Porcine Model of the Arterial Switch Operation: Implications for Unique Strategies in the Management of Hypoplastic Left Ventricles.

There are no reports on the performance of the arterial switch operation (ASO) in a normal heart with normally related great vessels. The objective of this study was to determine whether the ASO could be performed in a healthy animal model. Cardiopulmonary bypass (CPB) and coronary translocation techniques were used to perform ASO in neonatal piglets or a staged ASO with prior main pulmonary artery (PA) banding.

Anisotropic Polytetrafluoroethylene Cardiovascular Conduits Spontaneously Expand in a Growing Lamb Model.

Background: Insertion of conduits from the right ventricle (RV) to the pulmonary artery (PA) is a commonly used technique for repair of congenital heart defects. The vast majority of infants and children will require reoperation and/or re-intervention to replace the conduit. Some children may require multiple reoperations, with the risk of death and morbidity increasing significantly with each subsequent operation.

Feasibility Study of Catheter-Based Interventions for Anisotropic Expanded Polytetrafluoroethylene Cardiovascular Conduits in a Growing Lamb Model.

Background: Cardiovascular repair in children often requires implant of conduits which do not have growth potential and will require reoperation. In the current study we sought to determine the feasibility of catheter-based interventions of anisotropic conduits inserted as interposition grafts in the main pulmonary artery (MPA) of growing lambs.

Methods: Lambs underwent interpositional implant of either an anisotropic expanded polytetrafluoroethylene (ePTFE) (Test) conduit or conventional PTFE (Control) conduit.

Use of virtual reality for pre-surgical planning in separation of conjoined twins: A case report.

We describe the use of virtual reality technology for surgical planning in the successful separation of thoracopagus conjoined twins. Three-dimensional models were created from computed tomography angiograms to simulate the patient's anatomy on a virtual stereoscopic display. Members of the surgical teams reviewed the anatomical models to localize an interatrial communication that allowed blood to flow between the two hearts.

Mechanical hemolysis in pediatric patients associated with rapid transfusion and one-way valve.

Background: Four similar transfusion reactions involving infants were reported in less than 1 year. After transfusion of red blood cells (RBCs) via syringe in the operating room, each patient experienced discolored urine, laboratory evidence of hemolysis, and acute kidney injury. Clerical and serologic investigations were unremarkable.

Minimizing the risk of preoperative brain injury in neonates with aortic arch obstruction.

Objective: To determine whether prenatal diagnosis lowers the risk of preoperative brain injury by assessing differences in the incidence of preoperative brain injury across centers.

Study Design: From 2 prospective cohorts of newborns with complex congenital heart disease studied by preoperative cerebral magnetic resonance imaging, one cohort from the University Medical Center Utrecht (UMCU) and a combined cohort from the University of California San Francisco (UCSF) and University of British Columbia (UBC), patients with aortic arch obstruction were selected and their imaging and clinical course reviewed.

Results: Birth characteristics were comparable between UMCU (n = 33) and UCSF/UBC (n = 54).

Preoperative B-type natriuretic peptide levels are associated with outcome after total cavopulmonary connection (Fontan).

Objective: The study objective was to determine the association between preoperative B-type natriuretic peptide levels and outcome after total cavopulmonary connection. Surgical palliation of univentricular cardiac defects requires a series of staged operations, ending in a total cavopulmonary connection. Although outcomes have improved, there remains an unpredictable risk of early total cavopulmonary connection takedown.

Course, predictors of diaphragm recovery after phrenic nerve injury during pediatric cardiac surgery.

Background: Hemidiaphragm paralysis from phrenic nerve injury is a known complication of congenital cardiac surgery. Return of diaphragm function has been reported; however, prior studies on this subject have been limited by small numbers, static assessment methods, or observation of plicated or non-plicated patients alone. To describe return of function, we reviewed fluoroscopy and ultrasonography in all diagnosed cases of diaphragmatic paralysis.

Brain injury and development in newborns with critical congenital heart disease.

Objective: To determine the relationship between radiologically identifiable brain injuries and delayed brain development as reflected by brain metabolic and microstructural integrity.

Methods: Term newborns with congenital heart disease (CHD) (120 preoperatively and 104 postoperatively) were studied with MRI to determine brain injury severity (BIS), microstructure reflected by fractional anisotropy (FA) and average diffusivity (Dav), and metabolism reflected by N-acetylaspartate (NAA)/choline (Cho) and lactate/Cho. Brain development is characterized by increasing NAA/Cho and white matter FA, and by decreasing Dav and lactate/Cho.

The effect of preoperative nutritional status on postoperative outcomes in children undergoing surgery for congenital heart defects in San Francisco (UCSF) and Guatemala City (UNICAR).

Objective: The objective of this study was to determine the association between preoperative nutritional status and postoperative outcomes in children undergoing surgery for congenital heart defects (CHD).

Methods: Seventy-one patients with CHD were enrolled in a prospective, 2-center cohort study. We adjusted for baseline risk differences using a standardized risk adjustment score for surgery for CHD.

Differential responses of the right ventricle to abnormal loading conditions in vivo: possible pathophysiologic mechanisms.

Objective: The right ventricle (RV) demonstrates differential adaptations in response to pressure versus volume loading, a phenomenon that may be important in the management of children and adults with congenital heart disease (CHD). The purpose of this study is to elucidate possible transcriptional mechanisms of the RV response to pressure versus volume loading in vivo.

Methods: Fetal lambs had aortopulmonary shunting or pulmonary artery (PA) banding.

Single-ventricle anatomy predicts delayed microstructural brain development.

Background: Term newborns with congenital heart disease (CHD) show delayed brain development as early as the third trimester, especially in single-ventricle physiology (SVP). Mechanisms causing delayed brain development in CHD are uncertain but may include impaired fetal brain blood flow. Our objective was to determine if cardiac anatomy associated with obstruction to antegrade flow in the ascending aorta is predictive of delayed brain development as measured by diffusion tensor imaging and magnetic resonance spectroscopic (MRS) imaging.

Rosiglitazone preserves pulmonary vascular function in lambs with increased pulmonary blood flow.

Background: Pulmonary vascular function is impaired with increased pulmonary blood flow (PBF). We hypothesized that a peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist would mitigate this effect.

Methods: An aorta-to-pulmonary-artery shunt was placed in 11 fetal lambs.

Tezosentan increases nitric oxide signaling via enhanced hydrogen peroxide generation in lambs with surgically induced acute increases in pulmonary blood flow.

We have previously shown that acute increases in pulmonary blood flow (PBF) are limited by a compensatory increase in pulmonary vascular resistance (PVR) via an endothelin-1 (ET-1) dependent decrease in nitric oxide synthase (NOS) activity. The mechanisms underlying the reduction in NO signaling are unresolved. Thus, the purpose of this study was to elucidate mechanisms of this ET-1-NO interaction.

Size of the right ventricle-to-pulmonary artery conduit impacts mid-term outcome after the Norwood procedure in patients weighing less than 3 kg.

Objective: The optimal shunt size for patients who have the Norwood operation with a right ventricle-to-pulmonary artery conduit is controversial. The goal of this study is to compare outcomes of 2 shunt sizes in this population.

Methods: Between 2002 and 2010, 75 consecutive patients diagnosed with hypoplastic left heart syndrome and its variants underwent the Norwood procedure with a right ventricle-to-pulmonary artery conduit.

Pulmonary interstitial glycogenosis: an unrecognized etiology of persistent pulmonary hypertension of the newborn in congenital heart disease?

Background: Pulmonary interstitial glycogenosis (PIG) arises from a developmental disorder of the pulmonary mesenchyme and presents clinically with reversible neonatal respiratory distress and/or persistent pulmonary hypertension of the newborn (PPHN).

Objective: We report two cases of PIG in patients with congenital heart disease (CHD) and evidence of PPHN.

Results: Both cases demonstrated the hallmark PIG histologic finding of diffuse, uniform interstitial thickening due to the presence of immature interstitial cells containing abundant cytoplasmic glycogen.

Prenatal diagnosis of atrial restriction in hypoplastic left heart syndrome is associated with decreased 2-year survival.

Objective: To compare the course of hypoplastic left heart syndrome (HLHS) patients diagnosed prenatally with any degree of atrial restriction with those without evidence of atrial restriction.

Design: Retrospective, cohort.

Methods: Prenatally diagnosed HLHS patients from August 1999 to January 2009 were categorized as nonrestrictive versus restrictive, defined by left atrial hypertension on pulmonary venous Doppler and/or an intact interatrial septum.

Surgical management of left ventricular outflow tract obstruction.

Background: Left ventricular outflow tract obstruction (LVOTO) is caused by a spectrum of lesions. This study was performed to determine the outcomes of surgical management of LVOTO.

Methods: All patients who had surgery of the LVOT between 2002 and 2010 were retrospectively reviewed.

Early outcomes of primary sutureless repair of the pulmonary veins.

Background: The "sutureless" repair technique has improved outcomes for post-repair pulmonary vein (PV) stenosis. The purpose of this study is to determine the early outcomes of primary sutureless repair of pulmonary venoocclusive disease in infants with congenital PV stenosis-hypoplasia or PVs at high risk for progressive stenosis.

Methods: This is a retrospective review of infants who had primary sutureless repair of the PVs from October 2002 to April 2010.

Prenatal diagnosis of hypoplastic left heart syndrome in current era.

We sought to evaluate the relation of a prenatal diagnosis (preDx) with morbidity and mortality during the initial hospitalization in a contemporary cohort of patients with hypoplastic left heart syndrome (HLHS). A retrospective study of patients with HLHS presenting from 1999 to 2010 was performed. Patients with genetic disorders or a gestational age <34 weeks or who had intentionally received comfort care only were excluded.

Infection and white matter injury in infants with congenital cardiac disease.

More than 60% of newborns with severe congenital cardiac disease develop perioperative brain injuries. Known risk factors include: pre-operative hypoxemia, cardiopulmonary bypass characteristics, and post-operative hypotension. Infection is an established risk factor for white matter injury in premature newborns.

Early results of the "clamp and sew" Fontan procedure without the use of circulatory support.

Background: A modification of the Fontan operation was recently applied, which includes anastomoses of the extracardiac conduit to the right pulmonary artery and inferior vena cava using simple clamping with no additional circulatory support, venous shunting, pulmonary artery preparation, or prior maintenance of azygos vein patency. The objective of this study is to assess the outcomes of this novel off-pump "clamp and sew" Fontan procedure.

Methods: This is a retrospective review of all patients having a Fontan procedure between January 2009 and October 2010 at a single institution.

Aortic stenosis in a patient with Hurler's syndrome after bone marrow transplantation.

We describe a case of severe aortic stenosis in a 16-year-old male with Hurler's syndrome who had prior bone marrow transplantation. The excised aortic valve leaflets showed characteristic pathologic findings of Hurler's syndrome. This is the first case report of aortic valve replacement in a patient with Hurler's syndrome treated with bone marrow transplantation that demonstrates progression of the aortic valve disease despite treatment.

Stage II palliation of hypoplastic left heart syndrome without cardiopulmonary bypass.

Objectives: Bidirectional cavopulmonary anastomosis has been performed without cardiopulmonary bypass for some single-ventricle heart defects. Limited data are available for the outcomes of off-pump bidirectional cavopulmonary anastomosis in infants with hypoplastic left heart syndrome. The purpose of this study is to determine the early outcomes for stage II palliation of hypoplastic left heart syndrome without cardiopulmonary bypass.

Ross-Konno and endocardial fibroelastosis resection after hybrid stage I palliation in infancy: successful staged left-ventricular rehabilitation and conversion to biventricular circulation after fetal diagnosis of aortic stenosis.

We report a patient who presented during fetal life with severe aortic stenosis, left-ventricular dysfunction, and endocardial fibroelastosis (evolving hypoplastic left heart syndrome). Management involved in utero and postnatal balloon aortic valvuloplasty for partial relief of obstruction and early postnatal hybrid stage I palliation until recovery of left-ventricular systolic function had occurred. The infant subsequently had successful conversion to a biventricular circulation by combining resection of endocardial fibroelastosis with single-stage Ross-Konno, aortic arch reconstruction, hybrid takedown, and pulmonary artery reconstruction.