Sutureless and rapid deployment valves: implantation technique from A to Z-the INTUITY Elite valve

In the last two decades, sutureless (Perceval, Livanova PLC, London, UK) and rapid deployment (INTUITY Elite, Edwards Lifesciences, Irvine, CA, USA) valves were introduced to the market as an innovative alternative to traditional valves for patients needing aortic valve replacement (AVR). These devices have been used and studied extensively across these fifteen years, and have proven to be a valid alternative treatment option compared to sutured biological valves, particularly helpful in minimally invasive cardiac surgery, and an almost curative treatment to patients with intermediate to high surgical risk, filling the gap between transcatheter and traditional AVR. However, both sutureless and rapid deployment valves require special steps for implantation, and also a learning curve. Proper specific training to all surgical team members is required as mandatory by the manufacturers. The aim of this review article is to provide cardiac surgeons with a thorough guide on the implantation technique from A to Z, for each of these two prosthetic devices. In this second part of our review article, we will focus on the INTUITY Elite valve

Sutureless and rapid deployment valves: Implantation technique from A to Z-the perceval valve

In the last two decades, sutureless (Perceval, Livallova PLC, London, UK) and rapid deployment valves (RD) (Intuity, Edwards Lifesciences, Irvine, CA, USA) were introduced to the market as an innovative alternative to traditional valves for patients requiring an aortic valve replacement (AVR). These devices have been studied extensively and in use across the last fifteen years. They have proven to not only demonstrate comparable results with conventional sutured biological valves-particularly helpful in minimally invasive cardiac surgery-but also provide an almost curative treatment to patients with intermediate-to-high surgical risk, filling the gap between transcatheter aortic valve implantation (TAVI) and traditional AVR. However, both sutureless and RD valves require special steps for implantation, resulting in a learning curve. Specific training for all surgical team members is mandatory, as recommended by the manufacturers. The aim of this review article is therefore to provide cardiac surgeons with a thorough guide on the implantation technique for each of these two prosthetic devices, from A to Z. In this first article, we will start by focusing on Perceval

Minimally invasive aortic valve surgery

Since their introduction, it has been demonstrated that minimally invasive aortic valve replacement (MIAVR) approaches are safe and effective for the treatment of aortic valve diseases. To date, the main advantage of these approaches is represented by the reduced surgical trauma, with a subsequent reduced complication rate and faster recovery. This makes such approaches an appealing choice also for frail patients [obese, aged, chronic obstructive pulmonary disease (COPD)]. The standardization of the minimally invasive techniques, together with the implementation of preoperative workup and anesthesiological intraand post-operative care, led to an amelioration of surgical results and reduction of surgical times. Moreover, the improvement of surgical technology and the introduction of new devices such as sutureless and rapid deployment (SURD) valves, has helped the achievement of comparable results to traditional surgery. However, transcatheter technologies are nowadays more and more important in the treatment of aortic valve disease, also in low risk patients. For this reason surgeons should put new efforts for further reducing the surgical trauma in the future, even taking inspiration from other disciplines. In this review, we aim to present a review of literature evidences regarding minimally invasive treatment of aortic diseases, also reflecting our personal experience with MIAVR techniques. This review could represent a tool for a well-structured patient assessment and preoperative planning, in order to safely carrying out an MIAVR procedure with satisfactory outcomes

Mitral Valve Repair Techniques With Neochords: When Sizing Matters

Mitral valve (MV) repair procedures have evolved over time and multiple approaches have been proposed also for the repair with neochords implantation. This article compiles the currently available approaches for implanting and sizing neochords, to restore a proper coaptation of the MV leaflets and a good systo-dyastolic movement. The described techniques are aimed at standardizing chordal measurement, in order to reduce variability in chordal length. The placement of annuloplasty ring before chordae implantation should be avoided. Regardless of the technique chosen, it is important that the implanted chordae do not interfere with normal native chordae, to avoid the risk that neochordae may heal together or get damaged. This article aims to give an overview of the most common sizing techniques available

The effect of unbalanced demographic structure on marriage and feritlity patterns in isolated populations: the case of Viking settlements in Greenland.

Can the decline of a small and isolated population occur as a consequence of a random imbalance in the sex ratio at birth and/or in the male/female mortality rates in subsequent age groups? We should stress here the use of the term “random”. Indeed, the imbalance we refer to is what occurs in a small population as the ultimate result of pure chance. This hypothesis (of the imbalance of the sex ratio) was studied in particular by the Italian statistician Corrado Gini (1957), although it had previously been put forward by other authors (Livi 1941, 1944). More specifically, Gini explained the extinction of the medieval settlements in Greenland using this hypothesis.The recent publication of Lynnerup’s book (1998) concerning the demography of these settlements, based on the archaeological evidence of skeletal remains, prompted us to re-evaluate Gini’s treatise. We wanted to give a statistical contribution – using a Bayesian inference – to evaluate Gini’s hypothesis of that extinction. The extinction of the settlements in Greenland is widely regarded as “almost an enigma hinting at some inexplicable and dramatic event veiled by the passage of time” (Lynnerup1998, p. 8).The aim of this paper is therefore to check Gini’s hypothesis from a Bayesian point of view. In this scheme, the prior distribution is the probability of an imbalance in the sex ratio occurring in the history of a small and closed population as a result of random and unfavourable alterations of the sex-ratio at birth and at death. In order to evaluate such a probability, a Monte Carlo technique that uses historical, demographic and biometric constants (Livi Bacci 1998) will be outlined. The posterior probability is then updated in the light of some archaeological data

A combined Pòlya process and mixture distribution approach to rainfall modelling

International audienceA new probabilistic interpretation of at site rainfall sequences is introduced for the development of a stochastic model of rain. The model, is divided into two sub models; the first one describing the total number of rainfall spells within a window of time is described by a Pòlya process in order to reproduce better the variable probability of occurrence of rainfall during storm events (due to the presence of different numbers of rainfall cells); the second sub model, conditional on the first one, describes the total quantity of rainfall in the time window, given a number of rainfall spells. The probabilistic rainfall model, which has shown interesting properties in reproducing the probability distribution of observed data at time scales ranging from one hour to twenty-four hours, may be the basis for a number of applications which include the development of a conditional stochastic generator of rain, within the frame of real-time flood forecasting, and the derivation of a probabilistic distribution of rainfall extremes at the various time scales

Space-Air-Ground Integrated 6G Wireless Communication Networks: A Review of Antenna Technologies and Application Scenarios

A review of technological solutions and advances in the framework of a Vertical Heterogeneous Network (VHetNet) integrating satellite, airborne and terrestrial networks is presented. The disruptive features and challenges offered by a fruitful cooperation among these segments within a ubiquitous and seamless wireless connectivity are described. The available technologies and the key research directions for achieving global wireless coverage by considering all these layers are thoroughly discussed. Emphasis is placed on the available antenna systems in satellite, airborne and ground layers by highlighting strengths and weakness and by providing some interesting trends in research. A summary of the most suitable applicative scenarios for future 6G wireless communications are finally illustrated