Hybrid palliation in hypoplastic left heart syndrome

Innovative interventional catheterization techniques for congenital heart disease

Since 1929, when the first cardiac catheterization was safely performed in a human by Dr. Werner Forssmann (on himself), there has been a rapid progression of cardiac catheterization techniques and technologies. Today, these advances allow us to treat a wide variety of patients with congenital heart disease using minimally invasive techniques; from fetus to infants to adults, and from simple to complex congenital cardiac lesions. In this article, we will explore some of the exciting advances in cardiac catheterization for the treatment of congenital heart disease, including transcatheter valve implantation, hybrid procedures, biodegradable technologies, and magnetic resonance imaging (MRI)-guided catheterization. Additionally, we will discuss innovations in imaging in the catheterization laboratory, including 3D rotational angiography (3DRA), fusion imaging, and 3D printing, which help to make innovative interventional approaches possible.

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.

Alternative hybrid and staged interventional treatment of congenital heart defects in critically ill children with complex and non-cardiac problems

INTRODUCTION

An individually designed strategy of comprehensive alternative hybrid and staged interventional treatment (AHASIT) can be a reasonable alternative to conventional treatment of congenital heart defects, reduce the risk of cardiac surgery or interventions performed separately, and give an additional chance for critically ill children.

AIM

To present our experience and the results of AHASIT of severely ill or borderline children referred for surgery with the diagnosis of congenital heart defects.

MATERIAL AND METHODS

A group of 22 patients with complex cardiac and non-cardiac pathologies was retrospectively selected and analyzed. An individual preoperative severity scale was established for AHASIT patients, with one point for each of the following preoperative complications: prematurity, low body weight, cyanosis, intolerance to drug therapy, failed interventional treatment prior to admission, mechanical ventilation prior to the procedure, chronic respiratory failure and non-cardiac, mainly congenital malformations (congenital diaphragmatic hernia, lower extremity agenesia, duodenal atresia) and acquired problems (newborn edema, necrotic enterocolitis, intracranial hemorrhage, liver and renal failure, anemia and thrombocytopenia, infections or colonization with drug-resistant pathogens).

RESULTS

The analysis of the postoperative course showed that the patients with 5 AHASIT points or more had a more complicated postoperative course than the patients with 1 to 4 AHASIT points.

CONCLUSIONS

The AHASIT of pediatric congenital heart defects with complex and non-cardiac problems appeared to be an attractive option for selected severely ill patients. The strategy was found to be effective in selected neonates suffering from complex and accompanying non-cardiac pathologies, with positive final results of both cardiological intervention and planned surgery.

Advances in interventional and hybrid therapy in neonatal congenital heart disease

In addition to the considerable surgical advances in treating congenital heart diseases, hybrid and transcatheter therapies have become a cornerstone of neonatal cardiology within the last decade. Approaches to the care of cyanotic newborns with congenital heart disease focused on manipulations of the inter-atrial septum, right ventricular outflow tract obstructions, and on the arterial duct as the source for pulmonary blood flow. Currently, fewer interventional procedures are used in newborns and small infants to treat excessive pulmonary blood flow caused by shunt lesions, but transcatheter techniques and hybrid strategies have been developed to treat newborns suffering from inadequate systemic perfusion. However, transcatheter techniques are still not available to treat failing systemic ventricles without obvious structural disorders of the myocardium or dilated cardiomyopathies in newborns and infancy, despite new surgical-interventional strategies are already developed to avoid or to delay early heart transplantation. In conclusion, material and technical improvements have enabled transcatheter techniques to replace medical-based therapies to solve structurally dependent cardiovascular diseases. However, evidence-based and long-term follow-up data are required.

Use of a pressure guidewire to assess pulmonary artery band adequacy in the hybrid stage I procedure for high-risk neonates with hypoplastic left heart syndrome and variants

OBJECTIVE

The hybrid stage I procedure is an alternative palliative strategy for patients with hypoplastic left heart syndrome who traditionally have undergone the Norwood operation. At our institution, the hybrid stage I procedure is employed only for patients with high operative risk. Our objective was to describe our use of a pressure guidewire during the hybrid stage I procedure to assess quantitatively pulmonary artery band adequacy.

DESIGN

After reviewing the charts on all high-risk patients who underwent a hybrid stage I procedure at our institution, we compared two groups of patients: those who underwent the standard hybrid stage I palliation (standard cohort) and those with pressure wire-facilitated assessment of distal branch pulmonary artery pressure (pressure wire cohort) to evaluate the impact of pressure guidewire use on procedural risk, radiation time, patient outcomes, and need for reoperation for pulmonary artery band adjustment.

RESULTS

The pressure guidewire was used in 8 of 14 patients at the time of hybrid stage I procedure and was successful and without complication in all attempts. In the standard cohort, 67% of patients needed reoperation for pulmonary artery band adjustment, compared to 12.5% of patients in the pressure wire cohort (P =.09). Procedure time, radiation exposure, and survival to hospital discharge were not different between groups.

CONCLUSIONS

This novel use of a pressure guidewire to assess quantitatively pulmonary artery band adequacy at the time of placement is feasible, safe and may decrease the need for reoperation for pulmonary artery band adjustment.

[Update on pediatric cardiology and congenital heart disease]

The fields of pediatric cardiology and congenital heart disease have experienced considerable progress in the last few years, with advances in new diagnostic and therapeutic techniques that can be applied at all stages of life from the fetus to the adult. This article reviews scientific publications in a number of areas that appeared between August 2007 and September 2008. In developed countries, congenital heart disease is becoming increasingly prevalent in nonpediatric patients, including pregnant women. Actions aimed at preventing coronary heart disease must be started early in infancy and should involve the promotion of a healthy diet and lifestyle. Recent developments in echocardiography include the introduction of three-dimensional echocardiography and of new techniques such as two-dimensional speckle tracking imaging, which can be used for both anatomical and functional investigations in patients with complex heart disease, including a univentricular heart. Progress has also occurred in fetal cardiology, with new data on prognosis and prognostic factors and developments in intrauterine interventions, though indications for these interventions have still to be established. Heart transplantation has become a routine procedure, supplemented in some cases by circulatory support devices. In catheter interventions, new devices have become available for the closure of atrial or ventricular septal defects and patent ductus arteriosus as well as for percutaneous pulmonary valve implantation. Surgery is also advancing, in some cases with hybrid techniques, particularly for the treatment of hypoplastic left heart syndrome. The article ends with a review of publications on cardiomyopathy, myocarditis and the treatment of bacterial endocarditis.

Interventions complementing surgery as part of multistage treatment for hypoplastic left heart syndrome: one center's experience

BACKGROUND

Interventional procedures often are used as part of multistage treatment for hypoplastic left heart syndrome (HLHS). This study aimed to evaluate the efficacy of interventions in multistage treatment of HLHS.

METHODS AND RESULTS

Between 1999 and 2007, 78 interventions were performed for 58 children with HLHS at different stages of surgical treatment. Group 1, involving 30 interventions for 22 patients with postoperative pulmonary arterial stenosis, showed reduced pulmonary artery pressure and increased vessel diameter. Group 2, involving 15 interventions after the Norwood operation for 12 patients with aortic arch obstruction, showed success for 11 patients. Group 3, involving eight balloon angioplasties of narrowed Glenn anastomosis for seven patients, showed abolition of the pressure gradient between the superior vena cava and the right pulmonary artery. Group 4, involving eight interventional closures of a fenestration for eight patients after a Fontan operation, showed increased oxygen saturation for all eight patients. Group 5, involving seven interventions for six patients in whom venovenous collaterals were closed percutaneously, showed improved oxygen saturation. For Group 6, uncommon miscellaneous interventions were used to stabilize the patients' condition before the next surgical treatment.

CONCLUSIONS

Interventional procedures play an important role during multistage treatment of HLHS. They allow for a reduction in the number of operations or stabilization of the patients' condition before the next surgical treatment.

Hybrid balloon pulmonary valvuloplasty in a 700-g infant: Thinking outside the box

This report describes a unique Hybrid approach to balloon pulmonary valvuloplasty in a 700-g premature infant with pulmonary valve stenosis and very poor right ventricular function.