External valve

BACKGROUND: The indication for a mitral valve intervention is an important patient-relevant parameter for the assessment of process quality and the comparison of healthcare providers. In this article, we describe the development of a corresponding quality indicator for an external hospital quality assurance (QA) procedure in Germany. METHODS: An expert panel was set up by the aQua Institute to assist with the development of a QA procedure for mitral valve interventions and the associated quality indicators...

Proximity orbital and spin-orbit effects of bilayer graphene on monolayer WSe_{2} are investigated from first principles. We find that the built-in electric field induces an orbital band gap of about 10 meV in bilayer graphene. Remarkably, the proximity spin-orbit splitting for holes is 2 orders of magnitude-the spin-orbit splitting of the valence band at K is about 2 meV-more than for electrons. Effectively, holes experience spin valley locking due to the strong proximity of the lower graphene layer to WSe_{2}...

For highly-integrated microfluidic systems, an actuation system is necessary to control the flow; however, the bulk of actuation devices including pumps or valves has impeded the broad application of integrated microfluidic systems. Here, we suggest a microfluidic process control method based on built-in microfluidic circuits. The circuit is composed of a fluidic timer circuit and a pneumatic logic circuit. The fluidic timer circuit is a serial connection of modularized timer units, which sequentially pass high pressure to the pneumatic logic circuit...

Maternal autoantibodies to Ro/SSA are often linked to congenital heart block and rarely associated with structural defects. We describe the case of a fetus with anti-Ro-mediated second-degree block at 19 weeks, which progressed to a complete block, fibroelastosis, atrioventricular valve insufficiency, and semilunar valve stenosis/insufficiency at 20, 22, 24, and 26 weeks, respectively, although the fetus received transplacental anti-arrhythmic drugs. The 2150-g fetus was vaginally delivered at 35 weeks. An external pacemaker was inserted immediately after birth and replaced with permanent pacemaker at the age of 3 months...

Aims: There are limited data on coronary obstruction following transcatheter valve-in-valve (ViV) implantation inside failed aortic bioprostheses. The objectives of this study were to determine the incidence, predictors, and clinical outcomes of coronary obstruction in transcatheter ViV procedures. Methods and results: A total of 1612 aortic procedures from the Valve-in-Valve International Data (VIVID) Registry were evaluated. Data were subject to centralized blinded corelab computed tomography (CT) analysis in a subset of patients...

The nasolabial turnover flap was first described by Spear et al in 1987 for the coverage of full thickness defects of the lateral ala. It offered a single-stage repair that recreated the internal nasal lining, the external nasal valve, and the rounded contour of the ala without requiring a cartilage graft. A frequently encountered problem with the execution of Spear's original design is elevation of the ipsilateral commissure of the adjacent lip due to its broad proximal pedicle. Here, the authors describe a fusiform-type design with a proximal, superiorly tapered apex that relies on anteriorly coursing perforators from the underlying angular artery...

The generation of microparticles with non-spherical morphologies has generated extensive interest because of their enhanced physical properties that can increase their performance in a wide variety of clinical and industrial applications. A flow lithographic technique based on stop flow lithography (SFL) recently showed the ability to fabricate particles with 3D shapes via manipulation of the UV intensity profile in a simple 2D microfluidic channel. Here, we further explore this flow lithographic method, called non-uniform flow lithography (NUFL), to investigate the 3D-shape tuning ability for the generation of 3D magnetic microparticles and their potential applications...

The Ross procedure is an alternative option for young and middle-aged patients needing aortic valve replacement. We present an interesting case where the patient had a preexisting aortic homograft that was implanted because of previous infective endocarditis with aortic root abscess. The patient presented with biological degeneration of the homograft with resultant severe stenosis as well as insufficiency. We performed a redo root surgery to replace the homograft with the Ross procedure by using the autograft inclusion into a vascular graft technique...

Percutaneous transfemoral transcatheter aortic valve implantation (TF-TAVI) is generally an acceptable procedure but may be associated with vascular complications at femoral access sites, particularly in obese patients. This report aimed to describe a case of successful performance of our "double crossover technique" in an obese patient undergoing TF-TAVI with a percutaneous transfemoral intra-aortic balloon pump (TF-IABP). A 75-year-old man presented with heart failure due to a left ventricular ejection fraction of 35% and low-flow, low-gradient severe aortic stenosis...

Many tissues exhibit subatmospheric interstitial pressures under normal physiologic conditions. The mechanisms by which the lymphatic system extracts fluid from these tissues against the overall pressure gradient are unknown. We address this important physiologic issue by combining experimental measurements of contractile function and pressure generation with a previously validated mathematical model. We provide definitive evidence for the existence of 'suction pressure' in collecting lymphatic vessels, which manifests as a transient drop in pressure downstream of the inlet valve following contraction...

We describe the case of a 10-year-old male with a history of repaired Tetralogy of Fallot and known intramural right coronary artery (RCA) who presented for bioprosthetic pulmonary valve replacement. The operation was complicated by postoperative ventricular fibrillation arrest. Selective coronary angiography revealed external compression of the mid-RCA by a mediastinal chest tube that improved immediately upon removal of the tube. Ultimately, the patient required additional unroofing of the intramural coronary for full recovery...

BACKGROUND: Atrial tachycardias (ATs) are a significant source of morbidity in adults with congenital heart disease (CHD). This study evaluates the incidence and clinical predictors of AT in a cohort of patients with CHD. METHODS AND RESULTS: We included 3311 adults (median age at entry 22.6 years, 50.6% males) with CHD (49% simple, 39% moderate, and 12% complex) prospectively followed up in a tertiary center for 37 607 person-years. Predictors of AT were identified by multivariable Cox regression analysis accounting for left truncation...

Left atrial appendage (LAA) closure prevents thromboembolic risk and avoids lifelong anticoagulation due to atrial fibrillation (AF). Nowadays, AtriClip, a modern epicardial device approved in June 2010, allows external and safe closure of LAA in patients undergoing cardiac surgery during other open-chest cardiac surgical procedures. Such a surgical approach and its epicardial deployment differentiates LAA closure with AtriClip from percutaneous closure techniques such as Watchman (Boston Scientific, Marlborough, MA, USA), Lariat (SentreHEART Inc...

PURPOSE: Hemodynamic performance of aortic valve bioprostheses is essential for reliable function and durability. So far, the supra-annularly implanted stentless Sorin Freedom Solo (SFS) demonstrated unsurpassed hemodynamic properties. As contemporary stented and externally mounted pericardial bioprostheses, like the Labcor Dokimos Plus (LDP), also improve hemodynamic performance, these types of valves were compared in this study. METHODS: A total of 218 patients, who underwent aortic valve replacement with the LDP or the SFS, were matched retrospectively 1:1 on variables affecting hemodynamic measurements: implanted valve size, age, sex, and body surface area (BSA)...

Here, we present a multifunctional microfluidic device whose integrative design enables to combine cell culture studies and quantitative single cell biomolecule analysis. The platform consists of 32 analysis units providing two key features; first, a micrometer-sized trap for hydrodynamic capture of a single Saccharomyces cerevisiae (S. cerevisiae) yeast cell; second, a convenient double-valve configuration surrounding the trap. Actuating of the outer valve with integrated opening results in a partial isolation in a volume of 11...

BACKGROUND: Because nasal function and shape are so closely intertwined, quantitative assessments can better define their relationship and how they are affected by septorhinoplasty. OBJECTIVE: The aim of this prospective study was to perform an analysis of the nasal airflow resistances and a three-dimensional (3D) evaluation of the soft-tissue changes after closed septorhinoplasty. METHODS: Before surgery (T0) and 6 months after closed septorhinoplasty (T1), 30 patients underwent symptoms evaluation by means of the Italian version of the Nasal Obstruction Symptom Evaluation scale, endoscopic fiberoptic nasal examination, and visual analog scale for subjective assessment of nasal obstruction...

The principle of control signal amplification is found in all actuation systems, from engineered devices through to the operation of biological muscles. However, current engineering approaches require the use of hard and bulky external switches or valves, incompatible with both the properties of emerging soft artificial muscle technology and those of the bioinspired robotic systems they enable. To address this deficiency a biomimetic molecular-level approach is developed that employs light, with its excellent spatial and temporal control properties, to actuate soft, pH-responsive hydrogel artificial muscles...

BACKGROUND: Urethrocutaneous (UC) fistulae are common complications after hypospadias surgery and they have been a serious problem for surgeons since the repair was first attempted. We present the results of our multicentre retrospective study for repairing UC fistulae using the Patio ("preserve the tract and turn it inside out") repair described by Malone. MATERIALS AND METHODS: A total of 16 boys (Eschweiler 2, Lingen 4, Reading 10) at the ages of 1-10 years were treated for UC fistulae...

Introduction Ventilation with a bag valve mask (BVM) is a challenging but critical skill for airway management in the prehospital setting. Hypothesis Tidal volumes received during single rescuer ventilation with a modified BVM with supplemental external handle will be higher than those delivered using a standard BVM among health care volunteers in a manikin model. METHODS: This study was a randomized crossover trial of adult health care providers performing ventilation on a manikin. Investigators randomized participants to perform single rescuer ventilation, first using either a BVM modified by addition of a supplemental external handle or a standard unmodified BVM (Spur II BVM device; Ambu; Ballerup, Denmark)...

Chemomechanical polymers that change their shape or volume on stimulation by multiple external chemical signals, particularly on the basis of selective molecular recognition, are discussed. Several examples illustrate how such materials, usually in the form of hydrogels, can be used for the design of chemically triggered valves or artificial muscles and applied, for example, in self-healing materials or drug delivery. The most attractive feature of such materials is that they can combine sensor and actuator within single units, from nano- to macrosize...