based heat sinks, with lightweight and moldability features as well as high-performance and reliability, are promising candidates in solving such inconvenience. The present work deals with the experimental evaluation of the temperature effect on the thermophysical properties of nanocomposites made with polylactic acid (PLA) reinforced with two different weight percentages (3 and 6 wt%) of graphene nanoplatelets (GNPs).
View Article and Find Full Text PDFTwo stochastic models are proposed to describe the evolution of the COVID-19 pandemic. In the first model the population is partitioned into four compartments: susceptible S, infected I, removed R and dead people D. In order to have a cross validation, a deterministic version of such a model is also devised which is represented by a system of ordinary differential equations with delays.
View Article and Find Full Text PDFThe definition of temperature in non-equilibrium situations is among the most controversial questions in thermodynamics and statistical physics. In this paper, by considering two numerical experiments simulating charge and phonon transport in graphene, two different definitions of local lattice temperature are investigated: one based on the properties of the phonon-phonon collision operator, and the other based on energy Lagrange multipliers. The results indicate that the first one can be interpreted as a measure of how fast the system is trying to approach the local equilibrium, while the second one as the local equilibrium lattice temperature.
View Article and Find Full Text PDFMany research efforts have been directed towards enhancing the thermal properties of polymers, since they are classically regarded as thermal insulators. To this end, the present study focuses on the thermal investigation of poly(lactic acid) (PLA) filled with two types of carbon nanotubes (trade names: TNIMH4 and N7000), two type of graphene nanoplatelets (trade names: TNIGNP and TNGNP), or their appropriate combination. A significant increase in the thermal conductivity by 254% with respect to that of unfilled polymer was achieved in the best case by using 9 wt% TNIGNP, resulting from its favorable arrangement and the lower thermal boundary resistance between the two phases, matrix and filler.
View Article and Find Full Text PDFIntroduction: Based on recent data, the indication for transcatheter aortic valve implantation (TAVI) is expanding to individuals at lower surgical risk, who are generally younger than subjects historically treated for severe aortic stenosis. Indeed, younger patients have traditionally been under-represented in current TAVI literature. The aim of the present study is to report about clinical features, procedural outcomes and mid-term outcomes of patients younger than 70 who underwent TAVI in a single high-volume center.
View Article and Find Full Text PDFAortic valve regurgitation is a not negligible complication of prolonged support with continuous-flow left ventricular assist device (LVAD) and is associated with recurrence of heart failure and reduced survival. Transcatheter aortic valve implantation has been described as a feasible option in this setting, usually with self-expanding prosthesis. Giving the absence of valvular calcification, a proper prosthesis oversizing should be guaranteed in order to achieve sufficient sealing and avoid prosthesis migration or paravalvular leak.
View Article and Find Full Text PDFSutureless aortic bioprostheses were introduced more than ten years ago, with the aim of decreasing cross-clamp time and thus becoming the first choice in older patients for many surgeons. However, published data are limited to a 5-year follow-up, and some cases of deterioration have already been described. High-risk patients who once have benefitted from a fast sutureless aortic replacement and now are experiencing a prosthesis dysfunction, could take advantage of a percutaneous Valve-in-Sutureless technique.
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