Patent arterial duct occlusion with two amplatzer duct occluder devices

It is accepted practice to close large patent arterial ducts (PDA) with Amplatzer duct occluder devices, with extremely low rates of residual PDA. This article reports a child who required device closure of PDA with two Amplatzer PDA devices on two separate occasions, despite the first device deployment being a standard placement of an appropriately sized Amplatzer device in the usual position.peer-reviewe

Paediatric wheezy admissions at and around school holiday periods

Objective: To study the influence of school holidays on paediatric admissions with wheezing. Design, setting and patients: Retrospective analysis of all admissions due to wheeze in the paediatric age group. Regional hospital catering for all such admissions, subdivided by age group. Outcome measures: Comparison of hospitalisations due to wheezing before, during and after school holiday periods. Results: Summated admissions showed an increase in admissions over the Christmas period for preschool children, and a decrease for school age children. In Easter and at the start of the summer holidays, admissions decreased in all age groups, except for the late school age group which showed increased admissions in April-May. After the summer holidays, a rise in admissions was noted for all ages. Conclusions: Our findings support the multiphenotypic theory for the precipitation of wheezy attacks, with a changeover from a predominantly viral respiratory trigger to a more atopic form of the disease at around 10 years of age. Prophylaxis during school periods is especially important, and advice leading to prophylaxis dose reduction in the benign summer months should be accompanied by advice to restart adequate prophylaxis medication prior to restarting school.peer-reviewe

Right ventricular outflow tract stenting : effective palliation for Fallot’s tetralogy

Traditionally, the management of infants with Fallot’s tetralogy (TOF) with excessively reduced pulmonary flow and cyanosis has been palliation until or unless complete repair is feasible. Palliation involves a procedure that augments pulmonary flow. Most series recognise two subgroups of patients at high risk even in the current era: the cyanotic neonate/infant with small pulmonary arteries and those with complex anatomical variants of tetralogy and/or significant comorbidities such as additional congenital heart lesions (e.g associated Atrio Ventricular Septal Defect) or other congenital anomalies. There is an argument for palliation of these high-risk groups to allow for future potentially more effective elective repairpeer-reviewe

“Bendy” stents help negotiate hairpin intracardiac curves

Simple transposition of the great arteries (TGA) occurs in 0.2 per 1000 live births. The condition is surgically repaired in the neonatal period by the arterial switch procedure (ASO) sometimes preceded by an atrial septostomy. The ASO involves transecting the great arteries and relocating them to the appropriate ventriculo-arterial (VA) connection with attachment of the disconnected coronary arteries to the aorta. In the process, the attachment of the pulmonary artery to the right ventricle involves the Le Compte manoeuvre and to achieve this the pulmonary arteries must be fully mobilised and sometimes the main pulmonary artery may require patch augmentation as well. Nevertheless, pulmonary artery stenosis (PAS) is one of the potential problems with the ASO. However, with improved surgical techniques, this has dropped from around 15% in the 1980s to less than 3%. Apart from surgical revision when PAS occurs, there are interventional options which include angioplasty and/or stent insertion. The latter is preferred in small children and works well in around 60% but may require repeat procedures. In older patients or when angioplasty fails, stent insertion can be considered. These procedures may involve negotiating tight bends in order to reach the site of stenosis. The passage of non-premounted stents may be problematic in such situations, especially with longer stents and tighter bends as they tend to slip off balloon. We describe several techniques that may facilitate such interventions, and these were utilised in an adolescent patient who had had ASO for TGA in the neonatal period. These included manually giving the mounted stent a slight bend in order to help the balloon-stent assembly negotiate hairpin bends.peer-reviewe

Inhibition of light tunneling for multichannel excitations in longitudinally modulated waveguide arrays

We consider evolution of multichannel excitations in longitudinally modulated waveguide arrays where refractive index either oscillates out-of-phase in all neighboring waveguides or when it is modulated in phase in several central waveguides surrounded by out-of-phase oscillating neighbors. Both types of modulations allow resonant inhibition of light tunneling, but only the modulation of latter type conserves the internal structure of multichannel excitations. We show that parameter regions where light tunneling inhibition is possible depend on the symmetry and structure of multichannel excitations. Antisymmetric multichannel excitations are more robust than their symmetric counterparts and experience nonlinearity-induced delocalization at higher amplitudes.Comment: 17 pages, 6 figures, to appear in Physical Review