Balloon aortic valvuloplasty for aortic stenosis in neonates, children, and young adults

A potentially curative fetal intervention for hypoplastic left heart syndrome

Hypoplastic left heart syndrome (HLHS) encapsulates a spectrum of complex congenital cardiovascular malformations involving varying degrees of underdevelopment of the left-sided heart structures. However, despite improved survival rates since the introduction of staged surgical reconstruction, treatment options for HLHS remain palliative rather than curative. A major limiting factor in the development of definitive curative therapy for HLHS is an incomplete understanding of its pathogenesis. Currently, the aetiology HLHS is best conceptualised by the 'flow theory' of cardiogenesis, which states that normal cardiac development is reliant on the interrelationship of normal flow patterns of blood through the developing heart, and appropriate growth of the cardiac valves and myocardium. Thus, congenital cardiac malformations, such as HLHS, are thought to arise when these two processes are incorrectly coupled in utero. The rationale for the hypothesis proposed herein rests upon the flow theory of cardiogenesis. Morphological studies of HLHS indicate that, although underdeveloped, all left-sided cardiac structures are present and anatomically correct. Further, of the various structural abnormalities that can occur within the spectrum of HLHS, the presence of a ventricular septal defect (VSD) is rare. The rarity of a VSD within the morphological spectrum of HLHS suggests the syndrome may not develop in the presence of a functionally significant VSD. Presumably, the presence of a functional VSD establishes a communication between the two ventricles during cardiac development, and preserves the normal pressure-flow-dependent growth of the left ventricular (LV) myocardium, despite inflow/outflow valve defects. It is proposed that surgical creation of a VSD in utero will 'rescue' the LV of hearts with left-sided valvular deformities that render them susceptible to the development of HLHS later in gestation. In evaluating this hypothesis, potential techniques for surgical creation of a VSD in utero are offered. These techniques are based on already established catheter-based in utero interventions, and conventional postnatal percutaneous procedures for VSD creation. Further discussion is also offered on techniques to avoid, and manage, potential complications (i.e. conduction system damage) of the proposed technique(s). Finally, if VSD creation in utero is indeed practically feasible, and successfully establishes the hypothesised hemodynamic and myocardial growth normalisation within the abnormally developing LV, the clinical implications are profound. This procedure may hold a potential cure for almost every sub-type of HLHS.

Neonatal Aortic Stenosis is a Surgical Disease: An Interventional Cardiologist View

The application of balloon valvotomy as primary treatment for neonatal congenital aortic stenosis is contentious. In this debate, we discuss data comparing outcomes of a percutaneous and surgical strategy between two tertiary centers that have adopted opposite therapeutic strategies. The outcomes with surgical and balloon therapies appear comparable. These contemporaneous data validate the empiric switch to primary balloon valvotomy in the modern era.

Neonatal Interventions for Left-Sided Obstructive Lesions: Alternatives to Surgery

Percutaneous neonatal cardiac interventions are effective in management strategies. Aortic valve dilation has become a first line therapy with excellent outcomes and low morbidity equivalent to surgery. Percutaneous intervention for coarctation of the aorta can safely postpone surgical intervention in small unwell neonates, allowing stabilization and growth. Stent implantation can provide a stable and predictable relief of obstruction; however, care should be taken to implant stents so that they can be removed subsequently. As experience increases, the role of percutaneous techniques in the management of high-risk neonates with coarctation of the aorta will become better defined and improve the outcomes.

Recommendations of the British Paediatric Cardiac Association for therapeutic cardiac catheterisation in congenital cardiac disease

The aims of these recommendations are to improve the outcome for patients after, and to provide acceptable standards of practice of therapeutic cardiac catheterisation performed to treat congenital cardiac disease. The scope of the recommendations includes all interventional procedures, recognising that for some congenital malformations, surgical treatment is equally as effective as, or occasionally preferable to, interventional treatment. The limitations of the recommendations are that, at present, no data are available which compare the results of interventional treatment with surgery, and certainly none which evaluate the numbers and types of procedures that need to be performed for the maintenance of skills. Thus, there is a recognised need to collect comprehensive data with which these recommendations could be reviewed in the future, and re-written as evidence-based guidelines. Such a review will have to take into account the methods of collection of data, their effectiveness, and the latest developments in technology. The present recommendations should, therefore, be considered as consensus statements, and as describing accepted practice, which could be used as a basis for ensuring and improving the quality of future care.

Left ventricular outflow obstruction

Patients with LVOT obstruction require lifelong follow-up because the obstruction may be progressive or recurrent. Several procedures are usually required, either by surgery or by interventional cardiac catheterization, to repair or palliate the obstructive lesion. The treatment of these patients continues to evolve, and, despite the complexity of these patients' lesions, the morbidity and mortality rates have decreased and are expected to decrease further in the future.

Interventional catheterization for congenital heart disease--limited "surgery" without the chest scar

The desire for less invasive treatments and for reduction of the cost of hospitalizations has spurred the development of interventional catheterization. The range of corrections that can be performed through the use of catheters is much more limited than what can be accomplished with surgery, but in patients with certain conditions, interventional catheterization techniques offer results similar to those of surgery at considerably less pain and expense. We expect the range of defects that can be treated nonoperatively to continue to increase in the years to come.