Phase Engineering via Aluminum Doping Enhances the Electrochemical Stability of Lithium-Rich Cobalt-Free Layered Oxides for Lithium-Ion Batteries.

Lithium-rich, cobalt-free oxides are promising potential positive electrode materials for lithium-ion batteries because of their high energy density, lower cost, and reduced environmental and ethical concerns. However, their commercial breakthrough is hindered because of their subpar electrochemical stability. This work studies the effect of aluminum doping on Li1.26Ni0.15Mn0.61O2 as a lithium-rich, cobalt-free layered oxide. Al doping suppresses voltage fade and improves the capacity retention from 46% for Li1.26Ni0.15Mn0.61O2 to 67% for Li1.26Ni0.15Mn0.56Al0.05O2 after 250 cycles at 0.2 C. The undoped material has a monoclinic Li2MnO3-type structure with spinel on the particle edges. In contrast, Al-doped materials (Li1.26Ni0.15Mn0.61-xAlxO2) consist of a more stable rhombohedral phase at the particle edges, with a monoclinic phase core. For this core-shell structure, the formation of Mn3+ is suppressed along with the material's decomposition to a disordered spinel, and the amount of the rhombohedral phase content increases during galvanostatic cycling. Whereas previous studies generally provided qualitative insight into the degradation mechanisms during electrochemical cycling, this work provides quantitative information on the stabilizing effect of the rhombohedral shell in the doped sample. As such, this study provides fundamental insight into the mechanisms through which Al doping increases the electrochemical stability of lithium-rich cobalt-free layered oxides.

Long-term outcome after right ventricle to pulmonary artery conduit surgery and reintervention.

BACKGROUND: Reconstruction of the right ventricular outflow tract with a conduit is an established surgical procedure in congenital heart disease and reinterventions are common. OBJECTIVE: An increasing number of patients have a conduit, but there are few population-based studies of long-term outcomes after conduit surgery, reoperations, and transcatheter pulmonary valve replacement. METHODS: In April 2015, all adult patients with a conduit were identified in the Swedish National Registry for Congenital Heart Disease (SWEDCON). Data on patients who died before age of 16 years are not included in the registry and thus not included in the study. RESULTS: We found 574 patients with a mean age 36.1 years. The largest proportion had tetralogy of Fallot (45%). In total there were 762 operations and 50 transcatheter pulmonary valve replacements. Mean age at first conduit operation was 20.2 years. Long-term survival up to 48 years including perioperative mortality (<1%) was 93% at 20 years. The most common cause of death was cardiac-related. Higher age at first conduit operation was associated with increased mortality risk. Reintervention-free survival was 77% and 54% at 10 and 20 years, respectively. Conduit reinterventions were common. Ten-year reintervention-free survival after first conduit reintervention (n = 176) was significantly lower than after first conduit operation (70% vs 77% p = .04). Higher age at first conduit operation was associated with a reduced risk of reintervention, whereas male sex and complex malformations were associated with increased risk of reintervention. CONCLUSIONS: The mortality of repeated conduit reinterventions is low. The need for reintervention of conduits is considerable, and reintervention-free survival after the first conduit reintervention is poorer than after first conduit implantation. The findings in this study only applies for patients reaching 16 years of age.

RV to PA conduits: impact of transcatheter pulmonary valve replacement in adults - a national register study.

OBJECTIVE: The use of a conduit is an established surgical method for reconstruction of the right ventricular outflow tract in congenital heart disease; however, its limited durability makes reintervention almost inevitable. We studied the trends in new implantation, reoperation, and transcatheter pulmonary valve replacement (TPVR) from a Swedish national perspective. DESIGN AND RESULTS: The Swedish registry of congenital heart disease (SWEDCON) was used to collect data. From 2000-2014, there was an increase in adult patients with conduits from 122 to 536. There were 60 surgical conduit replacements, 40 TPVRs and 176 new conduit implantations in the study period. Perioperative mortality was <1%. The yearly number of new implantations and reoperations both doubled over the study period. Patients with new implantations were older (mean age, 36 years) compared with the reoperation and TPVR groups (mean age, 26 years) with the majority of patients having tetralogy of Fallot. The majority of conduit reinterventions were surgical also after the introduction of TPVR in 2007, with no significant difference regarding diagnosis, gender, age, or previous number or longevity of conduits. CONCLUSION: The number of adults with conduits increased steadily with most conduit-related operations being new implantations in patients with tetralogy of Fallot. Surgical conduit replacements increased significantly and represented the majority of conduit reinterventions after the introduction of TPVR, indicating that TPVR is not used for the majority of patients with conduit failure. Diagnosis, gender, age, or previous number or longevity of conduits had no impact on choosing surgical replacement vs. TPVR.

Surgical Treatment for Infective Endocarditis: A Single-Centre Experience.

Background A considerable proportion of patients with acute infective endocarditis require surgical treatment. The aim of this study was to collate our short- and medium-term results of surgical treatment of infective endocarditis and to compare the results in native and prosthetic endocarditis. Method Total 254 operations for infective endocarditis from January 2008 to May 2015 were included in this retrospective study. There were 182 operations for native valve endocarditis and 72 for prosthetic valve endocarditis. Patient characteristics, operative details, complications, and mortality were registered. Results The endocarditis was left sided in 247 operations (146 aortic, 78 mitral, and 23 double-valve) and right-sided in 7 (5 tricuspid and 2 pulmonary). Twenty-two patients (8.7%) died within 30 days (7.7% with native valve endocarditis and 11.1% with prosthetic valve endocarditis, p = 0.31). Severe perioperative complications occurred in 99 of 254 operations (39%). Overall cumulative survival at 1 and 5 years was 86% and 75%, respectively, and it was not significantly different for native and prosthetic endocarditis (p = 0.31). Eighteen patients (8%) had one (n = 16) or two (n = 2) recurrent episodes of endocarditis requiring surgery. Conclusion Surgery for infective endocarditis is still associated with a high early mortality rate and a considerable complication rate. Long-term outcome is acceptable. In our study population, morbidity and mortality were not significantly different in native and prosthetic endocarditis.

Endovascular Closure of Chronic Dissection Entries in the Aortic Arch Using the Amplatzer Vascular Plug II as a Sealing Button.

PURPOSE: To present a new endovascular technique to avoid open surgical arch reconstruction in selected patients with aneurysmal dilatation due to small chronic dissection entries in the aortic arch. TECHNIQUE: The true and the false lumen of the aortic arch are catheterized from the femoral arteries. An Amplatzer Vascular Plug II (AVP II) is advanced through the proximal entry from the false lumen side and deployed as a sealing button in the entry hole, with 1 disc in the true lumen and the remaining 2 discs in the false lumen. This technique was used in 4 patients with chronic dissection involving the aortic arch, three of whom had had previous surgery for acute type A aortic dissection. In 3 patients, the false lumen of the thoracic aorta was successfully obliterated, with thrombosis and aortic diameter reduction during follow-up. In 1 patient, false lumen flow persisted, and he was subsequently treated with a total arch reconstruction and frozen elephant trunk. CONCLUSION: Endovascular closure of small proximal dissection entries in the aortic arch with an AVP II used as a sealing button is feasible and may be an alternative to open surgical arch reconstruction in selected patients with chronic aortic dissection and secondary aneurysm expansion.

Structure Characterization and Properties of K-Containing Copper Hexacyanoferrate.

Copper hexacyanoferrate, Cu(II)[Fe(III)(CN)6]2/3·nH2O, was synthesized, and varied amounts of K(+) ions were inserted via reduction by K2S2O3 (aq). Ideally, the reaction can be written as Cu(II)[Fe(III)(CN)6]2/3·nH2O + 2x/3K(+) + 2x/3e(-) ↔ K2x/3Cu(II)[Fe(II)xFe(III)1-x(CN)6]2/3·nH2O. Infrared, Raman, and Mössbauer spectroscopy studies show that Fe(III) is continuously reduced to Fe(II) with increasing x, accompanied by a decrease of the a-axis of the cubic Fm3̅m unit cell. Elemental analysis of K by inductively coupled plasma shows that the insertion only begins when a significant fraction, ∼20% of the Fe(III), has already been reduced. Thermogravimetric analysis shows a fast exchange of water with ambient atmosphere and a total weight loss of ∼26 wt % upon heating to 180 °C, above which the structure starts to decompose. The crystal structures of Cu(II)[Fe(III)(CN)6]2/3·nH2O and K2/3Cu[Fe(CN)6]2/3·nH2O were refined using synchrotron X-ray powder diffraction data. In both, one-third of the Fe(CN)6 groups are vacant, and the octahedron around Cu(II) is completed by water molecules. In the two structures, difference Fourier maps reveal three additional zeolitic water sites (8c, 32f, and 48g) in the center of the cavities formed by the -Cu-N-C-Fe- framework. The K-containing compound shows an increased electron density at two of these sites (32f and 48g), indicating them to be the preferred positions for the K(+) ions.

Increased aortic wall thickness on CT as a sign of prosthetic valve endocarditis.

Background Increased wall thickness in the aortic root has been suggested as an early sign of prosthetic valve endocarditis (PVE). However, there are no previous studies on the aortic wall thickness after aortic valve replacement (AVR) or in patients with PVE. Purpose To identify a clinically useful cutoff value for aortic wall thickness to detect PVE. Material and Methods Chest computed tomography (CT) studies (n = 303) on patients with a prosthetic aortic valve were retrospectively analyzed. CT studies on patients without PVE (n = 260) were compared with CT studies on patients with definite PVE (n = 43). A receiver operator characteristic (ROC) analysis was performed. Results In non-PVE patients, the wall thickness during the first 3 months postoperatively (n = 70, 4.5 ± 1.7 mm) was increased compared to beyond 3 months postoperatively (n = 190, 3.2 ± 1.0 mm, P < 0.001). Beyond 3 months postoperatively, the wall thickness 95th percentile was 5.0 mm without signs of further decrease with time. The wall thickness in PVE patients was 6.8 ± 3.0 mm (n = 43). Beyond 3 months postoperatively, ROC analysis yielded an area under the curve of 0.89 (95% CI, 0.81-0.96). With a cutoff value of 5 mm the sensitivity was 67%, specificity 95%, positive likelihood ratio 14.1, and negative likelihood ratio 0.35 of increased wall thickness in detecting PVE. Conclusion In the early postoperative period after AVR, the aortic wall thickness is increased compared to the late postoperative period. After 3 months, the wall thickness has decreased and stabilized. Increased wall thickness (>5 mm) beyond 3 months postoperatively significantly increases the likelihood of PVE.

Lithium and calcium carbides with polymeric carbon structures.

We studied the binary carbide systems Li2C2 and CaC2 at high pressure using an evolutionary and ab initio random structure search methodology for crystal structure prediction. At ambient pressure Li2C2 and CaC2 represent salt-like acetylides consisting of C2(2-) dumbbell anions. The systems develop into semimetals (P3m1-Li2C2) and metals (Cmcm-Li2C2, Cmcm-CaC2, and Immm-CaC2) with polymeric anions (chains, layers, strands) at moderate pressures (below 20 GPa). Cmcm-CaC2 is energetically closely competing with the ground state structure. Polyanionic forms of carbon stabilized by electrostatic interactions with surrounding cations add a new feature to carbon chemistry. Semimetallic P3m1-Li2C2 displays an electronic structure close to that of graphene. The π* band, however, is hybridized with Li-sp states and changed into a bonding valence band. Metallic forms are predicted to be superconductors. Calculated critical temperatures may exceed 10 K for equilibrium volume structures.

ECG-gated computed tomography: a new role for patients with suspected aortic prosthetic valve endocarditis.

OBJECTIVES: The aim of this prospective study was to investigate the agreement in findings between ECG-gated CT and transoesophageal echocardiography (TEE) in patients with aortic prosthetic valve endocarditis (PVE). METHODS: Twenty-seven consecutive patients with PVE underwent 64-slice ECG-gated CT and TEE and the results were compared. Imaging was compared with surgical findings (surgery was performed in 16 patients). RESULTS: TEE suggested the presence of PVE in all patients [thickened aortic wall (n = 17), vegetation (n = 13), abscess (n = 16), valvular dehiscence (n = 10)]. ECG-gated CT was positive in 25 patients (93 %) [thickened aortic wall (n = 19), vegetation (n = 7), abscess (n = 18), valvular dehiscence (n = 7)]. The strength of agreement [kappa (95 % CI)] between ECG-gated CT and TEE was very good for thickened wall [0.83 (0.62-1.0)], good for abscess [0.68 (0.40-0.97)] and dehiscence [0.75 (0.48-1.0)], and moderate for vegetation [0.55 (0.26-0.88)]. The agreement was good between surgical findings (abscess, vegetation and dehiscence) and imaging for ECG-gated CT [0.66 (0.49-0.87)] and TEE [0.79 (0.62-0.96)] and very good for the combination of ECG-gated CT and TEE [0.88 (0.74-1.0)]. CONCLUSION: Our results indicate that ECG-gated CT has comparable diagnostic performance to TEE and may be a valuable complement in the preoperative evaluation of patients with aortic PVE.

Sr2GaScO5, Sr10Ga6Sc4O25, and SrGa0.75Sc0.25O2.5: a play in the octahedra to tetrahedra ratio in oxygen-deficient perovskites.

Three different perovskite-related phases were isolated in the SrGa(1-x)Sc(x)O(2.5) system: Sr(2)GaScO(5), Sr(10)Ga(6)Sc(4)O(25), and SrGa(0.75)Sc(0.25)O(2.5). Sr(2)GaScO(5) (x = 0.5) crystallizes in a brownmillerite-type structure [space group (S.G.) Icmm, a = 5.91048(5) Å, b = 15.1594(1) Å, and c = 5.70926(4) Å] with complete ordering of Sc(3+) and Ga(3+) over octahedral and tetrahedral positions, respectively. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) (x = 0.4) was determined by the Monte Carlo method and refined using a combination of X-ray, neutron, and electron diffraction data [S.G. I4(1)/a, a = 17.517(1) Å, c = 32.830(3) Å]. It represents a novel type of ordering of the B cations and oxygen vacancies in perovskites. The crystal structure of Sr(10)Ga(6)Sc(4)O(25) can be described as a stacking of eight perovskite layers along the c axis ...[-(Sc/Ga)O(1.6)-SrO(0.8)-(Sc/Ga)O(1.8)-SrO(0.8)-](2).... Similar to Sr(2)GaScO(5), this structure features a complete ordering of the Sc(3+) and Ga(3+) cations over octahedral and tetrahedral positions, respectively, within each layer. A specific feature of the crystal structure of Sr(10)Ga(6)Sc(4)O(25) is that one-third of the tetrahedra have one vertex not connected with other Sc/Ga cations. Further partial replacement of Sc(3+) by Ga(3+) leads to the formation of the cubic perovskite phase SrGa(0.75)Sc(0.25)O(2.5) (x = 0.25) with a = 3.9817(4) Å. This compound incorporates water molecules in the structure forming SrGa(0.75)Sc(0.25)O(2.5)·xH(2)O hydrate, which exhibits a proton conductivity of ∼2.0 × 10(-6) S/cm at 673 K.

The relative contribution of prosthetic gradients, systemic arterial pressure, and pulse pressure to the left ventricular pressure in patients with aortic prosthetic valves.

AIMS: aortic valve replacement (AVR) in patients with aortic stenosis reduces the left ventricular (LV) pressure and the LV mass. However, residual LV hypertrophy at follow-up is a common finding with negative prognostic impact. In the present study, we investigate the contribution of the prosthesis (size, type, and gradients) and the load opposed by the arterial system to the mean LV pressure (MLVP). METHODS AND RESULTS: twenty-five patients with a bileaflet mechanical (n = 12, size 19-27) or stented biological (size 21-25) valve were included. After weaning from bypass, continuous Doppler recordings (transoesophageal transducer) and simultaneous LV and aortic pressure measurements were performed (high-fidelity catheters). The mean prosthesis gradients with catheter or Doppler were moderately correlated to MLVP (R(2) = 0.40 and 0.34, P = 0.002 and <0.0001). In a multiple regression model, the relationship between MLVP and prosthesis gradient, mean blood pressure, and pulse pressure was strong for both mechanical and biological valves. Using catheter prosthesis gradients, we could explain 97% of the variability in MLVP and when using Doppler gradients 91%. CONCLUSION: in the present study of patients with aortic prosthetic valves, we demonstrate the importance of the load opposed by the arterial system for the LV pressure. Our findings suggest that the MLVP can be estimated from easily obtainable Doppler data and blood pressure measurements. In analysing predictors of LV mass regression, morbidity, and mortality following AVR, the equations might be of interest.

Macroscopic rods from assembled colloidal particles of hydrothermally carbonized glucose and their use as templates for silicon carbide and tricopper silicide.

Self-aggregated colloids can be used for the preparation of materials, and we studied long rod-like aggregates formed on the evaporation of water from dispersed particles of colloidal hydrochar. The monodispersed hydrochar particles (100-200 nm) were synthesized by the hydrothermal carbonization of glucose and purified through dialysis. During the synthesis they formed colloidal dispersions which were electrostatically stable at intermediate to high pH and at low ion strengths. On the evaporation of water, macroscopically large rods formed from the dispersions at intermediate pH conditions. The rods formed at the solid-water interface orthogonally oriented with respect to the drying direction. Pyrolysis rendered the rods highly porous without qualitatively affecting their shape. A Cu-Si alloy was reactively infiltrated into the in-situ pyrolyzed hydrochars and composites of tricopper silicide (Cu3Si)-silicon carbide (SiC)/carbon formed. During this process, the Si atoms reacted with the C atoms, which in turned caused the alloy to wet and further react with the carbon. The shape of the underlying carbon template was maintained during the reactions, and the formed composite preparation was subsequently calcined into a Cu3Si-SiC-based replica of the rod-like assemblies of carbon-based colloidal particles. Transmission and scanning electron microscopy, and X-ray diffraction were used to study the shape, composition, and structure of the formed solids. Further studies of materials prepared with reactive infiltration of alloys into self-aggregated and carbon-based solids can be justified from a perspective of colloidal science, as well as the explorative use of hydrochar prepared from real biomass, exploration of the compositional space in relation to the reactive infiltration, and applications of the materials in catalysis.

Silicoaluminophosphate (SAPO)-Templated Activated Carbons.

Microporous activated carbon was prepared by depositing and pyrolyzing propylene within the microporous voids of SAPO-37 and subsequently removing the template by a treatment with HCl and NaOH. The carbon had a high surface area and large micropore and ultramicropore volumes. The yield, crystallinity, morphology, and adsorption properties compared well with those of a structurally related zeolite-Y-templated carbon. No HF was needed to remove the SAPO-37 template in contrast to the zeolite Y template, which could be of industrial importance.

Influence of the Presence of Different Alkali Cations and the Amount of Fe(CN)6 Vacancies on CO2 Adsorption on Copper Hexacyanoferrates.

The CO2 adsorption on various Prussian blue analogue hexacyanoferrates was evaluated by thermogravimetric analysis. Compositions of prepared phases were verified by energy-dispersive X-ray spectroscopy, infra-red spectroscopy and powder X-ray diffraction. The influence of different alkali cations in the cubic Fm3m structures was investigated for nominal compositions A2/3Cu[Fe(CN)6]2/3 with A = vacant, Li, Na, K, Rb, Cs. The Rb and Cs compounds show the highest CO2 adsorption per unit cell, 3.3 molecules of CO2 at 20 C and 1 bar, while in terms of mmol/g the Na compound exhibits the highest adsorption capability, 3.8 mmol/g at 20 C and 1 bar. The fastest adsorption/desorption is exhibited by the A-cation free compound and the Li compound. The influence of the amount of Fe(CN)6 vacancies were assessed by determining the CO2 adsorption capabilities of Cu[Fe(CN)6]1/2 (Fm3m symmetry, nominally 50% vacancies), KCu[Fe(CN)6]3/4 (Fm3m symmetry, nominally 25% vacancies), and CsCu[Fe(CN)6] (I-4m2 symmetry, nominally 0% vacancies). Higher adsorption was, as expected, shown on compounds with higher vacancy concentrations.

Surgical treatment for isolated mitral valve endocarditis: a 16-year single-centre experience.

OBJECTIVES: Despite progress in management, mitral valve endocarditis (MVE) is still a life-threatening disease. We report our experience in surgical treatment of infective isolated MVE. METHODS: A total of 140 operations in 128 patients for MVE performed between January 2000 and December 2015 were included in a retrospective study. There were 109 (78%) operations for native and 31 (22%) operations for prosthetic valve endocarditis. Preoperative and postoperative characteristics and mortality of patients were registered. Cox regression identified factors associated with mortality. Mean follow-up period was 68 months (range 1-168 months) and 100% complete. RESULTS: There were 13 deaths within 30 days after the 140 operations (9%). Severe perioperative complications occurred in 59 (42%) operations. Overall cumulative survival was 73% ± 4 at 5 years and 62 ± 5% at 10 years after the first operation. Age, diabetes, EuroSCORE II and perivalvular abscess were independent predictors for long-term mortality. Valve repair was performed in 76 (54%) operations and replacement in 64 (46%) operations. Thirty-day mortality for repair was 1%, and 5-year and 10-year cumulative survival was 86 ± 4% and 77 ± 6%, respectively. In the replacement group the 30-day mortality was 19% and cumulative survival at 5 years and 10 years was 55 ± 7% and 41 ± 8%, respectively. Postoperative complications occurred in 21% and 67%, respectively, after operations for repair and replacement. Ten (8%) patients had 12 reoperations for recurrent endocarditis. CONCLUSIONS: MVE requiring surgical treatment is a challenging disease with high hospital mortality after valve replacement. Mitral valve repair can be performed in suitable endocarditis patients with excellent results. Age, diabetes and EuroSCORE were independently associated with mortality in a multivariable model.

SUePDF: a program to obtain quantitative pair distribution functions from electron diffraction data.

SUePDF is a graphical user interface program written in MATLAB to achieve quantitative pair distribution functions (PDFs) from electron diffraction data. The program facilitates structural studies of amorphous materials and small nanoparticles using electron diffraction data from transmission electron microscopes. It is based on the physics of electron scattering as well as the total scattering methodology. A method of background modeling is introduced to treat the intensity tail of the direct beam, inelastic scattering and incoherent multiple scattering. Kinematical electron scattering intensity is scaled using the electron scattering factors. The PDFs obtained after Fourier transforms are normalized with respect to number density, nanoparticle form factor and the non-negativity of probability density. SUePDF is distributed as free software for academic users.

Impact of Oxygen Deficiency on the Electrochemical Performance of K2 NiF4 -Type (La1-x Srx )2 NiO4-δ Oxygen Electrodes.

Perovskite-related (La1-x Srx )2 NiO4-δ (x=0.5-0.8) phases were explored for possible use as oxygen electrodes in solid electrolyte cells with a main focus on the effect of oxygen deficiency on the electrocatalytic activity. (La1-x Srx )2 NiO4-δ solid solutions were demonstrated to preserve the K2 NiF4 -type tetragonal structure under oxidizing conditions. Acceptor-type substitution by Sr is compensated by the formation of oxygen vacancies and electron holes and progressively increases high-temperature oxygen nonstoichiometry, which reaches as high as δ=0.40 for x=0.8 at 950 °C in air. The electrical conductivity of (La1-x Srx )2 NiO4-δ ceramics at 500-1000 °C and p(O2 )≥10-3  atm is p-type metallic-like. The highest conductivity, 300 S cm-1 at 800 °C in air, is observed for x=0.6. The average thermal expansion coefficients, (14.0-15.4)×10-6  K-1 at 25-900 °C in air, are sufficiently low to ensure the thermomechanical compatibility with common solid electrolytes. The polarization resistance of porous (La1-x Srx )2 NiO4-δ electrodes applied on a Ce0.9 Gd0.1 O2-δ solid electrolyte decreases with increasing Sr concentration in correlation with the concentration of oxygen vacancies in the nickelate lattice and the anticipated level of mixed ionic-electronic conduction. However, this is accompanied by increasing reactivity between the cell components and necessitates the microstructural optimization of the electrode materials to reduce the electrode fabrication temperature.

Surgical Treatment of Aortic Prosthetic Valve Endocarditis: A 20-Year Single-Center Experience.

BACKGROUND: Despite progress in diagnostic methods and treatment, aortic prosthetic valve endocarditis (PVE) remains a life-threatening disease. We report the outcome of all operations for aortic PVE performed at our institution over the past 20 years. METHODS: Eighty-seven operations performed in 84 patients between 1993 and 2013 were included in this retrospective study. An aortic homograft was used in 56 (64%) cases, a mechanical prosthesis was used in 20 (23%) cases, and a bioprosthesis was used in 11 (13%) cases. Early and late complications and mortality were compared between the first and second decades of our experience. Predictors of mortality were identified with Cox regression. Mean follow-up was 5.5 years (range 0-17 years). RESULTS: Nine patients (10%) died within 30 days, and severe perioperative complications occurred in 36 patients (41%). Overall cumulative survival was 80% at 5 years and 65% at 10 years. Four (12.9%) of the patients treated with mechanical or biological prostheses had a recurrent episode of endocarditis, compared with none of the patients treated with homografts (p = 0.006). During the second decade, 30-day mortality was lower (3.6% versus 22%; p = 0.007) and 5-year cumulative survival was higher (88% versus 66%; p = 0.027). Age, preoperative serum creatinine, and severe perioperative complications were independent predictors of mortality during follow-up. CONCLUSIONS: Aortic PVE is associated with a high rate of early complications and substantial early mortality. Patients who survive the immediate postoperative period have satisfactory long-term survival. The risk of recurrent endocarditis is low, especially in patients treated with homografts. The results have improved during the past decade.

Homograft reconstruction of the right ventricular outflow tract in adults with congenital heart disease: a systematic review.

Reconstruction of the right ventricular outflow tract with a homograft is an established surgical method in congenital heart disease. Studies from children and adolescents suggest that homograft durability is shorter than the life expectancy of the patient; therefore, durability in adults is addressed in this systematic review. The PubMed database was searched in May 2012 and repeated in May 2015 with the terms 'homograft AND pulmonary valve', generating 665 hits. We included only studies involving more than 50 patients with a mean or median age >18 years. Six studies with a cumulative total of 560 patients were included. The long-term mortality rate was 2-8.8% at 8.1-10 years. Reintervention was common during patients' life spans, with a 10-year event-free survival rate of 78-80%. Early postoperative echocardiographic or magnetic resonance imaging defects appear to predict rapid homograft degeneration. Further studies on various malformations and risk markers for degeneration are needed to make qualified and accurate decisions regarding lifetime management.

Picture book support for preparing children ahead of and during day surgery.

Aim To develop and evaluate the use of a specific picture book aiming to prepare children for anaesthesia and surgery. Methods An intervention comparing two different information methods before ear, nose and throat day surgery was performed. The intervention involved using a specific information sheet and a specific picture book. Parents (n=104) of children aged 2-12 years completed open-ended questions that were analysed with qualitative content analysis. They were divided into two groups: one group received routine information and one received routine information and the intervention. Findings The picture sheet and picture book were valuable aids to prepare small children for anaesthesia and surgery by explaining the procedures that would take place. The parents expressed that knowledge of the procedures made them and the child feel secure. Conclusion Peri-operative information through pictures supports children and their parents during day surgery and may be helpful in future healthcare visits.